AV sync problem and picture quality

[midiboy]

Hi guys,

well, I have tried GB-PVR over the last couple of weeks, including the new version released yesterday and there are two problems I cannot seem to solve so I though I might ask here.

I have a Hauppauge PVR500 dual tuner card by the way.

First problem is that audio always lags video in liveTV mode (and subsequent recordings of course). I have already done a forum search on this topic and the solutions I found (defrag harddisc and/or add a registry switch for the TV card driver) did not help at all.

Also, I am 100% sure that this is a problem inside GB-PVR. Why? Because I have tried many other programs (Dscaler, Mediaportal, SageTV, ChrisTV) and all those programs work fine. No AV sync issues there.

So if on the same system, same drivers, same time etc. 4 programs work fine and one does not, where is the solution usually ?

I have tried to change various default settings for the card but could not find any setting that influences AV sync. Maybe someone can give me a hint ?

Second problem is that picture quality is worse in GB PVR than in those other apps I mentioned and this is due to interlacing artefacts that are visible in GB_VCR even though I have the "deinterlacing filter" active for the LivePreview mode.

Dscaler obviously has the best quality but even ChrisTV, Mediaportal and SageTV without Dscaler filters are way better than GB-PVR. I changed the default bit rate values for the card but these obviously do not help with interlacing artefacts.

I do not want to use ffdshow for deinterlacing, maybe there could be alternatives (like integrate Dscaler filters etc.) arranged for in the future.
Maybe someone can help out a bit !

Thanks,
Alex

[midiboy]

no reply ?

mhh ...

[Darx-starz]

Hi Mate. You are asking a lot of questions and I will try and help if I can. Perhaps split up the issues that you have and post them 1 at a time.
Whats your most pressing problem?

BTW all the PVR programmes out there dont touch the video at all. Just record it and display it to a certain bit rate etc

[midiboy]

Hi Darx-starz,

well, the most pressing problem as you put it would be the AV sync problem. Audio is always late in GB-VCR but not in Dscaler, ChrisTV, Mediaportal etc.

Thanks for your help,
Alex

[capone]

Is GB using same MPEG decoders as those other apps?

[midiboy]

Well,

Dscaler uses Dshow and I cannot set the decoder to be used there but all the other apps are set to use the Moonlight Elecard decoder including GB_PVR

Bye,
Alex

[capone]

try setting it manually in the control panel, or use the one that came w/ the card (invervideo).  

I have the same problem w/ recorded files & ffdshow.  If you have anything doing post-processing (like dscaler), it's possible you will lose sync.  I turned it off until I install the new card w/ enough processing power to handle it again.

[sub]

GB-PVR does not do any playback itself, and has no control over audio/video sync. You problem is most likely caused your combination of directshow filter used / installed on your machine.

GB-PVR effectively says to Directshow 'please play this file'. If the user as specified a decoders/renderers other than 'system default', then it tells directshow it would prefer to have those filters used. GB-PVR then steps out of the way and lets playback proceed. Filters/decoder installed on your machine can take precedence over the decoder you have selected as your 'prefer decoder'.

Post processing filters such as FFDShow can also cause problems with AV sync.

[midiboy]

Hi Capone,

first, no decoder came with the card. I am using the Hauppauge PVR 500 MCE card, there is no software coming with it.

Second, I am not using ffdshow or any other processing. The AV sync issue appears with or without using the "Deinterlacer" processing filter in GB.

How can I use Dscaler as a postprocessor in GB ? That would be cool, but I did not find a way to do that ...

[mikey]

They explicity construct the playback graph, wheras I let the system generate. My approach provides some advantages, allowing a wider range of post-processing filters to be automatically used, but comes with the disadvantage of unpredictable choice of directshow filters. This approach works fine for the vast majority of users, but every so often we get a user that has problems.