Merge commit 'a2664c91'

* commit 'a2664c91':
  atrac3: move the 'samples_per_frame' field from ATRAC3Context to where it is used
  atrac3: remove unused ATRAC3Context field, samples_per_channel
  atrac3: use AVCodecContext.block_align instead of keeping a private copy
  atrac3: move the 'delay' field from ATRAC3Context to where it is used
  atrac3: move the 'version' field from ATRAC3Context to where it is used

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