Preparations to FFmpeg bump to 4.4

[galad87]

Fixed FFmpeg audio encoders and some new deprecation warnings that happens when linking to FFmpeg 4.4.

Test on:

• Windows 10+ (via MinGW)
• macOS 10.13+
• Ubuntu Linux

[Nomis101]

Thanks for working on this. They added a patch to enable constant quality for videotoolboxenc and to use b-frames for HEVC and H264.
FFmpeg/FFmpeg@efece44
So, I assume we don't need our patches anymore??

[galad87]

The only videotoolbox patches that will be needed for 4.4 should be A25-videotoolbox-trc.patch and A26-videotoolbox-hevc-10-extradata.patch

[octavedo]

FFmpeg 4.4 audio encoders problem is fixed.

But, choosing H-265 10-bit (VideoToolbox) for video encoding give the following errors:

[08:50:16] encavcodecInit: H.265 10 bit (VideoToolbox)
[08:50:16] encavcodec: encoding with stored aspect 1/1
[08:50:16] sync: first pts video is 0
[08:50:16] sync: first pts audio 0x1 is 1620
[08:50:16] encavcodec: avcodec_send_frame failed
[08:50:16] encavcodec: avcodec_send_frame failed
[08:50:16] encavcodec: avcodec_send_frame failed
[08:50:16] encavcodec: avcodec_send_frame failed
[08:50:16] encavcodec: avcodec_send_frame failed
[08:50:16] encavcodec: avcodec_send_frame failed
[08:50:16] encavcodec: avcodec_send_frame failed

Hope the above helps.

Thank you.