This reverts commit ccff2c404d7ea9f5b21ede8ae57bb79feec7eb94.
Fixes#10081.
The new approach breaks embedding subtitles into video-only or
audio-only files. FFMpeg provides a trick: add '?' after the argument of
'-map' so that a missing stream is ignored. For example:
opts = [
'-map', '0:v?',
'-c:v', 'copy',
'-map', '0:a?',
'-c:a', 'copy',
# other options...
]
Unfortunately, such a format is not implemented in avconv, either.
I guess adding '-ignore_unknown' if self.basename == 'ffmpeg' is the
best solution. However, the example mentioned in #9063 no longer serves
problematic files, so I can't test it. I'll reopen#9063 and wait for
another example so that I can test '-ignore_unknown'.
23495d6a39