Slashdot Mirror


Audio Compression Primer

Hack Jandy writes "For those of you with a little extra time this afternoon, check out Sudhian's primer to all things concerning audio compression. The article details everything from DRM to CRC matrixes (with a healthy dosage of Ogg)."

236 comments

  1. Is FLAC worth it? by Megaweapon · · Score: 4, Insightful

    "FLAC is the Linux users lossless audio codec of choice"

    Unless your doing some form of audio editing or "production" recording, is lossless really worth the extra size compared to a 192kbps Ogg or MP3? I usually have more problems with static from the stupid 3.5mm jack than a lossy format.

    --
    I'm sure "SlashdotMedia" will improve on all the wonders that Dice Holdings blessed us all with
    1. Re:Is FLAC worth it? by Anonymous Coward · · Score: 0

      short answer: no.
      longer answer: try it.

    2. Re:Is FLAC worth it? by quanticle · · Score: 1, Interesting

      Unless you want to maximize the number of songs you can get on the .mp3 player, there's no reason *not* to use lossless, what with the low cost of storage nowadays.

      --
      We all know what to do, but we don't know how to get re-elected once we have done it
    3. Re:Is FLAC worth it? by k3v1n · · Score: 2, Funny

      I personally think 256kbps or even 192kbps is good. But it depends on your output (speakers, headphones) and more importantly your ears. Some people don't mind 92kbps while others won't settle for anything less than vinyl (usually people with $30k+ wrapped up in their setups...)

      In short--its entirely up to you!

    4. Re:Is FLAC worth it? by Anonymous Coward · · Score: 0

      "FLAC is the Linux users lossless audio codec of choice"

      What about all the people who use free systems on GNU or BSD userland without linux?

    5. Re:Is FLAC worth it? by t_allardyce · · Score: 1, Funny

      Considering 4GB is enough to store about 6 hours of CD quality uncompressed audio, if you're an audiophile with a hard-drive based music player you would probably want to try it, except most mp3 players don't have much RAM so you will probably get allot of skipping if you move it around. Still, people are going to start storing uncompressed or losslessly compressed music on their computers more and more since capacity and price are pretty good now and most people can't be assed to compress all the music they've ripped - you have to decide on the bit rate and then what if you compress your whole CD collection and decide you want it at a higher quality, you might as well just keep it lossless.

      --
      This comment does not represent the views or opinions of the user.
    6. Re:Is FLAC worth it? by stratjakt · · Score: 3, Interesting

      Most of us aren't exactly audiophiles.

      I'll go stereo to mono and reencode at 22khz for my tv captures. It sounds the same to me.

      As for mp3s, etc, the only time I ever listen to it in the car, and there's so much ambient noise, it's not worth bothering. Hell, 128k joint stereo sounds like the CD to me, I don't know any better.

      I don't listen to much music anymore. All the bullshit and RIAA and this is legal and blah blah blah, it's all killed music as an artform for me. I used to play guitar in bands, and love playing music. It's just dead to me now. White noise.

      --
      I don't need no instructions to know how to rock!!!!
    7. Re:Is FLAC worth it? by jasoncc · · Score: 2, Informative

      I use FLAC because converting from a lossy format to another lossy format can produce crappy results. If I choose a lossy format for all my audio and then I need the audio to be in some other lossy format, I might be screwed.

      You might choose Ogg for your audio then sometime in the future, a new lossy format sweeps the industry. Your Ogg files might not convert well to the new format.

      and besides...Disk is Cheap!

    8. Re:Is FLAC worth it? by itp · · Score: 3, Interesting

      I keep my entire CD collection on disk as FLAC, and then transcode to the lossy format(s) most useful to me at the time (currently Vorbis to play in my Rio Karma). If I ever need a new format I can go back to the FLAC and reencode without transcoding from another lossy format.

    9. Re:Is FLAC worth it? by pthisis · · Score: 1

      Unless your doing some form of audio editing or "production" recording, is lossless really worth the extra size compared to a 192kbps Ogg or MP3? I usually have more problems with static from the stupid 3.5mm jack than a lossy format.

      Well, I store all my new rips as flac. Disk is cheap, the time it takes to rip all my albums is not. I just encode to ogg for my player, but if I need mp3 (or another bitrate) or something else I can regenerate it without having to rip all over again or do a double-lossy compression.

      --
      rage, rage against the dying of the light
    10. Re:Is FLAC worth it? by pete-classic · · Score: 2, Insightful

      The nice thing about FLAC is you don't have to commit to a lossy codec or particular encoding settings. I can re-encode from the same rip every time a new lossy codec comes out, or if I decide I want more music at lower quality on my portable player, or whatever.

      -Peter

    11. Re:Is FLAC worth it? by Anonymous Coward · · Score: 0

      it's all killed music as an artform for me. I used to play guitar in bands, and love playing music. It's just dead to me now.

      lol now that's just dead plain stupid. letting the RIAA have such an influence on your lousy life - you seem to be really weak if that's possible..

    12. Re:Is FLAC worth it? by Dogtanian · · Score: 2, Interesting

      Hell, 128k joint stereo sounds like the CD to me, I don't know any better.

      Really seems to depend on the codec; I can get 128kbps MP3s with notlame that sound really good through moderately decent headphones, but I download other people's 128kbps MP3s and you can hear the artifacts clearly.

      Have they been re-encoded once or more (losing quality), re-encoded from a slower bitrate, or was the encoder that did it just severely crap? Who knows.

      I notice that 192kbps MP3s seem to be more common now than they were during my first wave of filesharing, I mean legally downloading...

      BTW, the music business has been amoral and full of bullshit since.... well, the 1950s at least. The mafia had their fingers in a *lot* of pies at that time.

      --
      "Slashdot - News and Chat Sites Deviant". (Click "homepage" link above for details).
    13. Re:Is FLAC worth it? by Jherek+Carnelian · · Score: 2, Insightful

      Unless your doing some form of audio editing or "production" recording, is lossless really worth the extra size compared to a 192kbps Ogg or MP3?

      300GB hard disk = $150.
      Average flac compressed CD =~ 250MB
      That equals 1200 albums stored on $150 of hardware, or 13 cents per CD and it is only getting cheaper.

      The question should really be - for long term storage, is it really worth not going lossless? Remember, you can always convert from flac to your favorite lossy format at whatever bitrate you want, but you can never convert from lossy back to lossless.

    14. Re:Is FLAC worth it? by pavon · · Score: 2, Interesting

      I was going to do this and then I realized that FLAC only cuts the file size in half, and like you said, disk is cheap. So I just ripped them to WAV, which can read by every encoder ever created on any platform, unlike flac which requires me to install extra software, and possibly go through a seperate step depending on if the encoder for the format of the week supports FLAC.

    15. Re:Is FLAC worth it? by DrRobert · · Score: 1

      I have purchased over 3000 CDs and LPs over the years, they are ripped into flacs and stored on about 1.2 TB on a linux box which streams them to various squeezeboxes and steros in the house. I have the collection also ripped as 128 AAC (about 100GB) for the iPoD in the car (since the car noise makes sound quality largely irrelevant to me). For headphone or home stereo it drives me nuts if its not losseless. The cost of this whole setup is really insignificant campared to the cost of the CDs, LPs, and the stero equipment itself.

    16. Re:Is FLAC worth it? by pla · · Score: 2, Interesting

      I keep my entire CD collection on disk as FLAC, and then transcode to the lossy format

      Same here... I began a search last year for a Vorbis CD player, and found that they simply do not exist (I've heard rumors of a few available only in random SouthEast Asian countries, but that doesn't really do me a whole lot of good).

      So rather than either transcode my OGGs to MP3s, or rip my CD collection again (for the third time... Boy did I every choose poorly to pick VQF the first time) to MP3 to keep alongside my OGGs (wasting twice as much room), I decided to just go for lossless.

      Now, I can reencode to MP3 for portable devices. I can reencode to Vorbis for putting on a DVD to take to work or a friend's house (or anywhere I can use a PC to listen to it). I could encode to AAC to listen on an iPod, if I had one. And in an absolute worst-case scenario, I can create a bitwise-exact duplicate of my original CD if, for example, the dog eats it.

      Disk space has grown cheap enough that, when I stopped to think about it, it looked like a no-brainer. It takes literally weeks to rip a largish collection of audio CDs. A 200GB HDD costs under $100. So, I ripped one last time to lossless, and will never need to touch those CDs again.

    17. Re:Is FLAC worth it? by Edward+Faulkner · · Score: 2, Insightful

      I keep my entire CD collection on disk as FLAC, and then transcode to the lossy format(s) most useful to me at the time (currently Vorbis to play in my Rio Karma). If I ever need a new format I can go back to the FLAC and reencode without transcoding from another lossy format.

      That's exactly why I switched to FLAC as well. When you choose a lossy codec, you're locking yourself in to it. With FLAC, I can reencode to anything else with minimal effort and no transcoding loss.

      My flac albums are an average of 5 times larger than ogg vorbis (quality 6). Not that bad, and disk keeps getting cheaper.

      --
      "The danger is not that a particular class is unfit to govern. Every class is unfit to govern." - Lord Acton
    18. Re:Is FLAC worth it? by eno2001 · · Score: 1

      Odd this should come up. Last week, I just finished installing Fedora Core 3 on my laptop and saw that it comes with Sound Juicer instead of GRIP. I also noticed that it can rip to Ogg Vorbis, FLAC or uncompressed WAV. I decided to do a quick comparison of file size since I'd never tried FLAC before. I ripped a CD (the first 13 tracks of the Wild Palms soundtrack) and wound up with three directories:

      Ogg Vorbis (192K): 43 Megs
      FLAC: 325 Megs
      Uncompressed WAV: 575 Megs

      I would have to guess that your choice should be based on your needs. If you are interested in portability, then space is probably a bigger issue than quality. So Ogg Vorbis at 192K should be just fine. If you are more interested in the highest quality and want to save on some space, then FLAC should be a perfect fit. If you just need the absolute purest audio you can get from a CD, then WAV (or some other uncompressed format) is the way to go. Base you choice on the need.

      --
      -"...bad old ideas look confusingly fresh when they are packaged as technology" - Jaron Lanier (Digital Maoism on Edge.o
    19. Re:Is FLAC worth it? by Tribbin · · Score: 1

      Why don't you just listen to the FLAC then? If it's already on your disk?

      --
      If you mod this up, your slashdot background will turn into a beautiful sunset!
    20. Re:Is FLAC worth it? by Rei · · Score: 1

      I have my 300 gigs filled to the brim with stuff. I have a friend whose almost-terabyte is almost filled, so I could triple my available space and still be able to fill it up in no time. No matter how fast disk space prices improve, we pack rats will always have our disks full.

      --
      We're practicing our labials.
    21. Re:Is FLAC worth it? by Rei · · Score: 1

      Space to store my music compressed = 300GB
      Space to store my music in FLAC = 1.5TB
      Cost for the extra storage = 600$
      Money that I don't have = 600$

      Seriously... if I had 600$ to blow away, I'd use it to upgrade my lousy 256k/s DSL to ~750k/s for the next 2 1/2 years.

      Besides, who is to say whether you'll have everything that you'll want for the future? What if you decide that you want cd covers and and there's a neat piece of hardware to simplify their creation? What if the future is multichannel sound? What if the future is sound sampled from 88200 kbs discs?

      On that latter topic, you'd have a much higher file quality if you did lossy compression on an 88200 disc than if you did lossless on a 41000. So as far as recording goes, if you can up your sample rate and use lossy compression, do it. Lossless audio compression really is a niche.

      --
      We're practicing our labials.
    22. Re:Is FLAC worth it? by tepples · · Score: 1

      For one thing, how much FLAC audio can you fit on a 512 MB handheld device?

    23. Re:Is FLAC worth it? by Phil+Urich · · Score: 1

      Oh, so true. That's why I don't care much about trying to "encode small and save space" anymore; I've realized that I can easily max out the space no matter how much it is, like gas expanding to fill a container . . . no matter how big the container is, the gas will take up the entirety of it. Might as well keep things high enough quality that I have no regrets at all about what I can fit into the space, I figure. (not that I use FLAC most of the time . . . I generally go with just higher-setting Ogg-Vorbis, but I pounce on shared FLAC files when I see them . . . I have many from-the-soundboard concert recordings that I am quite grateful are in FLAC, at very least because of the idea now that I can think "this is as much of the quality as could ever have been preserved", and it's a comforting thought, that recordings like that can exist, in perpetuum, without degredation)

      --
      I remember sigs. Oh, a simpler time!
    24. Re:Is FLAC worth it? by valkraider · · Score: 1

      Now, I can reencode to MP3 for portable devices. I can reencode to Vorbis for putting on a DVD to take to work or a friend's house (or anywhere I can use a PC to listen to it). I could encode to AAC to listen on an iPod, if I had one.

      iPods play MP3. You don't have to use AAC.

    25. Re:Is FLAC worth it? by TheWickedKingJeremy · · Score: 1

      If you just need the absolute purest audio you can get from a CD, then WAV (or some other uncompressed format) is the way to go.

      Except that WAV is no more "pure" than FLAC - that's the beauty of a lossless format :) You can always decode back to WAV from FLAC.

      --

      my religion lies somewhere between buddhism and super monkey ball - pamphlet?
    26. Re:Is FLAC worth it? by TheWickedKingJeremy · · Score: 1

      I agree completely - staying with a lossless format is a no-brainer with the storage available today.

      I think the only real question is, how soon until FLAC becomes pointless because you might as well stick with WAVs? I suppose there will always be benefits to wrapping WAVs inside of another format, which can store things like tags and other such metadata. Also, the coming of better-than-CD audio formats will only increase the want/need for lossless compression.

      --

      my religion lies somewhere between buddhism and super monkey ball - pamphlet?
    27. Re:Is FLAC worth it? by TheWickedKingJeremy · · Score: 1

      I don't listen to much music anymore. All the bullshit and RIAA and this is legal and blah blah blah, it's all killed music as an artform for me. I used to play guitar in bands, and love playing music. It's just dead to me now. White noise.

      You just need to stop letting MTV tell you what to listen to. There is a ton of great music out nowadays - it just isn't on the radio.

