[FFmpeg-devel] [PATCH] lavf/dashenc: Add support for per-stream container type selection.

Andrey Semashev andrey.semashev at gmail.com
Wed Nov 14 16:21:54 EET 2018

On 11/14/18 4:52 PM, Jeyapal, Karthick wrote:
> On 11/14/18 1:41 PM, Andrey Semashev wrote:
>> On 11/12/18 3:55 PM, Andrey Semashev wrote:
>>> Suppose you want to create a DASH stream consisting of VP8, H264, Vorbis
>>> and Opus substreams to cover the best compatibility with clients (which
>>> are mostly web browsers, but not necessarilly all of them). AFAIK, you
>>> cannot put all these codecs neither in mp4 nor webm. An "auto" option
>>> would put Opus in webm container, leaving clients not supporting webm
>>> not able to play audio. With explicit container selection one could put
>>> Opus content in mp4 or both webm and mp4 (in which case the substream
>>> would be duplicated).
>>> An example of a client that is picky about container format is Safari on
>>> OS X High Sierra. I don't have one to test, but reportedly it supports
>>> Opus only in caf format, and I've read someone hacked it to play Opus in
>>> mp4 if disguised as AAC. I know lavf/dashenc doesn't support caf (yet)
>>> but it may support it in the future, so the container format selection
>>> would become even more relevant then.
>> So, what do we decide about this patch?
> I understand your point. But all your examples are still theoretical(say caf is not supported in dashenc. And opus example doesn't mention any sample clients for that use-case).
> My view is that, if we can find one practical example where this advanced patch will be of immediate use(which cannot be done by auto option), then let us review and push this patch.
> If we can't find any immediate practical use-case, which could be tested and verified in popular clients then let's go for auto option.

Ok, thanks for your comments.

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