[FFmpeg-cvslog] dcadec: reorganise context data

ffmpeg | branch: master | Alexandra Khirnova | Fri Oct 2 17:53:26 2015 +0200| [58b42345b38b46d11c32e11d9c57517f99d6a601] | committer: Luca Barbato dcadec: reorganise context data place primary audio coding header data into DCAAudioHeader structure to make DCAContext clearer and move channel

[FFmpeg-cvslog] dcadec: make a number of samples per subband per subsubframe a named constant

ffmpeg | branch: master | Alexandra Khirnova | Fri Sep 18 13:34:20 2015 +0200| [d0a3e89d41b05f9ed0e7401c352b60ed4f4d1ed5] | committer: Luca Barbato dcadec: make a number of samples per subband per subsubframe a named constant Signed-off-by: Luca Barbato > http://git.videolan.org/gitweb.