      --

      my religion lies somewhere between buddhism and super monkey ball - pamphlet?
    28. Re:Is FLAC worth it? by stratjakt · · Score: 1

      Nope, people like you constantly berating me with how great all "indy" music is killed that genre too.

      Some of it's probably good. A lot of it is just bozos making noise.

      --
      I don't need no instructions to know how to rock!!!!
    29. Re:Is FLAC worth it? by damiam · · Score: 1

      Yeah, but why not? You get better quality for the same space (or the same quality in less space). If you've already got the FLAC files, all you've got to do is leave the encoding running overnight - no extra effort from you.

      --
      It's hard to be religious when certain people are never incinerated by bolts of lightning.
    30. Re:Is FLAC worth it? by kLaNk · · Score: 1

      You can't be serious can you?

      Assuming you paid ~10 bucks an album you are looking at $60,000 to pay for enough music to fill up 1.5TB at each album running ~250MB.

      So you spend around 60 grand on music and then use the need to spend 600 dollars as an excuse? You can't be serious can you?

      Oh yeah, the above paragraphs were written assuming you obtained your music legally.

    31. Re:Is FLAC worth it? by Just+Some+Guy · · Score: 1
      I think the only real question is, how soon until FLAC becomes pointless because you might as well stick with WAVs?

      Never. Debian packages all ship with compressed text documentation even though it probably only saves a few hundred bytes in many cases. The manpages on most Unix systems are gzipped until you actually read them. Compare a 2KB text file with a several-meg .wav - if it's worthwhile to compress the former, then there will be a benefit to compressing the latter for years to come.

      --
      Dewey, what part of this looks like authorities should be involved?
    32. Re:Is FLAC worth it? by the_partisan · · Score: 0

      I encode in FLAC when I borrow CDs, or have a beat-up CD I can get a good extraction from (I use Exact Audio Copy with AccurateRip).

    33. Re:Is FLAC worth it? by Anonymous Coward · · Score: 0

      Nope, people like you constantly berating me with how great all "indy" music is killed that genre too.

      What are you, 14 and got hormones making you stupid and contrary?

      Show me one person, just one person (you are not a person) who says "all indy music" is great.

    34. Re:Is FLAC worth it? by Jherek+Carnelian · · Score: 1

      who is to say whether you'll have everything that you'll want for the future? What if you decide that you want cd covers and and there's a neat piece of hardware to simplify their creation? What if the future is multichannel sound?

      Yoda says, This does not my premise invalidate. Appliable equal to lossy as lossless.

      On that latter topic, you'd have a much higher file quality if you did lossy compression on an 88200 disc than if you did lossless on a 41000. So as far as recording goes, if you can up your sample rate and use lossy compression, do it.

      Yoda says, Lossy algorithms understand you not. At 44Khz artifacts likely same as 88Khz as psychoacoustic model likely throws out same sounds at bitrate any.

    35. Re:Is FLAC worth it? by TheWickedKingJeremy · · Score: 1

      Wow, other people seem to hold a lot of sway over you, don't they? :) Ok, I will stop "constantly berating" you now. Cheers

      --

      my religion lies somewhere between buddhism and super monkey ball - pamphlet?
    36. Re:Is FLAC worth it? by Refrozen · · Score: 1

      Definately, would you save an image as a JPEG if GIF (okay, fine PNG you silly copyright open-source crappy advocates) is around? Lossless compression for audio is no where near what lossy compression is. Clearly, with audio, if you cannot tell the difference between piece A and B (compressed) then if you aren't doing development, there is no big deal. But with hard-drives getting so big and cheap, we might as well go for the best quality possible.

    37. Re:Is FLAC worth it? by Rei · · Score: 1

      > Appliable equally to lossy as lossless.

      Applicable. And both make you have to dig out your CDs again. Additionally, you skipped the other possibilities that I listed - and I hardly listed all possibilities. One has absolutely no way to know what formats will arrive in the future - and formats seem to change pretty rapidly nowadays.

      > Lossy algorithms understand you not

      No, you do not understand them (and please stop speaking like that, it makes for an annoying discussion). If your CD is 44100 khz, you lose all sounds greater than 22050 hz, and lose resolution on high frequency sounds less than 22050 hz. It doesn't matter how strong the signal strength was; the resolution is trashed or the signal is lost altogether.

      Lossy audio compression works completely differently: it *picks* which frequencies to toss, based on how important they are. There are a number of heuristics used, all designed to model the human ability to hear - signal strength, human sensitivity to the frequency, frequency masking, etc. Consequently, lossy compression is a *much better* way to choose which signals to lose than the arbitray cutoff imposed by the sampling rate.

      True audio data has infinite bandwidth requirements. We have to impose a method to cull down this. Limiting the sample rate is one. Picking important frequencies is another. The latter method works far better than the first (although limitations of reality force that we do this after some degree of sampling ;) ).

      --
      We're practicing our labials.
    38. Re:Is FLAC worth it? by cyberfelon2k5 · · Score: 1
      I personally never understand this reasoning. If you own the original CD then you're not locking yourself into anything. If I wanted to rip my music to a different format I'd use the source material, not my MP3's. To use FLAC to store all your CD's on your hard drive just seems like a waste of space to me... after all, you've already paid for your own "master" of sorts, why make your own?

      However, I like the idea of FLAC being used for downloaded music. That is where I think your reasoning makes sense, since paying for an MP3 is locking yourself into a lossy codec. Paying for a FLAC music file lets you decide how much you want to compress it, if at all. However, as the article points out, the lack of DRM is something that will ensure legal music download sites never adopt the format.

    39. Re:Is FLAC worth it? by Edward+Faulkner · · Score: 1

      I personally never understand this reasoning. If you own the original CD then you're not locking yourself into anything. If I wanted to rip my music to a different format I'd use the source material, not my MP3's. To use FLAC to store all your CD's on your hard drive just seems like a waste of space to me... after all, you've already paid for your own "master" of sorts, why make your own?

      I have two reasons. First, I've had my physical CD collection stolen, which sucks. I wish I had lossless rips of all those disks. Consider it a backup.

      Second, reripping the whole collection is a major pain. Popping disks in is annoying, but the worst part is going through the effort to make all the tags useful and consistent. CDDB is pretty hit or miss, especially for the labelling of classical albums. So it needs supervision.

      --
      "The danger is not that a particular class is unfit to govern. Every class is unfit to govern." - Lord Acton
    40. Re:Is FLAC worth it? by Rei · · Score: 1

      Oh please. Don't pretend you know anything about me or my tastes in music.

      I'll put it to you this way: remember back when mp3s were too large for you to reasonably store on your computer unless you had money to burn? There was another type of music that was popular in some circles back then, called "tracked music" - .mod, .s3m, .xm, .it, .669, .mtm, and probably half a dozen more formats that I'm forgetting. Tracked music only contains actual audio data for the samples; the notes played with those samples are stored like sheet music. It was the "realistic" equivalent of midi. The files were generally tiny, ranging from "chip" music (usually 10k) to full orchestral/vocal pieces that approached one meg. The average size was probably 100-200k per file (with an average length of 4 minutes or so). I had over a gig of the stuff.

      Another example: During the run-up to the Iraq war, angry antiwar artists started writing pieces and posting them to the net. Everyone from Chumbawumba to the Beastie Boys to a bunch of very talented artists you've never heard of before. I downloaded a gig in a couple days without even trying.

      Heck, just today I drained that site posted to slashdot of all of its content (211 megs between the two posted contests, after I deleted the tracks that I didn't like). Of course, most of my music I get from friends - I don't even know where they get it.

      Now that there's essentially limitless music out there by truly excellent artists, why people would purchase what the recording industry decides you are supposed to like now is beyond me.

      I'm not saying that I've never purchased a CD or that I don't have any RIAA-spawned music on my computer - far from it. But I'll put it this way: should somehow all copyright-enforced music suddenly become impossible to copy and all traces of infringing copies vanish from the world, my hard drives will still be able to remain perennially full, thank you very much. There's just too much good stuff out there.

      --
      We're practicing our labials.
    41. Re:Is FLAC worth it? by Pieroxy · · Score: 1

      Well, it all depends on the hardware you are using to listen to your music. MP3 degrades the sound in two different ways:
      1. Artifacts. That is the easiest way to recognise an MP3. Because you can hear them!!!
      2. Frequency decay. This is tricky and you need a lot of attention to hear it. Some frequencies are cut off, that is the whole concept of MP3 compression. Some of them would be audible or perceptible.

      all in all, I'm backing up all my CDs in MP3, 320kbps. I used to do it at 256kbps, but I did a few month ago a double blind test with a friend of mine: I brought a CD with 4 audio tracks, all the same, "Dogs" from the album Animals (Pink Floyd).

      The purpose of the game was for him to reorder all 4 tracks in order of quality: 160kbps, 192kbps, 256kbps and the original wave track, as extracted. He didn't know the order of the tracks on the CD.

      He plugged the CD in his CD player, and sat with me on the couch. After listening for the first 20 seconds of the 4 tracks, he told me: 160, 256, original, 192. And he was right.

      From that day, I back up all my CDs in 320kbps. Probably a mistake. I should back up the WAV files directly.

    42. Re:Is FLAC worth it? by Dogtanian · · Score: 1

      MP3 degrades the sound in two different ways: [...] I brought a CD with 4 audio tracks, all the same, "Dogs" from the album Animals (Pink Floyd) (My emphasis!)

      MP3 degrades the sound in another way; it doesn't do quadraphonic ;-)

      Maybe I'm being stereotypical, but my mental stereotype of a Pink Floyd fan is someone with an expensive hi-fi, obsessed with quality sound. Frankly, I'd expect them to be the target audience for DVD-A and SACD.

      As a genuine question (re: backing up as WAVs; and if you're that concerned, storage is probably cheap enough to get away with saving as lossless, though you could still compress it as FLAC or whatever)...

      ....don't you find the CD *itself* lacks the sound quality you'd want? I mean, I know DVA-A and SACD are aimed at people who like quality hi-fi who want an excuse to buy the same stuff for a fifth time, but I can also believe that the CD itself is limited. Not that I object to CD sound quality personally, but I can understand other people being able to notice its limitations, especially on the kind of material they listen to.

      --
      "Slashdot - News and Chat Sites Deviant". (Click "homepage" link above for details).
    43. Re:Is FLAC worth it? by Anonymous Coward · · Score: 0

      Lossless isn't about quality. Are you surprised to hear that? Most people are.

      Lossless is about having an exact, bit-for-bit duplicate of your original disc: a proper archive. With a proper lossless archive, you aren't locked into any one format. You can make mp3's from your flac's for use in portable players (which I do). You could even re-create your entire cd collection, bit-for-bit, if you had to.

      With lossy, you are locked into the format forever. You can't go back to the original wav; you can't re-encode to a different format; you are stuck. This is why lossy is unsuitable for archiving.

    44. Re:Is FLAC worth it? by Anonymous Coward · · Score: 0

      Of course, with a flac archive it's a snap to convert back to the original wav, exactly bit for bit, or convert to any other format. So there's no good reason to waste so much space with wav. With flac, you can have your cake and eat it too.

      Don't think of flac as your "end format", think of flac as your archive format. Flac is simply the starting point from which you can convert to any possible other format.

    45. Re:Is FLAC worth it? by kLaNk · · Score: 1

      I never mentioned one thing about your taste in music.

      If you are in the position to make the choice of what format to store your music in, 99% of the time you are wanting to create digital versions of your hard copies. The vast majority of music that is published on the internet is published in a lossy format (that I have seen anyway, I could just be really naive as you suggest). An individual really have no choice what format it is in and moving it to a lossless encoding format like FLAC is pointless at best.

      You very well could have 300GBs of free legal music without purchasing a CD. But if that is the case, this conversation is pointless and your original post didn't have much meaning (since you have no real choice in the lossy-lossless format question).

      My original statements still stands. For an individual in the position where they have to make a choice between FLAC or some lossy encoding, the extra costs associated with purchasing the extra storage space is dwarfed by the price of the original material you want to encode. Meaning yes, FLAC is worth it.

    46. Re:Is FLAC worth it? by Doctor+O · · Score: 1

      You are correct. Just rip them to WAV and zip that. Yesterday /. had that article about all those KDE protocol handlers including, you guess it, zip:/. Makes for the same size as FLAC, except that I don't need to install anything, it'll work out of the box.

      --
      Who is General Failure and why is he reading my hard disk?
    47. Re:Is FLAC worth it? by Jherek+Carnelian · · Score: 1

      Additionally, you skipped the other possibilities that I listed

      Because I was editing for readability, all your points apply just as much to audio ripped lossless as they do ripped lossy. In other words, the whole point was meangingless which is why Yoda answered you.

      Lossy audio compression works completely differently: it *picks* which frequencies to toss, based on how important they are. There are a number of heuristics used, all designed to model the human ability to hear - signal strength, human sensitivity to the frequency, frequency masking, etc. Consequently, lossy compression is a *much better* way to choose which signals to lose than the arbitray cutoff imposed by the sampling rate.

      The key element you ignore is that the first thing most, if not all, of these heuristics do is toss the high frequencies because the vast majority of humans aren't sensitive enough to them to make them worth the bit-budget. For example, by age 35 the average human male is unable to hear much beyond 16KHz, never mind 40KHz. The heuristics that don't toss hi-freqs pay for it with other artifacts like pre-echo and over-ring which are even more of a distraction to the average "audophile." You come up with an audiophile lossy compression algorithm and maybe that will change, but until then the algorithms available to the average user today aren't going to do much with higher sample rates.

  2. Virtually dismisses lossy compression by Sanity · · Score: 4, Insightful
    This article doesn't seem to talk much about ogg at all, unless I am missing something, in fact, it virtually dismisses all lossy algorithms in favour of lossless algorithms which achieve only 50% compression (instead of 90% compression with lossy).

    Each to their own, but I am more than satisfied with oggs or mp3s encoded at a reasonable bitrate - I think the popularity of hardware such as iPods suggest that most other people are too.

    1. Re:Virtually dismisses lossy compression by Tenebrious1 · · Score: 1

      I was wondering, did I read the same article as the submitter? Ogg was mentioned... once? Oh, and there was a little gif which said Ogg. Not anywhere near what I'd call "a healthy dosage of ogg".

