Thread: Re: [Mvpmc-devel] DVB UK Recordings sound and picture going out of sync
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From: <ge...@ac...> - 2006-08-28 00:11:54
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On Mon, 28 Aug 2006 00:30:26 BST, mar...@mh... wrote: > I've noticed this getting worse recently, by recently I mean the last > month or so. I generally keep up with the latest from GIT (which I > compile myself) so could be either that or something relating to quality > changes on the DVB network in the UK. > > Has anybody else noticed? Is there anything I can do about it / logs or > other files I can send for somebody who knows what they are doing to > analyse ? > > Help would be much appreciated as it's beginning to spoil my viewing now :( > > Mark Does it get out of sync on its own? Or is this only after you have skipped forward or backward in the file? If it gets out of sync on its own, then I'd suggest you hit the MENU button during playback, go into the auido stream menu, and find out what kind of audio stream you're listening to. If it is AC3, then it does not surprise me that you are having problems, since AC3 audio has sync problems in general. If it only gets out of sync when you skip around in the file (or when you start playback), and you are using mpeg1/2 audio, then you have the following two options: - Seeking in the file should often get the audio/video back in sync, so you can skip forward and back, and often get back in sync. - Hitting the record button (small red circle) will momentarily pause the video, allowing the audio to catch up. This only works if the audio is behind the video, and you may have to hit it several times before the video pops back in sync. If none of this helps, can you provide a short video sample? Jon |
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From: Charles B. <cgb...@go...> - 2006-08-28 12:49:23
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> > > Date: Mon, 28 Aug 2006 00:30:26 +0100 (BST) > From: mar...@mh... > Subject: [Mvpmc-devel] DVB UK Recordings sound and picture going out > of sync > To: mvp...@li... > Message-ID: <113...@ma...> > Content-Type: text/plain;charset=iso-8859-1 > > I've noticed this getting worse recently, by recently I mean the last > month or so. I generally keep up with the latest from GIT (which I > compile myself) so could be either that or something relating to quality > changes on the DVB network in the UK. > > Has anybody else noticed? Is there anything I can do about it / logs or > other files I can send for somebody who knows what they are doing to > analyse ? > > Help would be much appreciated as it's beginning to spoil my viewing now > :( > > Mark Well I'm not sure it is much to do with mvp, but I am having similar > problems and I think it's rexeption rather than anything else. Losing sync > seems to be preceded but some bad pictures. I find that the back key will > sync things up nicely. Charles. |
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From: <ge...@ac...> - 2006-08-29 13:16:51
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On Tue, 29 Aug 2006 10:53:47 BST, Malcolm Smith wrote: > ge...@ac... wrote: > > On Mon, 28 Aug 2006 00:30:26 BST, mar...@mh... wrote: > > > >> I've noticed this getting worse recently, by recently I mean the last > >> month or so. I generally keep up with the latest from GIT (which I > >> compile myself) so could be either that or something relating to quality > >> changes on the DVB network in the UK. > >> > >> Has anybody else noticed? Is there anything I can do about it / logs or > >> other files I can send for somebody who knows what they are doing to > >> analyse ? > >> > >> Help would be much appreciated as it's beginning to spoil my viewing now : >( > >> > >> Mark > >> > > > > Does it get out of sync on its own? Or is this only after you have skipped > > forward or backward in the file? > > > > If it gets out of sync on its own, then I'd suggest you hit the MENU button > > during playback, go into the auido stream menu, and find out what kind of > > audio stream you're listening to. If it is AC3, then it does not surprise > > me that you are having problems, since AC3 audio has sync problems in > > general. > > > > If it only gets out of sync when you skip around in the file (or when you > > start playback), and you are using mpeg1/2 audio, then you have the > > following two options: > > > > - Seeking in the file should often get the audio/video back in sync, > > so you can skip forward and back, and often get back in sync. > > - Hitting the record button (small red circle) will momentarily > > pause the video, allowing the audio to catch up. This only works > > if the audio is behind the video, and you may have to hit it > > several times before the video pops back in sync. > > > > If none of this helps, can you provide a short video sample? > > > > Jon > > > > ------------------------------------------------------------------------- > > Using Tomcat but need to do more? Need to support web services, security? > > Get stuff done quickly with pre-integrated technology to make your job easi >er > > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo > > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > > _______________________________________________ > > Mvpmc-devel mailing list > > Mvp...