[mythtv-users] Remote Mythfrontend Problem

Tue Jul 21 08:23:53 UTC 2009

Well to summarise:

The problems only occurs on the frontend machine while watching live tv.

I have tested on the backend machine by running a frontend on that 
machine at the same time as watching the same channel on the frontend 
machine. The frontend machine suffers the problems and errors in the 
log. the backend machine, running frontend does not suffer from problems 
nor errors in the log.

I have repeated the above tests by connecting the frontend machine 
directly to the backend machine with a new piece of network cable and 
the problems are exactly the same.

If I watch live tv on the frontend machine with the problems and 
glitches present I can then watch the recording made of that live tv 
session without any problems at all, even when streaming directly from 
the backend.

What I think will help me understand the situation is the difference 
between watching luve tv and watching a recorded tv session streamed 
from the backend. Could someone here with enough knowledge help me 
understand the differences between the two.

The first and obvious difference I can think of is that while watching 
live tv the backend is recording that tv session.

Is there any other disk activity occurring during the watching of live TV?

Are the formats of the live tv and streamed recorded tv streams different?

Are there any other differences I should be aware of?

Regards,

Steve

FYI:

frontend log snippet at start of watching live tv:
2009-07-17 18:38:19.250 Connecting to backend server: 10.200.1.250:6543 
(try 1 of 5)
2009-07-17 18:38:19.256 Using protocol version 40
2009-07-17 18:38:19.303 TV: Attempting to change from None to WatchingLiveTV
2009-07-17 18:38:19.311 Using protocol version 40
2009-07-17 18:38:20.704 New DB connection, total: 3
2009-07-17 18:38:20.751 New DB connection, total: 4
2009-07-17 18:38:20.770 Connected to database 'mythconverg' at host: 
10.200.1.250
2009-07-17 18:38:20.809 Connected to database 'mythconverg' at host: 
10.200.1.250
2009-07-17 18:38:20.924 NVP: Disabling Audio, params(-1,2,44100)
libGL warning: 3D driver claims to not support visual 0x5b
2009-07-17 18:38:21.072 VideoOutputXv: XVideo Adaptor Name: 'Intel(R) 
Video Overlay'
2009-07-17 18:38:21.143 OSD Theme Dimensions W: 640 H: 480
2009-07-17 18:38:23.055 TV: Changing from None to WatchingLiveTV
2009-07-17 18:38:23.066 The realtime priority setting is not enabled.
Initialize Yadif Deinterlacer. In-Pixformat = 1 Out-Pixformat=1
yadifdeint: size changed from 0 x 0 -> 720 x 576
2009-07-17 18:38:23.100 Video timing method: DRM
2009-07-17 18:38:23.450 XMLParse::LoadTheme using 
/usr/share/mythtv/themes/MythCenter-wide/ui.xml
2009-07-17 18:38:24.436 RingBuf(/video/1001_20090717183822.mpg): Waited 
1.0 seconds for data to become available...
2009-07-17 18:38:24.436 Checking to see if there's a new livetv program 
to switch to..
2009-07-17 18:38:25.451 RingBuf(/video/1001_20090717183822.mpg): Waited 
2.0 seconds for data to become available...
2009-07-17 18:38:25.451 Checking to see if there's a new livetv program 
to switch to..
2009-07-17 18:38:25.839 NVP: Prebuffer wait timed out 10 times.
Initialize Yadif Deinterlacer. In-Pixformat = 1 Out-Pixformat=1
yadifdeint: size changed from 0 x 0 -> 720 x 576
2009-07-17 18:38:27.608 VideoOutputXv: XVideo Adaptor Name: 'Intel(R) 
Video Overlay'
2009-07-17 18:38:28.639 AFD: Opened codec 0x4947760, id(MPEG2VIDEO) 
type(Video)
