Stefano Sabatini <[email protected]> added the comment:
ffmpeg currently doesn't properly supports filtering with more than one output. Let's consider the command: ffmpeg -i INPUT OUTPUT1 OUTPUT2 INPUT has size wxh, OUTPUT1 has size w1xh1, OUTPUT2 has size w2xh2. A filterchain is automatically added for scaling from the input to the output, in particular a scale filter is added to the end of the filter to rescale the decoded frame to the size requested by the output. The problem is that in this case the last scale filter will use the size w2xh2 for both OUTPUT1 and OUTPUT2. A possible solution requires the use of a distinct filterchain for each input and for each output. This would allow for example to properly process a command of the kind: ffmpeg -vf IN_VF -i INPUT -vf OUT_VF1 OUTPUT1 -vf OUT_VF2 OUTPUT2 while currently this command will only configure a single filterchain corresponding to OUT_VF2. ---------- topic: +ffmpeg ________________________________________________ FFmpeg issue tracker <[email protected]> <https://roundup.ffmpeg.org/issue2040> ________________________________________________
