New Script - A/V Sync Tester

I found the page of a utility called (Can't quite recall - AviSynch ?) a few days ago. AviSynch helps you find the A/V offset of your unsynchronized AVI file. In other words, if you have a delay in Audio or Video, Avisynch will help you automatically fix it. Unfortunately, the app was written for Linux.

How does it do this? Crudely, but effectively... It automatically remuxes the "bad audio sync" AVI file many times, adding a 100 millisecond offset on each run. You'll need to play back the resulting files, hopefully stumbling across one that now plays with proper A/V sync.

I think these batch scripts I threw together will do the same for us Winders users. This is pretty early-stage stuff, but it seems to work rather well. The RAR file below contains 2 scripts - Negative_Values.bat and Positive_Values.bat, each batch adding delay of up to 1 second, or removing delay of up to 1 second - All in 100 ms increments.

What does that mean to you? It means you'll need to have 11X the available disk space on your hard drive as the space occupied by the source Xvid or Divx file. I split up the process into 2 batch files so you wouldn't need 22 times the space to test it out.

The results of either Negative_Values or Positive_Values is copied to the OUTPUT subfolder in the directory. Had to do it that way to avoid an endless loop.

As usual, your source AVI can't have spaces in the name.

http://www.wikiupload.com/download_page.php?id=101945

mirror:
http://www.bestsharing.com/files/dY1Dp5g240487/AV_SYNC_TESTER.rar.html

Try it out on this Clip. Play the file and you'll immediately see the sync error. Copy AVI into same folder as AV_Sync_tester and run _Positive_Values.bat. Have a look in the output folder when done. Looks like 300 or 400 ms did the trick

test_clip.avi



Example Output Folder

Here's the result of running both the Negative and Positive Values batch files on a file called "My_Movie_Trailer.AVI"

N-0050ms-My_Movie_Trailer.avi
N-0100ms-My_Movie_Trailer.avi
N-0200ms-My_Movie_Trailer.avi
N-0300ms-My_Movie_Trailer.avi
N-0400ms-My_Movie_Trailer.avi
N-0500ms-My_Movie_Trailer.avi
N-0600ms-My_Movie_Trailer.avi
N-0700ms-My_Movie_Trailer.avi
N-0800ms-My_Movie_Trailer.avi
N-0900ms-My_Movie_Trailer.avi
N-1000ms-My_Movie_Trailer.avi
P-0050ms-My_Movie_Trailer.avi
P-0100ms-My_Movie_Trailer.avi
P-0200ms-My_Movie_Trailer.avi
P-0300ms-My_Movie_Trailer.avi
P-0400ms-My_Movie_Trailer.avi
P-0500ms-My_Movie_Trailer.avi
P-0600ms-My_Movie_Trailer.avi
P-0700ms-My_Movie_Trailer.avi
P-0800ms-My_Movie_Trailer.avi
P-0900ms-My_Movie_Trailer.avi
P-1000ms-My_Movie_Trailer.avi

---------------------------------------------

Edit: Updated with Sample Clip to Test. Seems to work pretty well on Xvid and Divx sources.

Soopafresh, (this is just a guess) I don't have the time right now, but
maybe if you give the:

cygwin1.dll

file (in a folder) and play around with the command line syntax, you might
be able to figure out how to obtain a method for a win command line setup
string. Then again, I could be wrong. But, isn't that what this file was
created for, I thought ?

-vhelp 4223

Actually, I'm just creating a batch scripted functional equivalent of that util, except for us Windows users. I hope you check it out, Vhelp. Like I said, it is crude, but it works suprisingly well.

Edit - I'm uploading to a mirror site, as Bestsharing seems to be on the fritz at the moment.

It can be simplified - No need to unpack the packed bitstream, or normalize the audio for that matter, although the transcode to CBR mp3 isn't the worst thing in the world.

http://www.wikiupload.com/download_page.php?id=101945

Download the test clip as well from the link above. It'll take all of 30 seconds to run it, especially since the video example is only 15 seconds long.

Imagine being able to simply answer this too-frequently-asked question : "I just converted my DVD to AVI and now the sync is off by around half a second. How do I figure out the delay and how can I fix it ?" That's basically what I'm aiming for