@li... > > https://lists.sourceforge.net/lists/listinfo/mvpmc-devel > > > Jon, > > I have 2 sources of recording > 1. PVR250 capturing composite > 2. UK DVB-T > > With 1 it will go out of sync if you use FFWD or skip forward through > adds, normally however 1 skip back will bring it back in. It doesn't > normally get out of sync on playback alone. > > With 2 it depends on the signal quality - recently I've been having some > poor reception so sync can > move a long way out - 1 or 2 secs in extreme cases. To fix this repeated > skip backs sometimes work, the "record" button does not. These are not AC3. > > Is it possible to periodically monitor the timestamps on the streams? > That way the code could insert pauses to cope with sync issues. It should be. But without documentation on how to use the IBM kernel modules, we're stuck trying to figure it out ourselves. > Also ocassionally the decoder thread seems to crash with poor quality > streams- it stops playback and won't respond to stop etc, but the GUI > thread is fine. You can go back to the menu and choose another > programme, but playback will not work until you either reboot or restart > the GUI with Power off/on > > -malc- I've never seen this. Even hitting stop does not fix the problem? Do you know what sort of debug output mvpmc gives on stdout/stderr when this happens? Jon |
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From: <mar...@mh...> - 2006-08-29 14:04:35
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I do frequently get out of syncs followed by a crash that I have to reboo= t the box for as STOP doesn't work....never really thought the two would be related though Mark > > On Tue, 29 Aug 2006 10:53:47 BST, Malcolm Smith wrote: >> ge...@ac... wrote: >> > On Mon, 28 Aug 2006 00:30:26 BST, mar...@mh... wrote: >> > >> >> I've noticed this getting worse recently, by recently I mean the la= st >> >> month or so. I generally keep up with the latest from GIT (which I >> >> compile myself) so could be either that or something relating to >> quality >> >> changes on the DVB network in the UK. >> >> >> >> Has anybody else noticed? Is there anything I can do about it / lo= gs >> or >> >> other files I can send for somebody who knows what they are doing t= o >> >> analyse ? >> >> >> >> Help would be much appreciated as it's beginning to spoil my viewin= g >> now : >>( >> >> >> >> Mark >> >> >> > >> > Does it get out of sync on its own? Or is this only after you have >> skipped >> > forward or backward in the file? >> > >> > If it gets out of sync on its own, then I'd suggest you hit the MENU >> button >> > during playback, go into the auido stream menu, and find out what ki= nd >> of >> > audio stream you're listening to. If it is AC3, then it does not >> surprise >> > me that you are having problems, since AC3 audio has sync problems i= n >> > general. >> > >> > If it only gets out of sync when you skip around in the file (or whe= n >> you >> > start playback), and you are using mpeg1/2 audio, then you have the >> > following two options: >> > >> > - Seeking in the file should often get the audio/video back in sync= , >> > so you can skip forward and back, and often get back in sync. >> > - Hitting the record button (small red circle) will momentarily >> > pause the video, allowing the audio to catch up. This only works >> > if the audio is behind the video, and you may have to hit it >> > several times before the video pops back in sync. >> > >> > If none of this helps, can you provide a short video sample? >> > >> > Jon >> > >> > --------------------------------------------------------------------= ----- >> > Using Tomcat but need to do more? Need to support web services, >> security? >> > Get stuff done quickly with pre-integrated technology to make your j= ob >> easi >>er >> > Download IBM WebSphere Application Server v.1.0.1 based on Apache >> Geronimo >> > http://sel.as-us.falkag.net/sel?cmd=3Dlnk&kid=3D120709&bid=3D263057&= dat=3D121642 >> > _______________________________________________ >> > Mvpmc-devel mailing list >> > Mvp...@li... >> > https://lists.sourceforge.net/lists/listinfo/mvpmc-devel >> > >> Jon, >> >> I have 2 sources of recording >> 1. PVR250 capturing composite >> 2. UK DVB-T >> >> With 1 it will go out of sync if you use FFWD or skip forward through >> adds, normally however 1 skip back will bring it back in. It doesn't >> normally get out of sync on playback alone. >> >> With 2 it depends on the signal quality - recently I've been having so= me >> poor reception so sync can >> move a long way out - 1 or 2 secs in extreme cases. To fix this repeat= ed >> skip backs sometimes work, the "record" button does not. These are not >> AC3. >> >> Is it possible to periodically monitor the timestamps on the streams? >> That way the code could insert pauses to cope with sync issues. > > It should be. But without documentation on how to use the IBM kernel > modules, we're stuck trying to figure it out ourselves. > >> Also ocassionally the decoder thread seems to crash with poor quality >> streams- it stops playback and won't respond to stop etc, but the GUI >> thread is fine. You can go back to the menu and choose another >> programme, but playback will not work until you either reboot or resta= rt >> the GUI with Power off/on >> >> -malc- > > I've never seen this. Even hitting stop does not fix the problem? Do = you > know what sort of debug output mvpmc gives on stdout/stderr when this > happens? > > Jon > |
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From: John H. <hon...@nc...> - 2006-08-29 14:45:56
