[FFmpeg-user] Video processing stopped prematurely on resolution change

[Martin Ždila]

Hello

I have two videos where one of them changes it resolution (rotation) twice.
I would like to join them side by side. I've used following command:

ffmpeg -y -i a.webm -i b.webm -filter_complex "
  color=color=black:size=640x240 [base];
  [0:v] setpts=PTS-STARTPTS,
scale=320x240:force_original_aspect_ratio=decrease [left];
  [1:v] setpts=PTS-STARTPTS,
scale=320x240:force_original_aspect_ratio=decrease [right];
  [base][left] overlay [tmp1];
  [tmp1][right] overlay=x=320" \
-c:v libx264 -preset fast -c:a copy -t 30 output.mkv

The problem is that the result video (output.mkv) ends at second resolution
change and doesn't continue beyond that. It looks like a bug of ffmpeg.
Could somebody please confirm it or suggest a workaround? Attached attach
including debug output can be found at
http://filebin.ca/2z6yMpuLdtyP/videotest.tgz.

Thank you
-- 
Martin Ždila