[meta-intel] [yocto] Cedartrail zero-copy texture updates

[Chris Tapp]

Hi Marc,

On 24 Feb 2014, at 19:21, Marc Ferland <ferlandm at sonatest.com> wrote:

> On Mon, Feb 24, 2014 at 03:46:07PM +0000, Chris Tapp wrote:
>> I'm trying to get zero-copy GLES textures working using Danny /
>> Cedartrail (PVR) so I can stream video frames into a GLES
>> application.
>> 
>> Googling hasn't really helped that much with how to do this, but I
>> think I need to use eglCreateImageKHR and a client-side buffer so
>> that glEGLImageTargetTexture2DOES() can be used to bind the texture
>> to an image in memory.
>> 
>> eglCreatePixmapSurfaceHI() looks like it allows client memory to be
>> used as a colour-buffer which can be passed to eglCreateImageKHR,
>> but I can't seem to be able to create a context which supports
>> pixmaps.
>> 
>> Are there any examples out there to show how to put all of this
>> together?
>> 
> Documentation about this stuff is indeed sparse and hard to find!
> 
> I once tried (and failed!) to do something similar on crownbay but the
> texture data was mapped to a polygon mesh (no video acceleration
> stuff).
> 
> The documentation that I came across mentionned using the
> GL_TEXTURE_STREAM_IMG extension to implement the zero-copy texture
> transfers. Maybe the same extension is available on cedartrail.

I don't think is it. I tried to find this before and could only find GL_IMG_texture_stream2 listed in the GL extensions (for which I can find no documentation!).

> The pdf used to be hosted on intel (emgd section) web site, but it
> looks like it was taken down. I can check if I still have it somewhere
> if you're interested.

Yes please :-)

Chris Tapp

opensource at keylevel.com
www.keylevel.com