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ge...@ac... wrote: > On Tue, 29 Aug 2006 10:53:47 BST, Malcolm Smith wrote: >> ge...@ac... wrote: >>> On Mon, 28 Aug 2006 00:30:26 BST, mar...@mh... wrote: >>> >>>> I've noticed this getting worse recently, by recently I mean the last >>>> month or so. I generally keep up with the latest from GIT (which I >>>> compile myself) so could be either that or something relating to quality >>>> changes on the DVB network in the UK. >>>> >>>> Has anybody else noticed? Is there anything I can do about it / logs or >>>> other files I can send for somebody who knows what they are doing to >>>> analyse ? >>>> >>>> Help would be much appreciated as it's beginning to spoil my viewing now : >> ( >>>> Mark >>>> >>> Does it get out of sync on its own? Or is this only after you have skipped >>> forward or backward in the file? >>> >>> If it gets out of sync on its own, then I'd suggest you hit the MENU button >>> during playback, go into the auido stream menu, and find out what kind of >>> audio stream you're listening to. If it is AC3, then it does not surprise >>> me that you are having problems, since AC3 audio has sync problems in >>> general. >>> >>> If it only gets out of sync when you skip around in the file (or when you >>> start playback), and you are using mpeg1/2 audio, then you have the >>> following two options: >>> >>> - Seeking in the file should often get the audio/video back in sync, >>> so you can skip forward and back, and often get back in sync. >>> - Hitting the record button (small red circle) will momentarily >>> pause the video, allowing the audio to catch up. This only works >>> if the audio is behind the video, and you may have to hit it >>> several times before the video pops back in sync. >>> >>> If none of this helps, can you provide a short video sample? >>> >>> Jon >>> >>> ------------------------------------------------------------------------- >>> Using Tomcat but need to do more? Need to support web services, security? >>> Get stuff done quickly with pre-integrated technology to make your job easi >> er >>> Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo >>> http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 >>> _______________________________________________ >>> Mvpmc-devel mailing list >>> Mvp...@li... >>> https://lists.sourceforge.net/lists/listinfo/mvpmc-devel >>> >> Jon, >> >> I have 2 sources of recording >> 1. PVR250 capturing composite >> 2. UK DVB-T >> >> With 1 it will go out of sync if you use FFWD or skip forward through >> adds, normally however 1 skip back will bring it back in. It doesn't >> normally get out of sync on playback alone. >> >> With 2 it depends on the signal quality - recently I've been having some >> poor reception so sync can >> move a long way out - 1 or 2 secs in extreme cases. To fix this repeated >> skip backs sometimes work, the "record" button does not. These are not AC3. >> I investigated the stb chip audio/video HW a while back. Can't remember exactly, but if the audio & video streams get more than ?1sec? out of sync then the hardware can't sync them back up. >> Is it possible to periodically monitor the timestamps on the streams? >> That way the code could insert pauses to cope with sync issues. > The timestamps can not be directly monitored. The way things work are: 1: User space audio & video stream buffers feeding info to the kernel. 2: Kernel audio & video buffers. When userspace writes to the kernel a/v devices the data is placed at the end of the kernel A/V buffers. 3. STB uCode processes/consumes the kernel A/V buffers to feed the hardware. So where we are with the userspace buffers is not an indication of where hardware is actually at. There does not appear to be any STB registers that we can read to tell us the last audio or video PTS processed by HW. However there are some other indicators that we may able to use to detect out of sync. I think we should be able to detect and prevent out-of-sync conditions by adding some more intelligence to how we feed the userspace A/V buffers and start the HW processing. Check out mvpstb_mod. It can be used to do dumps of the STB AV registers while streaming. One interesting thing to see is how full the kernel A/V buffers are when streaming is started. I remember seeing instances where the STB HW processed the streams faster than userspace wrote the data to the kernel. This can possibly lead to out-of-sync or a blank screen. I'm in process of rebuilding my development box now. When done I'll look into this some more. Following is some notes from when I looked into things a while back. John... --------- Been poking around the STB HW. Pretty sure I've figured out how to determine when HW has finish with video &| audio streams. Also may have figured out how to tell if A/V is out-of-sync. To clarify, If I hit the record button many times fast I can screw up A/V sync. The condition can be detected with the VID_PTS_DELTA register. From a HW perspective the PTS timestamps appear to be useless. Since we can't read the video PTS there is no reference for the audio PTS to be compared to. The STC counters appear to just be free runners. i.e. they have no correlation to the streams other than what the user code sets them to. There appears to be enough info to determine where in the kernel's stream buffers HW (uCode) is currently at. Not sure how useful it will be though. It's also interesting to watch how the kernels buffers fill & drain when starting a new mpg. May give some insight into why streams sometimes get out of sync when jumping. Figure the next step is to implement a kernel thread to monitor things every 50 to 100mS then add API's to get the status. Also, I'll probably do something like create a history buffer so we can trigger a dump of the last 5 seconds when a condition occurs. <rest deleted> |