      But then maybe I just don't know what a healthy dosage might be. Could it be that seeing Ogg mentioned three times in an article could be fatal?

      --
      -- If god wanted me to have a sig, he'd have given me a sense of humor.
    2. Re:Virtually dismisses lossy compression by tsanth · · Score: 2, Informative

      Given the topics in the audio section (it has an audio section!), the site seems to lean more towards audiophiles.

      I don't agree with the dismissal of lossy algorithms either, but I think it makes sense given the context.

    3. Re:Virtually dismisses lossy compression by Anonymous Coward · · Score: 0

      Although iPods can play AAC lossless now.

    4. Re:Virtually dismisses lossy compression by Anonymous Coward · · Score: 1, Insightful

      The iPod plays Apple Lossless. In fact, the recent huge up-surge in iPod popularity (4.5 million sold over this year's holiday season) follows after the release of Apple Lossless. So you just might be wrong about people's preferences, Sanity.

    5. Re:Virtually dismisses lossy compression by Sebastopol · · Score: 2, Informative

      Yes, I noticed the article is 3 PAGES LONG! It makes only passing reference to other codecs. Not much of a primer, and it didn't take the entire afternoon to read, it to 5 minutes.

      Did I miss a crucial link or something?

      --
      https://www.accountkiller.com/removal-requested
    6. Re:Virtually dismisses lossy compression by Anonymous Coward · · Score: 0

      No freaking way. The average consumer is convinced that 128kbps mp3s sound as good as CDs. Lossless doesn't sell 4.5 million iPods. Marketing, holidays, and the prevalance of broadband large mp3 collections do.

    7. Re:Virtually dismisses lossy compression by bobbuck · · Score: 1

      Does the iPod have digital audio out? If not is the analog out good enought to justify using lossless formats over compressed?

    8. Re:Virtually dismisses lossy compression by damiam · · Score: 1

      No, the iPod doesn't have digital out (except Firewire/USB). But while I can't personally, I've seen quite a few people claim they can distinguish between lossless and a 256kbit MP3 on the iPod.

      --
      It's hard to be religious when certain people are never incinerated by bolts of lightning.
    9. Re:Virtually dismisses lossy compression by Sanity · · Score: 1

      Yeah, and I have heard people claim they can hear the difference between cheap digital cables and expensive digital cables...

    10. Re:Virtually dismisses lossy compression by Anonymous Coward · · Score: 0

      Did I miss a crucial link or something?

      Yeah, retard, you missed two letters in the word "took":
      it to 5 minutes

      I guess we know that your canadian, at least. Luzer.

  3. Developers? by Anonymous Coward · · Score: 1

    What was that trash? "FLAC coding is kind of like run length encoding."

    Yeah, kind of, except that you'd be lucky to get a sub-unity compression ratio using RLE on sampled music... FLAC != pkzip for crying out loud, and even pkzip is out of the league of this "primer".

    That and phrases like "your compressed file might use up more data" are nauseating. How do you use up data? I think he meant "disk space".

    1. Re:Developers? by Anonymous Coward · · Score: 1, Interesting


      FLAC != pkzip for crying out loud

      I just did a test here with a raw WAV file gzip'd at -9 :

      1224704 Jan 13 13:41 soundtest.wav
      981055 Jan 13 13:41 soundtest.wav.gz


      so not even close to the 50% of FLAC.

    2. Re:Developers? by Anonymous Coward · · Score: 2, Insightful

      More ranting.

      And what the fuck is this? The sampling rate of the sound has absolutely nothing to do with "rounding errors". There is rounding only within the sample itself, as it is quantized to an x-bit value.

      This guy should take a math class.

    3. Re:Developers? by Anonymous Coward · · Score: 0

      This article is trash. (mod this insightful)

    4. Re:Developers? by mcbevin · · Score: 1

      The parent is correct in asserting that FLAC coding is nothing like RLE. If any lossless audio codecs use any form of run length encoding, its a very small part of their engines and seldom serves much purpose.

      Take a look at my site for the theory - http://www.lossless-audio.com/theory.htm . This describes how La works, but the other lossless audio codecs are all quite similar, except that some earlier ones like FLAC differ in how the prediction stage works - FLAC most often uses LPC coefficients to predict the signal, but sometimes uses non-adaptive prediction or IF THE SIGNAL IS PURE DIGITAL SILENCE uses RLE. This is in contrast to the adaptive prediction used by La, Wavpack, Monkey's Audio etc.

  4. 128K should be enough for everyone by killmister · · Score: 2, Interesting

    I know that even large radio stations use 128Kbit sampling frequency. I have heard musicians saying they cannot distinguish the difference between the audio sound played by CD and MP3 with 128Kbit encoding. I have switched from 128K to VBR 320K but just because "that is a good style".

    --
    MySQL Error 1040: Can't return sig, Too many connections!
    1. Re:128K should be enough for everyone by aceh0 · · Score: 3, Insightful

      FM Radio is far from CD quality hence there isnt really a need to use very high bitrate MP3s or whatever

    2. Re:128K should be enough for everyone by Moonlapse · · Score: 1

      I can notice the difference between 128 CBR and 192 VBR, especially when listening to music on hi-quality speakers a la Bose. But above that its all just numbers.

      --
      - I got my free iPod and a free Nintendo DS....why not
    3. Re:128K should be enough for everyone by stratjakt · · Score: 1

      128K isn't sampling frequency, that would be a ridiculously high smapling frequency (capturing tones up to 64k, way higher than you or your dog could even hear).

      128K is the bitrate, sampling (on a CD) would be 44.1khz, which can reproduce up to 22.05khz tones (the upper end of our ability to hear).

      Some guy has a law that says you need to sample at a rate twice as frequent as the signal your sampling. Makes sense if you think about it.

      --
      I don't need no instructions to know how to rock!!!!
    4. Re:128K should be enough for everyone by statusbar · · Score: 2, Interesting

      FM and AM radio transmissions have worse quality than 128 kbit mp3 anyways.

      Just recently I finally heard the difference between a 128 kbit mp3 and the uncompressed version in a blind test. It required good speakers and amplifier. Some instruments in certain frequency bands were definitely quieter and some instruments had their stereo imaging slightly wrong. Some transaural 3-d effects were diminished. It surprised me to hear the difference because I know that my ears have been damaged by playing in loud bands.

      --jeff++

      --
      ipv6 is my vpn
    5. Re:128K should be enough for everyone by XoloX · · Score: 1

      I you've truly heard musicians say such things, well, fuck man, their in the wrong business!

      I they can't distinguish between 128kbit mp3 and a cd, their cd's are very fucked up, or they should get a decent stereo!

      Don't you notice the constant background noise even 192kbit gives you?

      God.........

    6. Re:128K should be enough for everyone by wfberg · · Score: 2, Informative

      FM Radio is far from CD quality hence there isnt really a need to use very high bitrate MP3s or whatever

      Or consider this; since FM radio has a limited range of frequencies that come across well, songs that are intended to be widely played on FM radio (e.g. Britney Spear's latest "hit" song) are actually engineered to sound best in those frequencies. With the end result that when you hear Britney Spears on the radio, the track sounds just like it does on the CD.

      Meanwhile, quality music, lovingly mixed onto CD by people who actually give a damn, sounds like crap on the radio..

      In other words; if you can't hear the difference between 128kbps and higher, it might just be that you're listening to mass produced music.

      As for musicians preferring 128kbps? Well, sound engineers usually don't sit on stage with zillion Watt speakers right next to their fragile precious ears for a reason..

      Me, I have crap taste in music AND I'm tonedeaf, so whatever, 128kbps all the way! ;-)

      (MPEG artifacts in video drive me nuts, though)

      --
      SCO employee? Check out the bounty
    7. Re:128K should be enough for everyone by Anonymous Coward · · Score: 0

      I'm a musician and I sure as hell can hear the difference. I also run my own home studio and record live. I can also hear the difference between ogg and mp3 at just about any resolution. Ogg is much closer to the original recorded sound.

    8. Re:128K should be enough for everyone by Anonymous Coward · · Score: 0

      I encode all my music at 192k (using AAC), and don't notice any background noise. Not all of us have good ears I guess.

    9. Re:128K should be enough for everyone by SpinJaunt · · Score: 1
      hi-quality speakers a la Bose
      'Suppose you're one of those that think _ are the shnitZ too.
      --
      /. is good for you.
    10. Re:128K should be enough for everyone by iepiep · · Score: 1

      that guy is nyquist .. and that 44.1kHz is called the nyquist frequency

    11. Re:128K should be enough for everyone by Osty · · Score: 1

      Some guy has a law that says you need to sample at a rate twice as frequent as the signal your sampling. Makes sense if you think about it.

      That "some guy" would be Nyquist, who found that you need to sample at least twice as fast as the highest frequency in a waveform if you want to be able to reconstruct that waveform. Sample at a lower rate and you run into "aliasing".

      As a visual example, look at the spinning wheels of a car on a TV show. As the car starts moving, the wheel looks like it's spinning forward, because it's spinning slower than half the sampling rate of the TV cameras. As the wheel increases in rotational speed, it will eventually look like it's rotating in reverse, or even stopped. That's because it's now gone past the Nyquist frequency for reconstructing the proper spinning of the wheel, and there's no longer enough information to accurately depict the wheel. Wheels don't do this in real life, because your eyes sample fast enough to reconstruct the full waveform.

    12. Re:128K should be enough for everyone by killmister · · Score: 1

      Background noise comes from a cheap (well standard on some motherborads) soundcard...

      --
      MySQL Error 1040: Can't return sig, Too many connections!
    13. Re:128K should be enough for everyone by pthisis · · Score: 3, Informative

      especially when listening to music on hi-quality speakers a la Bose

      Bose is doesn't make high-quality speakers, they make expensive speakers that don't perform nearly as well as alternatives (for instance, the Acoustimass satellites use crappy paper cones that perform poorly in the upper frequencies). A $300 pair of B&W DM302's will thrash anything Bose makes soundly for sound quality. Also investigate Hale, Thiel, or Paradigm. If you really want to spend thousands, spend it on Magnepan (Magneplanar 1.6Q) or Vandersteen (2ce signature) or the higher end speakers from the companies I already mentioned. But those DM302's are good enough to be highly rated by places like Stereophile magazine and they're an incredible deal.

      If you really want a bunch of little satellite speakers, Energy makes a much better sounding (and somewhat cheaper) system like that. I hear from people I trust that Tannoy makes an incredible one as well, but I haven't heard it.

      --
      rage, rage against the dying of the light
    14. Re:128K should be enough for everyone by pthisis · · Score: 1

      bang-olafson _are_ the shnitZ! Nobody else that I know of makes interesting art pieces that also function as average speakers.

      --
      rage, rage against the dying of the light
    15. Re:128K should be enough for everyone by radish · · Score: 1

      Remember - "Bose" and "high quality" should never co-exist in a sentence without a "not" in there somewhere. Bose sell cheap speakers at very high prices.

      --

      ---- Den ene knappen er powerknapp, den andre er Bender voice knapp "Bite My Shiny Metal Ass"

    16. Re:128K should be enough for everyone by Anonymous Coward · · Score: 0
      128Kbit sampling frequency . . . 128Kbit encoding

      Seems you're confusing two completely different concepts:

      Sampling frequency is how often the ADC takes a sample. For CDs this is 44.1Khz . . . it often goes up to 96Khz for very high-end applications.

      Encoding bitrate is the target file size of a chunk of music encoded with a lossy algorithm. 128k means that the music will take up 128 kilobits of storage per second of audio. Uncompressed CD audio has an effective bitrate of 1411k, but it's not encoded with a lossy algorithm, so the concept is really not applicable.

      Notice that these concepts are COMPLETELY DIFFERENT AND UNRELATED.

    17. Re:128K should be enough for everyone by XoloX · · Score: 1

      Thanks for your reply, but I know the difference between background noise from a soundcard and low bitrate mp3's.

      See, when I play them at 320kilobytes p/s, or when I play a FLAC file, there's no noise.....

      Get the point?

      - XoloX

    18. Re:128K should be enough for everyone by Engineer+Andy · · Score: 1

      i second that opinion. I own a pair of B&W 305 (they're a few years old now) but they kick anything I've auditioned at a bose dealership. to be honest, i only went shopping at the bose shop to confirm what i'd heard about their product being overpriced crap.

      --
      "And we have seen and do testify that the Father sent the Son to be the Savior of the World" 1 John 4:14
    19. Re:128K should be enough for everyone by Tribbin · · Score: 1

      128kbit mp3 sounds a bit 'metalic', especially with some particular sound effects or instruments, like clapping audience. Ogg has other audible characteristics on low rate bitrate. Distortion is audible, no question about it.

      --
      If you mod this up, your slashdot background will turn into a beautiful sunset!
    20. Re:128K should be enough for everyone by silverfuck · · Score: 1
      hi-quality speakers a la Bose

      BOSE = Buy Other Sound Equipment. Expensive, and they sound like dirt.

      --
      You know you've been IMing too long when you almost say 'lol' out loud to a non-geeky friend...
    21. Re:128K should be enough for everyone by Anonymous Coward · · Score: 0

      128K should be enough for everyone
      Thank you Mr. Gates.

    22. Re:128K should be enough for everyone by Anonymous Coward · · Score: 0
      Some guy has a law that says you need to sample at a rate twice as frequent as the signal your sampling.

      Another guy has a law that says that the total energy of an object can be measured by multiplying its mass by the square of the speed of light.

      These guys and their laws ...

    23. Re:128K should be enough for everyone by kmactane · · Score: 1

      I used to believe 128K was fine... even on my Cambridge Soundworks speakers, my 128K MP3s played just fine. Then I started getting gigs as a DJ. I took a bunch of those MP3s, burned them onto audio CDs, and took them out to clubs.

      Most of them still sounded okay, but anything with a lot of bass (i.e., anything really danceable) sounded like absolute ass on a club sound system. The bass came out all fractured and distorted.

      The problem is much less noticeable with 192K MP3s, and almost completely absent when I move up to 256K. The bitrate really does matter, and not just to audiophiles with hi-fi systems in their living rooms. Even drunken clubgoers could tell something was whacked with some of my 128K tracks.

