Stuttering on LiveTV (1 Viewer)

[rlevis]

I haven't posted to this thread previously. A few of us in New Zealand are experiencing the same issue on some specific DVB-T SD channels, but not the HD channels. Different hardware and codecs but same problem.

One thing I don't think has been mentioned in this thread is that in all cases, pressing pause for just a second resolves the problem. So when watching from the timeshift file back 1 second, all is well. The problem only occurs at the end of the timeshift buffer.

I think this should provide all the clues the developers need to resolve this problem. An SD channel is writing about 4 times less data than an HD channel. There must be a circumstance where the reader is not able to read all the data that has just been written when dealing with smaller amounts of data with SD channels. Perhaps some sort of Windows cache issue, I'm not sure.

I think the solution is to ensure the reader is always a few hundred milliseconds behind the writer.

We are all hoping for a solution, as it gets tedious always pausing for a second after changing to SD channels. I hope this helps you tourettes to fix this before the 1.0 release.

Regards,
Ross.

 

[Shazell]

I suspect removing the frame dropping causes a slow lost of synchro between audio and video because discontinuities are not passed to the codec.

I can't confirm because I've quite never discontinuities...

Thats why its called experimental It's possible that some codecs handle the issue nicely, but who knows if there will be some drifting.

Another vote here for the tsreader posted by Ambass.

Instead of the audio/video stutter with the standard tsreader I now see only the occasional mild video corruption and most importantly, NO skipping of audio - which was a huge pain.

Can this fix be included in svn so it gets rolled out with future revisions of the TS reader?

after 20496 SVN version its possible to use the experimental C:\RelaxTsReaderForBadReception.txt setting.

Can I just confirm that all I need to do is create the file C:\RelaxTsReaderForBadReception.txt and the fix is applied.

How can I see if is active?

 

[rlevis]

I should clarify that there are 2 different issues with stuttering being discussed on this thread. One issue appears to be reception or TV card problems causing corrupt data being sent to the decoder causing a stutter.

But I am referring to the several other reports on this thread who mention stuttering when watching SD channels live. This is not a reception or TV card problem since recording a program plays back perfectly with no stutter, and timeshifting back 1 second also plays back perfectly.

I thought I should clarify that.

Ross.

 

[tourettes]

Yes, only thatfile needs to be created to activate the experimental code. There is no indicators if its on/off, but if you have had discontinuity errors in log and stuttering, the stuttering should be gone and instead you should see decoding errors.

Now some codecs (like Nvidia MPEG2 decider) is still dropping frames as its how the codec has been designed.

 

[psykoman]

I suspect removing the frame dropping causes a slow lost of synchro between audio and video because discontinuities are not passed to the codec.

I can't confirm because I've quite never discontinuities...

Thats why its called experimental It's possible that some codecs handle the issue nicely, but who knows if there will be some drifting.

Another vote here for the tsreader posted by Ambass.

Instead of the audio/video stutter with the standard tsreader I now see only the occasional mild video corruption and most importantly, NO skipping of audio - which was a huge pain.

Can this fix be included in svn so it gets rolled out with future revisions of the TS reader?

after 20496 SVN version its possible to use the experimental C:\RelaxTsReaderForBadReception.txt setting.

Can I just confirm that all I need to do is create the file C:\RelaxTsReaderForBadReception.txt and the fix is applied.

How can I see if is active?

Tried this experimental setting. But nothing changed. It was strange, it worked well for me a week after installing RC3. Suddenly the stuttering appeared (watching only SD channels). Using TV option since RC3, never tested with previous RC.

 

[Ambass]

The filtering status is written at the begenning of TsReader.log

ambass.

 

[rlevis]

Tried this experimental setting. But nothing changed. It was strange, it worked well for me a week after installing RC3. Suddenly the stuttering appeared (watching only SD channels). Using TV option since RC3, never tested with previous RC.

The tsreader change made no difference to my stuttering on some SD channels either. That makes sense to me since the modification only to allows corrupted data to be passed through to the video decoder. Since recording the channel or timeshifting the channel plays back perfectly for me, it is obvious there is no data corruption. So this is not likely to help you either.

No one seems to know what is causing this type of stuttering. This other new thread may provide a clue. The description of the problem on this thread sounds identical to my problem with some SD channels exhibiting stutter and some not, and no HD channels.

A solution was found by changing the audio decoder from MPA to MS MPEG-1/DD. I tried various audio decoders some time ago and it didn't help me, but my situation is different in that our digital TV in New Zealand uses the AAC+ codec for audio, and I've only got one to choose from which is the MonoGram AAC Decoder. But it sounds like it may be related to audio codecs.

Ross.

 

[tourettes]

As an extra note to all users. Nvidia's MPEG2 decoder will always drop corrupted video frames (i.e. wont display any blocky image). That might be a reason why the experimental RelaxTsReaderForBadReception is not showing any changes on some systems.

 

[psykoman]

Tried this experimental setting. But nothing changed. It was strange, it worked well for me a week after installing RC3. Suddenly the stuttering appeared (watching only SD channels). Using TV option since RC3, never tested with previous RC.

The tsreader change made no difference to my stuttering on some SD channels either. That makes sense to me since the modification only to allows corrupted data to be passed through to the video decoder. Since recording the channel or timeshifting the channel plays back perfectly for me, it is obvious there is no data corruption. So this is not likely to help you either.

No one seems to know what is causing this type of stuttering. This other new thread may provide a clue. The description of the problem on this thread sounds identical to my problem with some SD channels exhibiting stutter and some not, and no HD channels.

A solution was found by changing the audio decoder from MPA to MS MPEG-1/DD. I tried various audio decoders some time ago and it didn't help me, but my situation is different in that our digital TV in New Zealand uses the AAC+ codec for audio, and I've only got one to choose from which is the MonoGram AAC Decoder. But it sounds like it may be related to audio codecs.

Ross.

Ok. I've tried every other codec but MS MPEG-1/DD for audio. Big stutter is gone, now and there there is a _slight_ stutter. Nevertheless the problem should be found.

Maybe it was the same problem that has driven me crazy when I setup Vista and MP. TV didn't start or hang up during live view – until I found out it was the audio codec. AC3Filter, ffdshow, Cyberlink every time the same. Until I installed MPA (didn't install it with MP because I wanted to use AC3Filter) and used it until today –*with stutter!

Thx for the hint!

 

[upspace]

i have the same massive stuttering with live sd tv here as well.

it cannot be the signal quality (works great in dvbviewer on dvb-c card) and i definitely don't believe that this massive stutters comes due to fragmented or not isolated disks for timeshifting.

again on dvbviewer it works 1a but want media portal because wife feels more comfortable (especially in media navigation)