[FFmpeg-user] Encoded NAL data changes when creating mp4

Carl Eugen Hoyos cehoyos at ag.or.at
Sun Feb 10 10:50:18 CET 2013

Richard Hubbard <richmh58 <at> gmail.com> writes:

> I am trying to use ffmpeg to generate an mp4 from 
> an elementary stream. I do not want the encoded NAL 
> data to change, but it seems to be getting changed.

With -vcodec libx264, they have to change, 
use -vcodec copy if you want them unchanged.


> ffmpeg -i cama1_vtc_c.avc -sameq -vcodec libx264 
> -profile main -level 30 -an cama1_vtc_c_ffmpegMain30_sameq.mp4
> ffmpeg version 0.7.13, Copyright (c) 2000-2011 the FFmpeg developers

This is too old now (hundreds of bugs have been fixed 
since), please update to current git head.

Unrelated: -sameq does not (nearly) do what you expect, 
remove it, the option has been removed in later versions.

Carl Eugen

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