[Mesa-dev] hardware xvmc video decoding with nouveau

Maarten Lankhorst m.b.lankhorst at gmail.com
Fri Jul 29 17:15:50 PDT 2011

On 07/30/2011 01:57 AM, Younes Manton wrote:
> On Fri, Jul 29, 2011 at 7:45 PM, Maarten Lankhorst
> <m.b.lankhorst at gmail.com> wrote:
>> On 07/30/2011 01:05 AM, Younes Manton wrote:
>>> On Fri, Jul 29, 2011 at 6:46 PM, Maarten Lankhorst
>>> <m.b.lankhorst at gmail.com> wrote:
>>>>> 2nd patch isn't needed. You shouldn't call vl_video_buffer_create_ex,
>>>>> you should override the create_buffer hook yourself and do what you
>>>>> want. I'll push the 1st one later.
>>>> What create_buffer hook do you mean? If you mean
>>>> pipe_video_decoder->create_buffer, it creates a pipe_video_decode_buffer,
>>>> I need to create a pipe_video_buffer.
>>> pipe_context->create_video_buffer
>> My current nouveau_video_buffer_create calls vl_video_buffer_create_ex
>> with an extra flag set to indicate I want a linear resource. If no capable
>> hardware is found normal resources are used instead. Since I added a
>> fallback to g3dvl, it made sense to me that I just added an extra flag
>> during creation instead of copy pasting the video buffer implementation.
>> The only thing different between vl_video_buffer and
>> nouveau_video_buffer_create is that the latter sets
>> NOUVEAU_RESOURCE_FLAG_LINEAR, rest can be identical.
> Yeah, I realize that, but look at what struct vl_video_buffer has
> under the covers, there's a bunch of state related to shader-based
> decoding. You don't need any of that, what's the point of creating it?
> Besides, if/when pipe_video_decode_buffer goes away even more
> shader-specific stuff will end up in vl_video_buffer to bridge the
> gap. Simply define your own VPE-specific pipe_video_buffer that 1)
> checks that the requested format is NV12, 2) creates 1 luma resource
> and 1 chroma resource. For nv50 you can pass the linear flag, for nv40
> it will also have to pass the linear flag, for nv30 it will need more
> specialized version to deal with the fact that nv30 doesnt even
> support linear or regular non-POT textures.
The problem is that I don't know whether create_buffer is called
for vdpau or xvmc. If it was just xvmc I'd agree with you, but
create_video_buffer can be called for vdpau too. I can't
guarantee that the kernel and the graphics card support PMPEG
decoding either, in which case I do want to fall back to g3dvl.

pipe_video_buffer should just contain the minimum,
and all vl_mpeg_ related state should be split off from it.


More information about the mesa-dev mailing list