Adding an audio file of a different source that is in a different format

[kwanbis]

Hi everyone,

I need help syncing audio between two MKV files.

Original File:
* Video: 23.976216 fps
* Audio: Spanish (AC3, 48 kHz, 32 bps)

New File (Better Video)
* Video: 29.970628 fps
* Audio: English (AAC, 48 kHz, 32 bps)

I’d like to keep the better video from the new file but use the Spanish audio from the original file. The problem is, when I merge the Spanish audio with the new video, the audio gets out of sync.

I tried speeding up the Spanish audio by 1.25x, but it doesnt work.

Is there a proper way to adjust or stretch the original audio to match the new video’s framerate without affecting quality too much?

Thanks in advance!

[davexnet]

Compare the run times (hours,minutes and seconds) of the two videos, them it will be clearer what you have to do

[timtape]

Speeding up the Spanish audio by 1.25 should get you a lot closer but it will eventually drift out. I'd speed it up to three, not two decimal places, eg: 1.251 for better accuracy.

[jagabo]

29.97 fps and 23.976 fps would normally have the same running time. The 29.97 fps video simply has 1.25 as many frames (a duplicate every 5 frames). It's most likely you have two different cuts of the movie (releases in different countries often have different cuts).

You'll have to analyze the videos to determine exactly what needs to be done. Then you'll probably have to use an audio editor to remove and add sections here and there.