sync problems with NTSC 720p 59.98 fps with 25 fps audio

[mav_top]

when the HDTV is 1080i 29.97 fps

1) i resize it to a 1280x720 23.976 fps (using telecine and decimate)

2) get a perfect synced audio muxing with the original audio

3) get a perfect synced audio, bringing the video to 25 fps in VDUBMOD and muxing with a PAL audio 25 fps

I get problems when i do the same with a HDTV NTSC 720p 59.98 fps

1) i reduce the framerate to 23.976 fps (with selecteven and decimate)

2) get a perfect synced audio muxing with the original audio

3) get sync problem, when , bring the video to 25 fps in VDUBMOD and try to muxing with a PAL audio 25 fps

I can get the sync for only some seconds then all go bad, the video is perfect but i can't put the audio synced.

I compared the same video in the PAL native format with that in the HDTV format decimated in 23.976 then converted to 25fps, the original PAL format is slower, seems that in the process of removing double frames i lost some frames, so the movie is faster and get out of sync with the original PAL audio.

Is it normal ? Or i'm doing something wrong ?

thanks in advance
mav_top

[Guest]

What happens with FDecimate(25)?

I used it on the stream you sent and the clip came out at 2 minutes 50 seconds and a rate of 25.0 fps. The audio was also 2:50. I don't see why you wouldn't be able to sync those.