[mythtv-users] Re: Need advice with 'Pixelization"

Larry K lunchtimelarry at gmail.com
Sat Apr 16 20:25:48 UTC 2005


Well, it sure appears as though I spoke prematurely. 

When I enable deinterlacing (Bob 2x), my system becomes unstable. I am 
mostly unsuccessful with the other options as well (XvMC h/w decoding, 
libmpeg2). I also tried realtime priority, but I have not done the suid root 
thingy, so the log indicates that option was rejected. 

Below is a snippet of my mythfrontend log. Perhaps Jarod or others who use 
the mythtv-suite distro can weigh in regarding what deinterlacing methods 
are available? My video quality is not great without deinterlacing, but 
looks wonderful with deinterlacing...until it crashes and burns :) 

Thanks,
Larry

2005-04-15 21:34:34.675 mythfrontend version: 0.17.20050130-1
www.mythtv.org<http://www.mythtv.org>
2005-04-15 21:34:34.675 Enabled verbose msgs : important general
2005-04-15 21:34:34.748 mythfrontend version: 0.17.20050130-1
www.mythtv.org<http://www.mythtv.org>
2005-04-15 21:34:34.748 Enabled verbose msgs : important general
2005-04-15 21:34:35.236 Switching to square mode (blue)
2005-04-15 21:34:35.363 Switching to square mode (blue)
2005-04-15 21:34:36.106 Joystick disabled.
2005-04-15 21:34:36.152 Registering Internal as a media playback plugin.
2005-04-15 21:34:36.294 Registering MythDVD DVD Media Handler as a media 
handler
2005-04-15 21:34:36.294 Registering MythDVD VCD Media Handler as a media 
handler
2005-04-15 21:34:36.390 Joystick disabled.
2005-04-15 21:34:36.413 Registering Internal as a media playback plugin.
2005-04-15 21:34:36.423 Registering MythDVD DVD Media Handler as a media 
handler
2005-04-15 21:34:36.423 Registering MythDVD VCD Media Handler as a media 
handler
2005-04-15 21:34:36.634 Registering MythMusic Media Handler as a media 
handler
SIP listening on IP Address 192.168.1.101:5060
<http://192.168.1.101:5060>NAT address
192.168.1.101 <http://192.168.1.101>
2005-04-15 21:34:37.536 Registering MythMusic Media Handler as a media 
handler
SIP listening on IP Address :5060 NAT address
SIP: Cannot register; proxy, username or password not set
Destroying SipFsm object
2005-04-15 21:34:52.321 Connecting to backend server:
127.0.0.1:6543<http://127.0.0.1:6543>(try 1 of 5)
SIP: Cannot register; proxy, username or password not set
2005-04-15 21:34:52.321 Connecting to backend server:
127.0.0.1:6543<http://127.0.0.1:6543>(try 1 of 5)
2005-04-15 21:34:52.329 Using protocol version 14
2005-04-15 21:34:52.332 Using protocol version 14
2005-04-15 21:34:52.392 Using protocol version 14
2005-04-15 21:34:52.412 Using protocol version 14
2005-04-15 21:34:54.510 Opening audio device '/dev/dsp'.
2005-04-15 21:34:54.510 Opening OSS audio device '/dev/dsp'.
2005-04-15 21:34:54.521 Using XV port 105
2005-04-15 21:34:54.785 Realtime priority would require SUID as root.
2005-04-15 21:34:54.808 Changing from None to WatchingLiveTV
2005-04-15 21:34:54.897 Video timing method: USleep with busy wait
2005-04-15 21:34:57.572 taking too long to be allowed to read..
2005-04-15 21:35:02.567 RemoteFile::Read() failed in 
RingBuffer::safe_read().
2005-04-15 21:35:02.573 taking too long to be allowed to read..
2005-04-15 21:35:04.788 Waited 2 seconds for data to become available, 
waiting again...
2005-04-15 21:35:05.965 prebuffering pause
2005-04-15 21:35:06.789 Waited 2 seconds for data to become available, 
waiting again...
2005-04-15 21:35:08.790 Waited 2 seconds for data to become available, 
waiting again...
2005-04-15 21:35:10.792 Waited 2 seconds for data to become available, 
waiting again...
2005-04-15 21:35:12.788 RemoteFile::Read() failed in 
RingBuffer::safe_read().
2005-04-15 21:35:12.794 Waited 2 seconds for data to become available, 
waiting again...
2005-04-15 21:35:12.812 Changing from WatchingLiveTV to None
--More--(65%)


On 4/15/05, Larry K <lunchtimelarry at gmail.com> wrote:
> 
> OK, I went into mythfrontend -> Settings -> TV settings -> Playback, and 
> added the Bob 2x Deinterlace option, as well as the "Use video as Timebase" 
> option. This seemed to correct the artifacts that I was seeing, both in live 
> TV, and in peviously recorded material. Based ont his, can I assume that the 
> artifacts were there becasue of the way the encoded video was being decoded 
> for display? As opposed to it being a flaw in the way the PVR-250 was 
> encoding the video in the first place? 
> 
> I went on to experiment further with the XvMC hardware decoding, and that 
> seemed to introduce stutter. I noticed that the CPU consumption of 
> mythfrontend dropped by 50% when I did this. Based on this, I assume that 
> when this box is not checked, myth is doing XvMC software decoding instead? 
> So, one way or the other, XvMC decoding is being done? 
> 
> I did not try libmpeg2 or XV. I gather that XV and XvMC are mutually 
> exclusive options. Is that correct? And what about libmpeg2? Is that to be 
> used in combination with either XV or XvMC? I guess at some point, it will 
> become increasingly difficult to discern any improvement, as the picture 
> quality gets closer to nirvana.
> 
> On 4/14/05, Will Dormann <wd at pobox.com> wrote:
> > 
> > Larry K wrote:
> > > I'll bet that's my problem, then. FWIW, my recordings are 2.2GB/hour,
> > > which seems pretty reasonable.
> > >
> > > I'll try the Bob Deinterlacing when I get home. Thanks! This forum 
> > rocks! 
> > 
> > For the best quality TV-out:
> > 
> > - Make sure MythTV is compiled with OpenGL Vsync support (Otherwise Bob
> > won't look smooth)
> > - Use a resolution of 800x600
> > - Set Playback option to "Use Video as Timebase" 
> > - Use Bob Deinterlacing
> > 
> > An earlier version of my tips are here:
> > http://mythtv.info/moin.cgi/NVidiaMX4000HowTo
> > 
> > I'm planning on updating them to work with the recent builds. Probably 
> > once 0.18 is released. The main difference is now it should be set to
> > use XV instead of XvMC (XV has higher CPU usage, but is less "quirky")
> > and also use libmpeg2 for decoding.
> > 
> > 
> > -WD
> > 
> 
>
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