Consistent audio/video sync problem

[ascot]

Hello all,

I am growing increasingly frustrated with my audio sync problem. I have been playing around with this problem here and there for two weeks and cannot get things in order.

Please excuse my terminology as I am an intermediate computer user but this whole video thing is new to me:

Hardware:

Capture card = Hauppauge WIN-TV model 401, uses 878 chip
Audio = onboard
Hard drive = 80 GB but partitioned with 40GB avail, 7200rpm
Intel motherboard with P4 1.7 GHz processor

Software:

WIN XP
drivers - using the BT8x8 third party driver recommended in other threads
capture program - using VirtualDubVCR @ 352X480
codec - like Huffyuv but also tried PICVideo MJPEG
audio captured at 16-bit stereo 48Khz

I have tried changing various settings with no change in the result. The audio is always running behind the video from the captured AVI file straight through to the test burn. If I try shortening the audio or resampling, it either doesn't stay in sync for the duration or it doesn't change much of anything. The audio/video are close but you always see it before you hear it.

I'm trying to transfer VHS to DVD. I do not want to purchase any new hardware, if I can prevent it, until I get comfortable with what I'm doing.

The capture card is old but I got it dirt cheap off eBay. It says (c) 1996 and makes no mention of Win XP but it does work. Eventually I would like to add another hard drive just for video capture.

Any ideas?

[sacajaweeda]

I have a similar card and all the stuff I capture is out of synch like what you're experiencing. What I do is use a delay offset in my AVISynth scripts when I'm manipulating the source AVI files with the different programs I use. My hardware setup calls for a -.200 delay to get everything synched back up.

[fmctm1sw]

Hello all,

Hardware:

Capture card = Hauppauge WIN-TV model 401, uses 878 chip
Audio = onboard
Hard drive = 80 GB but partitioned with 40GB avail, 7200rpm
Intel motherboard with P4 1.7 GHz processor

That's funny.. Almost exactly the same as me. But the card is based on the 848 chipset I believe.....

Software:

WIN XP
drivers - using the BT8x8 third party driver recommended in other threads
capture program - using VirtualDubVCR @ 352X480
codec - like Huffyuv but also tried PICVideo MJPEG
audio captured at 16-bit stereo 48Khz

Ok, are you trying to say "virtualdub" or "virtualvcr"?

The capture card is old but I got it dirt cheap off eBay.

Any ideas?

Ouch! Easy on the wintv card killer I've been using that for about 18 months now with great results..
Let me know what capture app you are using, I have almost exactly the same setup..

[ascot]

The capture app is VirtualDub but the icon says "VirtualDubVCR". I guess it's a mod allowing someone to use WDM drivers.

The title bar says "VirtualDub 1.4.9.2 (build 13722/release).

I also have installed VirtualDub 1.5.10 (build 18160/release) but it doesn't make a difference which one I use, i.e. the results are the same.

[sacajaweeda]

It's a hardware issue. Use a delay.

[bottle-necked]

ascot, Welcome to the forum..

When capturing in AVI with my card and MMC I seem to always have a similar problem. I have had good results capturing AVI with MainConcept MPEG Encoder. You may want to try that program/

The way I correct my audio offset is sorta a two step process. First I open my AVI in VirtualDub and check the File Information command on the File Menu. My offset value can be calculated by subtracting audio time from video time in this case. Here is an example of the File Information Box and the information on this example file.


You can notice by the time values the audio stream is 560ms lower than the video stream. By using 'Interleaving' in VirtualDub I can simply input 560ms in the box labeled "Delay Audio Track By", set the audio mode to 'Direct Stream Copy', then 'Save As Wav' and save out a corrected version of my audio stream. I can then encode this avi file using any program I choose, convert my new audio file to Mp2 and mux back to the video and I will have good sync. I don't usually do it this way though. I simply take my 560ms number and go to TMPGenc. I can enter this number in Settings under "Source Range" and "Audio Gap Correct" but I must enter it as a minus number (-560). This saves me a step or two and still gives me good sync.

Hope this helps
Good luck.

[ascot]

bottle-necked, I can get the offset using the method you described. So I go to TMPGenc to encode and the result is still not in sync. It is still running behind. Ugh. I am using an 80ms offset. I tried it as +80 and -80 and it's behind both ways. What's up with that? I did test burns to confirm, too. Here is the info on the AVI:

[fmctm1sw]

What setting do you have under "timing" in virtualdub? I click "adjust video clock dynamically to match audio clock" or something like that... Have you tried virtualvcr ?