    24. Re:128K should be enough for everyone by ColaMan · · Score: 1

      nyquist's theory only proves true if your waveform is a sine (or other regular) wave. For example :

      A 10kHz waveform sampled at 20kHz would be one single point at the peak of one wave and the trough of another. What happens when you go to put it back together? Well, basically you just get a smoothed line from one point to another.

      What if your waveform had a peak that (for example) was sustained and then suddenly dropped to the trough? Well , all you'd get out the other end would be the same line from the peak to trough as you did before. (Purists will note that that wave will be a mish-mash of frequencies higher than that of the "base" frequency... but go with me here.)

      So, when 44kHz sampling is used, you have to remember that at 22kHz, all you're getting is a very rough approximation of what went in. And even at 11kHz, all you're getting is 4 points per full cycle of your waveform.

      This is also something to remember when using digital scopes at the extremes of their sampling rates - the waveform you see might not be the waveform that's actually there.

      --

      You are in a twisty maze of processor lines, all alike.
      There is a lot of hype here.
    25. Re:128K should be enough for everyone by stratjakt · · Score: 1

      Yes, I knew the law, and I understand the law, it's pretty common sense if you draw, say, a 1khz digital pulse, and then imagine sampling it at 1khz, you'd either get all ones or all 0's.

      I just forgot the guys name.

      I'll forget it again in about 5 minutes.

      --
      I don't need no instructions to know how to rock!!!!
    26. Re:128K should be enough for everyone by recursiv · · Score: 1

      If you get constant background noise at 192 kbps, I suspect you are also getting constant background noise from the source material.

      ie, 192kbps introduces virtually no discernible signal distortion.

      --
      I used to bulls-eye womp-rats in my pants
    27. Re:128K should be enough for everyone by the_partisan · · Score: 0
      I have heard musicians saying they cannot distinguish the difference between the audio sound played by CD and MP3 with 128Kbit encoding.

      This is probably due to hearing loss.

    28. Re:128K should be enough for everyone by Moonlapse · · Score: 1

      I was talking more along the lines of car speakers, since thats what i have.

      --
      - I got my free iPod and a free Nintendo DS....why not
    29. Re:128K should be enough for everyone by pteron · · Score: 1

      Not to put too fine a point on it, this is drivel.

      Your 10kHz waveform sampled at 20kHz can *only* be a sine wave. By definition, if it isn't a sine wave, then it has components at harmonics (multiples) of its frequency which will be outside of your sampled bandwidth. All signals can be decomposed into a set of sine waves and providing all of the frequencies of those sine waves lie within your Nyquist bandwidth, you can perfectly reproduce the original signal, whatever shape it was.

      The reconstruction filter only needs 2 (plus a small delta) samples per cycle to completely reproduce the sine wave, it is in no way an approximation of the original waveform.

    30. Re:128K should be enough for everyone by jetmarc · · Score: 1

      > Just recently I finally heard the difference between a 128 kbit mp3
      > and the uncompressed version in a blind test.
      >
      > It surprised me to hear the difference because I know that my ears
      > have been damaged by playing in loud bands.

      This is not surprising at all. It is very probable that you would not
      have heard the difference, if your ears werent damaged. (Actually you
      state that you really didnt hear it before recently)

      MP3 encoders contain a psycho-acoustic model of what "we" think that
      the ear/brain perceives when hearing sound. This model has been created
      with excessive tests on large groups of humans, man and women, of various
      races.

      Based on this model, the encoder decides which parts of the sound are
      perceived by the listener, and which parts are not. For example, a loud
      noise blinds away quiet sounds in a near frequency band.

      Going from important sound features down to less important features, the
      encoder packs information into the MP3 frame, until the bitrate is exhausted.
      (That is why a 256kbps file has more quality than a 128kbps file)

      In your case however, with your damaged ears, the psycho-acoustic model
      is WRONG. If you cant perceive - say - sounds in a certain frequency band,
      loud noises in that band wont blind away other sounds nearby. For the
      "standard" listener it would, for you it wont! Therefore the encoder
      (wrongly) decides to remove the quiet sounds, although YOU (and only very
      few more people) would have heard them.

      That is what makes people with ear damage the first who notice MP3 artefacts,
      even at surprisingly high bitrates.

      Marc

    31. Re:128K should be enough for everyone by pthisis · · Score: 1

      Ahh. Bose makes okay car speakers. JBL is worth checking out.

      --
      rage, rage against the dying of the light
  5. Waste of time . . . by barryman_5000 · · Score: 4, Insightful

    Not very informative for slashdot ppl. I think we should have had an article more about code or something. I think most slashdotters understand codecs and the differences in lossless and lossy compressions. Waste of 15 minutes.

    1. Re:Waste of time . . . by thijsa · · Score: 1

      Yeah, a quite lossless compressed version of the story would be something like "Lossy compression sux0rz".

    2. Re:Waste of time . . . by Anonymous Coward · · Score: 1, Insightful

      No they don't. Most people still think lossless is all about quality, and the only reason to go with lossless is because you think you're an "audiophile". That couldn't be further from the truth.

      Lossless is useful because it's the only proper way to archive digital music. With a proper lossless archive, you can convert to any lossy format for use in a portable music player (which I do often). You're not locked in like you would be with a lossy collection. You could re-create your entire cd collection, bit-for-bit, if you had to. You have your archive forever, and you'll never have to touch your cd collection again. That is the difference between lossless and lossy audio compression.

    3. Re:Waste of time . . . by barryman_5000 · · Score: 1

      roflmao, I wish I had modpoints for comments like this.

  6. being pedantic, but... by demonbug · · Score: 2, Informative
    Trying to transmit audio data with uncompressed audio or video is not the easiest task. After all, even an audio CD contains data that transmits at 1400kb/s



    Shouldn't that be 1200 kb/s? 150 KB/s * 8 = 1200 kb/s, right? Or is the 150 KB/s figure I'm using incorrect (I could have sworn that was the 1x CD speed)?

    1. Re:being pedantic, but... by stratjakt · · Score: 2, Informative

      441000hz*16bits*2 channels = 1411200 bits per second, 1400 kb/s

      The 150KB number is for CD-ROM data storage, the gap between the two data rates is for the extra error detection and correction.

      --
      I don't need no instructions to know how to rock!!!!
    2. Re:being pedantic, but... by stratjakt · · Score: 2, Informative

      Err, that would be error codes and positional information.

      There's even a little more room, in the subcode channels where one can hide the data for CD+G (karaoke) or CD-TEXT.

      --
      I don't need no instructions to know how to rock!!!!
    3. Re:being pedantic, but... by Piquan · · Score: 2, Informative

      Shouldn't that be 1200 kb/s? 150 KB/s * 8 = 1200 kb/s, right? Or is the 150 KB/s figure I'm using incorrect (I could have sworn that was the 1x CD speed)?

      Data CDs are 150 KB/s at 1x, but you're missing an important difference between data and audio CDs.

      CD sectors are 2352 bytes (I'm ignoring subchannels here). Data CDs have 2048 data bytes, plus 304 bytes of error-correction data, so every bit comes off perfectly. Audio CDs have no error correction, so they use all 2352 bytes for audio data (on the assumption that a few bits missed won't hurt). That means that audio data is moved 14.8% faster (in b/s) than 9660 data. 1200*1.148 = 1378.

      Another calculation you can use instead: 44100 samples/sec * 2 channels/sample * 16 bits/channel = 1411200 bits/sec, or 1378 K/s.

    4. Re:being pedantic, but... by Phreakiture · · Score: 1

      Shouldn't that be 1200 kb/s? 150 KB/s * 8 = 1200 kb/s, right? Or is the 150 KB/s figure I'm using incorrect (I could have sworn that was the 1x CD speed)?

      Permit me to be even more pedantic :-)

      150kB is approximately the right speed, but is tweaked for ISO FS overhead. Audio CD's have no file system, and can thus store 746MB of PCM audio per 74 minute CD or 807MB of PCM audio per 80 minute CD.

      The actual rate is 44100Hz * 16 bits * 2 channels = 1 411 200 bits/second.

      --
      www.wavefront-av.com
    5. Re:being pedantic, but... by Xyde · · Score: 1

      iTunes reports 44.1khz, 16 bit Stereo .wav and .aiff files to be 1411kbps.

    6. Re:being pedantic, but... by Piquan · · Score: 1

      iTunes reports 44.1khz, 16 bit Stereo .wav and .aiff files to be 1411kbps.

      We're talking about the same number here: 1.41e6 bits/sec. It appears that iTunes is basing their numbers on kilobit=1000 bits. Since I had been comparing to a value based on that 150KB/s number, in which 1KB=1024 bytes, I used 1024 instead, hence 1378.

  7. AAC by sometwo · · Score: 3, Informative
    So what about AAC used by Apple in their music store?

    I did a little googling and found this (http://www.teamcombooks.com/mp3handbook/13.htm):
    AAC (Advanced Audio Coding) is not a MPEG layer, although it is based on a psycho-acoustic model. Sometimes referred to as MP4, AAC provides significantly better quality at lower bit-rates than MP3. AAC was developed under MPEG-2 and also exists under MPEG-4.

    AAC supports a wider range of sampling rates (from 8 kHz to 96 kHz) and up to 48 audio channels, plus up to 15 auxiliary low frequency enhancement channels and up to 15 embedded data streams. AAC works at bit rates from 8 kbps for mono speech and up to in excess of 320 kbps for high-quality audio. Three profiles of AAC provide varying levels of complexity and scalability.

    AAC software is much more expensive to license than MP3 because the companies that hold related patents decided to keep a tighter reign on it. Most AAC software is geared towards professional applications and secure music distribution systems, so it may be a while before you see AAC in consumer-oriented products.
    1. Re:AAC by Skuto · · Score: 4, Interesting

      AAC is *much LESS* expensive than MP3. Just compare the licensing costs from Vialicensing (AAC) vs Thomson (MP3).

      The parent is plain wrong. ("Don't believe all you read on the internet, kids")

    2. Re:AAC by Phat_Tony · · Score: 1

      Since this article is mostly about lossless codecs and barely mentions the lossy ones, I don't see it as unusual that it doesn't mention AAC. It doesn't mention MP3 Pro, Real Audio, VQF, or many others, either.

      The interesting information from Apple that it leaves out is about Apple Lossless Encoder. This is built into iTunes, so it's easy to rip to this format on both Macs and PC's. Obviously, it can be played back with iTunes too. It compresses to about 60%. It can be played back on the iPod, and it does support Apple's DRM scheme.

      Another comparison of lossless formats, can be found here.

      --
      Can anyone tell me how to set my sig on Slashdot?
  8. FLAC will live forever by parvenu74 · · Score: 2, Informative

    Because the code is open source, FLAC will be around forever and available on whatever OS/Platform you want to use it on if you feel like compiling the software.

    Another reason it's going to be around and much more prevalent as time goes on is that the compression is so good and the speed/resource usage figures are so attractive. When I rip CD's to FLAC I am limited to 40x by my burner (CPU utilization is around 20-25%). When I rip the same CD to ogg, I top out under 30X because the processor has reached 100% utilization.

    Fast. Free. Efficient. Frugal with the CPU. What else do you need?

    1. Re:FLAC will live forever by Omega697 · · Score: 1

      Fast. Free. Efficient. Frugal with the CPU. What else do you need?
      How about 5 times the storage space? If I encoded all my CDs with FLAC, not only would I have hardly anything on my Rio Karma, but my entire hard drive would be filled.

    2. Re:FLAC will live forever by testerus · · Score: 1
    3. Re:FLAC will live forever by delus10n0 · · Score: 0, Flamebait

      Not to mention quite a few high-end audio companies (McIntosh, Escient) are producing "media center" type appliances that directly support ripping to MP3 or FLAC. Guess what audiophiles are gonna choose?

      If you were at CES 2005, you could find FLAC-enabled devices all over..

      --
      Not All Who Wander Are Lost
    4. Re:FLAC will live forever by QuasEye · · Score: 1

      (Posting after most people have stopped looking at this article, but oh well.)

      I think the difference may just be in your encoder software, or maybe FLAC is just spending more time sleeping on disk accesses. If I remember right, FLAC is just ogg + (the difference between the ogg and the source material). That means that for the ogg, you're just encoding ogg, but for FLAC, you're encoding ogg, decoding ogg, and finding the difference.

  9. 16 bit CD encoding by Sebastopol · · Score: 1

    Ok, mod me down if I'm clueless, but on the first page: "Compact Discs use a bit depth of 16, allowing for 2 ^ 16 possible levels."

    I always thought CDs were encoded in 12 bit, not 16?

    --
    https://www.accountkiller.com/removal-requested
    1. Re:16 bit CD encoding by seinman · · Score: 1

      You thought wrong. 16 bit, 44.1 khz.

    2. Re:16 bit CD encoding by stratjakt · · Score: 1

      Well, you were always wrong!

      How about that!

      CD is 16 bit stereo PCM at 44.1khz, no more no less.

      --
      I don't need no instructions to know how to rock!!!!
  10. I still hear MDCT distortions by ikewillis · · Score: 2, Insightful
    I've stopped liking Modified Discrete Cosine Transform-based codecs like Vorbis, MP3(+), etc. even though they (i.e. aoTuV Vorbis) consistently win in low bitrate listening tests among random listeners. Why? Well, unfortunately, I've been listening to audio encoded with this transform for so long that I can't help but hear the distortions they create, namely pre-echo (which is often described as a 'muddiness' or an 'underwater' sound) and distorted treble detail (often described as 'twinkling')

    Call me crazy, but I insist that there are certain 'killer' tracks where I can hear this distortion even at higher bitrates in advanced MDCT codecs like Vorbis, namely Led Zeppelin / Rock and Roll whose drumline consists of a ridiculous number of cymbal crashes in rapid succession.

    The way I see it, the future is lossless. With hard drives burgeoning to over 500GB and Fiber-to-the-Home becoming a reality within the near future, why bother saving a little extra space at the cost of degraded quality, which, the more you listen to audio compressed with a certain transform, the more likely you are to hear distortions? I think in the future we'll see a greater trend towards lossless audio compression with codes like FLAC and its ilk.

