New Standard: USAC, sussesor of (HE)-AAC Options

[IgorC]

It's a new standard (Unified Speech and Audio Coding – USAC, aka MPEG-D part 3).
It has reached a status of Final Draft International Standard.

Basic information http://en.wikipedia.org/wiki/Unified_Speech_and_Audio_Coding
There are some papers about new compression schemes in internet.

There was a verification test where USAC was compared to HE-AAC v1/v2 on range of bitrates 8-96 kbps. http://mpeg.chiariglione.org/meetings/tori...orino_press.htm
The report should be available in September – October.

Some anonymous source has indicated that USAC was clearly superior to HE-AAC and it did very good on speech though something like "USAC at 48 kpbs = HE-AAC at 64 kbps" shouldn't be expected. It's more like 20-25% of bitrate gain at 20-32 kbps and 10-12% at 64 kbps. That's still pretty good.

There is no information if USAC will be used at higher bitrates as ( LC-AAC's area). The core coder of USAC includes a new enhanced SBR (eSBR).
Both SBR and new eSBR have no advantage over LC-AAC at bitrates higher than 80 kbps. It’s unclear if eSBR can be disabled at higher bitrates.


It will be interesting to hear opinions and if somebody knows something more about it.

[hlloyge]

Problem with Linux isn't finding encoders for it, it's the expected price and the fact that, for that price, there is no such complete toolbox available as is Premiere for Windows.
Personally, I don't use speech codecs, but I welcome any improvement in that field. Because knowledge could be used in building new, more efficient general purpose encoders.

[C.R.Helmrich]

Well, USAC is just that: a general purpose codec. Quality improvements were made not only w.r.t. speech but also high-frequency reconstruction, stereo, overall entropy, and parametric transform coding.

Chris

This post has been edited by C.R.Helmrich: Oct 13 2011, 21:27