This thread is turning into a really useful source of info. I hope I can add this to the ‘knowledge base’:
This from nVidia’s FAQ section on the NVDVD application:
When hardware acceleration is enabled, the “Decoder Format” section of the NVDVD Video property page will indicate the DXVA mode that is currently being used. If hardware acceleration is disabled or not available on the system, the same section will indicate a software mode such as YUY2.
DXVA stands for DirectX Video Acceleration, a standard defined by Microsoft to allow video decoders to access the video acceleration capabilities of the graphics hardware in the system. All display drivers that pass Microsoft’s WHQL testing support this standard.
For us linux users:
1. this from Wiki:
XvMC is the Linux equivalent of the Microsoft Windows DxVA API (DirectX Video Acceleration). X-Video Motion Compensation, often abbreviated as XvMC, is an extension of the X video extension for the X Window System. It allows video programs to offload portions of the MPEG2 decoding process to the GPU hardware. The portions offloaded are Motion Compensation and iDCT (Inverse Discrete Cosine Transform). XvMC can pass IDCT decoding, and motion-compensation decoding to the video card, offloading that workload to the GPU, which is better suited to this kind of decoding than modern general purpose CPU’s. On most modern CPU’s, the use of XvMC is required to decode 1080i HDTV in real time. Applications which are known to take advantage of XvMC are MPlayer, MythTV, and xine.
2. this from the OpenChrome web site:
The CLE266 is quite well supported: 2D acceleration, 3D acceleration, Xv and mpeg2 decoding using XvMC should work just fine. There is no support in the driver for the video capture functionality. The maximum image size of the mpeg2 decoder is 1024x1024, so don’t try to use HDTV with this chip.
For the CN400 and PM800 the 2D and 3D acceleration should work nicely. Xv and XvMC are also functional but may cause the computer to lock up if the video window is moved around extensively. It is on our todo list to fix this bug. The mpeg2 decoder of CN400 / PM800 is capable of decoding HDTV. However, none of the developers have had any decent HDTV output devices (or sources for that matter) to test the implementation. There are reports that HDTV stutters when subtitles are used, but we have been unable to verify this. XvMC currently decodes mpeg2. Support for mpeg4 acceleration with xine is underway. For what we know, the display interrupt should be fully functional with these devices. There is support for the vt1623 tv encoder present on the CN400, but support is not complete for the vt1625 HDTV encoder present on some Commel motherboards.
For those of us that didn’t know, the OpenChrome project produce (linux) video drivers for VIA mobos thereby providing an alternative to those produced by VIA themselves. The CN700 (present on the EN15000) is not yet supported by the OpenChrome project.
