joining videofiles with slightly different framerates

[Freak666]

i have captured 4 avi files from a vhs source and they have slightly different framerates (24.998, 24.988, 24.991). i wanted to append them in virtual dub but it gives me an error message: "cannot append segment. the video streams have different sampling rates." i changed the frame rate but changing the framerate causes bad audio/video sync. how can i change the framerate without getting that desync problem? or is there another way to append those avi files without changing the framerate?
i would be thankful for any kind of help.

[Scuba]

You can seperate the audio from the video, merge the video parts and put the audio back...

[Freak666]

changing the frame rate does not affect the audio stream so i does not make a difference if i seperate the audio stream first, then equalize the framerates and join the avi files or if i change the frame rate without seperating audio and video. both procedures give inadequate results. even virtual dub says that changing the framerate with source rate adjustment will cause audio/video desynchronization.
frame rate decimation would not cause desync but i don't want do decimate the frame rate, i want to put it up a little bit.

[Scuba]

Let me ask somthing else,
How the hell did you cam up with such frame rates in the first place ?

[Freak666]

that is just the way my graphic card is capturing. it never captures exactly 25 fps. always 24.something or 25.something fps. don't ask me why, i don't know.

[Scuba]

I think that you need a new card.....:rolleyes:
If this is how it captures it's very bad. Also if you will try to play out from such framerate I think that you will have lot's of errors unless you get a TBC.

[Freak666]

i have never had any errors because of the odd framerates. my graphic card is totally ok and i think there is no need to buy a new one just because it does not capture exactly 25 fps. i just need a solution for my problem. there must be a way! btw what is a TBC?

[Scuba]

Time Base Corrector.
It's a device used to fix problem in analog video signal.
Known to fix audio sync problems from VHS among things.
Expencive but do a good job and allaround recomended thingy.

[Freak666]

is there a way to solve my problem without spending a lot of money (that a do not have anyway)? what about a special programme?

[Freak666]

i can't believe that nobody knows a solution... what a pity...

[unit01]

Hi there,

If i were you I'd take the four frame rates and them together and then divide by four to get the average.

You may find that even if you have a large continuous capture and you say cut it into pieces with vdub each part would have a slightly different frame rate.

I dloaded a 1/2 hour clip from a pub and it was strangely cut into 20 two minute pieces instead of rars and on inspection of the files many were a slightly different framerate however when i averaged them out and reset them all then appended the files in vdub the film was in sync.

If you still have problems I'd suggest you use avi_io imho the best capture program if you can get it to work with your cap system. Also I've heard from this forum a guy made a mod of vdub that now caps with audio synching correctly

http://www-user.rhrk.uni-kl.de/~dittrich/sync/VirtualDub-1_4_8__sync1_01b/VirtualDub-1_4_8__sync1_01b.zip

Bong the exe in ya Vdub folder and give it a shot

Anyway good luck :)

[movmasty]

try to merge the files with ProjectDivX or aviutl.

[Freak666]

thanks a lot for your advice! :)

[henriQ]

Hi.
You got 3 parts and lets assume the audio stream is equivalent in
specs in all of them. So no problems wiil arise in this area.
Now, go to divx-digest.com\software and download a small but useful
application 'avifrate' (or there about).
Select as token the 'middle' average value, i.e.: 29'9989, 29'9979,
29'9981 - this last one.
Take the other 2 slices, open them and insert 29'9981 in the box of
'new frame rate'. Apply.
Go back to VDub open the avi file slice you want in 1st place, then
"append" the 2nd & the 3th. And that's it.
Regards.

HN

[movmasty]

You got 3 parts and lets assume the audio stream is equivalent in
specs in all of them. So no problems wiil arise in this area.
Now, go to divx-digest.com\software and download a small but useful
application 'avifrate' (or there about).*(dont take it from doom9.org (http://www.doom9.org/Soft21/Editing/avifrate110.zip) coz could contain viruses :rolleyes: .)
Select as token the 'middle' average value, i.e.: 29'9989, 29'9979,
29'9981 - this last one.
Take the other 2 slices, open them and insert 29'9981 in the box of
'new frame rate'. Apply.
Go back to VDub open the avi file slice you want in 1st place, then
"append" the 2nd & the 3th.
Naturally this wont work, but you had some fun :D

[movmasty]

Hi Avery"cool"Lee
-merge avis 1
I saw many ppl on the doom forum asking how merge avis with slightly different frame rate.
you could do with tools like ProjectDivx or aviutl,
not with vdub cause its too sensible also to very small differences(23.99999)
further,for math reasons,very shorth avis wont save at any given fps.

could you make a little fix for this?
i mean let merge,say from 24.099 to 23.901.

-merge avis 2
Often appended files in vdub doesnt work after saving,
to make they always works, you have to manually cut at least one frame before to append another file,
seems like vdub doesnt erase the index,or a part of it,when saving in direct copy.

Could you do something regard this?

[theoneyouknowleast]

you could always just change the framerate of all the files to 24.990 and merge them. the diffrence in fps is pretty small, there is a good chance you won't see much of a synch issue.


I think of this as the lazy mans fix.