[AudioSync] PAL to NTSC with different duration.

[LenyQua]

Hello, videohelp
I read this article, but the questions remained: https://forum.videohelp.com/threads/312812-25fps-source-Ac3-to-23-976fps

My trouble:
I have a DVD's auido stream with spec: AC3, 448 kbps, 6 ch, 1:59:00.960 / from PAL (25 fps)
& video stream with spec: 23.976 (24000/1001) FPS, 1:58:04.011
i need to adapt audio stream from pal source.

I did:
eac3to with command line ' eac3to pal.ac3 ntsc.ac3 -448 -slowdown' result: 2:04:05.920 (PAL duration.sec * 25 / 23.976)
how "stretch" this stream for muxing with video stream (1:58:04.011)?

If i overlay audio with duration 2:04:05.920 to video 1:59:00.960, then audio delay progressive on timeline, e.g.:
01:34 - ~ +1000ms
17:30 - ~ +1500-2000ms
28:23 - ~ +2500ms etc…

I really hope for your help. Thank you!!!

p.s. audio & video identical (dvd & bluray)

[redwudz]

Not sure why this was posted in the Test Forum. Moving you to Video Conversion Forum

Moderator redwudz

[LenyQua]

Thank, redwudz.
I assumed that a similar topic already exists.

[sneaker]

First: do not look at the durations. They will only confuse you. Play in a player and use your eyes and ears to see if there is desync.

If i overlay audio with duration 2:04:05.920 to video 1:59:00.960

Why would you try to slow down the PAL audio and then try to mux with the PAL video? Of course that won't work.

Try to slow down the PAL audio and mux with the NTSC video. Is it in-sync? If not: constant delay or progressively getting worse?
If it is getting progressively getting worse: try to mux PAL audio as is (without slowdown) with the NTSC video. Is it in-sync? If not: constant delay or progressively getting worse?

Note: some PAL vs NTSC DVDs may be of different cuts. E.g. Director's cut with extra scenes, some censoring etc.

(P.S.: it is also possible to just change video fps using e.g. mkvmerge without actual re-encoding. So take PAL audio and NTSC video and set video fps to 25)

[manono]

p.s. audio & video identical (dvd & bluray)

Obviously, they're not. And I don't mean the framerate but the frame count. As sneaker mentioned, you may have two different cuts of the movie.

If one were just a speeded up PAL version of the same cut of the film, then the difference in times would be about 5 minutes.

[fltk10]

I have actually had this problem myself today and solved it this way:
Demux the audio and video. Convert the audio to a format that Audacity can import and then correct the speed with Audacity.
NTSC (23,976) to Pal (25,00) = 0,959
Pal to NTSC = 1,047
Mux the video and the corrected audio with MKVToolNix