[mythtv-users] video stutter with VDPAU and 1080i DVB

Johnny Walker johnnyjboss at gmail.com
Fri Jan 15 15:04:28 UTC 2010


On Sat, Jan 9, 2010 at 11:53 AM, Michael T. Dean
<mtdean at thirdcontact.com> wrote:
> On 01/09/2010 11:11 AM, Justin Smith wrote:
>>
>> I get a slight but annoying stutter in video playback of live TV on my
>> mythTV box and I was wondering if anyone had any ideas on how to
>> troubleshoot this. It only occurs for one 1080i HD DVB channel - other HD
>> channels are fine (FWIW: Ch9 HD in Australia).
>>
>> The stuttering is confirmed in the frontend log (-v playback) with lines
>> like this:
>>
>> NVP(6): Video is 3.19567 frames behind audio (too slow), dropping frame to
>> catch up.
>>
>> When I set the audio output device to NULL, the stuttering (and log lines)
>> disappear. But as I'm not too good at lip reading... :)
>>
>
> I'd start with:
> http://www.mythtv.org/wiki/Troubleshooting:Prebuffering_pause .  Also, make
> sure you're not using PulseAudio.

I'm having tearing at the top of the screen during panning when I'm
trying to just playback 720p from an HDPVR. I've turned off the
de-interlacers (as someone pointed out I'm not using interlaced
content) but I'm still getting issues.

I was able to replace the ram in my Acer Revo 1600 to 2gbs and now
Video ram is 512 and yet this issue persists.

I've got the following in the logs:

2010-01-15 06:46:21.519 Connected to database 'mythconverg' at host: 10.0.1.199
2010-01-15 06:46:21.688 Using Idle Timer. 62 minutes
2010-01-15 06:46:21.691 TV: Attempting to change from None to Watching
WatchingLiveTV
2010-01-15 06:46:21.695 MythContext: Connecting to backend server:
10.0.1.199:6543 (try 1 of 1)
2010-01-15 06:46:21.697 Using protocol version 50
2010-01-15 06:46:21.743 Spawning LiveTV Recorder -- begin
2010-01-15 06:46:24.748 Spawning LiveTV Recorder -- end
2010-01-15 06:46:24.776 We have a
playbackURL(myth://10.0.1.199:6543/2025_20100115064624.mpg) &
cardtype(HDPVR)
2010-01-15 06:46:25.212 We have a RingBuffer
2010-01-15 06:46:25.264 TV: StartPlayer(0, Watching WatchingLiveTV,
main) -- begin
2010-01-15 06:46:25.735 AFD: Opened codec 0xae5b2890, id(H264) type(Video)
2010-01-15 06:46:25.735 AFD: codec AAC has 2 channels
2010-01-15 06:46:25.736 AFD: Opened codec 0xad7a1d90, id(AAC) type(Audio)
2010-01-15 06:46:25.991 Opening audio device 'default'. ch 2(2) sr 48000
2010-01-15 06:46:25.991 Opening ALSA audio device 'default'.
2010-01-15 06:46:26.103 mixer unable to find control Master 1
2010-01-15 06:46:26.467 NVP(2): Forcing decode extra audio option on
(Video method requires it).
2010-01-15 06:46:26.469 OSD Theme Dimensions W: 1280 H: 720
2010-01-15 06:46:27.291 TV: StartPlayer(0, Watching WatchingLiveTV,
main) -- end ok
2010-01-15 06:46:27.291 TV: Changing from None to Watching WatchingLiveTV
2010-01-15 06:46:27.291 TV: State is LiveTV & mctx == ctx
2010-01-15 06:46:27.292 Using realtime priority.
2010-01-15 06:46:27.297 Video timing method: USleep with busy wait
2010-01-15 06:46:27.297 TV: UpdateOSDInput done
2010-01-15 06:46:27.297 TV: UpdateLCD done
2010-01-15 06:46:27.305 TV: ITVRestart done
2010-01-15 06:46:27.395 ScreenSaverX11Private: DPMS Deactivated 1
2010-01-15 06:46:27.489 Loading window theme from
/usr/share/mythtv/themes/Mythbuntu/schedule-ui.xml
2010-01-15 06:46:27.862 NVP(2): prebuffering pause
2010-01-15 06:46:27.916 NVP(2): prebuffering pause
2010-01-15 06:46:46.580 New DB connection, total: 3
2010-01-15 06:46:46.583 Connected to database 'mythconverg' at host: 10.0.1.199
2010-01-15 06:46:48.753
RingBuf(myth://10.0.1.199:6543/2025_20100115064624.mpg): Waited too
long for ringbuffer pause..
2010-01-15 06:46:49.115 NVP(2): Forcing decode extra audio option on
(Video method requires it).
2010-01-15 06:46:49.246 AFD: Opened codec 0xae5b2890, id(H264) type(Video)
2010-01-15 06:46:49.246 AFD: codec AAC has 2 channels
2010-01-15 06:46:49.247 AFD: Opened codec 0xae5d4460, id(AAC) type(Audio)
2010-01-15 06:46:49.803 WriteAudio: buffer underrun
2010-01-15 06:46:49.946 WriteAudio: buffer underrun
2010-01-15 06:46:50.079 WriteAudio: buffer underrun
2010-01-15 06:46:50.113 WriteAudio: buffer underrun
2010-01-15 06:46:50.213 WriteAudio: buffer underrun
2010-01-15 06:46:50.346 WriteAudio: buffer underrun
2010-01-15 06:46:50.380 WriteAudio: buffer underrun
2010-01-15 06:46:50.445 WriteAudio: buffer underrun
2010-01-15 06:46:50.511 WriteAudio: buffer underrun
2010-01-15 06:46:50.578 WriteAudio: buffer underrun
2010-01-15 06:46:50.645 WriteAudio: buffer underrun
2010-01-15 06:46:50.711 NVP(2): prebuffering pause
2010-01-15 06:46:50.712 WriteAudio: buffer underrun
2010-01-15 06:46:50.713 NVP(2): prebuffering pause
2010-01-15 06:46:50.717 NVP(2): prebuffering pause
2010-01-15 06:46:50.737 NVP(2): prebuffering pause
2010-01-15 06:46:50.745 NVP(2): prebuffering pause
2010-01-15 06:46:50.763 NVP(2): prebuffering pause
2010-01-15 06:49:13.558 TV: Attempting to change from Watching
WatchingLiveTV to None
2010-01-15 06:49:13.732 WriteAudio: buffer underrun
2010-01-15 06:49:15.738 TV: Changing from Watching WatchingLiveTV to None

So I went through the
http://www.mythtv.org/wiki/Troubleshooting:Prebuffering_pause page and
the nothing seems to help. The system is SNOOZING at 12% CPU in top
during playback.

Version is 0.22.0+fixes23097-0ubuntu0+mythbuntu3 and I've tried the
185, 190 and now even 195 beta nvidia driver.

I changed the audio output from alsa:default to alsa:hdmi and to my
surprise it actually worked - but there was still this flicker on the
top of the image as if it was trying to keep up. Modern Family is
filmed with this 'Mtv Style Camera work' where there's a great deal of
panning and motion at the same time.

What astounds me is that people are reporting this ion on the Revo
1600 plays back 1080i just fine but I'm working with 720p and it's got
these prebuffering pauses.

Of course Composite is already disabled in my xorg.conf.

What else am I missing?


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