2009-07-17 18:38:28.640 AFD: codec MP3 has 2 channels
2009-07-17 18:38:28.640 AFD: Opened codec 0x4952610, id(MP3) type(Audio)
2009-07-17 18:38:28.640 AFD: codec MP3 has 1 channels
2009-07-17 18:38:28.641 AFD: Opened codec 0x73b92b0, id(MP3) type(Audio)
2009-07-17 18:38:28.641 AFD: Opened codec 0x73b9690, id(DVB_SUBTITLE) 
type(Subtitle)
2009-07-17 18:38:28.855 Opening audio device 'default'. ch 6(2) sr 48000
2009-07-17 18:38:28.855 Opening ALSA audio device 'default'.
2009-07-17 18:38:28.895 Mixer unable to find control PCM 2
2009-07-17 18:38:28.895 Mixer unable to find control PCM 3
2009-07-17 18:38:28.895 Mixer unable to find control PCM 4
2009-07-17 18:38:28.896 Mixer unable to find control PCM 5
2009-07-17 18:38:28.896 mixer unable to find control Master 1
2009-07-17 18:38:29.051 NVP: Prebuffer wait timed out 10 times.
2009-07-17 18:38:30.108 NVP: Enabling Audio2009-07-17 18:38:30.108 NVP: 
Enabling Audio
2009-07-17 18:38:32.314 NVP: Prebuffer wait timed out 10 times.
2009-07-17 18:38:35.509 RingBuf(/video/1030_20090717183833.mpg): Waited 
1.0 seconds for data to become available...
2009-07-17 18:38:35.509 Checking to see if there's a new livetv program 
to switch to..
2009-07-17 18:38:35.995 NVP: Prebuffer wait timed out 10 times.
2009-07-17 18:38:36.527 RingBuf(/video/1030_20090717183833.mpg): Waited 
2.0 seconds for data to become available...
2009-07-17 18:38:36.527 Checking to see if there's a new livetv program 
to switch to..
2009-07-17 18:38:37.660 NVP: Prebuffer wait timed out 10 times.
Initialize Yadif Deinterlacer. In-Pixformat = 1 Out-Pixformat=1
yadifdeint: size changed from 0 x 0 -> 704 x 576
2009-07-17 18:38:39.325 NVP: Prebuffer wait timed out 10 times.
2009-07-17 18:38:39.519 AFD: Opened codec 0x2aaabc0503c0, id(MPEG2VIDEO) 
type(Video)
2009-07-17 18:38:39.520 AFD: codec MP3 has 2 channels
2009-07-17 18:38:39.520 AFD: Opened codec 0x2aaabc00f730, id(MP3) 
type(Audio)
2009-07-17 18:38:39.520 AFD: Opened codec 0x2aaabc005cf0, 
id(DVB_SUBTITLE) type(Subtitle)
2009-07-17 18:38:39.520 AFD: codec MP3 has 1 channels
2009-07-17 18:38:39.520 AFD: Opened codec 0x2aaabc046b50, id(MP3) 
type(Audio)
2009-07-17 18:39:02.397 [mpeg2video @ 0x3b9533f620]ac-tex damaged at 12 33
2009-07-17 18:39:02.397 [mpeg2video @ 0x3b9533f620]Warning MVs not available
2009-07-17 18:39:16.810 [mpeg2video @ 0x3b9533f620]00 motion_type at 29 6
2009-07-17 18:39:16.815 [mpeg2video @ 0x3b9533f620]Warning MVs not available
2009-07-17 18:39:16.931 [mpeg2video @ 0x3b9533f620]Warning MVs not available
2009-07-17 18:39:27.884 [mpeg2video @ 0x3b9533f620]00 motion_type at 38 22
2009-07-17 18:39:28.048 [mpeg2video @ 0x3b9533f620]ac-tex damaged at 9 8
2009-07-17 18:39:28.169 [mpeg2video @ 0x3b9533f620]00 motion_type at 38 32
2009-07-17 18:39:44.635 [mpeg2video @ 0x3b9533f620]ac-tex damaged at 22 23
2009-07-17 18:39:44.782 [mpeg2video @ 0x3b9533f620]ac-tex damaged at 28 9
2009-07-17 18:39:44.900 [mpeg2video @ 0x3b9533f620]ac-tex damaged at 22 22
2009-07-17 18:39:50.345 [mpeg2video @ 0x3b9533f620]00 motion_type at 33 23
2009-07-17 18:39:57.056 [mpeg2video @ 0x3b9533f620]ac-tex damaged at 22 34
2009-07-17 18:39:57.356 [mpeg2video @ 0x3b9533f620]00 motion_type at 12 34
2009-07-17 18:39:57.356 [mpeg2video @ 0x3b9533f620]00 motion_type at 12 5
2009-07-17 18:39:57.356 [mpeg2video @ 0x3b9533f620]00 motion_type at 6 6
2009-07-17 18:39:57.357 [mpeg2video @ 0x3b9533f620]invalid mb type in B 
Frame at 5 7
2009-07-17 18:38:32.314 NVP: Prebuffer wait timed out 10 times.

