Merge remote-tracking branch 'cehoyos/master'

* cehoyos/master:
  Set bits_per_raw_sample when reading j2k frames.
  libopenjpegdec.c: Correctly scale gray16 output if precision < 16
  Use rc_max_rate if no video bit_rate was specified when muxing mxf_d10.
  Store the video bit_rate in the context when muxing mxf.

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