[mythtv-users] trouble with nvidia and bob x2 deinterlacing

Inor Kuo inorkuo at hotmail.com
Wed Mar 19 21:45:29 UTC 2008


>>>> I have searched for and read every thread I could find on bob deinterlacing
>>>> but I am still experiencing significant shaking or jitter when using bob x2
>>>> with sd and hd recordings (NTSC). Originally I was using a modeline I found
>>>> in the mythtv wiki for my tv and the refresh rate came out to just under 60
>>>> so myth wouldn't use bob x2. In my reading I had come across threads where
>>>> people suggested using xvidtune to adjust the modeline so that the refresh
>>>> rate was just over 60.
>>>>
>>>> Modeline from wiki "1368x768 at 85" 85.50 1368 1414 1526 1798 768 771
>>>> 777 795 +hsync –vsync
>>>>
>>>> Modeline tweaked "1368x768 at 85" 85.50 1368 1400 1720 1792 768 783 791
>>>> 795 +hsync –vsync
>>>>
>>>> Xvidtune wouldn't let me adjust on the fly so I used a modeline calculator
>>>> http://xtimingsourceforge.net/cgi-bin/xtiming.pl and put in
>>>> my tv's specs and made adjustments until the refresh rate was over 60.
>>>> after a reboot with my tweaked modeline in xorg.conf, xvid showed the
>>>> following.
>>>>
>>>> Pixel Clock: 85.50 MHz
>>>> Horizontal Sync: 47.71 kHz
>>>> Vertical Sync: 60.02 Hz
>>>>
>>>> My tv is a Vizio 50" Plasma that I got from Costco about almost 2 years ago.
>>>> The specs from the manual are as follows.
>>>>
>>>> Resolution Refresh (Hz) H.Freq (kHz) V.Freq (Hz) H.Sync V.Sync Pixel Freq (MHz)
>>>> 1366x768 60 47.7 60.00 P N 85.500
>>>>
>>>> At this point, myth let me use bob x2 but like another user reported here
>>>> http://www.gossamer-threads.com/lists/mythtv/users/310039?do=post_view_threaded#310039,
>>>> it looked like there was an earthquake going on, moreso for sd than hd
>>>> recordings.
>>>>
>>>> I am running mythtv version 0.21 compiled from source on Ubuntu 7.10 Gutsy
>>>> with an onboard Nvidia GeForce 6150 gpu using nvidia driver version 169.12,
>>>> 1gb of ram, 2gb of swap, and an Amd Athlon 64 X2 Dual Core 4200+ processor.
>>>> The plasma tv is connected to the computer via vga.
>>>>
>>>> Nvidia settings
>>>> 0/OpenGLImageSettings=1
>>>> 0/XVideoTextureSyncToVBlank=1
>>>> 0/XVideoBlitterSyncToVBlank=1
>>>> 0/XVideoSyncToDisplay=1
>>>>
>>>> In mythfrontend, I have "enable OpenGL vertical sync for timing" checked.
>>>>
>>>> I have a total of 3 combined frontend backend machines and I tried getting
>>>> bob x2 to work on the other two as well with the same shaky results.
>>>>
>>>> Monitor GPU Nvidia Driver Version Processor
>>>> Setup 1 50"P50HDTV Vizio Plasma onboard nvidia 6150 169.12 AMD64X2 DC 4200+2.2ghz
>>>>
>>>> Setup 2 42"GV42L Vizio LCD TV onboard nvidia 6150 1.0.9639 AMD64X2 DC 3800+2.0ghz
>>>>
>>>> Setup 3 19"Samsung 920NW LCD nvidia geforce 7300LE 100.14.19 Intel C2D 6420 2.13ghz
>>>>
>>>> On all 3 machines I had to adjust the modelines to get the refresh rate
>>>> above 60 using the native resolutions of the screens (although 1368x768 was
>>>> the closest I could get to 1366x768 for the 2 vizio's).
>>>>
>>>> I've read that there is some jitter to be expected with bob x2 enabled but
>>>> what I am seeing is unwatchable for sd recordings. It's better on hd
>>>> recordings but it gives you a headache after a while.
>>>>
>>>> I would really like to get bob working correctly but I am fairly new to all
>>>> of this deinterlacing and refresh rate stuff. I feel that I have done as
>>>> much as I can on my own and at this point I don't know what else to do so
>>>> I'm turning to the community for help. If anyone can offer any suggestions
>>>> it would be greatly appreciated.
>>>
>>>
>>>
>>> Inor,
>>>
>>> You're probably on the right track... I suggest you take one box and
>>> do a scientific approach only changing one setting at a time.
>>>
>>> First of all you need to get some debugging going however:
>>>
>>> mythfrontend -v playback>/tmp/frontendlog 2>&1
>>>
>>> should provide you with some nice logs.
>>>
>>> Check that you are indeed using bob deinterlace (it'll say so in the
>>> logs). That myth has recognized the refresh rate correctly etc...
>>>
>>> My personal idea is that you might need to turn off "enable OpenGL
>>> vertical sync for timing" .
>>>
>>> Cheers
>>>
>>> Steve
>>
>>
>> Logfile #1
>>
>>
> Ok I'm not too up on 1080i playback (I only have SD). And frankly
> that's probably pushing the envelope, but looking at log #1 you might
> want to look at:
>
> 2008-03-19 14:24:55.305 nVidiaVideoSync: VBlank ioctl did not work,
> unimplemented in this driver?
> 2008-03-19 14:24:55.305 DRMVideoSync: Could not open device
> /dev/dri/card0, No such file or directory
> 2008-03-19 14:24:55.305 RTCVideoSync: Could not set RTC frequency,
> Permission denied.
> 2008-03-19 14:24:55.306 Set video sync frame interval to 33366
> 2008-03-19 14:24:55.309 Using audio as timebase
> 2008-03-19 14:24:55.309 Video timing method: USleep with busy wait
>
> It indicates that it is using USleep as the timing method which is
> generally considered not or good especially as it couldn't set the RTC
> frequency. Have a look at the wiki (search for RTC I think), to see if
> you can get better than this....
>
> BTW your TV is 1080i right?
>

