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polack
23rd January 2008, 13:24
Hi guys.
After weeks of tries and failures finally I decided to ask here for help. My problem is I've got (1) episode of tvshow in 29.97 fps with poor video quality but great sound and the same episode(2) in excellent video quality (25 fps) and useless sound(french language:( ). What I'm trying to do i taking audio from from the first one and adjusting it to good video(2). I know that I should to change fps of audio to 25 fps but I can't find a way to do this. Of course I already tried besweet, belight, adobe audition, goldwave, ac3machine, and the result is completely useless. The lenght of episode (1) is 21:22 and 21:14.72 of episode (2) because of removing from the secend one some black frames between scenes.
What I checked first was playing video(2) with sound (1) just after demuxing sound with Virtualdub mod without any changes. As a result was gradually delayed sound but nearly correct at the video end. So when I tried to change fps of sound from video(1) then I recieved sound with lenght 25:37, doesn't matter wheter I used besweet method 25->29.97 or belight with the same method or with goldwave or adobe udition(25/29.97 = 83.416) - time/pitch - stretch I always recieved audio with lenght about 25:37 totally not adjusted to video. The result was the same when I changed sampling rate from original 44100 khz to 48000. Can anyone help me?! I rode a lots of topics in this forum nad others and these methods usually works. Why in this case they don't?
Sorry for my very bad english.

tebasuna51
23rd January 2008, 15:57
With different video sources not exist automatic method, you need do manual sync by scenes:

1) Decompress the audio to wav file (BeSweet)
2) Split the good video by scenes (VirtualDub)
3) Split also the wav file at same scenes (Audition)
4) Synchronize each scene: cut/add silence at begin/end and stretch (Audition)
5) Join the resultants wav's and encode to your desired format (Audition/Besweet).
6) Mux full video and audio (VirtualDub)

polack
23rd January 2008, 16:45
Thanks mate. Sounds good. I'll try this method. Let's hope it works.

scharfis_brain
23rd January 2008, 18:35
There generally is NO need to resample audio for a 25fps to 29.97fps video-conversion.

the DURATION of the video (and audio) stays the SAME, if a TV-show is converted from PAL (25fps/50fps) to NTSC (29.97fps/59.94fps).

speedup/slowdown only happens for Film-conversions between
NTSC (23.976fps) and PAL(25fps). This introduces a shortening or stretching of about 5% in duration and a pitch of about a half tone.

Just imagine, one would slowdown a 29.97fps NTSC TV show to 25fps PAL. This is a whopping 20%!

So I assume that the default conversion setting in Besweet/Belight is WRONG and misleading.

polack
24th January 2008, 09:07
I don't know if they're wrong I always use or default settings or advised by experienced users on topics about converting audio.