frontend log snippet when watching recorded tv:
2009-07-21 00:02:29.781 TV: Attempting to change from None to 
WatchingPreRecorded
2009-07-21 00:02:29.814 AFD: Opened codec 0x11efce40, id(MPEG2VIDEO) 
type(Video)
2009-07-21 00:02:29.815 AFD: codec MP3 has 2 channels
2009-07-21 00:02:29.815 AFD: Opened codec 0x11e40c70, id(MP3) type(Audio)
2009-07-21 00:02:29.815 AFD: codec MP3 has 1 channels
2009-07-21 00:02:29.815 AFD: Opened codec 0x11e1daf0, id(MP3) type(Audio)
2009-07-21 00:02:29.815 AFD: Opened codec 0x11e18eb0, id(DVB_SUBTITLE) 
type(Subtitle)
2009-07-21 00:02:31.093 RingBuf(/video/1001_20090720232000.mpg): Waited 
1.0 seconds for data to become available...
2009-07-21 00:02:32.102 RingBuf(/video/1001_20090720232000.mpg): Waited 
2.0 seconds for data to become available...
2009-07-21 00:02:32.476 AFD: Opened codec 0x11e292f0, id(MPEG2VIDEO) 
type(Video)
2009-07-21 00:02:32.476 AFD: codec MP3 has 2 channels
2009-07-21 00:02:32.476 AFD: Opened codec 0x10518ab0, id(MP3) type(Audio)
2009-07-21 00:02:32.476 AFD: codec MP3 has 1 channels
2009-07-21 00:02:32.477 AFD: Opened codec 0x10522eb0, id(MP3) type(Audio)
2009-07-21 00:02:32.477 AFD: Opened codec 0x1049a7c0, id(DVB_SUBTITLE) 
type(Subtitle)
2009-07-21 00:02:32.483 Opening audio device 'default'. ch 6(2) sr 48000
2009-07-21 00:02:32.483 Opening ALSA audio device 'default'.
2009-07-21 00:02:32.497 Mixer unable to find control PCM 2
2009-07-21 00:02:32.497 Mixer unable to find control PCM 3
2009-07-21 00:02:32.497 Mixer unable to find control PCM 4
2009-07-21 00:02:32.497 Mixer unable to find control PCM 5
2009-07-21 00:02:32.497 mixer unable to find control Master 1
2009-07-21 00:02:32.609 VideoOutputXv: XVideo Adaptor Name: 'Intel(R) 
Video Overlay'
2009-07-21 00:02:32.678 OSD Theme Dimensions W: 640 H: 480
2009-07-21 00:02:34.537 The realtime priority setting is not enabled.
2009-07-21 00:02:34.537 TV: Changing from None to WatchingPreRecorded
2009-07-21 00:02:34.576 Video timing method: DRM
2009-07-21 00:04:58.987 TV: Attempting to change from 
WatchingPreRecorded to None
2009-07-21 00:04:59.116 TV: Changing from WatchingPreRecorded to None

On 15/07/09 10:04, Steve Milner wrote:
> Hello all.
>
> After several days of trying to understand this myself I must now ask
> for help.
>
> I have a remote mythfrontend and I am noticing a high level of digital
> artefacts while watching live tv (DVB-T).
>
> There are occasional sound glitches including (high pitched short
> sqeaks) as well as small areas (sometimes very large areas) of the
> screen which fail to update or contain grey.
>
> It seems that when I first start watching a channel then for a minute or
> so there are relatively few problems, but they then get worse. But of
> course that could be just my perceptions.
>
> Sound glitches occur about every minute or so and the small areas of
> picture problems about every 10-20 seconds.

[snip]