[FFmpeg-devel] [PATCH 2/2] avcodec/utils: Pretty print analog overscan style display aspect ratios

[Kieran Kunhya]

> iam not trying to look for anything, iam just trying to fix bugs
> and as is ffmpeg displays the wrong DAR in the printout for the
> overscan case (i belive this is a big part of the misuderstandings),
> you would get bt601 with some crazy nonsense DAR
> values instead of 16:9 and 4:3, this patch is intended to fix it

Wrong.

> internally ffmpeg only uses SAR which should already be correct for
> all cases

For BT601 you can only work on the basis that there is no direct
relationship between SAR and DAR owing to approximations and the fact
that the DAR applies to the active image.

See
https://web.archive.org/web/20130328121216/http://lipas.uwasa.fi/~f76998/video/conversion/

Kieran