[mythtv] v4l2_request API support in MythTV ffmpeg...

[Piotr Oniszczuk]

> That sounds good. Does it work with the new ffmpeg (branch devel/ffmpeg-resync in github)? I will be merging that into master sometime soon if all is well.

Yes. I already prepared &tested ver. for 4.4 FFmeg and it seems work on 4.4 FFmpeg well.

> 
> Are there patches to ffmpeg code itself or only to mythtv code?

I have 2 patches:
- one for ffmepg (so applies exclusively only on mythtv/external/FFmpeg)
- one for mythtv/configure

> Patches to ffmpeg code will have to go into our MythTV/FFmpeg repository and be merged into the mythtv repository.
> 
> If you have patches to include the preference is to open a pull request. If you prefer you can open a ticket with patches.

Well - i prefer ticket with patches.

> Let me know if you have a pull request or patches,

So maybe good will be do this in following way?
1. You will update FFmpeg to 4.4 in master.
2. I will make sure my v4l2_request code works well with master having updated FFmpeg 4.4.
3. Once p.2 will be good - i'll will provide You ticket with patches applicable for master with FFmpeg4.4.
 
> I can get them installed for you if they look good. It will be better for all if your changes are incorporated in the main code as long as they do not conflict with anything else we are doing.

So far none conflict is known for me.
I have v4l2_request code in production builds for x86_64 targets where mythtv was build with configure disabling support for v4l2_request and none conflicts nor issues were noticed.
What i need to verify is: compile/run of mythv on Linux kernel without v4l2_request kernel code.