[FFmpeg-devel] [PATCH 2/3] avcodec/nvenc: Handle non-square pixel aspect ratios

Kieran Kunhya kierank at obe.tv
Sat Jan 17 21:04:01 CET 2015

> FFmpeg is correct, there is absolutely no doubt about it: This "active"
> pixels nonsense is only relevant for certain very specific media, definitely
> not when encoding testsrc and decoding the result to showinfo. Demuxers or
> high-level tools may know when they are dealing with that kind of content,
> but encoders do not.

This is ridiculous. It's an incredible double standard that FFmpeg
will "fix" severely broken files, yet the basics of digital video that
have been around for decades are just ignored because they are

Testsrc is wrong then - note how downscaled HD test sequences like
parkjoy have 9 pixels of border when downscaled to SD - because it
follows the BT601 spec.

Where do you think 720x576 (or similar) content comes from? Magic
fairies that just happen to render at this resolution. No - it comes
from cameras that have an active picture of 702x576.


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