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From: Hugo v. d. K. <hvd...@va...> - 2006-08-28 05:30:56
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On Sun, 27 Aug 2006 ge...@ac... wrote: > > On Mon, 28 Aug 2006 00:30:26 BST, mar...@mh... wrote: > > I've noticed this getting worse recently, by recently I mean the last > > month or so. I generally keep up with the latest from GIT (which I > > compile myself) so could be either that or something relating to quality > > changes on the DVB network in the UK. > > > > Has anybody else noticed? Is there anything I can do about it / logs or > > other files I can send for somebody who knows what they are doing to > > analyse ? > > > > Help would be much appreciated as it's beginning to spoil my viewing now :( > > Does it get out of sync on its own? Or is this only after you have skipped > forward or backward in the file? > > If it gets out of sync on its own, then I'd suggest you hit the MENU button > during playback, go into the auido stream menu, and find out what kind of > audio stream you're listening to. If it is AC3, then it does not surprise > me that you are having problems, since AC3 audio has sync problems in > general. > > If it only gets out of sync when you skip around in the file (or when you > start playback), and you are using mpeg1/2 audio, then you have the > following two options: > > - Seeking in the file should often get the audio/video back in sync, > so you can skip forward and back, and often get back in sync. > - Hitting the record button (small red circle) will momentarily > pause the video, allowing the audio to catch up. This only works > if the audio is behind the video, and you may have to hit it > several times before the video pops back in sync. > > If none of this helps, can you provide a short video sample? With the latest 'official' build (0.3.0) I have hardly seen it. But here (NL) I have seen that NGC seems to be much harder to get into sync at startup compared to other channels. After that it only drops out of sync after jumping back or forth. And another hint to keep into sync better. Use the remote with full batteries. I have found out that I can do a number of normal operations still but can't resync when the batteries are getting low. Hugo. -- I hate duplicates. Just reply to the relevant mailinglist. hvd...@va... http://hvdkooij.xs4all.nl/ Don't meddle in the affairs of magicians, for they are subtle and quick to anger. |
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From: <mar...@mh...> - 2006-08-28 13:11:59
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I usually use either the skip keys or the number keys to jump to 10%, mainly as i record everything with 2 mins before and therefore jump into the show. The audio on all my records (I think) is 'Stream ID 0x0 - MPEG'. The red key used to bring it back into sync, but rarely does now and I en= d up having to use seek back to get it back into sync. It's worth noting I think that it doesn't go out of sync in the same plac= e every time....i.e. if i watch something, it goes out of sync, then I skip back a bit it won't go out of sync in the same place. I'll upload something a bit later that does skip to my server and email you the link if you think you can do something with it. Mark > > On Mon, 28 Aug 2006 00:30:26 BST, mar...@mh... wrote: >> I've noticed this getting worse recently, by recently I mean the last >> month or so. I generally keep up with the latest from GIT (which I >> compile myself) so could be either that or something relating to quali= ty >> changes on the DVB network in the UK. >> >> Has anybody else noticed? Is there anything I can do about it / logs = or >> other files I can send for somebody who knows what they are doing to >> analyse ? >> >> Help would be much appreciated as it's beginning to spoil my viewing n= ow >> :( >> >> Mark > > Does it get out of sync on its own? Or is this only after you have > skipped > forward or backward in the file? > > If it gets out of sync on its own, then I'd suggest you hit the MENU > button > during playback, go into the auido stream menu, and find out what kind = of > audio stream you're listening to. If it is AC3, then it does not surpr= ise > me that you are having problems, since AC3 audio has sync problems in > general. > > If it only gets out of sync when you skip around in the file (or when y= ou > start playback), and you are using mpeg1/2 audio, then you have the > following two options: > > - Seeking in the file should often get the audio/video back in sync, > so you can skip forward and back, and often get back in sync. > - Hitting the record button (small red circle) will momentarily > pause the video, allowing the audio to catch up. This only works > if the audio is behind the video, and you may have to hit it > several times before the video pops back in sync. > > If none of this helps, can you provide a short video sample? > > Jon > |
