Program clock reference forward jump (causes stutter) (1 Viewer)

[johnlc]

TV-Server Version: 1.0.0.0 RC1 svn19127
MediaPortal Version: 1.0.0.0 RC1 svn 19127
MediaPortal Skin: Blue Two Wide
Windows Version: Vista 32bit SP1
CPU Type: AMD BE-2350 2.1gHz
HDD: Samsung 750Gb
Memory: 2 Gb
Motherboard: Gigabyte GA-MA78GM-S2H
Video Card: nVidia 8500GT
Video Card Driver: 175.16
Sound Card: Realtek ALC889A codec
Sound Card AC3: optical
Sound Card Driver:
1. TV Card: FloppyDTV
1. TV Card Type: DVB-C
1. TV Card Driver: 4.5 (?)
2. TV Card:
2. TV Card Type:
2. TV Card Driver:
3. TV Card:
3. TV Card Type:
3. TV Card Driver:
4. TV Card:
4. TV Card Type:
4. TV Card Driver:
MPEG2 Video Codec: Cyberlink PVD8
MPEG2 Audio Codec: Cyberlink Audio PVD8
h.264 Video Codec: Cyberlink PVD8
Satelite/CableTV Provider:
HTPC Case: D-Vine
Cooling:
Power Supply: SilentMaxx 400W
Remote: MCE
TV: Panasonic TH42
TV - HTPC Connection: HDMI

My question is fairly simple: What causes these "Program clock reference forward jump" - so that I can eliminate the cause?

Because there is stutter when this happends, I have attached logs and in the bottom of tvserver_TsWriter.log you see this:

18-05-2008 09:37:18.991 DiskRecorder[TIMESHIFT] Info : Program clock reference forward jump ( 505287 ).
18-05-2008 09:41:34.353 DiskRecorder[TIMESHIFT] Info : Program clock reference forward jump ( 723881 ).
18-05-2008 09:44:51.100 DiskRecorder[TIMESHIFT] Info : Program clock reference forward jump ( 609162 ).
18-05-2008 09:46:40.940 DiskRecorder[TIMESHIFT] Info : Program clock reference forward jump ( 1766763 ).
18-05-2008 09:49:19.11 DiskRecorder[TIMESHIFT] Info : Program clock reference forward jump ( 239316 ).

And this matches exactly the stutters during the time I watched
But when it goes bananas like last night you also see stuff like this
17-05-2008 22:11:47.122 Discontinuity !
17-05-2008 22:11:47.122 tsheader:47090634079093d4a050
17-05-2008 22:11:47.122 Discontinuity !
17-05-2008 22:11:47.122 tsheader:47090634079093d4a050
17-05-2008 22:11:47.123 Discontinuity !
17-05-2008 22:11:47.123 tsheader:4709063f079093d4a0c0
17-05-2008 22:11:47.123 Discontinuity !

I hope someone has just some ideas on what can cause this?

 

[tourettes]

18-05-2008 09:37:18.991 DiskRecorder[TIMESHIFT] Info : Program clock reference forward jump ( 505287 ).
18-05-2008 09:41:34.353 DiskRecorder[TIMESHIFT] Info : Program clock reference forward jump ( 723881 ).
18-05-2008 09:44:51.100 DiskRecorder[TIMESHIFT] Info : Program clock reference forward jump ( 609162 ).
18-05-2008 09:46:40.940 DiskRecorder[TIMESHIFT] Info : Program clock reference forward jump ( 1766763 ).
18-05-2008 09:49:19.11 DiskRecorder[TIMESHIFT] Info : Program clock reference forward jump ( 239316 ).

These are caused by the broadcaster. For example if broadcaster changes its HW on the fly the PCR clocks might not be synced between those two devices. TsWriter tries to detect and patch these, but there can be slight stutter if the TsWriter code doesnt do the patching properly.

And this matches exactly the stutters during the time I watched
But when it goes bananas like last night you also see stuff like this
17-05-2008 22:11:47.122 Discontinuity !
17-05-2008 22:11:47.122 tsheader:47090634079093d4a050
17-05-2008 22:11:47.122 Discontinuity !
17-05-2008 22:11:47.122 tsheader:47090634079093d4a050
17-05-2008 22:11:47.123 Discontinuity !
17-05-2008 22:11:47.123 tsheader:4709063f079093d4a0c0
17-05-2008 22:11:47.123 Discontinuity !

These are almost always caused by a bad signal. Discontinuity tells that some data is lost.

 

[johnlc]

These are caused by the broadcaster. For example if broadcaster changes its HW on the fly the PCR clocks might not be synced between those two devices. TsWriter tries to detect and patch these, but there can be slight stutter if the TsWriter code doesnt do the patching properly.

Hm, I am not sure what you mean by "changes its HW on the fly" because then it should affect others than me.

 

[johnlc]

Mysteriously this disappeared when I moved Timeshift files to another disk.

Hm, only thought this was an option, not a required thing

 

[tourettes]

Mysteriously this disappeared when I moved Timeshift files to another disk.

Hm, only thought this was an option, not a required thing

I would say that its just bad luck and the issue is going to come back at some stage. "Program clock reference forward jump" is noticed before any data is written to the hard disk.

 

[johnlc]

hm maybe you are right, I will have to see. But right now I can switch the timebuffer location and make it come and go, so I hope this is enough.

Btw. signal full green (100%) when searching for channels.

 

[Paranoid Delusion]

But right now I can switch the timebuffer location and make it come and go, so I hope this is enough.

So if you change the timeshift buffer location to another drive it works 100% success, where is the recording folder, is it the same.
Reverting back to original location it fails, am i correct.

If for instance, you have your recording folder set as c:\recordings and then your timeshift as c:\recordings\timeshifting does this work, as i believe part of the problem may be timeshifting\recording to same folder.

 

[johnlc]

Okay, it was setup as this
Card1: c:\timeshift1
Card1 c:\recodings1
Card2: c:\timeshift2
Card2 c:\recodings2
This gives erros also when no recordings active

Now setup is:
Card1: D:\timeshift1
Card1 c:\recordings1
Card2: D:\timeshift2
Card2 c:\recordings2

This gives no errors, and actually right now watching 1 channel, and recording 2 others.

 

[johnlc]

These are almost always caused by a bad signal. Discontinuity tells that some data is lost.

Tourettes,
You are absolutely right - becase these happends sometimes, now, but after Ambass rewrite they seem to be handled much better, and don't cause troubles as they sometimes could before.

Why are you right, well the other evening my MP was busy recording HD, so I watched analog on TV, and saw Exactly the same stutter on the analog signal as I sometimes see on the Digital - so our TV supplier is hit himself by the issue - at least I have yet to believe that an analog signal can stutter (hanging/missing frames).