RFC: Video decode acceleration API

[Roland Scheidegger]

Jerome Glisse wrote:
> On 4/2/07, Stephane Marchesin <marchesin at icps.u-strasbg.fr> wrote:
>> Bian, Jonathan wrote:
>> > This is geared toward fixed function video decode pipelines, which is
>> > supported by a number of hardware implementations from Intel, Via,
>> > NVidia and ATI.
>> >
>> >
>>
>> What cards from nvidia are you talking about ? The video decoding
>> pipeline on those has disappeared during the geforce 6x00 era. I hear
>> the same happened on ATI.
>>
>> Stephane
>>
> 
> I believe there are starting to put again such things, i read somewhere
> that
> vista keep pixel shader too busy for letting them properly decode video,
> thus
> in the next generation card ATI likely put back a dedicated video decoder:
> 
> http://www.bit-tech.net/news/2007/03/16/r600_family_has_independent_video_processor/
> 
> 
> I think i did read somethings similar for nv g80 or latter card...
GeForce 6 and up already have a dedicated video processor of some sort.
It's hard to tell how much of "PureVideo" (or "PureVideo HD" for newer
cards) is actually using dedicated hardware, but apparently it was even
quite broken on the first geforce 6800 (nv40) and some things were never
enabled - that sure looks like dedicated hardware to me....
http://www.anandtech.com/video/showdoc.aspx?i=2305

The somewhat fixed and limited traditional video "decode" stuff (like
the back-end colorspace converters / scalers) are indeed gone AFAIK.

Roland