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From: <mar...@mh...> - 2006-08-28 20:34:57
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I do now have a file for you to look at, it's about 1 gig at the moment thou, any suggestions for getting it to you? I can put it on my server somewhere if you want a 1 gig download! Also, I notice you made the point about 'This only works if the audio is behind the video', in fact when it's going out of sync it's the other way round, the audio is in front of the video. Does that put a different light on things? Mark > > On Mon, 28 Aug 2006 00:30:26 BST, mar...@mh... wrote: >> I've noticed this getting worse recently, by recently I mean the last >> month or so. I generally keep up with the latest from GIT (which I >> compile myself) so could be either that or something relating to quali= ty >> changes on the DVB network in the UK. >> >> Has anybody else noticed? Is there anything I can do about it / logs = or >> other files I can send for somebody who knows what they are doing to >> analyse ? >> >> Help would be much appreciated as it's beginning to spoil my viewing n= ow >> :( >> >> Mark > > Does it get out of sync on its own? Or is this only after you have > skipped > forward or backward in the file? > > If it gets out of sync on its own, then I'd suggest you hit the MENU > button > during playback, go into the auido stream menu, and find out what kind = of > audio stream you're listening to. If it is AC3, then it does not surpr= ise > me that you are having problems, since AC3 audio has sync problems in > general. > > If it only gets out of sync when you skip around in the file (or when y= ou > start playback), and you are using mpeg1/2 audio, then you have the > following two options: > > - Seeking in the file should often get the audio/video back in sync, > so you can skip forward and back, and often get back in sync. > - Hitting the record button (small red circle) will momentarily > pause the video, allowing the audio to catch up. This only works > if the audio is behind the video, and you may have to hit it > several times before the video pops back in sync. > > If none of this helps, can you provide a short video sample? > > Jon > |
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From: Malcolm S. <ma...@po...> - 2006-08-29 09:53:58
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ge...@ac... wrote: > On Mon, 28 Aug 2006 00:30:26 BST, mar...@mh... wrote: > >> I've noticed this getting worse recently, by recently I mean the last >> month or so. I generally keep up with the latest from GIT (which I >> compile myself) so could be either that or something relating to quality >> changes on the DVB network in the UK. >> >> Has anybody else noticed? Is there anything I can do about it / logs or >> other files I can send for somebody who knows what they are doing to >> analyse ? >> >> Help would be much appreciated as it's beginning to spoil my viewing now :( >> >> Mark >> > > Does it get out of sync on its own? Or is this only after you have skipped > forward or backward in the file? > > If it gets out of sync on its own, then I'd suggest you hit the MENU button > during playback, go into the auido stream menu, and find out what kind of > audio stream you're listening to. If it is AC3, then it does not surprise > me that you are having problems, since AC3 audio has sync problems in > general. > > If it only gets out of sync when you skip around in the file (or when you > start playback), and you are using mpeg1/2 audio, then you have the > following two options: > > - Seeking in the file should often get the audio/video back in sync, > so you can skip forward and back, and often get back in sync. > - Hitting the record button (small red circle) will momentarily > pause the video, allowing the audio to catch up. This only works > if the audio is behind the video, and you may have to hit it > several times before the video pops back in sync. > > If none of this helps, can you provide a short video sample? > > Jon > > ------------------------------------------------------------------------- > Using Tomcat but need to do more? Need to support web services, security? > Get stuff done quickly with pre-integrated technology to make your job easier > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > _______________________________________________ > Mvpmc-devel mailing list > Mvp...@li... > https://lists.sourceforge.net/lists/listinfo/mvpmc-devel > Jon, I have 2 sources of recording 1. PVR250 capturing composite 2. UK DVB-T With 1 it will go out of sync if you use FFWD or skip forward through adds, normally however 1 skip back will bring it back in. It doesn't normally get out of sync on playback alone. With 2 it depends on the signal quality - recently I've been having some poor reception so sync can move a long way out - 1 or 2 secs in extreme cases. To fix this repeated skip backs sometimes work, the "record" button does not. These are not AC3. Is it possible to periodically monitor the timestamps on the streams? That way the code could insert pauses to cope with sync issues. Also ocassionally the decoder thread seems to crash with poor quality streams- it stops playback and won't respond to stop etc, but the GUI thread is fine. You can go back to the menu and choose another programme, but playback will not work until you either reboot or restart the GUI with Power off/on -malc- |
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