[ascot]

Whoa! I think I got it!

I recorded a new clip using VirtualVCR this time, which I just downloaded yesterday for the first time. The audio was still behind the video. I opened the clip in VirtualDub, used the Interlacing option to set it back 200 frames, and that did the trick. I have been using three checkpoints in the clip to check the audio/video sync.

I saved the file, encoded with TMPGEnc and burned with TMPGEnc DVD Author. I also "remastered" the resulting WAV file before burning using Cool Edit so I could burn two chapters - one with the original audio and one with my corrected audio. Both played in sync off the DVD.

Hopefully this will continue to work with longer clips.

Thanks for your help, everyone! The next challenge: encoding without pixelization. :P

[ascot]

BTW, my Timing setting in VirtualDub was "resample audio data dynamically to match video clock". Can I assume that if I capture in VirtualDub my offset will be the same or at least very close?

[gll99]

In virtualvcr did you set the master stream to audio (av synch). You can also play with the offset there so you don't have to reprocess the file.

[bottle-necked]

Adjusting for offset is going to be different for these two files because if you notice in my "File Information" my audio is shorter in time than the video, but in yours it's the other way around. I have did this type before but it is not as simple as I explained in my other post. In my post I said I can simply subtract the numbers then take the calcuation to TMPGEnc and reverse it (use a minus number) and it works. It does as long as I don't have dropped frames or something else wrong with the file. I don't so this method always fixes my offset problem when it as I discribed (audio stream shorter than video stream).

In your File Information box it shows the audio stream is actually longer than the video stream. You will find it necessary to use a different method to calculate for offset. If I use VirtualDub to capture AVI files I get this type of audio offset. I have never be able to do a simple calculation and determine the proper amount, but I can still find the proper amount by using the "Interleaving" command again, but this time I must 'play around' with the numbers to try and find the exact amount. The file I showed above in the box was like 560ms offset, but most every condition I have had like the box you show my numbers are more like 320-350ms. Simply input a number like 100ms and test play the file. Add like 50ms at a time till you get close then add a smaller amount until the file plays insync in VirtualDub's view screen. Once you establish good sync in the play window..... take that number to TMPGEnc and reverse it (make it the opposite) and enter it as I said above. If your VD number is 320ms then in TMPGEnc it would be -320ms. (or vice-versa). This is what I have found to be true for me. I have no idea if this will be true for your files and system(??)

VirtualDub is a very good program and there is NO way I understand all or part of it's functions, but this is the easiest ways I have found for correct my AVI files offset. Since I have started using these I am no longer afraid of outosync video because I know I can simply repair it using these methods. Progressive sync is another matter, but for a simple offset audio sync these methods is as simple as I could figure out. I hope they will work for you too.

Best of luck.

[barneystorm]

Hi, sorry I.m late on this thread!

There is a good walk through on this site that got me up and running a few years ago on this site, follow it through EXACTLY and you should be ok


https://www.videohelp.com/forum/userguides/89899.php

and I've also produced a guide of my own which you can download here

http://www.barneystorm.150m.com/VCD2.rtf

I'm using a Win TV card, 120gb hard drive (7200 rpm) with an 80gb partition I use just for video and audio editing, Athlon XP 2600, 768mb RAM.

A couple of things to remember..You MUST de-frag your hard drive space on a regular basis if you want good grabs, and make sure as much as is humanly possible is closed down before you begin the grab. If the source is good, you should be able to make perfect grabs. Have you noticed a lot of dropped frames?

One last thing, is the source you are grabbing from connected to the cards RF input or the phono socket? You'll get a better grab if you connect it directly through the phono (cinch) socket.

[kaayo]

Capture card = Hauppauge WIN-TV model 401, uses 878 chip
I've been using that for about 18 months now with great results...

Greetings, I also have that card and have tried recording MPEG1 & 2 & AVI even with high quality compression, using many different software programs - Mainconcept, PowerVCR, Intervideo WinDVR, Snapstream BTV, Virtualdub. However I can't get decent quality when burned to CD with Nero and played on my DVD through the TV - nothing approaching the quality of my 20 year old VHS VCR.

What's the secret? The program, driver, some secret settings? What kind of quality do you get?

Thanks, Don