FFmpeg 5.0 released

Version 5.0 of the FFmpegaudio and video toolkit has been released.

For this long-overdue release, a major effort underwent to removethe old encode/decode APIs and replace them with an N:M-based API,the entire libavresample library was removed, libswscale has a new,easier to use AVframe-based API, the Vulkan code was much improved,many new filters were added, including libplacebo integration, andfinally, DoVi support was added, including tonemapping andremuxing. The default AAC encoder settings were also changed toimprove quality.