Windows Media Audio Pro

• Microsoft Audio ID: 0x0162
• Company: Microsoft
• Samples: http://samples.mplayerhq.hu/A-codecs/WMA9/

The next generation of Windows Media audio codecs.

Extra data layout

This is a rough guess of the extra data from the asf container (little endian order).

byte 1-2    Size of extradata
byte 3-6    Channel mask (http://msdn2.microsoft.com/en-us/library/ms790436.aspx)
byte 7-14   Unknown
byte 15-16  Mask used for calculating samples per frame (int16_t)
byte 17-18  Unknown

Example extradata dump of a 5.1 file:

[18] [0] [3f] [0] [0] [0] [0] [0] [0] [0] [0] [0] [0] [0] [e0] [0] [0] [0]