Hi Steve,

It is a 720p.  I searched the list and found the following to fix the RTC
permissions problem.
"make sure your Myth user has read/write privs for /dev/rtc, and: echo 1024> /proc/sys/dev/rtc/max-user-freq"

and now my log looks like this
2008-03-19 17:23:47.366 NVP: ClearAfterSeek(0)
2008-03-19 17:23:47.445 nVidiaVideoSync: VBlank ioctl did not work, unimplemented in this driver?
2008-03-19 17:23:47.445 DRMVideoSync: Could not open device /dev/dri/card0, No such file or directory
2008-03-19 17:23:47.446 Set video sync frame interval to 33366
2008-03-19 17:23:47.446 Using audio as timebase
2008-03-19 17:23:47.446 Video timing method: RTC
2008-03-19 17:23:47.446 Refresh rate: 16662, frame interval: 33366

i did this over vnc again so i have no idea how it looks but as soon as i 
get home i will check it out.  can't wait to get out of the office...  I am a 
bit confused because in my search for the rtc fix, I found a discussion 
that suggests that when using nvidia gpu's, to turn on "opengl for vsync" 
and i have nvidia gpu's in all 3 of my machines.  i know that in past 
versions of myth i had audio/video sync issues on recordings from ABC 
over the air unless i used "opengl for vsync".  does "opengl for vsync" 
not play nice with bob x2?

this is the thread i was referencing.
http://www.gossamer-threads.com/lists/mythtv/users/270622?search_string=RTCVideoSync%3A%20Could%20not%20set%20RTC%20frequency;#270622

Thanks for all of your help so far.

Regards,
Inor
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