Framerate Conversion

[rackball]

Halo everyone. Is there anyone might know how to change the framerate of an mkv file, e.g. those 1280x720.
Any help would be appreciated. Thanks in advanced.

[guns1inger]

From what to what ?
For what reason ?

It may be as simple as demuxing, time stretching the audio, then remuxing with anew framerate setting, or it may mean completely re-encoding the file and reducing the quality substantially. You need to provide more detail before an accurate answer can be given.

[rackball]

I bag you pardon. Most of the mkv files are in 23,976 fps. My question is are there any ways to convert a mkv file from 23,976 fps to 25.000 fps without reencoding or reconverting? I know the longest and hardest way via an avi file.
Any help would be appreciated. Thanks in advance.

Thank you Guns1inger for your quick replay!

[guns1inger]

My question would be : why ?

Are you streaming to a PS3 or 360 that is PAL only ?

This *might* work (no promises)

Demux the content with mkvExtractGUI

If the audio is not AC3, convert to WAV. If it is AC3, or once you have a WAV file, use Besweet to stretch the audio from 23.976 to 25 fps.

Remux the video and audio content with mkvmerge, setting the framerate to 25 fps

Test the playback.

I don't know if this will be enough to force true 25 fps playback or not.

[cobalt]

But since there's an extra frame per second, the result will be rather stuttery, ain't it ?

[Alex_ander]

In the suggested method there are as many frames per second (no stuttering), duration is 4% shorter.

[jagabo]

In the suggested method there are as many frames per second (no stuttering), duration is 4% shorter.

No, the total number of frames for the entire film is the same. There are more frame per second (25 vs 24), each frame is displayed for a shorter period of time so you don't see any duplicates (jerkiness). And the running time is shorter.

[jman98]

I'm guessing that the original poster may have been trying to author a BluRay or HD DVD compatible disc and some authoring programs may require framerate changes. I have a copy of Scenarist's HD DVD authoring program and any 1280x720 video must without exception have either 60 fps or 50 fps or Scenarist won't touch it. Anyway, he seems to have lost interest, so until he comes back we might as well stop replying to this.

[Alex_ander]

In the suggested method there are as many frames per second (no stuttering), duration is 4% shorter.

No, the total number of frames for the entire film is the same. There are more frame per second (25 vs 24), each frame is displayed for a shorter period of time so you don't see any duplicates (jerkiness). And the running time is shorter.

Of course. Wanted to say the same (meant all frames are original ones) but failed, too tired by the end of the day (at my location).

[rackball]

I'm sorry. I had my holiday one week. I checked the method described by Guns1inger and it works superb. I demuxed the audio, converted it with BeSweet from 23,976 to 25,000 fps, then demuxed the video with MKVExtractGUI, then muxed all together in MKVMerge using setting of 25 fps and the movie plays fine. No jerkiness.

Thank you so much Guns1inger.

[guns1inger]

Glad it worked. Up until now it was only theoretical.