[mythtv-users] NVP: prebuffering pause

[Steven Adeff]

On 6/1/06, Dean Wilson <dean.k.wilson at gmail.com> wrote:
> I recently upgraded my system, but am having trouble with HD
> occasionally pausing during playback.  I don't know what's causing the
> problem -- it could be any number of things, since just about
> everything has changed.  Every time it pauses, I get this error:
>
> NVP: prebuffering pause
> XDS: Current Program Length 0:00 Time in Show 1:00.00
>
> This can be very distracting, so I've tried quite a bit to get it
> worked out.  Unfortunately, I'm running out of ideas.
>
> Here's my hardware setup:
>
> AMD X2 4200+
> 1GB Ram
> 5 Hard drives (4 SATA, 1 IDE) in software Raid5, with LVM on top of
> that (ext3 for main OS, xfs for media partitions.)
>
> And my software setup:
>
> Running svn as of 5/30/06 (had similar problems in .19 code)
> Bob deinterlacing
> XVMC is not enabled
> Standard mpeg2 decoder (same problem with libmpeg2)
> OpenGL vertical sync on
> Latest NVIDIA driver installed
>
> I initially thought that the hard drives were just too slow in Raid5.
> So I made sure that DMA was turned on for the IDE drive (not
> applicable for SATA, correct?), and checked the timing.  All drives
> return reponses similar to this one:
>
> /dev/hda:
>  Timing cached reads:   2404 MB in  2.00 seconds = 1203.25 MB/sec
>  Timing buffered disk reads:  184 MB in  3.02 seconds =  60.99 MB/sec
>
> Here are the frontend logs:
>
> 2006-06-01 09:45:28.457 TV: Attempting to change from None to
> WatchingPreRecorded
> 0: start_time: 8266.508 duration: 323.657
> 1: start_time: 8266.488 duration: 323.654
> stream: start_time: 91849.864 duration: 3596.418 bitrate=18828 kb/s
> 2006-06-01 09:45:28.681 AFD: Opened codec 0x98bd0a0, id(MPEG2VIDEO) type(Video)
> 2006-06-01 09:45:28.681 AFD: Opened codec 0x99a5080, id(AC3) type(Audio)
> 2006-06-01 09:45:28.682 Opening audio device 'spdif'.
> 2006-06-01 09:45:30.026 VideoOutputXv: XvMCTex: Init failed
> 2006-06-01 09:45:30.027 VideoOutputXv: XVideo Adaptor Name: 'NV10 Video Overlay'
> 2006-06-01 09:45:33.023 New DB connection, total: 3
> 2006-06-01 09:45:33.029 TV: Changing from None to WatchingPreRecorded
> 2006-06-01 09:45:33.030 New DB connection, total: 4
> 2006-06-01 09:45:33.031 Connected to database 'mythconverg' at host: 192.168.0.1
> 2006-06-01 09:45:33.033 Connected to database 'mythconverg' at host: 192.168.0.1
> 2006-06-01 09:45:33.038 Realtime priority would require SUID as root.
> 2006-06-01 09:45:33.155 Video sync method can't support double
> framerate (refresh rate too low for bob deint)
> 2006-06-01 09:45:33.169 Video timing method: SGI OpenGL
> 2006-06-01 09:45:42.630 XDS: Current VChip TV-14
> 2006-06-01 09:45:45.135 XDS: Current VChip MPAA-NR
> 2006-06-01 09:46:09.039 NVP: prebuffering pause
> 2006-06-01 09:46:09.126 RingBuf(/media/TV/1051_20060517210000.mpg):
> Waited 1.0 seconds for data to become available...
> 2006-06-01 09:46:11.260 XDS: Current Program Type 'Entertainment'
> 2006-06-01 09:46:12.881 XDS: Current Program Name: 'CSI: New York'
> 2006-06-01 09:46:15.751 XDS: Current Program Length 1:00 Time in Show 0:00.01
> 2006-06-01 09:46:20.595 XDS: Network Call 'NET1'
> 2006-06-01 09:46:35.746 XDS: Current Program Length 0:00 Time in Show 1:00.00
> 2006-06-01 09:46:43.165 XDS: Current Program Length 0:00 Time in Show 1:00.00
> 2006-06-01 09:47:09.795 NVP: prebuffering pause
> 2006-06-01 09:47:51.695 NVP: prebuffering pause
> 2006-06-01 09:47:51.790 RingBuf(/media/TV/1051_20060517210000.mpg):
> Waited 1.0 seconds for data to become available...
> 2006-06-01 09:48:03.726 NVP: prebuffering pause
> 2006-06-01 09:48:16.499 NVP: prebuffering pause
> 2006-06-01 09:48:16.571 RingBuf(/media/TV/1051_20060517210000.mpg):
> Waited 1.0 seconds for data to become available...
> 2006-06-01 09:49:04.437 NVP: prebuffering pause
> 2006-06-01 09:49:21.969 XDS: Current Program Length 0:00 Time in Show 1:00.00
> 2006-06-01 09:49:26.865 XDS: Current Program Length 0:00 Time in Show 1:00.00
> 2006-06-01 09:49:35.103 NVP: prebuffering pause

Whats the CPU load during playback?
Try a different or no deinterlacer.

Also make sure the mpg file is good. When my cable signal was weak the
playback looked ok but I was getting the prebuffer pauses, further
examination of the recorded mpegs showed lots of missing information.
Once I fixed the signal issue the prebuffer pauses went away.

-- 
Steve
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