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Which Lossless Audio Codec, and Why?
deadsquid puts forth a worthy follow up question to last week's query on audio codecs: "I'm about to re-rip my entire CD collection for the fourth time. I don't want to do it again, so have decided to invest in a small(ish) array and use a lossless codec to create a reference set of my music. From the reference, I plan on transcoding to a variety of bitrates (depending on where the final product will end up) and whichever format of the week suits the device(s) the transcoded content will ultimately sit on. I don't particularly care about encoding time, but would like something that transcodes nicely to MP3, WMA, OGG, and other formats in a reasonable length of time. I would like to ensure that track metadata is maintained in the reference, and is easily transferable when transcoded. I also want something that's not proprietary to an individual's or small group's whims. I'm thinking FLAC, but was wondering if other people had better experiences with other codecs. If you were to use a lossless encoding format, which would you use, and why?"
I made some comparisons of lossless compression techniques a while back. This web page contains the results of my own tests (for speech data) and links to the tests I found (for music). I use FLAC.
excerpt:
"I'm ripping my entire audio collection to lossless audio files and I need a cheap large-volume storage solution...."
Sorry, but I'm an avid audiophile, and just because all lossless audio codecs generate digital output streams identical to their digital input streams does not mean that they sound the same! We must verify that those bits still sound the same via our one way gold plated speaker cables!
The world will not get better through technology. We must seek to be better people.
Let me sum up this entire thread so far and everything that will eventually be added for you:
FLAC blah blah blah. Blah blah Monkey's Audio. Blah blah FLAC blah. Blah blah SHN! Blah. WAV. Blah blah OptimFROG blah blah blah. Blah blah. WMA. WMA?! Blah! Monkey's Audio blah. Blah blah FLAC.
There you go: FLAC.
You can't edit mp3s. Well, you can, but the results aren't good. You have to decompress the mp3, do your editing, and recompress, and chances are that you're going to get artifacts when you do this. So if you ever intend to use an audio file for any kind of editing, you really want it stored losslessly.
At Diamond Mountain University, we typically record all our classes, at 16bit 44khz mono, which consumes a substantial amount of disk space. When people record directly to MP3 it's a huge hassle because I can't take the audio and do dynamic range compression on it without creating artifacts, which means that you can't listen to it on your car stereo unless you have a luxo-mobile with really good sound baffling.
Right now I store all this stuff as AIFF files, but the idea of converting them to FLAC files is definitely attractive.
Not exactly. WAV is a FILE format, not an audio representation format. The audio data can be in any of dozens of formats, many of them involving lossy compression. One of the registered audio data formats (with ID 1) is straight PCM data, that is, uncompressed audio in the usual format. WAV files often contain straight PCM data, but they don't have to. (I've got some lecture notes on audio data and file formats here.)
Actually, if you get into signal processing and transmission line theory, you will see that cables make a difference, for the same reasons that you wouldn't use CAT3 wiring for gigabit networking or indoor extension cords outdoors in a thunderstorm. Of course, paying $50-$200 for a pair of headphones to use in a professional recording studio isn't unreasonable. Paying $2,000 for a pair of headphones to wear while jogging, on the other hand, is quite unreasonable. Sanity has a sliding scale.
But, yeah, there is a point at which you can't justify the extra cost, and you're just throwing away your money. It's like Joe Sixpack buying vintage wine when he can't tell the difference between it and the cheap stuff.
But, back on topic:
My experience with flac is that it is VERY quick to encode and decode. Compression isn't an order of magnitude like MP3, of course, but you might be able to shrink files by a significant quantity (not quite a clearance rack or going-out-of-business sale, but definitely like black Friday). Since it's so damn fast, it's trivial to re-encode flac to other formats.
--TheOrangeSquid Is it any wonder things seem so awry? We swim in a sea of confusion and don't have to think to survive
What the hell do you mean CODEC and LOSSLESS?
You guys make everything way too complex.
There are two methods for compressing data:
1) Lossless compression: Think zip/rar/sit/tar.gz etc. These output the source file bit for bit when decompressed.
2) Lossy compression: Think JPEG/MPEG/MP3 etc. These output with a lot of data stripped off, the best lossy compression attempts to remove as much as possible without affecting quality too much.
Just because something is compressed doesn't mean anything is lost.
Can I get an eye poke?
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