[Libva] HW scaling with libva

[Gwenole Beauchesne]

Hi,

2015-01-28 11:38 GMT+01:00 Ove Brynestad (ovebryne) <ovebryne at cisco.com>:
> Hi,
>
> While looking into image/video scaling and scaling quality on GPU's, I found that ffvademo seems like a good candidate to test the HW scalers on a Haswell with HD Graphics 4600. Now I would like to enable better filters than nearest/bilinear:
>
> - ffvademo currently uses the texture sampling scaler to scale the video to the window size, right?

Yes.

> - can these do 8x8 filtering in addition to nearest/bilinear? If so - how is this enabled?

Considering that HQ scaling patches to the driver were originally
tested with ffvademo, I'd assume yes. If not, this means I forgot to
push a couple of patches in there. I will check this out.

Basically, all you need to do is to add
VAProcPipelineParameterBuffer.VA_FILTER_SCALING_HQ to filter_flags.
This means that you need to create a VPP pipeline for that. It's not
possible to use GL command streams for that.

> - can the ffvademo format filter also do scaling by just enabling the scaling flags, or do I need to add another filter to use the media pipeline scaler?
> - Any templates/demos/suggestions on how to use the media pipeline scaler with 8x8 filtering via libva?

gstreamer-vaapi's GstVaapiFilter implementation is another example:
https://gitorious.org/vaapi/gstreamer-vaapi/source/bb1b147180a07647f355e1e43453920a6c1db9db:gst-libs/gst/vaapi/gstvaapifilter.c

But, as mentioned above, it's just a matter of using a VA/VPP pipeline
with filter_flags set accordingly.

Regards,
-- 
Gwenole Beauchesne
Intel Corporation SAS / 2 rue de Paris, 92196 Meudon Cedex, France
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