In this very intersting session, Stan Pennington talked about how Windows 7 adds support in native code for accelerating media transcoding and specific playback experiences through the new asynchronous Media Foundation transform (MFT) model. How to write and use accelerated MFTs, and how to license for preference in Windows Media Player and portable device operations with Windows Shell. He showed a managed sample using the transcoding API, and showed how the new Device Proxy simplifies AVStream driver based video capture in Media Foundation. Talked about in-box support for high-definition UVC webcams and the new extensibility model, along with how the new native Source Reader object allows easy capture integration into existing applications. Finally, demonstrates new tools for developing and debugging in Media Foundation.
MF Provides Hardware Codecs and Async support, HD Webcams support.MF Focused on unmanaged API – coding, transcoding must be really time, buffering, good response to flashing and other. Writing unmanaged you’ll have twice as faster comparing to managed, the GC is non-deterministic.
MF could expose configuration, control and status through managed APIs.
There are four media infrastructures Microsoft deals with:
- Video for Windows – ACM Codecs
- DShow – DVD, TV )Filter, DMO, ACM, VCM)
- Direct Show – WM True Streaming (DMO, ACM Codecs)
- WM FSDK – Key mainstream scenarios & nre features (MFT Codecs)
Media Foundation is the area Microsoft is investigating these days for media.
Typycal Microsoft usage in Windows 7
- MF – Playback for non streaming ASF, MP3, MPEG-4 and selected AVI permutations of digital still cameras
- New metadata handling in Shell Property Handlers
- Transcoding and new media sharing
- DShow – DVD, TV, MPEG-2, MPEG-1, custom I/O, video editing
- FSDK – Best compatibility for ASF true streaming
- Historic integration of ASF read, write.
Microsoft uses the whole three main infrastructure to get best end use experience. Windows media center uses WMP OCX with custom presenter.Window 7 change protected media path (PMP) in WMP and OCX.
Windows Vista PMP used for MF even with unprotected content, providing seamless cross-fade in mixed DRM/non-DRM playlists. Windows 7 PMP only used for DRM-protected content in MF.
Why should we use MF?
- Stream objects (IStream) for media input, output
- Most connectivity and data flow divorced from streaming components, moved to higher layer
- No push-pull component issues
- Better potential for dynamic changes
- Better control of threading
- More constrained components roles and graphs topologies
- Hardware Codecs – transcoding only or general for transcoding and playback
To have WM, you should install Windows 7 SDK.