* qatar/master:
  ac3enc: add macros for option names to make them more understandable.
  ac3enc: fix 'channel_coupling' option to actually allow 'auto'.
  cavs: fix some crashes with invalid bitstreams
  ac3enc: clip coupling coordinates during calculation
  Remove incorrect info in documentation of AVCodecContext.bits_per_raw_sample.
  lavc: fix parentheses placement in avcodec_open2().
Merged-by: Michael Niedermayer <michaelni@gmx.at>