    1. Re:I still hear MDCT distortions by LWATCDR · · Score: 1

      It really depends on what you are recording. For speech recording I see no real benifit for lossless like Flac.
      Things like talking books as such would do very well using Speex. The only problem is I have yet to see a mobil player that supports it.

      --
      See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
    2. Re:I still hear MDCT distortions by Anonymous Coward · · Score: 0

      The way I see it, the future is lossless. With hard drives burgeoning to over 500GB and Fiber-to-the-Home becoming a reality within the near future, why bother saving a little extra space at the cost of degraded quality, which, the more you listen to audio compressed with a certain transform, the more likely you are to hear distortions? I think in the future we'll see a greater trend towards lossless audio compression with codes like FLAC and its ilk.

      In a few years time, people will be saying "Codec?! What codec? Just upload me the god damn DVD-Audio image!"

    3. Re:I still hear MDCT distortions by ndevice · · Score: 1

      Cymbal crashes are the wideband of audio. Hard to compress with frequency transforms.

    4. Re:I still hear MDCT distortions by radish · · Score: 4, Interesting

      Not wanting to get some award for pedantry, but all music recording is "lossy". If you listen to a CD, you're not hearing the exact same sound you'd here in the studio, those cymbals sound diffrent due to sampling, quantization etc. So when it comes to "lossy compression" causing "artifacts" - it's only creating different artifiacts, there already were some.

      Of course this doesn't go against what you're saying at all, other than calling FLAC "perfect" is wrong. It might be the same as the CD, but that has it's own problems.

      --

      ---- Den ene knappen er powerknapp, den andre er Bender voice knapp "Bite My Shiny Metal Ass"

    5. Re:I still hear MDCT distortions by gfody · · Score: 1

      different encocers produce different output. most people sware by LAME and only with the highest quality settings. I'm sure the faster encoders take shortcuts sacrificing audio quality for encoding speed.

      the future is definately not lossless. why would we go backwards? with cpu's getting faster more emphesis will be put on accurate encoding instead of fast encoding and the distortions will eventually go away

      --

      bite my glorious golden ass.
    6. Re:I still hear MDCT distortions by Anonymous Coward · · Score: 0

      "Lossy compression" has a very specific definitition, which is different from the definition of "digital sampling". Saying that an uncompressed digital recording is "lossy" is wrong. Saying that it "doesn't accurately capture every nuance of the sound beyond a specific arbitrary point" is right.

    7. Re:I still hear MDCT distortions by be-fan · · Score: 1

      the future is definately not lossless.

      Sure it is. Once you hit 192KHz at 24-bit, there isn't a speaker-system on earth that can do any better, and certainly the human at the recieving end can't tell the difference. Since a human can only listen to so much music at a time, when you've got the storage to store everything lossless, why would you bother to compress it, if only to save on encoding time?

      --
      A deep unwavering belief is a sure sign you're missing something...
    8. Re:I still hear MDCT distortions by Anonymous Coward · · Score: 0

      Mod parent up

    9. Re:I still hear MDCT distortions by Anonymous Coward · · Score: 0

      Riiiight... you just keep hearing all those noises. I bet you also notice lots of bugs under your skin, too.

    10. Re:I still hear MDCT distortions by irc.goatse.cx+troll · · Score: 1

      So you use raw TIFFs for all of your images? We're already far past the point where we need to compress images, yet I've never seen any web page use anything other than jpegs/gifs (and the assorted .bmp.jpeg because someone thought you could convert a file by renaming it, but that doesnt count)

      Just because you have the extra space doesnt mean you should waste it. If you have the space for N lossless objects, and you can compress them at 50% (low compared to mp3/ogg), you free up half the disk.

      --
      Pain lasts, kid. Its how you know you're alive. Sometimes I think this growing up thing is just pain management-TheMaxx
    11. Re:I still hear MDCT distortions by Anonymous Coward · · Score: 0

      "If you listen to a CD, you're not hearing the exact same sound you'd here in the studio, those cymbals sound diffrent due to sampling, quantization etc."

      If the studio uses a DAW at 16/44.1k, your ADC and monitors+room may actually be better fidelity than they ones they playback with. The sample rate and quantisation is the same.

      A hell of a lot of CDs have been made on DAWs or digital tape multitracks running at 16/44.1 (PT was 16/44.1 for years+ADAT, Sony multi etc). If it's an internal DAW at 16/44.1 mix, there is no reason why it should sound worse at home, assuming your playback equipment is up to it. It could even sound better.

    12. Re:I still hear MDCT distortions by Anonymous Coward · · Score: 1, Funny

      The recording is lossy but that's irrelevant, the original live sound includes the bit where the drummer shouted "You fucking piece of shit, I'll kill you," because he saw one of the engineers touching his girlfriend. I don't want to hear that, I want to hear the 4:16 of decent music they produced after three days in the studio and two weeks of fiddling about in post-production.

      That 4 minutes 16 seconds is 16-bit PCM data played in the car CD player on the way home that night with a feeling of satisfaction. If it sounded OK when they did that, it will sound OK when I play back the FLAC file. If it sounded shit when they did that, I'm an idiot for buying it. Will it sound OK with Compressor-of-the-week at 128 kbit/s ? Maybe it will and maybe it won't, I'll let someone else take that chance.

    13. Re:I still hear MDCT distortions by be-fan · · Score: 1

      We're already far past the point where we need to compress images, yet I've never seen any web page use anything other than jpegs/gifs (and the assorted .bmp.jpeg because someone thought you could convert a file by renaming it, but that doesnt count)

      No, I don't use TIFFs for my images, but that's because my internet bandwidth is the limiting factor, not my storage space. Since I'm assuming we're talking about legally-ripped MP3s, internet bandwidth doesn't enter into the equation here. What's growing at a fast rate is disk space, not internet bandwidth.

      Now, if you've got an MP3 player with 1TB of disk, even if you store everything uncompressed, you can fit 1500 albums onto the thing. Since the rate at which people accumulate music is limited by physical factors, 1500 will be a lot of albums even 20 years from now when 1TB MP3 players are $100 on pricewatch. With that kind of storage, why would you bother compressing the music? Surely, the hassle of compressing the music overrides the advantage of being able to put an extra 1500 albums you don't have onto the player?

      --
      A deep unwavering belief is a sure sign you're missing something...
    14. Re:I still hear MDCT distortions by irc.goatse.cx+troll · · Score: 1

      "even 20 years from now when 1TB MP3 players are $100 on pricewatch. With that kind of storage, why would you bother compressing the music?"

      Because assuming prices are the same relationally to now, you could compress all of your music and it would fit on a 500gig mp3 player, which would presumably be half as expensive.

      --
      Pain lasts, kid. Its how you know you're alive. Sometimes I think this growing up thing is just pain management-TheMaxx
    15. Re:I still hear MDCT distortions by Anonymous Coward · · Score: 0

      Right, but for all practical purposes, the disc you buy at the store is the consumer's "master copy", and for that reason it's worth archiving in a lossless format.

    16. Re:I still hear MDCT distortions by Anonymous Coward · · Score: 0

      But the parent is spot-on. Is not that important the amount of bytes in the lossy copy, is the artifacts which are recognizable even at high bitrates. I'm too feed up with high frequencies plagued with charring sounds.

    17. Re:I still hear MDCT distortions by be-fan · · Score: 1

      Since when are hard-drive costs linear. Certainly, my 40GB iPod wasn't twice as much as my 20GB iPod. Beyond that, you hit a point where it is no longer economical to make anything cheaper. Note I said $100 MP3 player. If you can put a 1TB drive in a $100 player, nobody is going to bother making anything cheaper, because at that point, the to make a 500GB drive won't be any less than the cost to make a 1TB drive. Note how nobody makes 5GB HDD MP3 players anymore, for example, 32MB flash MP3 players...

      --
      A deep unwavering belief is a sure sign you're missing something...
  11. The actual meaning of lossless ?? Any clues? by gmania · · Score: 1

    Page 3:
    These are all mathematically lossless codecs. They theoretically should sound identical when using the same hardware and playback software. I don't believe I could conduct double blind or any other subjective test which would prove beyond any doubt that there are any differences between the options aurally.

    -> When something is mathematically lossless, proving the encoding / decoding algorithmes is the only way to go. Double Blind, Subjective??? I'm really sorry I read the whole thing, I want a refund for my time!

    1. Re:The actual meaning of lossless ?? Any clues? by stratjakt · · Score: 2, Informative

      If it's lossless, you should be able to take digital file A, compress it into compressed file B, and then if you uncompress B to get A', then A' = A.

      That is, the checksums for A and A' should match, etc.

      That's how I define mathematically lossless.

      Whatever this asshat is on about double blind and testing and all that, has more to do with the ability of his FLAC playing equipment to sound the same as his CD player, which is a whole 'nother ball of wax altogether.

      --
      I don't need no instructions to know how to rock!!!!
    2. Re:The actual meaning of lossless ?? Any clues? by Anonymous Coward · · Score: 0

      We all know it's you, Bruce.

    3. Re:The actual meaning of lossless ?? Any clues? by Anonymous Coward · · Score: 0

      Not quite right. Strictly speaking you are only correct if the decompression is done offline. If its done online, then a codec with very large excursions in average processing time could cause jitter. You would not see this decoding onto a disk file.

  12. more algorithms by barik · · Score: 5, Informative

    While the article is a primer, I was a little disappointed in the algorithmic treatment given in the article itself. Right now I know of two excellent free publications: Introduction to Sound Processing and The Sounding Object, which both treat the theoretical, DSP side of things. Any other resources that Slashdot readers can recommend for those who are interested in the subject of audio compression and representation?

    1. Re:more algorithms by Hal-9001 · · Score: 2, Informative
      Any other resources that Slashdot readers can recommend for those who are interested in the subject of audio compression and representation?
      • An older but good technical survey of digital audio compression, including MP3, is Davis Yen Pan, "Digital Audio Compression," Digital Technical Journal (Spring 1993). (PDF)
      • Some other technical reference material on MP3 is also available on the Digital Audio Systems website.
      • A more recent survey of perceptual coding of audio, which covers more recent formats like AAC, is Painter and Spanias, "Perceptual Coding of Digital Audio," Proc. IEEE (April 2000). (PDF)
      • Ogg Vorbis is documented on the Xiph.org website, but I found the documentation to be lacking when read from a signal processing perspective. Christopher Montgomery provides a better description from that perspective in a Slashdot interview from 2000. I found another good description in this thread in the hydrogenaudio forums--it hyperlinks a good block diagram of the encoding process.
      --
      "It take 9 months to bear a child, no matter how many women you assign to the job."
  13. transcoding by ceswiedler · · Score: 1

    I know that everyone says that transcoding loses quality. So when I finally got an iPod, I initially transcoded all of my .ogg files to .mp3, but planned on re-encoding later from the CDs. But when I re-encoded a few tracks with lame, and listened to them versus the transcoded track, I honestly couldn't tell a difference (even with headphones). If I ever notice poor quality on my iPod, I guess I'll re-encode then, but otherwise why bother?

    I believe that I used the default settings for both oggenc and lame, which was ~128 bit VBR in both cases.

    1. Re:transcoding by radish · · Score: 1

      Because not everyone is using $5 earphones to listen to stuff. Yes transcoding loses quality, no it's not much, yes you can tell with the right equipment. If you're just listening on an ipod with stock earbuds, don't do anything over 128kbps, you can't tell the difference. If you upgrade to decent phones (ala Shure E3) or a real hifi, then it's a different story.

      --

      ---- Den ene knappen er powerknapp, den andre er Bender voice knapp "Bite My Shiny Metal Ass"

    2. Re:transcoding by recursiv · · Score: 1

      Transcoding does lose quality, but probably not as much as the inherent quality drop between 128kbps ogg to 128kbps mp3, so you probably couldn't tell the difference between the transcoded mp3 and the first generation encoding.

      --
      I used to bulls-eye womp-rats in my pants
  14. i'm sorry you just exposed yourself by Anonymous Coward · · Score: 0

    especially when listening to music on hi-quality speakers a la Bose.

    bose?? high quality? you must be out of your mind.

  15. Missing "Apple Lossless Encoder" by Sebastopol · · Score: 1

    This article is already outdated. :) His discussion of lossless formats excludes the iTunes Apple Lossless encoder, which is supported by iPod. From their websites Import Music page:

    Weapon of Choice

    "However, you can choose to use different audio formats for any track that you import from CD. iTunes lets you convert your music to MP3s at high bit-rate for no additional charge. Using AAC or MP3, you can store more than 100 songs in the same amount of space as a single CD. Discerning customers and audiophiles want true CD audio, and now iTunes can give you that quality with the new Apple Lossless encoder. You'll get the full quality of uncompressed CD audio using about half the storage space. You can copy music in this format onto your iPod or iPod mini, to take perfect audio wherever you go"

    --
    https://www.accountkiller.com/removal-requested
  16. Har har... by Wraithlyn · · Score: 0

    "For those of you with a little extra time this afternoon..."

    Congratulations, you just defined a Slashdotter. ;P

    --
    "Mind, as manifested by the capacity to make choices, is to some extent present in every electron." -Freeman Dyson
  17. Re:One sad bit.. by Nemesis099 · · Score: 1
    I recently picked up a Philips DVP642 DVD player. It can play xvid & divx but can't play OGG. A few of the movies I download use OGG for audio and I have to resort to running the movie off my computer to the AV center.


    I have a question about OGG ever being supported in a player. OGG is under continuous development to make the compression better which is why they have the rating system of 1 through 5. This would mean that a 2 today would probably not be the same size as a 2 a year from now.

    My question is would a Digital player be able to play all variations of the OGG even while it is upgrading? If not then without firmware upgrades through the life of the model it wouldn't work. Otherwise if you wanted to make OGG files a year from now they wouldn't work on your player.

    If I'm wrong about this please let me know.
  18. "god" yourself... by Anonymous Coward · · Score: 0

    background noise? at 193kb? you are the one who needs you get a decent stereo. most likely a crappy DAC. or maybe pot.

    and if you are familiar with the musician's business, you'd know that almost all of them do appalling things to their ears. just go to any concert and you'll know the damage that musicians do to themselves. and that simply goes with the business. a business you obviously aren't very familiar with.

  19. 128/192 kbps is enough for everyone... by katharsis83 · · Score: 3, Insightful

    I second that.

