[FFmpeg-user] ffmpeg and aspect ratio changes with different container formats.

[Toerless Eckert]

Using ffmpeg to compress TV recordings (MPEG2/H264), one challenge
is changing aspect ratios within the recording.

A couple of years back, i asked about this and was told that

A) mp4 container _should_ be able to carry per-frame AR information,
   Q: can anyone confirm or deny this ?

B) That ffmpeg _should_ support this.
   Q: can anyone confirm or deny this ?

So far, B) seems to be "no" to me: Checking with latest/stable
(2.8.6) ffmpeg, when i encode from TV MPEG2-TS into eg: h264 .mp4
container format, there is seemingly no aspect rate encoded per
picture - ffmpeg/vlc/kodi all play such clips with only one AR.
Using TS container does work for all three players with h264 video.

Now i wonder if i should use TS for all my encodings with ffmpeg.
What would i loose over mp4 or mkv...

Thanks
    Toerless