libopusenc: Change default frame duration to 20 ms

20 ms is the default in the libopus encoder, and gives better
quality than 10 ms.

Signed-off-by: Martin Storsjö <martin@martin.st>
Merge remote-tracking branch 'qatar/master'

* qatar/master:
  libopusenc: Change default frame duration to 20 ms

See: 74906d3727ec3bd9b7b28dfa7a98ff6e8cf8b6d7
Merged-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/mpeg4videodec: use av_fast_padded_malloc() for bitstream buffer

Fixes use of uninitialized memory with vlc (sample from ticket3277)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>