Linux livetv video issues over network
#1
Issue: Livetv video stutters "blocky"
Details: Front End machine (specs below) connects to a mythtv 0.27 Back End (specs below) using XBMC gotham from the Ubuntu ppa and the myth plugin from jlbarriere68 ppa, results in a livetv stream that "stutters" (blocky video), audio sounds fine. If I rewind a few seconds the playback seems to be ok. Access via mythfronend is perfect with no issues at all in livetv or otherwise. Mythbackends tuner card is a PVR1600 using S-Video which is feed from a Directv Receiver (channel change via a script with commands sent over the network).

Log file contains:
Code:
20:05:25 T:139849928787712 WARNING: CDVDMessageQueue(audio)::Get - asked for new data packet, with nothing available
20:05:25 T:139850247395072 WARNING: Previous line repeats 13 times.
20:05:25 T:139850247395072 WARNING: CRenderManager::WaitForBuffer - timeout waiting for buffer
20:05:25 T:139850247395072 WARNING: Previous line repeats 11 times.
20:05:25 T:139850247395072 WARNING: CDVDMessageQueue(video)::Get - asked for new data packet, with nothing available
20:05:25 T:139849928787712 WARNING: CDVDMessageQueue(audio)::Get - asked for new data packet, with nothing available

Link to full log file:
XBMC.log

Setup:

Network:
-100 Mbps LAN
-Linksys WRT54G flashed with DDWRT

Front End Machine:
-Kubuntu 14.04
-XBMC 13.2, myth plugin 1.9.22, KDE 4.14.2, kernel 3.13.0-37-generic
-PPAs: XBMC stable, Kubuntu backports, jlbarriere68, xorg edgers
-Geforce GTX750ti (using 340 from xorg edgers)
-i7 4770k @ 4.2 Ghz
-16 GB
-250 GB SSD

Back End Machine:
-Mythbuntu 14.04
-MythTV frontend and backend 0.27
-Geforce MX4
-PVR1600 tuner card
-Pentium 4 HT 3.2Ghz
-2 GB
-250 GB PATA drive
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#2
On mythtv LiveTV is recorded like anything that is set to record. What happens if you play back the recording that was made during the LiveTV session?

It sounds like you are too close to the end of the livetv recording, which does create problems.

Do keep your backend up to date with mythbuntu repos too.
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#3
I'd agree with the idea of being to close to the end of the livetv recording. I'll have to test the particular scenario your propose in the first line in few days, hopefully. The backend is using the mythbuntu repos so its up to date (repos for 0.27).
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#4
Just tested a few recordings, one that was made during a LiveTV session and one that was made as a scheduled recording. Both playback with no issue on the remote Front End with XBMC. LiveTV is the only part that is "blocky".
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#5
There was a mythtv bug at one stage, can't recall if it was FE or BE, where some zeros were missed off a constant, so the FE was following the stream too close resulting in bad behaviour. But if your mythtv backend is up to date that bug disappeared a long time ago. When i think about it, that sounds like a frontend bug, so it might be a similar bug is in XBMC.

To clarify, if you pause live TV for a couple of seconds, then resume, does the problem go away?
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#6
Yes, when paused, or rewind for a few seconds the LiveTV stream plays fine. I just made sure to run a update on the Back end, and front end, and tried it again and the issue is still present.
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#7
Well it seems I was mistaken, pausing does not fix the issue, the only fix is using rewind. It seems pause may work if only paused for a long time or at random. Can't seem to find a pattern. I have found that version 1.9.16 seems to be more watchable vs 1.9.22 (more watchable as in it is less frequent with the "blocky" portion of the video, vs 1.9.22 after a few seconds goes into a almost totally distorted image). I did take a look at some advancedsettings.xml stuff in xbmc and tested
<pvr>
<minvideocachelevel>5</minvideocachelevel>
<minaudiocachelevel>10</minaudiocachelevel>
<cacheindvdplayer>true</cacheindvdplayer>
</pvr>

at various values but it had no effect(checked log, it is loading the settings).
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#8
(2014-10-16, 02:44)electrobs Wrote: Issue: Livetv video stutters "blocky"
Details: Front End machine (specs below) connects to a mythtv 0.27 Back End (specs below) using XBMC gotham from the Ubuntu ppa and the myth plugin from jlbarriere68 ppa, results in a livetv stream that "stutters" (blocky video), audio sounds fine. If I rewind a few seconds the playback seems to be ok. Access via mythfronend is perfect with no issues at all in livetv or otherwise. Mythbackends tuner card is a PVR1600 using S-Video which is feed from a Directv Receiver (channel change via a script with commands sent over the network).

