On Mon, Oct 08, 2001 at 03:54:14PM -0700, Sottek, Matthew J wrote: > > Basically I want to DMA a chunk of video ram into plain RAM. This > >is useful for: video capture, VBI/closed captioning, taking screen > >snapshots. > > I think you are going about this the wrong way. Video capture does > not need to get video ram into system ram. Whatever application is > doing the drawing needs to capture before putting the data in video > ram. If you are using a capture card then you need to have a client > that reads the data, stores it to disk, then copies it to video > ram via Xv. (NOT: capture card -> video ram->dma back to system ram)
You don't quite get the procedure (with the All-in-Wonder and ViVo cards): RF->Video Card->OnBoard Buffers->Overlay. Nothing leaves the card unless you need capture. There is no other card involved; The ATI captures directly into VRAM, which you then have to transfer to system ram. PCI reads are too slow for this purpose. > Also for cc etc you want to do the blending in the application > before putting the data in the video memory. XvMC does this with > hardware acceleration... just leave out the XvMCRender() call if > you have no Mpeg to decode. The video is captured directly into vram, then displayed into an color-coded overlay. All cc requires is drawing over the color-keyed area. R C _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
