[opus] Opus Todo

[Timothy B. Terriberry]

陈伟旭 wrote:
> So part of the wiki is out of date? Beside Opus-tools, I also concern 
> about the spec, optimization and future work in wiki. Could you tell me 
> about if they are out of date?
> On 08/28/2019 00:08, Ralph Giles <mailto:giles at thaumas.net> wrote:

For the Spec section:

There is a Matroska mapping, and it has been implemented in Firefox and 
FFmpeg (and Chrome and others). There is an ongoing effort to formally 
standardize Matroska in the CELLAR working group at the IETF. I am not 
certain that much attention has been paid to Opus specifically during 
that process, so contributions there might be welcome. See the working 
group's status page [1] and mailing list [2] for more information.

There is still no multichannel RTP mapping for Opus. At the last IETF 
meeting in Montreal there seemed to be some interest in an effort to 
finally make one, but I'm not aware of anyone who has started working on 
or published a draft yet.

The MP4 mapping is currently maintained by the original author at [3]. 
There has been some discussion of more formal publication through 
DASH-IF or similar, but I don't think that has gone anywhere yet. This 
has also been implemented in a number of places (Firefox, Chrome, 
L-SMASH, GPAC, FFmpeg, etc.). A notable gap here is for someone to look 
at the changes (if any) needed for Ambisonics support [4].

[1] https://tools.ietf.org/wg/cellar/
[2] https://www.ietf.org/mailman/listinfo/cellar
[3] https://github.com/VFR-maniac/Mp4Opus
[4] https://tools.ietf.org/html/rfc8486

I will leave Jean-Marc to comment on the Optimization and Future Work 
sections. I know at least some of those things have been worked on.