5b916d7a_d_DIVX_supported___WMPoweruser__Supported_Scenarios
[Decoder Support] HE-AAC v2 (eAAC+) This codec is unsupported in Windows Phone Emulator. [Container] 3GP, 3G2, MP4, M4A [Possible Audio Combinations] N/A [Max Capabilities] Up to 48 Kbps Constant or variable bit rate Up to 48 kHz 1 or 2 channels [Supported Scenarios] 
Receiving files as attachments in email and MMS messages (MMS does not support M4A) Playing or streaming media with the MediaElement API Playing media in the device Media Player Streaming media in Internet Explorer Mobile
Updates codec support list for Windows Phone 7 released, XVID and DIVX supported - WMPoweruser
Supported Scenarios