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kikkoman · Mar 12, 2003, 06:55 PM

Is the Quicktime IMA 4:1 codec lossless?

Kevin M. Dean · Mar 12, 2003, 07:03 PM

Nope.

kikkoman · Mar 12, 2003, 07:33 PM

Are there any lossless codecs available for the Mac?

Kenneth · Mar 12, 2003, 08:28 PM

What's about AIFF format?

joe_kr · Mar 12, 2003, 08:38 PM

Originally posted by kikkoman:
Are there any lossless codecs available for the Mac?

shorten
http://www.hornig.net/shorten/

but you only get about 50% savings from AIFF (raw)

kikkoman · Mar 12, 2003, 08:38 PM

I mean lossless compression

Originally posted by Kenneth:
What's about AIFF format?

Thinine · Mar 12, 2003, 08:38 PM

Is there even such a thing as lossless compression? In fact, no digital signal can be lossless, just nearly so.

joe_kr · Mar 12, 2003, 08:40 PM

Originally posted by Thinine:
Is there even such a thing as lossless compression? In fact, no digital signal can be lossless, just nearly so.

stuff it, zip, gzip, lha etc...

are all lossless compression

jokell82 · Mar 12, 2003, 09:21 PM

Shorten is the most commen, however Flac is pretty good as well. And since Shorten cannot handle high resolution audio files, flac should soon surpass it in its use (flac can handle 24/96 audio files, and beyond).

Check out etree.org for information on software to use. shntool is what I use, but it's a command line program so some people don't like it...

klinux · Mar 12, 2003, 10:05 PM

I know this is a Mac forum but Windows Media 9 claims to offer a mathematically lossless codec. I believe the compression ration is 2:1 (as opposed to ~10:1 for 128 kbps MP3). I say "claims" because I have not came across a review of that codec. If you have, let me know.

The lossless compression that joe_kr mentioned is for digital-digital lossless compression which is possible and is done everyday for the last 20 years. The compression we are talking about here is analog/digital/analog i.e. sound wave to CD/MP3/DVD etc back to sound wave. In theory, purists will say that any digital format is only an approximation of the original analog wave (although the approximation can approach infinite!) and thus will never be as good i.e. loss occurred.

However, in the last good independent study I read ( from Sound and Vision, formerly Stereo Review), they found that recordings made at 256 kbps or higher are virtually indistiguishable from those of the CD originals.

Now, the good thing about music is that each person is his or her best judge on what sounds the best. You can say that to your ears, you Logitech speakers sound better than my Magnepans or that you can hear the dramatic differences between a LAME 320 vs FH 320 vs WMA 320 vs CD original again and again. Good for you.

However, I tend to value the opinions of the guys at S&V, who have trained ears, listened to variety of source material in a standard setting using high fidelity reproduction equipments in double blind condition than that of an average person.

ARENA · Mar 12, 2003, 10:30 PM

Well, Apple claims AAC to be undistinguishable from the source file at mere 128Kbps bitrate, so despite it not being lossless, it seems (sounds) to be the way to go.

klinux · Mar 12, 2003, 10:46 PM

Ahh, Microsoft also claims they have the best codec. So does OGG, RealAudio, etc. Who'ya gonna believe? That's the $64k question.

As for AAC 128 kps being undistinguishable from the original? It would be great if it's true (I have not tried it myself) but unlikely IMHO.

wataru · Mar 12, 2003, 11:02 PM

Originally posted by kikkoman:
I mean lossless compression

AIFF isn't lossless? I always thought it was.

klinux · Mar 12, 2003, 11:38 PM

No compression though. Just like WAV is 'lossless' but is not compressed.

mangore · Mar 13, 2003, 03:25 AM

Anyone that knows how to code fairly well know if it's possible to make an iTunes plugin for shorten (.shn) files? That is, to play them as is?

Further, if anyone actually MAKES such a thing, I'd be willing to donate a small amount of cash!

I know XMMS has a plugin to play .shn files. I tried getting it to work through fink and x11 but I'm an idiot in such matters and couldn't get it to work

Any tips here would be great too.

Thanks!

booboo · Mar 13, 2003, 09:05 AM

Shorten gives about the maximum lossless compression on audio that I've ever seen.

I just wonder if it's worth it (for 2:1 max) and with the extra time, hassle involved etc., and with hard disk space being so cheap...

dfiler · Mar 13, 2003, 09:20 AM

I would assert that ALL digital audio formats are 'compressed'. What you're looking for is a 'more compressed' format.

