23.976 fps vs 24.000 fps encoding problems....

[mcmse1]

I've seen this problem with both AVI and MPEG2 files at the encoding and also authoring stages while producing a DVD.

The source file has 174426 frames and is encoded at 23.976 fps for a total running time of 121 minutes and 15 seconds. Some encoders and authoring tools I use seem to round the 23.976 fps to 24.000 fps which results in a movie time that is 121 minutes and 8 seconds. This is 7 seconds shorter than what the movie should be and causes sync problems with the audio.

Scenarios where I've seen this happen...

Using Virtualdub to frameserve the video to CCE. CCE initially reports the video at the correct length, 121 minutes and 15 seconds, but the final mpv file is 7 seconds too short.

Second, if I have a correct mpv file to start with and import it into SpruceUp, SpruceUp shortens the video length by 7 seconds... Like it thinks the framerate is 24 fps, not 23.976 fps...

Has anyone else encountered this and if so, how do I prevent this from happening?

Thanks
-Dan

[Lenny!]

u need to "take " the sound out of the movie !
using virtual dub amd frame srever :
1) virtual dub
open video file
audio------->full prosseing mode--> conversion ---->48,000 ,16 bit , stereo


2)file----->save wave

3) when u done to save the sound file do :
open video file
audio----------->direct--------> wav file
- and open the file that u did !
everything else is the same !

Lenny

[mcmse1]

Lenny,

Thanks for the reply but I still have the problem after trying what you said.

Currently I have a DV .avi file that only has the video encoded with no audio present. The DV file is 121 minutes, 15 seconds in length and has 174426 progressive frames at 23.976 fps. If you do the math you'll see everything checks out. Then I load the DV .avi file into CCE or TMPGEnc and encode it to an Elementary Stream MPEG-2 file. Then if I open the MPEG-2 file in WMP9 or VirtualDubMod the length reported is 121 minutes, 15 seconds which is what I expect. The movie plays fine.

If I import the ES MPEG2 file into SpruceUp (after running pulldown.exe on it), the movie length is reported as 121 minutes, 7 seconds. Second, if I look at the video information file produced by CCE, it also reports the video length as 121 minute, 7 seconds... 8 seconds shorter than it should be.

The way I see it, if an MPEG2 file has 174426 frames but is 121 minutes, 7 seconds in length, then the fps must be 24, not 23.976. So if WMP9 and VirtualDubMod report the movie fps as 23.976 but CCE and SpruceUP indirectly reports it as 24 fps, which one is it?

This driving me crazy!!!
Anybody have any ideas?
-Dan