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Audio Format Transcoding for Compatibility?
brandorf asks: "With the multitude of compressed audio formats that are available today, (MP3, Ogg, AAC, and FLAC to name very few) our music libraries start to spread across quite a few different formats. While this isn't a problem for desktop/media PC use, as programs like Winamp or iTunes have plugins available for almost every format. However, when it's time to start using a portable unit, it's unavoidable that some files will get transcoded. Have there been any studies or experiments as to how similar the codecs really are? Will transcoding from Format A to B sound worse than going from A to C? What's your experience with this?"
Use a lossless format for archival purposes (any format really since you won't use it on your portable), then use MP3 for everything else. MP3 is the only thing that pretty much every portable can play. OGG and Windows Media are a close second but I would never consider Windows Media format.
If you have a lossless source, the quality of the derived audio should be as good as an original rip of the CD itself. That's the whole point of lossless encoding. If you're going from lossy->lossy, then any transcoding will introduce garbage, but how much garbage depends on how good the original source is. .anacron
...not some thirteen olds insisting they can tell the difference between FLAC and Monkey's Audio codecs.
I'm twenty-one, and I can tell the difference: FLAC is GPLed, Monkey's Audio is not.
Essentially the same on a $20 boom box maybe. Listen to it on a decent hi-fi. On my sub-$1000 rig (Yamaha HTR-5150 reciever, a pair Boston Acoustic CR-9's), lossy sounds noticeably worse than non-lossy. With my Linux box as the audio source, and an S/PDIF-out (so you can't claim it's my crappy sound card's fault for a shitty signal), if I'm actually listening (as opposed to having music just "in the background" for a conversation) I can certainly hear the difference between 160kbps Vorbis and FLAC. Hell, I can often tell what compression method is used (between Vorbis and MP3) by the types of artifacts. MP3's, for instance, have a huge drop in harmonic complexity (VERY noticeable in violins and cello!) and a limp, flat, soundfield. Vorbis, though not as terrible as MP3, is a hair... soft and muddy.
Both work rather well for portable units with cheap headphones. But for my home system, it's FLAC and CD-Audio.
Lex orandi, lex credendi.
Requantizing audio of a given format to reduce its bitrate is likely to cause less of a problem than switching formats.
Simply put, each format has different criteria on what information is thrown away and what is not. Thus, for example, something that MP3 may keep but AAC throws away will not be present if you transcode from AAC to MP3, IN ADDITION to losing anything that AAC keeps but MP3 throws away. The same holds true in reverse.
retrorocket.o not found, launch anyway?
Fortunately, FLAC is "BSDed" not "GPLed" so it has a much better shot at widespread adoption - i.e. in commercial hardware and software products.
Myabe when you're thirty-one, you'll *really* be able to tell the difference.
The codec portions (libflac and friends) are BSD licensed; the FLAC tools themselves are GPL.
WavPack is another nice lossless BSD-licensed codec, which is more advanced in some respects, if not as well supported.
I've noticed significant reduction in lows and an unsettling amount of distortion when I go from vinyl to wax cylinder.
Run a green, felt-tipped pen around the outside of the wax cylinder. It will restore the low frequencies lost from vinyl. I would describe the restored sound as quite earthy, rather than airy though. If airy is what you're going for, I suggest making make two light applications of green felt-tipped marker, rather than one heavy one. This however, could result in very cinnamon flavored mids and highs though, so be careful. In a pinch, you could use a black felt-tipped pen, but don't just use any old Sharpie. Use something really expensive, preferably immediately after writing a page of taoist scriptures on parchment paper. Northern taoist is fine, but southern taoist would be better, especially if you listen to a lot of jazz. Unless it's smooth jazz. Oh, and insulate yourself with 24K gold arch supports before trying any of this, otherwise the earth's own vibrations could mellow your high frequencies, resulting in distinctly cedar-flavored vocals.
On my sub-$1000 rig (Yamaha HTR-5150 reciever, a pair Boston Acoustic CR-9's), lossy sounds noticeably worse than non-lossy.
That statement makes no sense whatsoever. Just digitally adjusting the volume down a little on your recording is "lossy" coding, since you can't recover the original signal from the reduced volume signal. Does that sound worse? I don't think so.
The point is: if you set the bitrate for a lossy codec high enough, you won't hear a difference. If you set it even higher, you won't hear a difference even if you re-encode in another lossy codec once. Etc. As a rule of thumb, the point at which that happens still is before you hit the bitrate of lossless audio codecs.
If you hear a difference, either you are using a bad codec, or you are setting the bitrate too low, or there is something else wrong with your setup.
Hard drive space is plentiful. Just rip everything to a lossless format, such as FLAC, or even .wav
... most... of it) that leaves 324GB in WAV or 162GB in FLAC.
A WAV file is about 10 times bigger than your average mp3, and lossless encoding can get down to about 5 times bigger. So taking a purely hypothetical Music directory of say 32.4 GB (no really, i've listened to
Hard drive space suddenly doesn't look quite so plentiful, even for music collections of a saner size.