[mythtv-users] Intel hd 4000 support

Michael T. Dean mtdean at thirdcontact.com
Mon May 13 14:16:02 UTC 2013


On 05/13/2013 03:13 AM, Stephen Worthington wrote:
> On Mon, 13 May 2013 14:54:23 +1000, you wrote:
>
>> On 13 May 2013 13:18, Rajil Saraswat wrote:
>>
>>> Hi
>>> I am in the market looking for an uktrabook which is easy to carry around.
>>> Most ultrabooks use intel hd 4000 graphics card. How well does mythtv
>>> support it? Does it provide hardware acceleration similar to vdpau?
>>> Tx
>>>
>> myth supports VAAPI hardware accelerated decoding.
>> nowhere near as powerful and flexible as VDPAU (especially in regards to
>> deinterlacing).
>>
>> The things to keep in mind, is that most laptop modern enough to have a
>> HD4000, are likely fast enough to software decode anything you throw at
>> them to start with.
> I found that was not quite true - CPU power alone was not quite
> enough.
>
> I have had an MSI GT70 laptop since late last year: Core i7-3610QM
> CPU, 12 GiBytes RAM, builtin HD4000 video.  There are few laptops with
> more CPU power than that.  When playing back HD video on CPU alone, I
> would often get a tearing effect towards the top of the screen.  I
> never really diagnosed the problem, but I think it was only on 1080i
> H.264 HD video.

Tearing--as opposed to dropped frames or "stuttery" playback--is 
generally caused by either bad video drivers or improper video driver 
configuration and has nothing to do with the CPU's ability to keep up 
with video decoding demans.  All of our video rendering methods (Xv, 
VA-API, OpenGL, and VDPAU) rely on the video card drivers to proper 
video sync, which will prevent tearing.  Most drivers require the user 
to explicitly enable sync--and often separately for Xv vs OpenGL/VDPAU.

That said, running at 2.3GHz, your CPU may not be able to keep up with 
high-bitrate H.264 decoding in software (so even if you fixed the driver 
configuration, you'd likely have dropped frames or other problems).  The 
3.3GHz turbo might do better, but I don't know that it could maintain 
that long enough for real playback.  However, you shouldn't have any 
problems with MPEG-2 playback.

>    SD and MPEG2 recordings certainly did not do it.  I
> did try changing various options, but never found anything better. And
> the colours were always a little off, a bit dark, and there was no way
> to adjust the colours - mythfrontend did not provide the colour
> settings I get on my main Nvidia based MythTV box.

Again, the drivers need to provide support for color adjustment (and/or 
"studio mode" and such).

It's quite possible the Intel drivers lack support for these things (or 
have them only partially implemented).  I have heard quite a few 
comments about the poor state of the Intel drivers (and it seems Intel 
doesn't care much about F/LOSS users--though they're starting to care 
more about "closed" Linux-based systems due to the mobile 
bubble^H^H^H^H^H^Hboom, but that probably won't help us too much).

>    The results were
> certainly viewable, but just a little annoying at times.
>
> When I tried VAAPI it worked for playing one program, but locked up
> the display on exit from VAAPI - to get things going again I had to
> swap to another TTY and restart lightdm and log in again.  But playing
> the program produced a rather better result - correct colours, no
> tearing.  And the colour settings were available, although I did not
> then need them.
>
> Then (a couple of months ago?) I ran across a post on this list saying
> that Intel had produced an installer that installed the latest VAAPI
> drivers and all the right matching packages, and they had VAAPI
> working as a result.  So I tried that and now have VAAPI running
> without any problems, although I have yet to test it in real life as I
> have not been away from home with the laptop since then.
>
> So I would certainly recommend trying VAAPI if you have problems with
> just using CPU alone:
>
>
> https://01.org/linuxgraphics/downloads/2013/intel-linux-graphics-installer
>
> BTW My GT70 also has an Nvidia (GT650?) GPU, but current software to
> access it from Linux (http://bumblebee-project.org) does not allow
> VDPAU to work.  I am hoping that will change in the not too distant
> future - rumour has it that there are changes coming in new kernels to
> help.

Why not use the proprietary nvidia drivers? Do they not support your GPU?

IMHO, VDPAU is the right tool for video playback on GNU/Linux and the 
right implementation of it is in the nvidia proprietary drivers.  
Regardless of AMD's recent announcement, their support for VDPAU is 
limited (but, we hope will improve over time).  And, as far as F/LOSS 
drivers go, well, they are works in progress.

Mike


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