Any tool to synch audio by parts or "chapters"?

[S4r0m]

Hi. I want to mux 2 audio streams in a video, the first is perefectly synchronyzed, the second goes very well at the beginning, but nearly in the end there's a problem: In the last 10 or 15 minutes of the video, the audio goes out of synchronization for about 1 second. You can notice this in for example, the explosions and the shoots of the weapons: they appear before the sound, but only during those last 15 minutes... The out of synch is constant, not progressive, i mean, it is about 1 second of delay until the end.

I was asking if there is a way to solve it without the need of recurring of software like adobe premier or sony vegas; I know they are excellent and easy to use. I've used them before. But they are expensive and i need to convert the files to something compatible with them and create the final video with them, which is a lot of time and a great loss of quality (audio 5.1, blurry video, etc.)

[poisondeathray]

Hi. I want to mux 2 audio streams in a video, the first is perefectly synchronyzed, the second goes very well at the beginning, but nearly in the end there's a problem: In the last 10 or 15 minutes of the video, the audio goes out of synchronization for about 1 second. You can notice this in for example, the explosions and the shoots of the weapons: they appear before the sound, but only during those last 15 minutes... The out of synch is constant, not progressive, i mean, it is about 1 second of delay until the end.

I was asking if there is a way to solve it without the need of recurring of software like adobe premier or sony vegas; I know they are excellent and easy to use. I've used them before. But they are expensive and i need to convert the files to something compatible with them and create the final video with them, which is a lot of time and a great loss of quality (audio 5.1, blurry video, etc.)

RE: premiere, vegas - You don't have re-encode the video, just use the old video. Presumably you are doing audio editing, not video editing ? Just export the audio track (You're only using the video as a visual aid)

You might be able to do this in something like audacity, try to visually match the waveforms since you have 1 stream that is in sync. Just highlight that last 15 minutes and edit it. Just shift the audio since it's a constant sync delay. If it's out of sync for 1 second, you might have to add 1 second of silence to fill up the time.

[S4r0m]

I'm trying audacity right now Thanks! I'll post later what happened.

Oh and in vegas and premiere sure i need to. If i have it as mkv or encoded with xvid, h264, divx, etc. The same for the audio, they do not accept DTS, AC3, AAC, etc... So, i do have to convert files to use them and the output file won't have the quality of the sources; Besides, that final output file must be re-converted again if i want it in x264... I want to avoid all those conversions.

[S4r0m]

Nop, audacity moves the whole audio, so it moves out of sync everything... Like i said, the first hour of the video is perfectly synchronized, there's only the last 15 minutes out of sync... Anyways, i had to finally use soundforge and vegas to fix it... Several hours of work just to fix one second of synchronization in the last 15 minutes of a video...

[manono]

Don't know how to entirely delete a reply. Can it be done?

[manono]

Nop, audacity moves the whole audio, so it moves out of sync everything...

No. Mark the place where the problem begins and either add silence or cut audio. Just as pdr explained.

In any event, the video can remain as-is.