[FFmpeg-devel] [PATCH v2 0/6] WebRTC sub-second live streaming support

[Michael Riedl]

On 11/15/23 22:45, Michael Niedermayer wrote:
> On Tue, Nov 14, 2023 at 01:59:48PM +0100, Michael Riedl wrote:
>> On 11/14/23 11:05, Tomas Härdin wrote:
>>> This patchset is missing tests. I know that we for some reason don't
>>> really have tests for protocols, but I feel the issue is worthwhile to
>>> bring up. I've worked a bit with WebRTC recently and it's fiddly, so
>>> it'd be nice to have some automated thing that keeps track of which
>>> WebRTC implementations this works with. Or maybe this is better handled
>>> with an external project, testing which implementations interoperate?
>>
>> I agree that having automated tests would be useful for stability in the future.
>> I tested the patchset with both SRS and Millicast, and it worked well.
>>
>> For automated testing, we could use FATE, but it needs an extra server with
>> protection and someone to keep it updated. Testing with paid services like
>> Millicast is tricky.
>>
>> Another option is an external project for WebRTC testing, but the challenge is
>> keeping it maintained and compatible with changes in implementations.
>>
>> External services might update their software, causing issues with tests. We
>> would need a plan for dealing with that.
>>
>> For paid services like Millicast, we need to figure out who pays for the tests.
>> Understanding the costs is essential if we want to use paid services for
>> testing.
>>
>> I'd like to hear your thoughts on these points and how you would propose to
>> proceed with adding tests for protocols like WebRTC.
> simple, add server support for this to FFmpeg.
>
> FATE is run in cases without network access (for example googles ossfuzz setup
> i belives does not permit the fuzzed code to access external things IIRC)
>
> The practice of implementing only one end of a protocol is honestly wrong.
> And if there is no usable free server, then even more so.
>
> thx

Server support was planned for later, but maybe it's better to do it now.
Multiple solutions are possible, but one solution requires adding 2 more
(de)muxers for server support to this patch series. It would also be possible to
split the patch series into 2 parts, one for WHIP client and server support and
one for WHEP client and server support. But I'm not sure which solution is
better.

My idea is to add 2 more (de)muxers for server support. This would allow us to
test the following:
- WHIP muxer (client) --> WHIP demuxer (server)
- WHEP muxer (server) --> WHEP demuxer (client)

Regardless, this will only test the implementation against itself. If that makes
sense and sounds reasonable, I will add the server support to this patch series.

Please let me know what you think.