    On repeated double-blind tests on very expensive equipment, even audiophiles are unable to distinguish between CD quality and LAME encoded 192 kbps MP3 files. Those who say they are able to aren't using double-blind tests or have super-human mutant ears. If you go check over at Hydrogen-Audio (where audiophiles and people who care far too much about LAME settings hang out), most of the forum posts indicate that anything above 192 kbps is transparent even to their equipment, which is pretty above average.

    On regular equipment, PC World did a small test a while ago on standard equipment: http://www.pcworld.com/reviews/article/0,aid,64123 ,pg,1,00.asp.
    Their results found that ~192 kbps is pretty much transparent as well.

    mp3-tech.org also has a listening test availible. On their run, they found 192 CBR kbps to be nearly transparent (*feels* different, but don't know why), and 256 kbps CBR to be completely transparent (can't tell compressed from source CD).

    "The listening equipment is the following :

    * Teac VRDS 25 CD reader
    * MIT T2 cables
    * Yamaha AX 1050 amplifier
    * Denon PMA 960 amplifier (for frequencies 50Hz)
    * Celestion speakers"

    This test was also done a while ago on an older mp3 compression program( c. 1998), so current LAME encoding probably allows for complete transparency at 192kbps or so.

    1. Re:128/192 kbps is enough for everyone... by Anonymous Coward · · Score: 0

      On repeated double-blind tests on very expensive equipment, even audiophiles are unable to distinguish between CD quality and LAME encoded 192 kbps MP3 files.

      *rolls eyes*

      How many times does this need to be explained? If I'm ripping my CD collection, I rip to Ogg FLAC. When I want to put music on an iPod, I transcode to MP3. When I buy a newer portable, I'll use Ogg Vorbis.

      If I'd ripped to a lossy format, I'd be transcoding from one lossy format to another, something that results in a fairly large drop in quality. It's either that or re-rip my CD collection every time a new format comes along.

      Why do people insist on characterising the use of non-lossy audio as some kind of unsupportable snobbery when they don't even understand the issues themselves?

    2. Re:128/192 kbps is enough for everyone... by rdnk · · Score: 1

      This is from TFA, I think we've found a superhuman here:

      (Part of the problem here is that different people have different levels of sensitivity. Personally, I can hear the difference between an MP3 encoding at 320K and one encoded at 256K. I also know people who can't hear a difference between 128K and 320K. This makes it difficult to test the variation across a wide audience.--Ed)
    3. Re:128/192 kbps is enough for everyone... by LuSiDe · · Score: 1

      Computer Techniek (C'T), a respected German magazine , also did a similar test.

      From my memory they had a professional panel of 12, diverse audiophiles and the outcome was IIRC as follows:
      * 128 kbit CBR was easily distinguishable.
      * 192 kbit CBR was not distinguishable except by 1 or 2 persons.
      * 256 kbit CBR was not distinguishable.

      However.

      The other day i downloaded a lossless track of a band called 'Morcheeba' (ambient/triphopish) with the name 'Shoulder Holster' and i converted it to OGG Vorbis -q 7. I swear to you, that on my simple SB Live! with computer speakers and simple headphones, the start sounded *fucked up*. It starts very quiet, then builds up louder, but OGG Vorbis just wastes the sound when it is _very_ quiet. If i just listen it, its not a big deal, but when i compare it and really aim to care then this is horrible!

      --
      WE DON'T NEED NO BLOG CONTROL.
  20. Nyquist by bsd4me · · Score: 1

    Some guy has a law that says you need to sample at a rate twice as frequent as the signal your sampling. Makes sense if you think about it.

    That would be Mr. Nyquist. In practice, you get about 80% of the ideal bandwidth due to a non-zero transition width in the anti-alias filter and extreme group-delay at passband edge.

    To be precise, you have to sample at twice the bandwith of your signal. For a lowpass signal (audio would count), this is twice the highest frequency present. For a bandpass signal (eg, RF), you can sample at twice the bandwidth of the signal(*) even though the actual frequency is much higher. This technique is known as under-sampling.

    (*) Assuming the input bandwith of the sample-and-hold circuit on A/D is sufficient.

    --

    (S(SKK)(SKK))(S(SKK)(SKK))

  21. Re:One sad bit.. by Anonymous Coward · · Score: 1, Informative

    Vorbis decoder is and has been done for a long time. Like other codecs, tweaks can always be made to the encoder to produce better results by using different psychoacoustic models, etc. As long as the output still follows spec, the decoder will still decode just fine. This is why your crappy MP3's from 1997 still play today, and fancy MP3's from today will still play on those old sound players from 1997. As long as the encoder follows spec, the decoder will always be able to decode it properly.

  22. Opera by Anonymous Coward · · Score: 0

    Any one else having a problem reading that page with Opera? I get this white rectangle which obscures part of the text.

  23. Matrixen? by NemosomeN · · Score: 1

    No, matrices.

    --
    I hate grammar Nazi's.
  24. They compressed their text! by Anonymous Coward · · Score: 0

    They're so into compression they compressed their text so much you can't read it! :)

    Seriously, their text is 10 pixels high. That's too small to read on anything but a very low resolution monitor. Even with my new 23" LCD wide-screen, 10 pixel high text is unreadable. Hey, how about learning how em's work before attempting to publish on the internet? There are way too many idiots now that claim to be webmasters that don't have a clue.

  25. Actually, you hear quantization distortion by cogito+ergo+blog · · Score: 2, Informative

    (Mod to -3, nitpicking)

    The MDCT in itself is actually lossless. Any distortion you notice is most likely introduced by the quantization applied post MDCT during compression.

    --
    "There is no dark side of the moon really. Matter of fact it's all dark."
  26. *snore....* by Anonymous Coward · · Score: 0

    I know, I know, a "primer" Useless article....

  27. Dear Ogg,Flac,Linux users by Letter · · Score: 0
    Dear Ogg,Flac,Linux users,

    I use CDs. No problems yet.

    Will report with more later.

    Letter

  28. ARRRG! He gets Nyquist WRONG! by wowbagger · · Score: 3, Informative
    According to the "Nyquist Theorem," you need to have twice as many digital samples as the frequency of the analog signal you are trying to represent to have enough data to accurately build it.


    WRONG!

    Nyquist's criterion is "You must have at least twice as many samples as the largest BANDWIDTH of the signal in order to correctly reconstruct it."

    You can take a 10.7 MHz signal, and sample it at 10000 samples per second, and correctly reconstruct it, so long as the signal is guaranteed to be bandwidth limited to 10.7 MHz +/- 2.5 kHz. This is often done in software defined radio to aquire the signal from the intermediate frequency (IF) of the analog front end.

    You also have to have an appropriate reconstruction filter at the output of the system in order to correctly recover the signal - if you don't have the right reconstruction filter, you will NOT reconstruct the signal correctly.

    You also have to take into account the effects of any signal modulation - take a 20 kHz sine wave, and burst it for 10 msec, and you widen the bandwidth of the signal by about 100 Hz (depending upon the exact shape of the burst - a perfect square burst will widen the signal as a sinc function and will, in effect, increase the bandwidth to infinity, which is why square bursts are generally Considered Harmful in communications work).

    Also, you don't oversample a signal in time to account for "rounding errors" - you oversample in time because the frequency response of sampling a system in time introduces a sinc response in frequency - by moving the sampling rate up you reduce the impact of this response on the recovered signal's frequency response. You also greately ease the requirements on the reconstruction filter - the filter can be wider (have fewer poles in the transfer function - thus fewer parts needed).
    1. Re:ARRRG! He gets Nyquist WRONG! by Anonymous Coward · · Score: 0

      " WRONG!

      Nyquist's criterion is "You must have at least twice as many samples as the largest BANDWIDTH of the signal in order to correctly reconstruct it.""

      You are wrong as well. You need MORE than at least twice as many samples as the largest bandwidth of the signal to correctly reconstruct it.
      That's why you can't sample a 10k sine with a 20k sample rate, as you need at least three samples to reconstruct a sine.

      Also, in the article it talks about using greater bit depths so
      "so those small background nuances are going to show up much closer to true form, and be less quantized in the digital format."
      without mentioning why... The only reason for more bits is to *lower the noise floor* (assuming the signal is properly dithered).
      An 8bit signal sounds the same as a 16bit one, just with more background noise.

    2. Re:ARRRG! He gets Nyquist WRONG! by Hal-9001 · · Score: 1
      You are wrong as well. You need MORE than at least twice as many samples as the largest bandwidth of the signal to correctly reconstruct it. That's why you can't sample a 10k sine with a 20k sample rate, as you need at least three samples to reconstruct a sine.
      You can sample and reconstruct a 10kHz sine wave with a 20kHz sampling rate, but the samples have to be taken at the peaks of the sine wave for the reconstruction to be accurate. In the worst case, the samples could be taken at the zeros of the sine wave, in which case the reconstruction is a straight line. That is why it is necessary, in general, to oversample, so that you collect enough data points to ensure that the reconstructed signal is a reasonable approximation of the original signal.
      --
      "It take 9 months to bear a child, no matter how many women you assign to the job."
    3. Re:ARRRG! He gets Nyquist WRONG! by Anonymous Coward · · Score: 0

      It does not matter if the samples are take at the peaks or the zero crossing (with 10k sine, 20k sample rate), the result is a line in either case, and will always be a straight line, no matter where on the sine the sample is taken. (If it's at zero then the result is a 'line' at zero).

      To reconstruct a sine wave, you need at least three points.

      Oversampling normally refers to something a little different, for example running an adc at a higher sample rate than the sample rate it outputs. It does not effect the bandwidth available at the given sample output rate, but makes manufacturing adcs cheaper for various boring reasons.

    4. Re:ARRRG! He gets Nyquist WRONG! by Hal-9001 · · Score: 1
      It does not matter if the samples are take at the peaks or the zero crossing (with 10k sine, 20k sample rate), the result is a line in either case, and will always be a straight line, no matter where on the sine the sample is taken. (If it's at zero then the result is a 'line' at zero).
      What you describe is sampling a 10kHz sine wave at 10kHz. In that case, only one point per period of the sine wave is sampled, and the reconstruction is a straight line. At a sampling rate of 20kHz, I can capture two samples per period from a 10kHz sine wave. In the best case, I capture a sample from the positive peak and a sample from the negative peak; in the worst case, I capture samples from the nulls. I can reconstruct a 10kHz sine wave from samples taken at the peaks, but I can only reconstruct a straight line from samples taken at the nulls.
      --
      "It take 9 months to bear a child, no matter how many women you assign to the job."
    5. Re:ARRRG! He gets Nyquist WRONG! by Anonymous Coward · · Score: 0

      Argh, you are totally right (peaks and nulls). My minds eye needs a monocle.

      Still, would it be true to say that it would be impossible to reconstruct the *amplitude* of the 10k sine, as you have no way of telling where on it's curve you had taken the samples?

      Ie, a full scale sine with samples taken when it's curve is at half scale would produce the same result as a half scale sine with the samples taken at the peaks. Changing the phase of the sine would change it's apparent amplitude.

    6. Re:ARRRG! He gets Nyquist WRONG! by Hal-9001 · · Score: 1
      Still, would it be true to say that it would be impossible to reconstruct the *amplitude* of the 10k sine, as you have no way of telling where on it's curve you had taken the samples?
      That is correct. I think pure sinusoidal signals give Nyquist sampling more trouble than general signals, so in fact most sampling schemes use a sampling rate just slightly higher than the Nyquist rate. For example, I think audio signals are bandlimited to 0-20kHz before being sampled at 44.1 kHz (for recording to a CD, for example), which is just marginally higher than the Nyquist rate of 40 kHz. (Also, there is generally less signal energy at higher frequencies, so accurate reconstruction of those amplitudes is not of critical importance.)
      --
      "It take 9 months to bear a child, no matter how many women you assign to the job."
    7. Re:ARRRG! He gets Nyquist WRONG! by Kiryat+Malachi · · Score: 2, Informative

      And you've just described "beating". Imagine that, instead of that 10k sine at 20khz sampling, you have a 9.99kHz sine at 20k sampling. The point on the waveform that you're sampling is going to slowly change from cycle to cycle, and you're going to wind up with a 9.99kHz sine wave amplitude modulating - "beating" - at 0.01kHz.

      --

      ---
      Mod me down, you fucking twits. Go ahead. I dare you.
      (I read with sigs off.)
  29. "humans can hear from 50 to 22,000Hz on average" by Stavr0 · · Score: 2

    Um, no. 20/20K is more accurate, and we lose a kHz every 5-10 years as we get older.

  30. FLAC is often worth it. by Venner · · Score: 3, Interesting
    I personally think 256kbps or even 192kbps is good. But it depends on your output (speakers, headphones) and more importantly your ears. Some people don't mind 92kbps while others won't settle for anything less than vinyl (usually people with $30k+ wrapped up in their setups...)
    I have a decent mid-range receiver & set of speakers*. I had a friend of mine administer a blind listening test on me. I could pick out the FLAC encode vs. the Ogg "higher quality" (I think it was -q7 or -q8) encode about 75% of the time.

    Most of the time I am content with a good Ogg encode (I mean, hell, I'd never have heard the difference if the samples weren't played back to back!) I generally only use FLAC for a) my favorite albums and b) classical music. Size wouldn't be an issue... but for the fact that I keep an oft-updated mirror of the data on a second computer. As drive space is become rather inexpensive, I forsee a time when lossless will be the way to go, except for portables.

    *Ascend Acoustics CBM-300 stereo pair, HSU sub, and a HK AVR-325 receiver.
    --
    A preposition is a terrible thing to end a sentence with.
    1. Re:FLAC is often worth it. by bobbuck · · Score: 1
      I have a decent mid-range receiver & set of speakers*. I had a friend of mine administer a blind listening test on me. I could pick out the FLAC encode vs. the Ogg "higher quality" (I think it was -q7 or -q8) encode about 75% of the time.

      Just curious, what ogg encoder/decoder software were you using? Was it recent?

      I also wonder if lossless formats will dominate in the future, because if you take away the 16bit 44.1kHz rule, Ogg/Vorbis can deliver a LOT more audio information than FLAC at the same bit rate.* (Wouldn't a 24bit 96kHz Ogg/Vorbis trump a "perfect" 16bit 44.1kHz FLAC and still be smaller?)

