question about audio/ video sync

[shokan22]

I sometimes have videos that have the sync problem, It is always the video lagging behind the audio. Why is that? Is it the software used? User lack of knowledge? Slow computer? What is it? It is always cable broadcast encoding where this happens. It doesn't happen often these days, but back in the early 2000s, happened a a lot.

[redwudz]

The video takes more processing power than the audio.
It's not uncommon for the video to freeze and the audio to continue if part of the system has performance problems.

This can be caused by a slower CPU, a slow video card or the playing software. Try a different software player first.

I would check the video card next and make sure it has up to date drivers if a different software player has no affect.

You can also check your CPU usage in 'Task Manager'. If the CPU is running near 100% during playback, that's a problem.

[shokan22]

My computer and video card are powerful. What happened during the encoding for these early videos? As I said above, it happened occasionally in the early 2000s. Sometimes it still happens, but not often. It's not my system in playback, it is the video product itself.

Was it the software used in the early 2000s, user error, low power CPU/ Video Card?

[davexnet]

You got to do some detective work, process of elimination. Check the task manager, as was suggested
Try the same files on another PC and/or known good files on this PC.

Are these files something you encoded yourself?

[shokan22]

You got to do some detective work, process of elimination. Check the task manager, as was suggested
Try the same files on another PC and/or known good files on this PC.

Are these files something you encoded yourself?

I have never have done encoding or will ever do. I just want to know why a lot of videos have video lagging behind audio.As I said above, this doesn't happen often these days, only about ten or fifteen years ago. I think it was lack of CPU power on machines of that time but what do I know?

[johns0]

What computer specs do you have?I never get any issues with video lagging even when watching a 1080p video and encoding at 100% cpu at the same time.

[theewizard]

You got to do some detective work, process of elimination. Check the task manager, as was suggested
Try the same files on another PC and/or known good files on this PC.

Are these files something you encoded yourself?

I have never have done encoding or will ever do. I just want to know why a lot of videos have video lagging behind audio.As I said above, this doesn't happen often these days, only about ten or fifteen years ago. I think it was lack of CPU power on machines of that time but what do I know?

in other words, you are playing somebody else's captures and encodes, and you want us to tell you why they are out of sync

try them on another PC, if they play in sync, it your pc can't keep up

if they are still out of sync, then who knows ? why..but probably some mistake in the capture, too high a video bitrate, dropped frames, bad source ?

[shokan22]

Somebody's else captures. My PC specs are powerful. These are videos from the early 2000s. I have already said this. All the out-of sync videos are permanently like that. I have tried VLC to correct them once I converted them to avi. but not with much luck. I don't care actually about the out of sync of these videos from 2007-2008. I just want to know how the out of sync happened. What was the problem with the original encoding from cable broadcast? No one here is giving me an answer.

[johns0]

Post your computer specs.

[shokan22]

Intel: can't remember, but it cost 600 dollars about three years ago
mobo: Asus p8Z 77
Video: GeForce GTX 690
Power: Corsair1050 watt.

The videos I mentioned also play out of sync also on my little net book. Both my tower and the laptop are fully updated with codecs. It was the original encoding that was the problem. What did that person do wrong 2007-2008? Getting an answer to this is like pulling teeth. The problem is not local, it is the original encoding. What was the problem with encoding the original cable broadcasts?

[johns0]

The 690 isn't the most powerful video card anymore,my 970 beats it easy,your video card is still good enough for all gaming and video processing ,sounds like the original videos have problems to begin with.

[shokan22]

yes, I know the 690 is not really current anymore. But why do the old videos from 2007-2008 on my netbook play in the exact same out of sync amount of time? Even on Youtube, these very same videos have the same amount of out of sync. The original encoder from cable braodcast had a problem. I just want to know what that was. Inquiring minds want to know

[hech54]

I have never have done encoding or will ever do.

I have tried VLC to correct them once I converted them to avi.

If you keep dishing out information with an eye dropper while contradicting yourself.....you will never get an answer.

[shokan22]

Ok I give up. I just wanted to know why video lags behind audio in some old caps that are downloaded and played on good PCs or from YouTube. I did not get an answer. No one knows. I don't think I was contradictory at all. But, anyway,....

Bye.

[theewizard]

Your right...
No one knows
There is no way to know, we don't have a way back machine
We don't know what went wrong, when it was encoded
If it is constant half second out , you can adjust that in vlc when playing back
Old video you don't watch?
It's a moot point anyway

[shokan22]

Your right...
No one knows
There is no way to know, we don't have a way back machine
We don't know what went wrong, when it was encoded
If it is constant half second out , you can adjust that in vlc when playing back
Old video you don't watch?
It's a moot point anyway

Good answer, thewizard. Thank you. Last time I heard someone use "moot point" was quite a while ago. A moot hill in the dark ages was a place where people met in the British Isles for adjudication, a court kind of thing. They also drank a lot and made merry.

Yes, I have converted MP4s, the old videos from Youtube I have mentioned, to avi and have done the the correction of video/audio sync correction in VLC. Sometimes it was as much as a full second.

My guess it was a combination of the encoding software used in the early 2000s plus low machine specs of the capper. The videos were the series called Time Team, produced by Tim Taylor and ran from 1994 to 2013. There were only a couple of years, 2007- 8 where the capper screwed up with a few episodes. All these episodes are available on YouTube. and also from Channel Four (UK) in DVD format which I recommend for better video quality.

Thanks again.