My workaround has been to use gawk to extract the start time of the input video and then pass this to ffmpeg using -ss. Often, these frames have no relationship to the rest of the video.

However, the output video incorrectly shows them. The input video suppresses these frames by setting the start time. iMovie splits the video into scenes, and it's common for a file to include a few additional frames from the previous scene before the video start time. I end up with these input files when I capture video from a Canon HV20 camera using iMovie. However, the beginning of the output includes frames that are before the start of the input, which is a problem.

I would be fine with small discrepancies. In more detail, ffprobe on the input gives the following duration and start:ĭuration: 00:00:00.70, start: 0.522533, bitrate: 46718 kb/s

You can download incorrect-start-frame.mov at , and a -report log from running this command with ffmpeg 2.8.4 at . % ffmpeg -i incorrect-start-frame.mov incorrect-start-frame.mp4 This is possible because the start time of the input is non-zero. mov container to mp4, the output includes additional frames that are before the start frame in the input.

Ffmpeg mov to mp4