Merge commit 'e807491f'

* commit 'e807491f':
  mpeg12dec: avoid signed overflow in bitrate calculation
  mpegvideo_parser: avoid signed overflow in bitrate calculation

This merge is a noop.

2017-04-29 12:54:15     @ubitux michaelni: is 740959fd enough to fix the overflow fixed in 58405de0?
2017-04-29 12:55:53     @ubitux same question with e807491f
2017-04-29 13:21:45     michaelni       ubitux, the libav code refered to is wrong for us and i doubt the problem it fixes applies to us.
2017-04-29 13:24:29     @ubitux michaelni: ok, for both commits?
2017-04-29 13:33:55     michaelni       yes, they do more or less the same thing
Merged-by: Clément Bœsch <u@pkh.me>