[FFmpeg-user] aspect ratio changes in the middle of the stream

Carl Eugen Hoyos cehoyos at ag.or.at
Fri Sep 6 13:05:58 CEST 2013

Michael Kasch - SmartCast <kasch <at> smartcast.de> writes:

> ffmpeg  -y -i test.ts  -vf "yadif, scale=iw*sar:ih ,
> pad=max(iw\,ih*(16/9)):ow/(16/9):(ow-iw)/2:(oh-ih)/2" 
> -aspect 16:9 test.mp4
> But often I have the situation that the ratio changes 
> in the middle of a stream. 4:3 Film with 16:9
> commercials, or first 4:3 and next show 16:9. Is there 
> a solution to get ffmpeg or x264 to recheck the aspect
> ratio every i-frame?

(Why only I-frames?)
The way I understand your question is that in some 
circumstances, output videos do not look the way 
you want them.
If this is correct, please post the command line you 
used together with complete, uncut console output for 
such a failing case.

Carl Eugen

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