Codecs Codec issues with HDTV (1 Viewer)

[TheBatfink]

When I installed the drivers I installed everything and told it to do a clean install. I don't use audio over HDMI though I use my motherboards onboard optical out. I guess its working as my receiver changed from DD to DTS etc ok. I gather that counts as a correct install?

Ok Tony, I was just worried the dropped frames might be causing the audio to desync.. Even the slightest bit and I can't stop staring at peoples mouths to see if I'm imaging it!! Freaks me out

Thanks for all the help your stars

 

[Owlsroost]

It actually drops (or repeats) frames - when necessary - to make sure the video & audio stay in sync

Tony

 

[TheBatfink]

Hey,

Well playback is much improved, certainly to a level of video I can live with.. I do however feel as though there are some syncing issues. It just feels ever so slightly out of sync, audio is infront of video..? Is there anyway I can measure this without watching mouths??
I'm also not sure if its moving in and out because sometimes I can't make my mind up then others it seems fractionally out.

I was using DVT-DVD but I have just tried LAV for DD+ and to me it was the same or marginally worse. I'm confused though if 'something' is supposed to be compensating with extra or skipped video frames?

Oh and this is Motherboard SPDIF to av receiver, video direct to TV with HDMI.

Thanks

 

[TheBatfink]

Definately have some livetv audio in and out of sync very slight? Is this a codec issue or?

 

[Owlsroost]

It might just be a difference in the processing delay through the TV (for the video) and your audio system. Some TV's can have several frames of delay in the video processing (which is why A/V receivers quite often have adjustable audio delays to compensate for this).

LAV audio decoder (and FFDShow) have an adjustable audio delay feature (if the audio is early) - check out the config

Tony

 

[TheBatfink]

This isn't a permant delay though. The channel always starts in sync and I think it moves in and out during playback, I can sit for a minute watching thinking this is definately out of sync and then it seems back, only to move out again?

Audio is always in front though when its occuring, never behind video.

Incidently watching a x264 video file HD with DTS audio in moving pictures I see no sync issues

 

[Owlsroost]

How far does it move out of sync ?

I don't know of any A/V sync issues with TV playback.

Tony

 

[Paranoid Delusion]

Is this with recordings and live tv, have you tried reclock as audio renderer, installs uninstalls cleanly so will not break anything.

 

[TheBatfink]

I've not replied because I wanted some more time to check. Sometimes it isn't and works fine, sometimes it moves out but later comes back in. If I tune a channel it is always in sync to begin with. Its always the audio early, its hard to tell but maybe upto 200ms? I experience this with both MS DTV-DVD as audio decoder and also with LAV 0.45 decoder (I have also tried turning off auto A/V sync correction but it didn't help).

LiveTV, but I think it also happens on TV recordings (I don't make that many). Is it worth also noting I watch some encrypted satellite channels on my setup? The audio stream is saying its AC3 and my receiver is showing Dolby Digital as the incoming format.

Its really annoying me now, once this is fixed my setup is 100% for the first time ever so I'd love to get to the bottom of it.

Never heard of reclock? Is it on this board?

Thanks

 

[Owlsroost]

Does it only happen with bitstreamed AC3 audio ?

If so, then try decoding everything in the PC as an experiment.

ReClock is an alternative audio renderer with the ability to adjust the master presentation clock and resample the audio (to avoid regular frame drops/repeats when the display and video frame rates don't exactly match), but a) it isn't recommended to use bitstreaming with it, and b) in my experience it sometimes misbehaves with live TV, but it's here - ReClock 1.8.7.7 (it works fine with video content etc - I use it myself)

Tony