      * This statement has not been verified by NASA.

    2. Re:FLAC is often worth it. by Jherek+Carnelian · · Score: 1

      Wouldn't a 24bit 96kHz Ogg/Vorbis trump a "perfect" 16bit 44.1kHz FLAC and still be smaller?)

      Only if you can't hear the difference at 16/44 -- Ogg works by "deleting" the sounds their psychoacoustic model says people won't notice are missing. If your personal hearing ability differs from what Ogg's model predicts, then you will hear the artifacts just as much at 24/96 as at 16/44.

      Plus, the relatively few people likely to benefit from 24/96 are sufficiently outside of the first standard deviation of the population's hearing ability as to be precisely the people for whom the ogg model is not a good match in the first place.

      So, people who would benefit from a 24/96 ogg are extremely small in number.

    3. Re:FLAC is often worth it. by Venner · · Score: 2, Interesting

      >>Just curious, what ogg encoder/decoder software were you using? Was it recent?

      Oggenc, using libogg 1.0 I believe. Played back with winamp 5, whatever they use as their decoder. We also tried converting the Ogg back to a PCM wave file and burning the new and old wav to CD, to see if that made a difference.*

      I'm not sure if there is a limitation on FLAC that makes it unable to carry more information than OGG, but remember that the real limitation would then be the CDs, which are mastered at 16bit/44.1kHz. I picked up several DVD-A disks on clearance and have been wanting to try them out. If nothing else, they should have a much better dynamic range than CD (and potentially SACD.) I just need a DVD-A player***.

      The point is, DVD-A will have a ton more data to encode than what we currently have with CD - if anyone ever bypasses the much-harder-to-break-than-DVD-video encoding scheme.

      *To be played back on a SACD* player, rather than a potentially noisy sound card jack.

      **on loan from said friend.

      ***Regular DVD players play back a DD/DTS track, rather than the higher-quality DVD-A track. Even that much sounds nice.

      --
      A preposition is a terrible thing to end a sentence with.
    4. Re:FLAC is often worth it. by bobbuck · · Score: 1
      So, people who would benefit from a 24/96 ogg are extremely small in number.

      I might be one of them though. I love the huge compression, I don't notice the ogg/vorbis artifacts, but I DO notice the clipping on some CD's. I bet clipping is almost nil on 24 bits. (It SHOULD be very rare on a regular audio CD, but it's not. Well, my scientific research involved ripping Faint by Linkin Park and looking at the waveform in Audacity. Lots of flats at the top and bottom that add noise and kill punch.)

    5. Re:FLAC is often worth it. by Venner · · Score: 1

      >> but I DO notice the clipping on some CD's
      Actually, that's probably the CD's fault. The trend in the industry is to make CDs louder and louder. CDs don't have a huge dynamic range with 16 bits, so when they push the gain, they clip on the master.

      It's another reason I'd love to see DVD-A (or I would even settle for SACD) really take off - room for more dynamic range.

      --
      A preposition is a terrible thing to end a sentence with.
  31. Good background, but heavily biased by bigberk · · Score: 2, Interesting

    (As an Engineer who has thoroughly studied ADC/DAC) I would say that the article presents a very good background on the issues of sampling and reconstruction of audio.

    However, the rest of the article is approached from the heavily biased opinion point of an "audiophile", which the majority of the population is not. These audio experts have fantastic equipment and a keen sense of hearing, allowing them to distinguish between the subtle difference between high fidelity recording and playback. Such people like software like foobar2000 and care a lot about dynamic range, and for the most part think that lossy encoding is a shame. This is a bit about being picky, and a bit about showing off, but either way it's a minority viewpoint.

    But such people are by far the minority of the public. Most of us don't get caught up in the subtle details of audio recording and playback, partially because we don't care, and partially because we don't have the fine equipment (electronics and human ear) to notice such things. So the article for instance completely dismisses lossy encoding, even though this is by far the most exciting frontier of modern audio compression. You can get 64 kbps (ogg vorbis) or 32 kbps (aac) streams that sound amazing to most people, as good as FM radio.

    As an Engineer that is what I find exciting, because we can transport "essentially the same" amount of media in far, far less bandwidth than it required a decade ago. And the efficiency is improving all the time, ditto for video.

    1. Re:Good background, but heavily biased by Anonymous Coward · · Score: 0

      Right, but you're missing the point of lossless compression (as most people do): permanent archiving. Lossy is useful for playback, of course, but lossless is the only way to properly archive your cd collection.

  32. Make the right choice. Choose Vorbis. by Anonymous Coward · · Score: 1, Interesting

    I had a Vorbis listening party this past Summer at my home. I told everyone to bring their favorite CDs and that I would rip their favorite track from the disc using MP3 and Vorbis. I did so at 64, 128, 256 and 384 k bitrates. We had a wonderful time conducting blind listening comparisons using both the AKG and Sennheiser cans as well as my Tannoy studio monitors, Yamaha stereo speakers and the Bose 901 series loudspeakers. (Each set in a room seasoned with the best in acoustics) Under such discriminating environments, Vorbis beat MP3 hadns down every time. Some people couldn't even tell the diffrerence between the 64k Vorbis and the 256k MP3. ONly going to prove my point that Ogg Vorbis is FAR superior to any other codec.

    After we had dinner (a fine French meal with wine if you must know), it was time for more listening tests. Initially the crowd was a little resistant, but by the time we'd listened to the wonderfully executed "Get Ur Freak On" by Missy Elliot for a fifth time, the crowd agreed that Ogg Vorbis was the winner hands down.

    It was a wonderful day and a great victory for Ogg Vorbis as I told everyone present that now that they were aware of the quality the Vorbis provides, they should show all of their friends and family. I provided them all with archive DLTs of the test set (music that they all brought with them) so that they could give it to their IT guys at work and have them load it up on the their Linux or Unix servers and share with their colleagues. They all promised that they would talk to their IT guys.

    So, this article has no idea what it's going on about because it isn't aware of the change that is taking the nation by storm with regard to Ogg Vorbis. I urge all of you to show your family and friends the right way to archive digital audio media and advise them to abandon MP3 and proprietary codecs. If you don't then it will be on your own hands...

  33. iPods don't play .ogg by me+at+werk · · Score: 2, Informative
    From Apple - iPod - Technical Specifications:
    • Audio formats supported: AAC (16 to 320 Kbps), MP3 (32 to 320 Kbps), MP3 VBR, Audible, AIFF, Apple Lossless and WAV
    • Upgradable firmware enables support for future audio formats
    The second bullet leaving the possibility there, but the page lists it as currently (meaning iPod users now, popularity etc) not supporting it.
    --
    For context, click Parent.
    1. Re:iPods don't play .ogg by Anonymous Coward · · Score: 0

      Unfortunately, it's true. The lack of Ogg support was the ONLY reason I got a Rio Karma instead.

  34. "VBR" 320kbps by silverfuck · · Score: 2, Informative
    I know that even large radio stations use 128Kbit sampling frequency.

    Sampling frequency would typically be 44.1KHz, bitrate would be 128kbps. Also, FM radio quality (with good reception) compares to about 96kbps well-encoded mp3, so there's not much point in them recording higher except for archival purposes.

    I have switched from 128K to VBR 320K

    You should be using LAME to encode, and LAME only goes up to 320kbps (blade for instance goes up to 384kbps, but is much lower quality), ergo you can only have 320kbps CBR, not VBR.

    And to everybody else out there who complains about background noise, you should be extracting digitally from the CD!

    flac doesn't seem to have come far enough yet for me (500+ albums is a lot of diskspace if it's around 300MB/album), but to my ears on my equipment (Klipsch £250 (pound sterling if that doesn't come out) speakers, cheapo SB Audigy2 soundcard), lame --preset standard (around 200kbps VBR) sounds damn near perceptual transparency.

    --
    You know you've been IMing too long when you almost say 'lol' out loud to a non-geeky friend...
    1. Re:"VBR" 320kbps by Anonymous Coward · · Score: 0
      FM radio quality (with good reception) compares to about 96kbps well-encoded mp3, so there's not much point in them recording higher

      Except that recording FM with lossy compression, at any bitrate, will further degrade an already degraded signal.

  35. Re:Make the right choice. Choose Vorbis. by valkraider · · Score: 3, Funny

    I had a Vorbis listening party this past Summer at my home.

    But no one came.

  36. Re:One sad bit.. by BlastM · · Score: 1

    While Ogg Vorbis encoders and decoders are still in development for the purposes of tweaking the compression and bugfixing, but for all intents and purposes, the bit stream format has been set in stone back with the 1.0 release quite a while ago.

    All encoders should be compatible with all decoders (with the exception of some extreme encoders such as the 2Kbps encoder). Vorbis is no longer a moving target (like Theora still is at the moment) and if you make a decoder you can be assured that it will play all Vorbis files from the past (since 1.0 of the format), present, and future.

    Xiph.org couldn't have made it any easier for hardware manufacturers, providing the integer codec Tremor (to run on embedded processors) and don't charge royalties for using or modifying a Vorbis codec in a hardware player (almost all other formats are patent-encumbered and charge royalties).

  37. perception of compression differs immensely by raresilk · · Score: 1
    It's interesting how hot people can get over this subject. People who can hear artifacts in lower-bitrate mp3s accuse the non-hearers of being audio philistines. People who can't hear those artifacts (or aren't bothered by them) accuse the hearers of being snobs. Others have pointed out that perception of artifacts may vary based on listening equipment (iPod headphones vs. high-range speakers vs. computer-gaming rig). The following additional reasons for differing perceptions, IMO, also should not be overlooked:

    Nature of material. The CD on my computer desk is Pete Tong's "Twisted Beats" - a DJ mix in which bass predominates and vocals are highly processed already. Although I haven't tried, I'm sure I could listen to that material for hours at a highly-compressed ratio without hearing any problems. The CDs stacked by the stereo in my living room include, e.g., Bach violin concertos recorded by Itzhak Perlman. Because of the numerous high transients in such material, I'm sure they'd stink in mp3 of anything less than the highest bitrate, and maybe even that. I've not tried this particular CD, but my experience encoding classical music in mp3 at anything lower than the highest bitrate has been dismal, and resulted in my throwing the files away. (In addition to violin, soprano vocals and all pieces recorded in a acoustically-rich environment such as a large church particularly stink as mp3. I've not tried them as OGG but I assume the same would hold. I also suspect the same is true for heavy-metal or other rock music that uses guitar distortion algorithms rich with high harmonics.) So perhaps when arguing about whether a particular bitrate or codec is transparent, a reference to the type of material would be in order.

    Individual hearing variation. I had my hearing tested at a job once, where they were worried about people losing their hearing because of high ambient noise and failure (not me) to wear ear protection around machines. The tech repeated the test at the highest range about 3 times, as I recall, and said that "I'm just re-doing it because we rarely have anyone who can hear that accurately up in that high range." The highest testing range where he found me unusually acute was only 10-20 kHz. We always read that the range of human hearing is 20 Hz to 20 kHz. Rarely is it acknowledged that this is an average, and that individual hearing will vary, especially at the theoretical extremes of human hearing. I therefore have no beef with people who can't hear high transient distortion, or with people who can't hear such highs at all (and thus are mystified by my pain when I listen to certain poorly-mixed CDs which fail to de-emphasize the extreme high range). But I do get annoyed at accusations of snobbery - I can hear it, OK?

    --
    No, no, no. This is not a sig.
    1. Re:perception of compression differs immensely by Mr.+Byaninch · · Score: 1
      My guess is that almost all Slash-Dotters are young people, who's hearing is still acute. It's a shame that crappy quality devices and purchased d/l's are depriving them of the complete experience. You mention classical cuts that wouldn't be acceptable at low bit rates. Answer me this, Batman: Would any artist OK a 128kbs version of his work? Oh, wait. You're saying, Oh yeah, 500,000 of them have, since that's how many songs are offered at 99 cents and 128kbs.

      Nope. That's the record companies doing. Let's do a thought experiment. How many musical artists have low quality mp3s of their or any other artists' work?

      Crap. I said I'd get off my soapbox a while ago. But this really boils my beans.

      --
      Sig not available, please try again later. If the problem persists, then the submitter is an idiot.
    2. Re:perception of compression differs immensely by raresilk · · Score: 1
      It should boil your beans. It is truly sad for both artists and listeners that much music is heard ONLY in 128kbps or lower bitrates. I listen at that bitrate fairly routinely, but only at my computer, on headphones or the gaming rig, and only to material that doesn't "whoosh" or "ring" or "hollow out" at that bitrate (e.g., the various streaming "SomaFM" stations which play chillout, industrial and trance stuff - fairly devoid of unprocessed highs.)

      Going off-topic a bit here, but other Dotters have raised similar concerns regarding the quality of CD mastering, pointing out that (in recent years) most pop CD audio has all of the headroom mastered off of it so it will sound uniformly loud, hence chopping off about 1/4 of the actual high end of the sound that was recorded, and leaving a clipped, distorted waveform where real audio used to be. Some were linked to very convincing and useful demonstrations of exactly why modern CDs (I'm talking full uncompressed audio CDs, even) sound like crap compared to older recordings. Most of the ranters who responded to these posts in the past would pop out a one-liner: "It's SUPPOSED to sound distorted, you old farts! It's heavy metal (or rock, or whatever)." Kind of forgetting that it's the old farts who INVENTED the fuzz stomp box and all of the other distortion methods used in rock guitar, but the Stones, Hendrix and Zeppelin were not stupid enough to run their whole MIX through a crude stomp box. Which is pretty much what happens to a modern CD even before it ever gets compressed to MP3.

      So rant aside, I guess what I'm saying is, given that the "original" material cranked out by the Music Mafia these days is so audio-impaired, perhaps it ain't the kids' fault they can't tell the difference. Which is to say, I'm agreeing with you, and it's sad.

      --
      No, no, no. This is not a sig.
  38. Choice of sample rate is a compression by tepples · · Score: 1

    "Lossy compression" has a very specific definitition, which is different from the definition of "digital sampling".

