There's a convention paper here:

http://www.nue.tu-berlin.de/Publikationen/...pers/aes115.pdf

It cites a reference encoder (for regular and entropy encoding) availible at, ftp://ftlabsrv.nue.tuberlin.de/mp4lossless/ but it's not open for public access. Is there any chance we'll see a public encoder soon? It would be great to finally have a set standard for lossless audio (which incidently performs better than MAC). The paper says that it will be a international standard by the end of 2004, but would it still be possible to see an encoder before that? Perhaps the Nero guys are looking into this since they seem to be our MPEG-4 champions as of late...

Did they just go ahead and beat the crap out of Monkey???

Read my lips: we all are switching to this within a couple of years...

Not really. The grand total of test data used for various sampling rates and bit depth is only 1GB, so I don't think any conclusion of statistical significance can be drawn from this.

Thanks,

We are investigating the latest audio-visual developments, but like SBR - we won't release anything MPEG-4 related until it becomes an official standard - currently the lossless codec is in WD state and probably it will be changed and extended in the near future.

MPEG-4 lossless will also make "scaleable" coding possible - i.e. AAC layer as "base" and losless as additional layer, making easy "peeling" for portable devices very easy and fast, or efficient streaming over various networks.

Won't that require an overhead which would require a higher bitrate than most other lossless formats?

I do understand though that a standard is a good thing.

Sorry but I was too busy with some other high-priority tasks, so I couldn't read all MPEG input documents regarding this - If I remember correctly, adding AAC layer woudn't compromise performance too much, but for exact figures you will have to wait until I re-read all documents made regarding MPEG-4 Amd 4

This kind of hybrid format would be really good for next-generation of DRM CD players since it would allow transparent playback of media in players, and copying of the AAC layer to the portable device directly (thus greatly increasing ripping speed), or using AAC layer for making "personal copies" - emulaitng good old tape-to-tape quality degradation Yeah, I know it sucks - but anyway it is better than being unable to copy at all.

Thank you for the reply.

MPEG lossless may eventually evolve into two parts, one for lossless only (amd4) just like the lossless audio codecs we have right now, e.g., flac, monkey, etc. The compression performance of this work is more or less at the level of monkey at this moment. The other part is a scalable system (amd5), which embeds an aac bit-stream as its core, and fine grain scalable (perceptually) up to lossless (with some small overhead in the overall compression performance). So this tool is a good news to those guys who are not sure which bit-rate they should use for their archive system. B)

from the paper:

Maybe that explains why LPAC froze in 2002. Tilman Liebchen is the LPAC guy.

It also hints at some design differences between FLAC and LPAC that give LPAC greater compression: 1) transmitting the quantized arcsine of the reflection coefficients (FLAC transmits the quantized filter coefficients, which are more sensitive to error); 2) a modification to the entropy coder at the center of the residual distribution.

And why don't any of these papers ever compare against FLAC dammit!

But I didn't see anything in there about lossy+lossless correction; maybe that is a separate codec.

Josh