[FFmpeg-devel] hardware aided video decoding

[Attila Kinali]

On Fri, 06 Jul 2007 13:04:28 -0400
"Joshua D. Boyd" <jdboyd at jdboyd.net> wrote:

> On Fri, 2007-07-06 at 11:14 +0200, Luca Barbato wrote:
> > should be avoided since most of the gfx design have very fast write and
> > painful slow read.
> 
> The open-graphics card is currently PCI-X with some discussion of moving
> to PCI-E, skipping AGP entirely.  So, read/write speed asymmetry isn't
> automatically a problem here, unless something gets build into the card
> firmware.

It is not yet clear whether OGP will have a fast read path.
If it needs just a few gates more, then it's no problem, but
if it's more, it will certainly dropped in favor of more important
features. Beside, reading and writing from PCI is slow. Although
OGP will support 64bit at 66MHz, this is just a merly 500MByte/s or
even just 240MByte/s if a single lane PCI-e is used. Thus transfereing
data back and forth will take a lot of time.

Hence, i'd like to first plan without any read back to host
memory for the moment.

			Attila Kinali

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