A/V Sync Problem Solved

[mwj]

I wasn't able to get much help with my problem so I'm posting this for the benefit of others who may get it in the future.

I've had a bit of a problem recently with A/V sync that has been driving me crazy. LiveTv, and even playback of a show that was currently recording, worked perfectly on both of my capture cards (PVR-250, ATI-550). When playing back shows, about 90% of them would have a problem where skipping (incl. commercial skips) would case the A/V to get out of sync - first I would get a few seconds of video with no sound, then the picture would freeze while the audio caught up, then the show would continue in sync. About 10% of my shows worked fine in GBPVR, and all the shows worked properly in WMP. This all started suddenly, GBPVR had been running flawlessly (save a few .NET errors) for over a month.

Eventually I narrowed it down to recordings being made on the Hauppauge card working perfectly, where recordings made on the ATI 550 would always have the problem. The behaviour was identical whether I used NVidia decoders or CyberLink decoders in GBPVR.

Then, one day I noticed that I no longer got the NVidia decoder icon in the task bar when I was watching shows.

Turns out that I had installed the trial version of the NVidia decoder. When it expired, GBPVR fell back to using the CyberLink decoders. The CyberLink decoder seems to exhibit the A/V sync problem 100% of the time with shows recorded on the ATI 550 (specifically a PowerColor 550 Pro PCI-E). The ATI card is configured first in GBPVR so most of my shows get recorded there.

The ATI-550 recordings work fine with the InterVideo NonCSS decoders that come with the Hauppauge card. If you don't have those, it seems that the sync problem is specific to the Cyberlink Audio Decoder, so you can use the Cyberlink Video Decoder with whatever other Audio Decoder you happen to have.

Hopefully this message will save someone the weeks of frustration that I've gone through.

[jzonearcade]

I had the same issue using a Hauppauge 500 and an ATI display card. I changed my audio to ffdshow and that seemed to clear things up.

[shotofadds]

I've been having similar problem with my AverTV A800. I've found that using DScaler for both audio & video, with FFDshow post-processing enabled is the only way I can get reliable audio/video sync.

It's not exactly good for the CPU usage though :/

[mwj]

I've seen references elsewhere to the fact that the ATI encoder screws up the time track in the recording, so some decoders have sync issues. Apparently there is somekind of software you can run to fix the time track in the recording, but I don't know what it is.

[sub]

Apparently there is somekind of software you can run to fix the time track in the recording, but I don't know what it is.

I'm guessing this is the Reclock filter. It sounds good in theory, but unfortunately it causes more problems for most people that try to use it.

[TornadoTJ]

To save me from hunting around, which tab is it in the config where you select this decoder?

[mwj]

It's under Playback - you can pick the video decoder, the audio decoder, and the audio renderer.