[meta-freescale] QtMultimedia on i.MX6

[Philip Craig]

On Wed, Jul 10, 2013 at 8:41 PM, Thomas Senyk
<thomas.senyk at pelagicore.com> wrote:
> On Wednesday, 10 July, 2013 20:32:05 Philip Craig wrote:
>> I'm not sure why it needs to be imx6 specific. Doesn't the opengl API make
>> it so that it doesn't need to be specific? The Qt eglfs platform is using
>> the vivante opengl libraries. As I understand it, the parts that need to be
>> imx6 specific are confined to the eglfs platform plugin.
>>
>> qt-gstreamer is at http://cgit.freedesktop.org/gstreamer/qt-gstreamer
>
> No. There is no vendor-independent way to map cpu/vpu based memory into gpu
> (/opengl) memory.
> Without 'mapping' one needs to copy/upload via glTexImage2D.
> This one single line(!) consumes >100% cpu of one iMX6 core  for 1080p.
> If you 'map' the cpu load is very easily <10%

Thanks for the explanation. Just to be sure I understand you: there is
no standard way to allocate dma buffers, so the gpu cannot do the copy
itself? I see that gst-plugins-gl relies on gstbufmeta from the
gst-fsl-plugins package to determine the physical address of dma
buffers allocated by the vpu plugin or by the v4l2src.

And yes, qt-gstreamer is using glTexImage2D. I guess that could be
patched, but then you may as well just patch QtMultimedia like you
were planning.