Log file contains:
Code:
20:05:25 T:139849928787712 WARNING: CDVDMessageQueue(audio)::Get - asked for new data packet, with nothing available
20:05:25 T:139850247395072 WARNING: Previous line repeats 13 times.
20:05:25 T:139850247395072 WARNING: CRenderManager::WaitForBuffer - timeout waiting for buffer
20:05:25 T:139850247395072 WARNING: Previous line repeats 11 times.
20:05:25 T:139850247395072 WARNING: CDVDMessageQueue(video)::Get - asked for new data packet, with nothing available
20:05:25 T:139849928787712 WARNING: CDVDMessageQueue(audio)::Get - asked for new data packet, with nothing available

Link to full log file:
XBMC.log

Setup:

Network:
-100 Mbps LAN
-Linksys WRT54G flashed with DDWRT

Front End Machine:
-Kubuntu 14.04
-XBMC 13.2, myth plugin 1.9.22, KDE 4.14.2, kernel 3.13.0-37-generic
-PPAs: XBMC stable, Kubuntu backports, jlbarriere68, xorg edgers
-Geforce GTX750ti (using 340 from xorg edgers)
-i7 4770k @ 4.2 Ghz
-16 GB
-250 GB SSD

Back End Machine:
-Mythbuntu 14.04
-MythTV frontend and backend 0.27
-Geforce MX4
-PVR1600 tuner card
-Pentium 4 HT 3.2Ghz
-2 GB
-250 GB PATA drive


This is just a guess as the log file is not a debug log.

You could try "Enable demuxing MPEG-TS" in Advanced configuration of mythtv addon. This worked for me in the UK using DVB.

Also set "Include more debug information in the log file" on the same page, this only has any effect when debugging is enabled (Settings System Debugging) which you can enable on demand.

Mike
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#9
Well from what I've read (I could be wrong, so please correct me, and point out some sources if I am) since I'm using a analog (S-VIDEO) capture MPEG-TS isn't of much use and is the incorrect format (should be MPEG-PS). I have tried it for giggles and it results in a video with bad colors (black and white with some lime green and purple) and vertical bars on a PVR1600 and works ok with a PVR150 except that the enable demux option in either the included mythtv plugin (cmyth) or jlbarriere68's ppa new API plugin results in player being stuck at "Buffer 0%". So none of that has helped. I have setup a mythtv server for testing and trying to fix this issue. I did try <minvideocachelevel>5</minvideocachelevel> and the associated audio value from 60 up to 20000 and at first 10000 seemed to work great with the cmyth plugin but it was inconsistent to say the least. So to clarify, my issue is with analog SVIDEO/Composite inputs using the MPEG-PS stream format. I have tried changing the bit rate in myth setup but no change in behavior has resulted. The only thing I've noticed is that for the most part, the jlbarriere68's ppa seems to be worse. As the included plugin does breakup but the image is more visible and sometimes works ok. jlbarriere68's ppa never works unless I rewind which fixes the issue for both plugins consistently. At this point I'll probably file a bug on the plugin and work on helping to find why this happens, as I haven't found anything else that has helped.
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#10
What is your capture device please?

Also could you please let us have the output of mediainfo on one of the recorded files?
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#11
Really mpeg-ps is not adapted to been readable in live. For few reasons. First it doesn t handle stream transport error, second payload size could be very big (64k) and player have to buffer. PS was designed for dvd or physical storage. Otherwise mpeg-ts is designed to handle streaming, with error handling and packet spliting.
Since 2 years we try to fix it , first in cmyth addon and tthe new now without success. Sad

Only way: let grow the player buffer
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#12
Makes sense, just odd that the MPEG-TS didn't work for mine either, and the problem was identical. Sadly this project is low on my todo list, but what information, logs, files and etc would help? I can over time get the data and then post it. Also for nickr the test server is:

Back End Machine:
-Mythbuntu 14.04
-MythTV backend 0.27
-Geforce MX4 (maybe ati? not sure)
-PVR150 tuner card (actually a Sony branded card but is identical)
-AMD athlon 1.2 GHz
-512 MB
-80 GB PATA drive
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