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Hydrogenaudio Forums > Lossless Audio Compression > Lossless / Other Codecs
puntloos
Well, the subject/description mostly says it all.

Im slightly fuzzy on the windows .wav format, however Im pretty sure that essentially it is a container format, like AVI is. As such, Ive seen .wav's containing mp3's, Ive heard of .wav containing DTS (?) etc.

- Can the same be done with a lossless format? (wavpack flac, monkey, I dont care)
- If it can be done, is my assumption true that most windows programs that use the standard windows interface to read the WAV file can suddenly use the lossless compression driver to dynamically read/write such data?

Or would doing this be a big waste of time?
greynol
Wave is a container for PCM data and nothing else.
spoon
Wave can have many formats, not just PCM - ADPCM, even mp3 can be embeded within wave files. There is one restriction, vbr is a no-no so your lossless codec would have to be a cbr encoder.
pest
nonsense deleted
greynol
Here's an interesting link:
http://www.borg.com/~jglatt/tech/wave.htm
Kef
QUOTE (greynol @ Sep 19 2006, 20:39) *
Wave is a container for PCM data and nothing else.


WAV can hold PCM and compressed data such as GSM audio, mp3 etc.

http://en.wikipedia.org/wiki/WAV
greynol
QUOTE (Kef @ Sep 19 2006, 12:44) *
WAV can hold PCM and compressed data such as GSM audio, mp3 etc.

spoon beat you to it, but I got the message loud and clear.
Kef
QUOTE (puntloos @ Sep 19 2006, 20:10) *
Well, the subject/description mostly says it all.

Im slightly fuzzy on the windows .wav format, however Im pretty sure that essentially it is a container format, like AVI is. As such, Ive seen .wav's containing mp3's, Ive heard of .wav containing DTS (?) etc.

- Can the same be done with a lossless format? (wavpack flac, monkey, I dont care)
- If it can be done, is my assumption true that most windows programs that use the standard windows interface to read the WAV file can suddenly use the lossless compression driver to dynamically read/write such data?

Or would doing this be a big waste of time?


I'd vote, big waste of time. AFAIK in order to use compressed audio in the wav container you need something called ACM (Audio Compression Module) in your windows/system32/ folder. I don't think there are any FLAC.acm or moneky.acm's available. Anyway, it's more trouble than it's worth. Better stick to whatever you are using now.




QUOTE (greynol @ Sep 19 2006, 21:48) *
QUOTE (Kef @ Sep 19 2006, 12:44) *
WAV can hold PCM and compressed data such as GSM audio, mp3 etc.

spoon beat you to it, but I got the message loud and clear.



Oops, I don't know how I missed his post. Sorry...
spoon
To tell you the truth I don't rate that article, some of the chunk headers are in the wrong case, and he mentions LIST chunks and goes on about 3 sub chunks within LIST and misses out the main INFO chunk (infact he says to ignore any LIST sub-chunk that is not labl, note, ltxt...hmmmm

Also he goes on about 'brain dead programmers' who embedd many different compressed types in waves - Microsoft has a standard list of the compressed formats (there are about 300), and with the right ACM codecs installed it works very well. I suppose if the guy is writing from the side of supporting wave files on anything that is non-Windows then these other wave_formats might be an inconvience.

Not mentioning Wave format extensible dates it somewhat.
greynol
He certainly wasn't afraid to tell you what he thinks, that's for sure.
MedO
QUOTE (spoon @ Sep 19 2006, 20:56) *
Wave can have many formats, not just PCM - ADPCM, even mp3 can be embeded within wave files. There is one restriction, vbr is a no-no so your lossless codec would have to be a cbr encoder.


I hope you know this rules out any lossless codec that actually does any compressing... well, seeing that I almost daily use software you wrote, I REALLY hope that wink.gif
jcoalson
there was at least one FLAC ACM floating around
http://www.hydrogenaudio.org/forums/index....showtopic=16048

the only use I see in it is getting FLAC to work in some legacy software that you can't update/change.

Josh
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