    OK. so if I take a 16 bit 44.1 kHz stereo waveform, mix/downsample/quantize it into 8 bit 22.05 kHz mono (8:1 data reduction), and turn it back into 16/44 stereo, then we're using "digital sampling" as a crude form of lossy compression, right?

    1. Re:Choice of sample rate is a compression by mixonic · · Score: 1

      The term I use most in mastering and other pro work is decimation for the sampling rate change and truncation for the word length, barring a dithering level before 8 bit.

      The words "lossy compression" I have only heard apply to a digital codec, going from string vibration to air vibration to electronic pulses to magnetic variation to digital pulse code modulation, all that would be considered transduction of energy, not lossy compression. True, it may be called "lossy" to stretch the meaning, but I think thats in the nature of any transduction.

      The problem with most lossy codecs arnt that they lose information, its that it doesnt sound graceful.

      -Matt

    2. Re:Choice of sample rate is a compression by tepples · · Score: 1

      going from string vibration to air vibration to electronic pulses to magnetic variation to digital pulse code modulation, all that would be considered transduction of energy, not lossy compression.

      Some sound cards' DACs operate natively at a high resolution (possibly 24-bit 96 kHz); when told to record at a lower resolution, they decimate and truncate the signal. Aren't decimation and truncation forms of crude lossy compression? Isn't all lossy compression based on a transformation into some other domain (e.g. finite differences for ADPCM, MDCT for MP3) followed by a truncation?

    3. Re:Choice of sample rate is a compression by mixonic · · Score: 1

      Compress: 1) to press or squeeze together 2) to reduce in size or volume as if by squeezing

      lossy yes, but I'm wouldnt apply the term compression. Its the difference between squeezing a sponge into half its size (compression) and cutting it in half (truncation/decimation).

      As for translation to a new format, I'm also wary of calling that transduction, altough I suppose it could be debated. Transduction is specific to a change in type of energy. Better word for format changes might be conversion?

      "Talking about music is like dancing about architechture" -Denny Purcell

      -Matt

      ps- not that any of this is even about music at this point :)

  39. Excuse me, Dr. Audio. by Anonymous Coward · · Score: 0
    Don't you notice the constant background noise even 192kbit gives you?

    Um, that noise is from the soundcard/computer.

  40. Tremor doesn't always help by tepples · · Score: 1

    Xiph.org couldn't have made it any easier for hardware manufacturers, providing the integer codec Tremor (to run on embedded processors)

    There are two kinds of devices that can theoretically decode MP3 but not Vorbis. Vorbis, even with the Tremor fixed-point implementation, generally requires more arithmetic operations and memory accesses per sample than MP3 does, and a device that decodes MP3 in real time at 95% CPU utilization (using the other 5% to drive the user interface and the storage device) may not run the Tremor decoder in real time. Worse yet, some players have the MP3 decoder on an ASIC that takes an MPEG audio bitstream on one pin and produces PCM on another, with no way to reprogram it for Vorbis.

  41. I think you mean Vorbis, not Ogg. And even then... by jbn-o · · Score: 1

    Many other posters have discussed the scant coverage of lossy encoding.

    There is a distinction between Ogg and Vorbis that is lost in the summary (and much of the discussion). Ogg is a container format which can hold many other kinds of data (video like Theora, audio like Vorbis, and lyrics in a format which is being worked on, just to name a few) including combinations of data encoded with various codecs. So the lossy encoding in question is Vorbis, not Ogg.

    Just because a program can understand the container does not mean that a user running that program can play the encoded performance. One should recognize this distinction so one can begin to understand what is going on with Ogg FLAC and Ogg Speex files. These files are not common, but we're better off understanding how things interrelate, even in a broad sense, not just memorizing a bunch of filename dot extensions.

  42. I smell BS by melted · · Score: 1

    Just put on a pair of Sennheiser HD580 or HD600 headphones, and you will EASILY hear the difference between 192kbps MP3 and uncompressed audio. And I do mean, easily. Even people who don't know what to listen for hear the difference and run to the store to buy HD580's. :0)

    1. Re:I smell BS by hedgehogbrains · · Score: 1
      How about 192kbps VBR?

      I listen to my music on a cd3o gadget and initially I ripped at 192 CBR and it was somehow much less satisying that the Marantz CD player I'd been using. However, when I went to 192 VBR it just felt great - there was no compromise required. VBR is massively superior to constant.

  43. Ars technica covered this recently by ianbean · · Score: 1

    Also of interest might be this article over at Ars Technica: "A guide to ripping and encoding music". It discusses some of the more practical aspects of music ripping and encoding.

  44. Musepack? by delus10n0 · · Score: 1, Flamebait

    What about musepack? It seems like this codec is constantly passed up; yet in my own testing, and double-blind testing with friends and family, they chose the MPC files 80% of the time over OGG and MP3.

    Also, if you do a frequency analysis of the raw input compared to MPC's --standard setting output, there's very little difference, where as MP3/etc. will do a "round" or "drop off" after a certain frequency, usually 16-20kHz.

    Anyways, hydrogenaudio.org is a great site for information about all this stuff..

    --
    Not All Who Wander Are Lost
  45. Hey! Me too! by Just+Some+Guy · · Score: 4, Insightful
    I do the exact same thing, except that I keep my entire CD collection on CD. If I ever need a new format, I can go back to the CD and reencode without transcoding from another lossy format.

    I've got about 350GB of lossless audio goodness in a set of nice oak bookshelves built into my wall. Considering that the time it takes to get up, get a CD, rip it, and encode it is not much longer than it takes to locate a FLACed album on my fileserver and encode it - that is, the encoding stage is several times longer than the "get up and rip the first track before starting to encode" phase - I think I'll stick with my current system.

    --
    Dewey, what part of this looks like authorities should be involved?
  46. WinRAR is worse than WinRK!!! by Anonymous Coward · · Score: 0
  47. WinRAR is worse than WinRK!!! by Anonymous Coward · · Score: 0
  48. Re:Hey! Me too! by inaeldi · · Score: 1

    The one advantage to having them on your computer already in lossless format is that you can encode multiple CDs faster than you would be able to sitting there and putting each CD in one after another.

  49. its all about the dynamics by soundproofing.noise · · Score: 1

    yeah like removal of harmonics from your fft means its totally loss less?????? wtf

  50. psycho acoustics are for psychos by soundproofing.noise · · Score: 1

    the man that had that idea did not realise what harmonic removal does at a psychological level.

  51. Rock and Roll (Re:I still hear MDCT distortions) by Anonymous Coward · · Score: 0

    When I read your comment about Led Zeppelin/Rock and Roll, I thought you were full of crap, but thought I'd test first before commenting.

    So, I skipped to that song in my playlist, and started listening, and at first it all seemed ok. Then, just before the first "Lonely Lonely Lonely Time" (about 50 seconds into the song), I heard it. (This is Vorbis with quality level of 7 - default is a mere 3)

    You bastard. I would never have noticed that if it weren't for you.

  52. alot of people complain of hearing strange things by soundproofing.noise · · Score: 1

    mp3 does damage your aural cognition

  53. Excellent article by Mr.+Byaninch · · Score: 1
    If you didn't read it and you like music, read it. It won't change your life, but it might get you thinking. My hearing is on the downside now, so lossless isn't important to me. But I'll always champion quality audio.

    Toss the crappy little earbuds, stop buying 99 cent songs that sound like crap, learn to really HEAR the music. Those $15 speakers on your PC are worthless. You should go buy decent speakers (they cost all of $40), but if you insist that the free speakers that came with you PC are 'good', then maybe you're hopeless.

    Rip at 192 or better. That's sort of settled in as the minimum. A few years ago, 128 was the 'miminum' because it didn't sound shitty but it could be 'shared' easily. But that's been replaced. Like 5 years ago. Catch up. The download sites like Napster, iTunes, Whatever, are serving up the 'good stuff' as it was declared to be seven or eight years ago! That's crap. Their 128 kbs junk isn't worth 9 cents, let alone 99 cents.

    Make your peace with it: Either you don't care that you're not hearing all the music, so 128 kbs is fine, or, you can and do hear the difference, and you'll not d/l (and definitely not pay for) anything less.

    Off soapbox now. :)

    --
    Sig not available, please try again later. If the problem persists, then the submitter is an idiot.
  54. Re:alot of people complain of hearing strange thin by Mr.+Byaninch · · Score: 1
    My bet is that listening to mp3s @128kbs or less damages your 'aural cognition'. Because they're crap!

    The poster's point is valid. So's mine. I say. Shun the crap below 192kbs :)

    --
    Sig not available, please try again later. If the problem persists, then the submitter is an idiot.
  55. Life above 20kHz by Venner · · Score: 1

    >>So, people who would benefit from a 24/96 ogg are extremely small in number.

    Have a read: "There's Life Above 20kHz!"
    http://www.cco.caltech.edu/~boyk/spectra/spectra.h tm

    Feel free to jump to section X & XI (results).

    I haven't been able to find too much more, newer work done on the subject, so I don't think there is a great deal of scientific interest in it. Interesting read though.

    --
    A preposition is a terrible thing to end a sentence with.
  56. You are wrong. Go read the flac specification. by seanadams.com · · Score: 1


    Flac is very much like run length encoding, in fact run length (ie DC signal) is one of block types.

    FLAC says take this starting point and extend it for X samples by applying one of four very simple formulae to generate each subsequent sample. Then take that signal and add this residual signal to it (which has a very small amplitude so can be expressed in a small number of bits) and you've got the output signal.

    It is WAY WAY simpler than a lossy codec, and thinking of it as having the RLE concept at its core is a perfectly reasonable way to understand it.

  57. Re:Make the right choice. Choose Vorbis. by Hitmouse · · Score: 1

    If you only compared Ogg to MP3, how can you claim "my point that Ogg Vorbis is FAR superior to any other codec."

  58. It's sort of a primer by mrmeval · · Score: 1

    it's also a polemic against lossy compression which is not appreciated.

    --
    I'd go on a Vegan diet but the delivery time from Vega is too long. --brownkitty
  59. Re:Make the right choice. Choose Vorbis. by Anonymous Coward · · Score: 0

    Simple. MP3 is far superior to any other codec except Ogg Vorbis. Why do you think everyone and his brother uses MP3? I'll give you a hint: It's not because it sucks. The MP3 Pro codec that came out later was really improvements upon the original MP3 codec that were bolted on from the Ogg Vorbis project. WMA is a joke. No one would ever consider WMA a serious codec.

  60. Re:Make the right choice. Choose Vorbis. by Anonymous Coward · · Score: 0

    ba-dam, tchza!!

  61. Re: Full hard drive by parvenu74 · · Score: 1

    I use FLAC for full quality archival, stored on my computer on the *other* 160GB HD. The way HD prices are dropping (less than $80 for 160GB; less than $200 for 300GB on NewEgg.com as I compose this response) pretty much anyone should be able to fit their entire collection on a large secondary drive (unless you have an exceedingly large CD library or are rather enthusiastic about offering "backup services" to all of your friends for their CD collections).

    When I want to go mobile with my music, I transcode to VBR mp3 since I can pack more music/GB that way; give the portable music player industry a few years and we'll have iPods packing upwards of 200GB and then we'll just dump our FLAC library to the iPod and goove out in lossless mode.

  62. Re:Check it out yuorself.. by japa · · Score: 1
    even audiophiles are unable to distinguish between CD quality and LAME encoded 192 kbps MP3 files. Those who say they are able to aren't using double-blind tests or have super-human mutant ears

    It's easy to test it yourself (if you have windows). winabx is a program for performing ABX-style listening tests. ie. You can change the sample "on the fly" and you should identify if the music played is sample A or sample B. After some runs it will tell you if you really identify the samples or if you are just guessing. I found out that with the genre I listen to vorbis encoded with -q4 is enough for me. Earlier I used -q7, which I know now to be overkill for me.
  63. Re:Hey! Me too! by Anonymous Coward · · Score: 0

    Considering that the time it takes to get up, get a CD, rip it, and encode it is not much longer than it takes to locate a FLACed album on my fileserver and encode it

    Do that for five albums. You have to stay by your computer and change CDs at intervals. Now do it for fifty albums. Now do it for five hundred albums.

    When you are talking about one or two albums, fair enough, there isn't much difference. But your solution doesn't scale well at all.

  64. 128/192 kbps is far from enough by Pieroxy · · Score: 1

    The hardware you use to listen is composed of two pieces of equipment: Your speakers and your ears.

    See this other post, and before you start asking, I encoded with lame, with the r3imx archive CBR profile (at least for the 256kbps track). And this is the second time I do this kind of test with two different people. So there is obviously a difference for him between 256kbps and uncompressed.

    And remember that if average joe cannot tell the difference with his $200 speakers, he will be disappointed when he'll buy (in 20 years) some nice audio setup and realizes he can throw away all of his MP3s.

  65. Question on the dynamic range by Maimun · · Score: 1
    From the article
    The other factor is called "dynamic range". Each bit represents around 6 decibels, a unit used with a logarithmic scale to define "loudness".
    Why does each bit represent 6 decibels? Is that a result one can derive somehow, or it was found experimentally to be the best?
  66. Re:Hey! Me too! by Anonymous Coward · · Score: 0

    But, what happens when your original cd collection (or even one disc) is lost, destroyed, or stolen? You're left with absolutely nothing.

    With a proper (lossless) archive, you can recreate your entire cd collection, bit for bit, if you had to.

    Others have mentioned speed of encoding to other formats, and that's another great advantage. I have scripts to convert my entire flac collection (over 200 discs) to mp3 in one swoop.

  67. Re:Make the right choice. Choose Vorbis. by Anonymous Coward · · Score: 0

    Does anyone here think that this guy is off his rocker? An "Ogg Vorbis Listening Party"? While I think that Ogg Vorbis really is one of the best codecs for lossy audio compression, I find this story hard to believe. Insightful? Please. I mean, for god's sakes!!! He gave all of his party goers a data tape to share with the network admins? What admin in his right mind would mount a tape from a non-IT person who said their brother-in-law or uncle gave it to them to propagate the Ogg Vorbis listening samples? If I had an admin who did that on my network, he'd be fired in an instant. We're talking IP theft here if this guy is telling the truth. Wake up people!!! This HAS to be a troll! Pull your heads out of your colletive ass and moderate appropriately.