To enable DirectX VA for streamed content, you must create a custom source filter like the one in the top diagram. The following diagrams illustrate the differences between the WM ASF Reader and the WMP Windows Media Source Filter. By contrast, the WM ASF Reader delivers compressed content downstream to the Windows Media Decoder DirectX Media Objects (DMOs), which are hosted inside the DMO Wrapper.
The WMP Windows Media Source Filter delivers decompressed data downstream directly to the audio and video renderers. Therefore, if you want to support DirectX VA when playing streamed content in a custom player, you must use an alternate mechanism, which is the one used by Windows Media Player beginning with the Windows Media 9 Series.īecause Windows Media Player was designed before the QASF filters had been developed, Windows Media Player has its own source filter, based on the Windows Media Format SDK, for playing Windows Media-based content. However, the WM ASF Reader filter does not support playback of streamed content. This means that, for local playback, applications can use the WM ASF Reader filter to play Windows Media-based content and DirectX VA hardware acceleration will be invoked automatically if the graphics card supports it. For end users, this makes possible high-bit-rate video such as full-screen DVD playback on older computers equipped with DirectX VA-compatible graphics cards.īeginning with the Windows Media Format 9 Series SDK, the DMO Wrapper filter supports DirectX VA. It enables software decoders to offload certain CPU-intensive operations to the graphics card for processing. BackgroundĭirectX Video Acceleration (DirectX VA) is an API specification for hardware acceleration of 2-D decoding operations. This section describes how to enable Microsoft® DirectX® Video Acceleration when playing streamed content in a custom player.
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