Film4 AV sync on MVP

[bgowland]

I have a slightly annoying problem with losing AV sync. when playing back recordings from Film4 on my MVP.

It's only slightly annoying in that if I FF/RW several times, I can get the AV to sync. and it stays that way until I FF or Skip an advert. In many cases, I'll lose sync. again and I have to do some more FF/RW juggling to get it back.

This is the only digital channel where I see this problem. I've looked at the stream info and it shows as...

Video: MPEG2, 15Mbs, 720 x 576i
Audio: MPEG1, 160kbps, 48Khz

Looking at BBC Three (which I record often and has solid AV sync. on the MVP), it shows...

Video: MPEG2, 6.5Mbps, 720 x 576i
Audio: MPEG1, 256Kbps, 48Khz

All digital recordings on my machine are recorded to dvr-ms then auto-converted ASAP to mpeg2.

Any ideas where the problem is being introduced? Could it be the dvr-ms -> mpeg2 transcode or the Transcode2MVP stage (or both). Is it worth trying a different version of the Cyberlink mux for the auto-transcode stage?

Cheers,
Brian

[sub]

Any ideas where the problem is being introduced? Could it be the dvr-ms -> mpeg2 transcode or the Transcode2MVP stage (or both). Is it worth trying a different version of the Cyberlink mux for the auto-transcode stage?

Yes, this would be my guess. The mux filter is responsible for generating all the timing information in the program stream. It would be worth testing a different mux version to see if helps.

I've also been meaning to modify GBPVRConvert so that it can use the ATI Mux, which would give you another option.

[bgowland]

Yes, this would be my guess. The mux filter is responsible for generating all the timing information in the program stream. It would be worth testing a different mux version to see if helps.

OK, thanks - I've got a few I can try. I'll turn off the option to delete the original dvr-ms file after auto-convert and try a few manual transcodes with the different versions for comparison. I'll also build a transcode graph with the ATI mux out of interest.

I've also been meaning to modify GBPVRConvert so that it can use the ATI Mux, which would give you another option.

That would be useful - even if it's just something like a config.xml setting it would be good.

Cheers,
Brian

[Graham]

It's only slightly annoying in that if I FF/RW several times, I can get the AV to sync. and it stays that way until I FF or Skip an advert. In many cases, I'll lose sync. again and I have to do some more FF/RW juggling to get it back.

I have the exact same symptoms using the Cyberlink decoder from the trial version of PowerDVD 6 but it ain't on Film 4 and I don't have a MVP. I record and playback DVR-MS files on a computer monitor.

I'll try going back to the Intervideo decoder supplied by Hauppauge with the Nova-T cards.

<Hint> I can live with having to stop and start GBPVR after playing eight recordings </hint>

Graham

P.S. I promise that I only used it for a few hours to do some experiments and I uninstalled it immediately afterwards but I didn't get "Intervideo decoder goes missing after eight playbacks" nor "E4 channel is missing" with MediaPortal.

[Graham]

I have just remembered something else!

I have always used the Hauppauge Intervideo decoders because they just work. Might be because the decoders and the Nova-T hardware are "made for each other".

Recent experiments with other decoders gave me unexpected audio filters in the graphs.

The only change that I made between the GBPVR sessions that created the attached was to change the Video decoder and the Audio decoder on the Playback tag.

I used the Cyberlink video and audio decoders from the trial version of PowerDVD 6 and from the trial version of WinDVD 8.

Regards

Graham

[bgowland]

sub - A quick follow-up FYI.

I recorded a film from Film4 and kept the dvr-ms file then I built a number of transcode graphs using different versions of the Cyberlink mux and also the one version of the ATI mux that I have.

Unfortunately, no change. The playback of the mpg files on the MVP either started with AV sync problems or would lose sync after using FF. Once again, I could get the sync back with several FF/RW operations.

So - no progress, I'm afraid.

One thing that occured to me is the original dvr-ms file. Is there any liklihood that it may be the source of the timestanp errors? Dvr-ms is, after all, just a wrapper around an mpeg file. The SB sink presumably does some sort of muxing when writing the file.

Cheers,
Brian

[sub]

One thing that occured to me is the original dvr-ms file. Is there any liklihood that it may be the source of the timestanp errors? Dvr-ms is, after all, just a wrapper around an mpeg file. The SB sink presumably does some sort of muxing when writing the file.

Yeah, you might be right.