GRAHAMUK · Mar 13, 2003, 11:41 AM

Originally posted by Thinine:
Is there even such a thing as lossless compression? In fact, no digital signal can be lossless, just nearly so.

Hmmmm, you are talking about quantization error presumably. This hasn't anything to do with compression, but is a "loss" associated with digitizing the original signal. Trouble is, what's the alternative? A 16-bit quantization (as used by audio CDs for example) has a quantization error which is equivalent to a noise signal 96 dB below the maximum signal level. In my book, that's inaudible. The best analogue system won't be able to do any better, and CD is just a consumer technology. Consider that analogue tape has a dynamic range of about 60dB for cassette speeds, and maybe 70-75dB for reel to reel. Professional systems use 24 bit (144dB dynamic range) or higher quantization levels, which is why digital recording equipment was invented. I'm just using audio as an example - the same applies to digitizing anything. Other distortions within the system will usually swamp the quantization error anyway, and in addition, the quantization error is actually dithered across the band by injection of half a bit's worth of white noise, so right down there at the -96dB level you still get good digitization, just with a rapidly deteriorating signal to (pure white) noise ratio.

Purists may argue that the "approximation" that quantization implies is somehow less "pure" than recoding in analogue, but a) it's bullshit - do the math - and b) it's a way for them to justfy spending silly amounts of money on obsolescent technology. Never really got that ;-)

As for compression (to get vaguely back on topic), what does "lossy" mean in terms of audio? Algorithms such as MP3 claim to discard only what you cannot hear. Taken at face value, that statement means that in terms of what you hear, such compression isn't lossy! Of course, the problem is that you can't take it at face value because it throws away things you can hear. But consider that the inner ear implements a very similar algorithm - it has to, there is no way the brain has the bandwidth needed to handle audio input otherwise. So if your ear is doing it, what's the problem? The trick is to find the EXACT algorithm that the ear uses, rather than a close approximation such as MP3, and then we'd have highly efficient, yet subjectively lossless audio compression. Give it a few years

Hopefully this was of interest and won't be seen as a kind of white noise of its own!

dfiler · Mar 13, 2003, 12:52 PM

Its easy to get sidetracked into the ancient analog vs. digital audio debate. Claiming with certainty that either format is 'better' just makes you look foolish and ignores the fact that reasonable and intelligent people have debated this issue for decades.

Back on topic:
Digital compression can be lossless. Digital data like (AIFF) can be compressed with zero loss of fidelity. The initial conversion from analog sound waves to a recording media is a gray area. Declaring this encoding as lossless or not is an exercise in semantics. Some fidelity is lost. However, the fidelity threshold for perceived lossless encoding is different for each listener.

A good source for info on lossless compression are 'taper' forums. (lossless when compared to an arbitrary baseline source such as CD audio) Some bands permit nonprofit recording and distribution of live concerts.

Ironically, non-technical looking Phish heads comprise one of the biggest communities based around the exchange of lossless audio recordings on the internet. I was impressed by the recording rigs they bring to Phish shows. Imagine a hundred 'tapers' each with a digital recording rig and 30 foot mic boom. Its like a forest of tri-podded microphones rising from a smoky horde of hippies

You might look into what format these people are using...

waffffffle · Mar 13, 2003, 05:38 PM

I do a lot of live audio downloading and trading and SHN is definitely the lossless format of choice. Flac is the future, but right now its not really the way to go. I have emailed the author of Shorten to ask about making an iTunes plugin. He didn't seem to receptive. It would be really nice if someone would make an iTunes port of the xmms plugin out there. MacAmp Lite X has a shorten plugin now (I requested it almost 2 years ago for MacAmp in OS 9). I don't have the knowledge to write the plugin myself but considering there is so much opensource code out there to work with it couldn't be all that hard. Maybe the guy who did the iTunes LAME encoder can do this as well...

Also DMB also a big SHN band. There are huge issues in the fan communities of all taper-friendly bands right now where people rip live shows to mp3, share them on the internet, which are then downloaded by other people, burned to CD and traded to others. The re-encoding of mp3s dilutes the trading pool (I've experienced it myself). Also archive.org's audio archive is just about the coolest place on the internet. Although it sucks that DMB's management recently demanded the removal of all DMB shows there are still a ton of other great bands up there.