You might consider to extend the extensible format to store custom data for your MFT, but wait, you have size limitation here. I am not going to share the exact size, this is something I am leaving for you to figure out . By the way, on Windows 8.1 we have reduced this size further….
This is because we do not have an inbox MF A-law decoder. This is not the case for U-law. WMP12 falls back to DirectShow to playback A-law content.
You can control DXVA programmatically using Media Foundation (MF). In Windows 7, the MF_TOPOLOGY_DXVA_MODE attribute can be set on a topology to disable DXVA. It can also be disabled by querying the decoder for IPropertyStore and setting MFPKEY_DXVA_ENABLED to false. Please make sure you understand the consequences before disbling DXVA.