deps/media-playback: In check for key-frame, use new FFmpeg 6.1 API

Browse Source

Fixes for using FFmpeg 6.1 due to deprecations. Uses `#if` macros to
allow builds for using older versions of FFmpeg.

AVFrame.key_frame was replaced with a flag in AVFrame.flags. The commit
adding the flag is [1] in FFmpeg's repository, and the deprecation is in
commit [2].

In summary of the "key_frame" change, AVFrame.key_frame is deprecated,
and AVFrame.flags indicates with a bit flag if it is a key frame (with
the enum/defined AV_FRAME_FLAG_KEY).

[1]: avutil/frame: add a keyframe flag to AVFrame
https://github.com/FFmpeg/FFmpeg/commit/cc11191fda0471017b03c1434d6d8cb79f6914e5

[2]: avutil/frame: deprecate key_frame
https://github.com/FFmpeg/FFmpeg/commit/3e06f6f04020bef32fa42bc9d7f96e76a46453aa

...

This commit is contained in:

500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f