[Nouveau] "Decode videos"

[Jimmy Rentz]

On Mon, 6 Dec 2010 23:05:10 +0100
Xavier Chantry <chantry.xavier at gmail.com> wrote:

> On Mon, Dec 6, 2010 at 7:35 PM, Mikhail Ramendik <mr at ramendik.ru>
> wrote:
> > Hello,
> >
> > http://nouveau.freedesktop.org/wiki/FeatureMatrix lists "Decode
> > videos" as WIP for NV30 and NV40 seies.
> >
> > As I have an NV44, I would really like to know - what is this
> > feature going to be? VDPAU support for these cards, or XvMC, or
> > something else?
> >
> 
> According to
> http://lists.freedesktop.org/archives/nouveau/2010-August/006142.html
> and the following mails/patches : XvMC.
> 
> Not sure what is possible on nv40 but that subject was discussed
> quickly here:
> http://lists.freedesktop.org/archives/nouveau/2010-May/005726.html

Initially I would say XVMC.  VDPAU expects full hw bitstream
decode.  XVMC only does decode starting at idct/mb.  I am guessing it
is possible to support VDPAU by doing the earlier stages in software
then handling the reset to hw.  Well, unless someone figures out some
way to handle the full pipeline in hw via shaders which is something
I have no time or knowledge.  

The latest version of the video decode/vpe/nv40 patches are here:
http://people.freedesktop.org/~jb17bsome/vpe/ddx/ddx_nouveau_vpe_v1.patch
http://people.freedesktop.org/~jb17bsome/vpe/drm/drm_nouveau_vpe_v5.patch
http://people.freedesktop.org/~jb17bsome/vpe/kernel/kernel_nouveau_vpe_v6.patch
http://people.freedesktop.org/~jb17bsome/vpe/mesa/mesa_pipe_video_nouveau_vpe_v3.patch 
For mesa you need to pull the pipe-video branch.  All the others apply
fine against the latest branches for the ddx, drm, nouveau kernel.

The current patches integrate vpe better with gem/ttm.  This means
that relocs/fences are emitted and it doesn't just pin all memory like
before. Though, it does runs much slower compared to my last non-gem
version located under the old directories in (ddx/drm/kernel/mesa).  I
am fairly certain from oprofile dumps that it is because of too many
relocs emitted or something, but I haven't followed up.

Anyway hopes this helps.

Jimmy