[mythtv-users] XvMC question

ojw at weilerfamily.com ojw at weilerfamily.com
Mon Jul 28 06:25:27 UTC 2008


Quoting Kevin Kuphal <kkuphal at gmail.com>:

> On Sat, Jul 26, 2008 at 11:56 PM, <ojw at weilerfamily.com> wrote:
>
>>
>> I'm having what seems to be an XvMC problem.  Perhaps someone
>> here can give me a sanity check...
>>
>> I'm running a P4 1.8Ghz (400Mhz FSB) with 640MB of RAM on a Dell
>> Dimension 4400.  I'm using a nvidia 6200 AGP based card (specifically,
>> this one:
>> http://www.newegg.com/Product/Product.aspx?Item=N82E16814130233)
>> I'm recording only mpeg2 streams from an ATSC tuner.  When I try
>> to playback 1080i based recordings, I'm averaging in the mid 70%
>> range on my cpu meter as reported by top and about every 5 seconds,
>> the video stutters.  Based on what I've heard on this list, this
>> sounds like this card should be able to offload some of that cpu
>> and that maybe I don't have XvMC set up correctly.
>>
>> I'm pretty sure I followed all the instructions at
>> http://www.mythtv.org/wiki/index.php/XvMC.
>>
>> Here are some of the things I have checked:
>>
>> "dmesg | grep nvidia" produces this:
>>
>> nvidia: module license 'NVIDIA' taints kernel.
>> NVRM: loading NVIDIA UNIX x86 Kernel Module  173.14.05  Mon May 19
>> 00:06:12 PDT 2008
>>
>> The kernel version is 2.6.25.4 compiled from sources from kernel.org.
>>
>> "/sbin/lspci | grep -i nvidia" produces:
>>
>> 01:00.0 VGA compatible controller: nVidia Corporation NV44A [GeForce
>> 6200] (rev a1)
>>
>> "/sbin/lsmod | grep -i nvidia" produces:
>>
>> nvidia               7091236  36
>> i2c_core               20756  12
>>
>> lgdt330x,qt1010,mt2060,mt352,zl10353,xc3028_tuner,tvp5150,tuner,nvidia,em28xx,i2c_i801,tveeprom
>>
>> The video card section of my xorg.conf looks like this:
>>
>> Section "Device"
>>     Identifier     "Videocard0"
>>     Driver         "nvidia"
>>     Option         "UseEvents" "true"
>>     Option         "XvmcUsesTextures" "false"
>>     Option         "NVAGP" "1"
>> EndSection
>>
>> When I do this "grep Motion /var/log/Xorg.0.log", I get this:
>>
>> (II) Loading extension XVideo-MotionCompensation
>>
>> Running "mythfrontend --version" produces this:
>>
>> Please include all output in bug reports.
>> MythTV Version   : exported
>> MythTV Branch    : tags/release-0-21
>> Library API      : 0.21.20080304-1
>> Network Protocol : 40
>> Options compiled in:
>>  linux release using_oss using_alsa using_backend using_dbox2
>> using_dvb using_frontend using_hdhomerun using_iptv using_ivtv
>> using_joystick_menu using_v4l using_x11 using_xrandr using_xv
>> using_xvmc using_xvmcw using_xvmc_vld using_bindings_perl
>> using_bindings_python using_opengl using_ffmpeg_threads using_live
>>
>> I created a playback profile that only uses xvmc.  The
>> "playback" setting screen (3 of 9) has only one line that
>> looks like this:
>>
>> if rez > 0 0 -> XvMC
>>
>> So I'm kinda at a loss.  I'm a newbie to MythTV so feel
>> free to point out the obvious.  I'm a competent linux admin
>> so if I need to run some more diagnostics from the command
>> line, I'd be happy and able to do that.
>>
>> Any thoughts?
>
>
> Also make sure you have the Composite extension disabled (double check the
> XvMC page as I'm sure it mentions this)

I checked this and I am indeed disabling the Composite extension.  In  
another post, william_munson at comcast suggested I check the contents  
of /etc/X11/XvMCconfig to make sure it has one line that says  
"libXvMCNVIDIA_dynamic.so.1" which it does, though I used a capital C  
in Config when I created the filename.  Just in case, I made a  
symbolic link from XvMCconfig to XvMCConfig.  None of that helped.

I did a little bit more searching and found that I probably should  
have built myth with the following config options:

--enable-opengl-video --xvmc-lib=XvMCNVIDIA

I did that, then remake'd the source and installed and still didn't  
affect cpu utilization.

I suppose now would be a good time to ask:

1.  Did I get the wrong card?

2.  If #1 is no, am I expecting too much out of my poor little old P4 1.8Ghz?

3.  Do I need to run nvidia-xconfig or nvidia-settings to help with  
this situation?

4.  In the XvMC samples page  
(http://www.mythtv.org/wiki/index.php/XvMC:Example_CPU_Savings), one  
note said that to get XvMC working, one had to turn on NvAGP.  I'm  
guessing I have it on based on my settings posted above but how do I  
know what to set it to or am I barking up the wrong tree?

Any other helpful hints to get XvMC working would be greatly appreciated.



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