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Ogg The Conqueror? RC2 Is Out
jonathan_ingram writes: "There has been a lot of discussion recently in Slashdot about sound compression formats. Much has been focused on
Ogg Vorbis, but the most recent version available has been a beta released in Feburary.
Today, RC2 of Vorbis
has been released. The most important of the
many changes
is
channel coupling,
which means that Vorbis can now encode bitsteams at a much lower
bitrate than before.
Try it out today!"
Unfortunately the poster didn't mention this, so I will.
This is a tuning release. Although all infrastructure like channel coupling is in place, the encoder itself is not ideally tuned yet. One of the goals of this release is to get people to test the new modes and report possible problems (samples were it goofs up). If you do this, be sure to try a blind test. Your mind _will_ play tricks on you otherwise.
Two known problems currently are pre/postecho on some really hard samples, and occasional 'hissing' in the low bitrate modes (< 160).
Both are known and will be fixed in the very near future. RC3 is already expected next week.
--
GCP
The only difference was that the low end was less impressive on the OGG than the CD. I put on a few songs and started them simultanously and switched the amp from CD to cassette in (which happened to be my computer). Although it is possible that the casette input amp is less accurate near the low end than the CD input amp, I doubt it. The speakers used were Bose 501s. Conclusion: at 256k/sec, OGG was fine at the high end, but strangely enough, not good enough at the low end.
You are comaring:
a) OGG -- decoded stream -- soundcard -- casette input -- amp -- speakers
b) CD -- decoded stream -- CD-D/A-converter -- CD-input -- amp -- speakers
If alternative a doesn't sound as good as b, this doesn't say anything about the ogg-encoding, because it isn't the only variable. Maybe the difference is caused by the different audio-characteristics of soundcard and CD-D/A-converter.
To get a valid comparison, rip the content of the CD as WAV. Then compare the WAV and the OGG, using the same soundcard and the same amp-input. Everything else is totally meaningless.
But even with this setting, there remains one additional variable: your psyche. If ogg and wav were bit-per-bit equal you will still recognize a difference when you know which one of the two you are hearing. So if you want to get meaningful results, you have to make a double-blind-test.
It's really sad how easy it is for the marketing guys to convince people that alternative codecs are inferior, because 95% don't understand anything about scientific methods or statistics. And they will do that, because they have the budget and we have not.
>There are no patent royalties for software MP3
>decoders.
This is wrong. Go take a look at http://www.mp3licensing.com/royalty/index.html
It's not because you don't pay that there are no licenses.
BTW. That page should be _the_ reason why Vorbis will succeed.
--
GCP
Channel coupling is a method of decreasing the bitrate while maintaining identical or similar quality. Vorbis supports multiple modes, from a "lossless stereo" to aggressive modes. The lossless mode produces greater compression with bit-for-bit identical output results to non-coupled modes. The more aggresive modes sacrifice some of the stereo separation in order to decrease the bitrate.
So, your question is a little silly. The whole point to having multiple bitrates is to allow the user to choose their preferred mix of quality and size. If an aggressive channel-coupling mode can provide significant size savings while having a minimal impact on quality, lots of people will find that worthwhile. And, as you would know if you read the link before posting, you don't have to sacrifice quality at all! Do you really need to ask why someone might want to encode in a mode which has a lower bitrate and identical quality?
I know I need to post this to the authors, but... It is my goal to replace my wife's and my CD collection of 400-500 discs with a hard drive. We'd like to be able to put the CDs in a closet and reclaim some living room space. So, I ripped 10 or so titles and compared them to the original. The rip quality was 256kb/sec. I'm not exactly an audiophile, but I won't tolerate noise, so maybe a lossy compression isn't right for me. I didn't notice any high end problems or artifacts like MP3. Stereo seperation was excellent. The only difference was that the low end was less impressive on the OGG than the CD. I put on a few songs and started them simultanously and switched the amp from CD to cassette in (which happened to be my computer). Although it is possible that the casette input amp is less accurate near the low end than the CD input amp, I doubt it. The speakers used were Bose 501s. Conclusion: at 256k/sec, OGG was fine at the high end, but strangely enough, not good enough at the low end. If the low end can be clarified / amplified (hard to tell, psychoacoustics are strange), I'll be OGGing away for a good long time.
Nick D'Amato strikes again- turns out OggDrop _is_ his doing. It does need CarbonLib but seems to not explode when operated, even so.
This is in contrast to the commercial product N2MP3, which faw down go SPLAT! Complete failure in proprietary land. Go get a newer computer, kid. (Yeah right...)
