On Fri, Jun 07, 2002 at 11:05:21AM -0700, Ian Romanick wrote: > On Fri, Jun 07, 2002 at 06:10:55PM +0100, Michael wrote: > > On Fri, Jun 07, 2002 at 09:42:08AM -0700, Ian Romanick wrote: > > > It's an interesting idea, BUT unless you can get help from the card > > > decompressing the JPEG on upload (perhaps the Radeon iDCT unit could help?) > > > -or- you come up with some sort of blazing fast, hand-tuned, assembly-coded > > > JPEG decoder, the performance will sink faster than the Titanic...and will > > > rot at the bottom of the ocean for just as long. :) > > > > On upload implies swapping which is already a 'big problem performance > > wise' for some applications and users so you've got negative time to do > > the decompression...;o) > > Exactly. My random thought about the Radeon was that we could store the > texture in DMA space as JPEG or a single frame of an MPEG or whatever then > use the Radeon's built-in engine to decompress it as it loads it DMAs it > into on-card memory. I would think that moving 1/10th the data across the > bus and decompressing it on the fly would be faster than copying the > original. Dunno...just a random thought, probably worthless.
Offtopic, but in a similar sense, I did wonder whether my dc10+'s ability to compress/decompress jpgs could be used for something like mozilla with a suitable interface for it to pass the image to, the card could even dma the result straight into the fb. On a more on-topic theme, I once wanted to do something like this a) read avi frame decompress with dc10+ into (preferably video) memory b) do 3d frame rendering with that memory as texture (without having to do any texture loading per frame) c) Capture 3d window contents d) Feed that into the dc10+ to make an mjpeg frame e) Write that frame to new avi f) rinse and repeat Sort of poor man's 3d video transitions but the alternative at the time was doing software 3d video transitions and software mjpeg encoding on a p166mmx you'll see that if the above managed 5fps it would be quick enough. I suspect you could do the above with even my lowly 800mhz duron and just use software mjpeg en/decoding. -- Michael. _______________________________________________________________ Don't miss the 2002 Sprint PCS Application Developer's Conference August 25-28 in Las Vegas -- http://devcon.sprintpcs.com/adp/index.cfm _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
