[FFmpeg-devel] [PATCH] Scalar: Multiple ouput with different resolutions, Issue 2040

Stefano Sabatini stefano.sabatini-lala at poste.it
Fri Mar 18 00:00:50 CET 2011

On date Thursday 2011-03-17 20:07:41 +0000, Manjunath Siddaiah encoded:
> Hi,
> If "CONFIG_AVFILTER" is enabled, scaling goes through filtering
> path. Since "AVFilterContext" variables are in
> "AVInputStream" structure we can't have different context for
> different outputs in case of multiple outputs. Because of this there
> will be video distortions or segmentation fault if we do multiple
> outputs with different resolutions.
> The solution is to move the "AVFilterContext" from "AVInputStream"
> to "AVOutputStream" structure so that there will be different filter
> contexts for each and every stream for multiple outputs.
> Tested the patch with taking single input stream and doing outputs with different resolutions as follows.
> ./ffmpeg -i ../MP4_009-720x480_100_128_44.1_30.mp4 -s 176x144 ../out1.mp4 -s 320x240 ../out2.mp4 -s 352x288 ../out3.mp4 -s 640x480 ../out4.mp4
> The same command now gives segmentation fault or distorted video outputs.

This patch seems a variant of:

commit 1762d9ced70ccc46c5d3e5d64e56a48d0fbbd4f7
Author: Michael Niedermayer <michaelni at gmx.at>
Date:   Mon Feb 14 23:02:10 2011 +0100

    Restructure video filter implemenattion in ffmpeg.c.
    This fixes several bugs like multiple outputs and -aspect mixed with -vf
    Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

which was applied against git.videolan.org (note: the same patch was
never applied to the git.ffmpeg.org - now git.libav.org - repo).

Can you confirm that the problem is fixed in current HEAD?

Thanks for your cooperation.
FFmpeg = Fierce and Fiendish Monstrous Practical Ecumenical Guru

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