[FFmpeg-devel] [FFmpeg-cvslog] lavf/cafenc: Allow muxing opus.

Carl Eugen Hoyos ceffmpeg at gmail.com
Wed Oct 18 04:10:39 EEST 2017

2017-10-17 23:48 GMT+02:00 James Almer <jamrial at gmail.com>:
> On 10/17/2017 6:20 PM, Carl Eugen Hoyos wrote:
>> 2017-10-17 22:20 GMT+02:00 James Almer <jamrial at gmail.com>:
>>>> ffmpeg | branch: master | Carl Eugen Hoyos <ceffmpeg at gmail.com <http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog>> | Tue Oct 17 21:35:28 2017 +0200| [a3accd0c3768933f15422c9dec596da0f436d786] | committer: Carl Eugen Hoyos
>>>> lavf/cafenc: Allow muxing opus.
>>>> QuickTime does not require the (unknown) kuki chunk for decoding.
>>> This at the very least requires limiting muxing to mono and stereo
>>> streams (The only kind of streams that work without channel mapping
>>> information in extradata),
>> Done, thank you!
>>> and a check for -strict experimental.
>> Why?
> Because we're creating these files blindly

This is not correct (and offending, no matter the issue
with the original patch).

> without a proper RE attempt

How do you know?

> or following any kind of encapsulation spec. And considering the
> official encoder/muxer adds a codec specific chunk we don't, the more
> reason to consider a muxing as barebones as this as something
> potentially non-compliant.

Imo, this is not a helpful approach:
The "official" demuxer/decoder accept the files, how does
it make sense to argue they are potentially non-compliant?

>>> Also, I'd have rather waited for Apple to update their docs about Opus
>>> in CAF.
>> As in: Until Godot arrives?
>> Sorry, I don't think it makes much sense to wait for a
>> specification that to best of our knowledge may never
>> appear.
> Apple published the spec for CAF

> detailing encapsulation details for the codecs it supports

Depending on the definition of "detailing":
(For most codecs, the encapsulation details had to be

> including the contents of the kuki chunk for most of them.

Could you elaborate? This is not how I remember it.

Carl Eugen

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