And as a result I have, for the first time, encoded several files into Ogg Vorbis and been able to play them back on a proper set of mastering-ready speakers in an acoustically suitable room... sorta. So, here's my observations so far- some good and some 'whoa! what the heck is that?'.
First of all- Ogg Vorbis DOES NOT lack bass. Trust me on this one. I have some projects being worked on that used my GPLed mastering software to fill in extremely low bass, and I used that to audition Ogg Vorbis. The highs are pleasingly uncolored, a bit 'whiter' than the original recording but it actually seems to help synthetic cymbals. Bright recordings lose absolutely nothing, it's quite impressive really. The lows go down forever, I'm speculating that people are used to some type of midbass wooliness that you get with mp3s? I flat guarantee that the _extreme_ lows get through uninhibited. Almost to a fault...
Here's the joker in the deck: every tune I encoded and played back was somewhat choppy- and VARI-SPEEDED.
I can't begin to imagine what would be causing that. It's really being done pretty damn well! It sounds very, very much like the original recording, with a bit of interference and choppiness, except the tempo is _significantly_ slower. Like more than 10 bpm slower. This is a pretty serious problem... and I don't believe it can be part of Quicktime because Quicktime has been able to avoid that sort of thing for many, many years.
A 300mhz G3 machine with 128M of RAM ought to be able to deal with this- if Ogg Vorbis is truly that processor-destructive that's a serious objection to it. It'll never work in embedded apps or portable players if it has to eat that much CPU. I'm hoping it's a bug. Actually I _know_ it is a bug, because dropouts are one thing with inadequate (ha!) CPU, but _varispeed_ should not be happening. There's no excuse for that as a reaction to inadequate CPU.
So, all told, I am delighted with what I've learned. And even with the problems I encountered, I can confirm that Ogg Vorbis _does_ have bass, deep bass, and that its tonal character, even at 128K, is quite impressive. If I was mastering for it I'd master stuff for soundstage depth knowing it would drag all the highs and lows out that it could, that it would make things 'whiter' and zippier kind of like Fraunhofer MP3 encoders, but in a less intrusive yet more effective way.
At the same time, this port of it is still 'freaky bizarre demo' quality and could not be used professionally. I'd love to know if this varispeed is happening strictly on playback- that would mean I had a commercial-quality free Nick D. _encoder_ and just didn't have a playback mechanism that worked properly.
Believe me, guys, I'm rooting for you. But I can't do this work for you, because I'm not a C-slinging programmer gunslinger. If I was, I'd have been trying to help out loooooong ago. Best I can do for now is state unequivocally: yes, Ogg sounds better than MP3 if you like clarity and wide-range frequency response. I look forward to when it grows up and can support platforms such as mine. I can't really give it a full-on audition, or include it in the mp3 study I did, because it's just plain not ready and not working reliably, but finally, at long last, it's working unreliably and that is enough to give me a taste. And I like where it's heading.
-Chris Johnson
I don't think there are any un-patented 5.1 channel codecs around.
Actually, if you look at the last answer on the Vorbis FAQ you'll see that Ogg Vorbis already supports encoding of up to 255 channels per stream, so, theoretically at least, it ought to be a cinch to use Vorbis for 5.1 audio.
This could be a real opportunity for Ogg to become the first mainstream audio codec to support 5.1 explicitly. It would be a real leg-up for Ogg's chances if it gets accepted as the choice of audiophiles, and having 5.1 supported before MP3 and WMA can only help with that. Those who have experimented with DVD Audio would finally have a format worth considering for ripping purposes, and it helps that Vorbis sounds very musical.
Encode MP3s, RC2-OGGs, and whatever else you like, at all the bitrates you are interested in. I recommend doing this for many different types of music you like.
IMPORTANT STEP 1:
Once they're on your computer, decompress them back into a .WAV file. Make sure you keep track of which .wav came from which compressed file. If you tested both MP3 and OGG at 3 different bitrates each, you will have 6 .WAV files for each song, plus the original .WAV (don't delete it). Then cut out relevant passages from each of the songs, maybe a minute each, with a wav editor.
IMPORTANT STEP 2:
Once you have these wav files on your hard drive, tell your roommate to burn them on a CD, in an order that he will write down but not reveal to you. Then put the CD into your stereo and get a good paid of headphones. Crank it up, and take notes on which versions of the passages sound the best and why. See how successful you are in identifying the original wav file when you don't know which it is. See if there is any pattern to your responses.
Until you do a double-blind test like this (come on, it's not difficult) you really shouldn't be shooting your mouth off about which format sounds better.