Audio synch problems after muxing.

[avengerevenge]

i have a same movie from two different sources,

1) First source is a bluray rip (mkv container), as usuall the FPS(frame rate) is 24, the length of the file is 3:8:35, the audio is
in DTS format, but i dont want this audio because it is in different language.......

2) Second source is a normal DvDrip(xvid-avi),the FPS(frame rate) is 25 (i think its a pal), the length of this file is 3:1:23.
The audio of this source is in AC3 format with 5.1 surrounding........i want this audio because its my language,hence i
want this audio to be muxed with the first source(bluray-mkv file).

So,i extracted the audio(from the second source) after changing the frame rate of the original video to 24(from 25),although the length of the file did not changed, i did this by using virtualdubmod,

Then i observed that the extracted audio started 8 seconds late when compared to the first source (bluray mkv file)............ I even adujsted this using delaycut.......

At last when i muxed the audio using megui....................i found that the audio was in sync during starting of the movie.....but went out, after a duration of time, the audio is really out of synch at the end of the movie(it went in minutes)...........now what should i do to synch the audio........pls guide me with necessary steps....i am really newbie in conversion and synching process..... its really driving me crazy. am i doing some thing wrong??????

[ggtop]

am i doing some thing wrong??????

Yes you did indeed. Go to your local store and buy a copy of that movie instead of d/l them.

ggtop

[yetanotherid]

I've literally driven myself mad trying to fix problems like that. Don't assume the video has the same number of frames. Plenty of times I've seen video where for some reason there's 100ms difference between fade times from one scene to another, 200ms there, and before you know it there's no hope of ever swapping the audio. Sometimes whole sections have been edited differently.

That aside... changing the frame rate won't drag the audio rate with it, as that seems to be what you thought would happen. Changing the frame rate will just put it out of sync with the audio.
You need to demux the audio you want to keep and remux it into an MKV using MKVToolNix, set the appropriate delay, and then set an appropriate amount of stretch for the audio track and save the MKV. It'll ether be trial and error, or if you can do the math taking into account the amount of audio delay used and the percentage of time stretch required.... it'll still be trial and error. ;)

Often, just before the process drives me completely mad, I find it easier to try different frame rates rather than to stretch the audio. Sometimes a .001 or .002 frame rate adjustment does the trick. Then in your case if you save the frame rate adjusted MKV, MKVToolNix will probably delete the first 8 seconds of the audio track (as you brought it forward by eight seconds). If you compare the duration of the new MKV with the old one, you'll be able to work out the difference as a percentage, Then if you really want to go back to 25fps, you'll have a rough idea how much to stretch the audio track (the one which had 8 seconds cut from it).

Have fun!