If you are unlucky you might see the following ffmpeg error message: Output #0, image2, to 'output.ppm': Stream #0.0: Video: ppm, rgb24, 144x108, q=2-31, 200 kb/s, 90k tbn, 29.97 tbc Stream mapping: Stream #0.0 -> #0.0 Press [q] to stop encoding av_interleaved_write_frame(): I/O error occurred Usually that means that input file is truncated and/or corrupted. The above error message was produced with a command like this ffmpeg -v 0 -y -i 'input.flv' -ss 00:00:01 -vframes 1 -an -sameq -vcodec ppm -s 140x100 'output.ppm' There are several possible reasons for the error message "av_interleaved_write_frame(): I/O error occurred".
  1. You are extracting a thumb and forgot to specify to extract a single frame only (-vframes 1)
  2. You have a broken input file.
  3. And finally: The target file cannot be written.
The above was caused by problem three. After a lot of trying I found that the target directory did not exist. Quite confusing.