Video to play at different fps with different audio?

[Disabled]

Hi,
I wanted to join a NTSC Movie with a PAL Audio source and am facing the different length problem.
The ideal solution would be:
track engl selected => video plays at 23.976 fps
track ger selected => video plays at 25 fps
Thus I could leave everything as is without reencoding.
Is this possible with matroska? (Or MP4 but I doubt it) That the fps changes with the audio stream?
Or else I saw this example placebo vid (http://www.matroska.org/~robux4/dvd/placebo/) with a menu and different frame sizes running in VLC, I suppose with that it would be possible to pass the vid a fps this way would it?
I tried to look into the chapter and menu xml files, but they are way to complicated for me...

Thanks a lot...

[unmei]

I doubt it, every chunk of data has a timestamp. The player would need to multiply each timestamp with a factor. Not that this were difficult, but i don't think this is viewed as something that the media should control (only the player).

Likewise i doubt that demo file resizes the video - just from looking at the menu.xml one sees that the chapters in there point to different time spans. It is most likely a video where that different segments of different resolutions are simply concatenated and the menu jumps to the segment with the selected resolution. Just a guess, tho.

Did you try how you like the german track slowed down by 1/25 ?
A good quality tempo changer that preserves pitch while keeping the artifacts at a minimum should make for a very acceptable result. Especially as it is well possible the audio track was already sped up from cinema "24fps" to tv "25fps" by the DVD authoring company (so you are just reversing what they modded ;)

[Disabled]

Somehow I'm pretty sure with control tracks this should be possible. I would even include two timestamp files and with audio a it uses the first and with audio b the second...
I know they might have sped up some audio, but I cannot believe that the studios today do not cover the pitch issue, and the german voices get recorded at the 25fps speed anyway.
I think youre right with the different resolution solution, this is a somehow different thing, I just wanted to show the already possible things doable with matroska.

*edit* during mux the following small txt file changes the framerate to what I want, they might get hardcoded to timecodes though... I still have hope that I can activate two timecode files for different audio files though...
>># timecode format v1
>>assume 25

[unmei]

i didn't mean to say they fuxored the pitch, i meant you should remember to preserve it when changing the tempo -- but yeah the *german* voice is probably not changed :) I notice i wrote that during "breakfast", it must have been before the coffee had any effect..

About control tracks, i don't know, i never played with those so far. But i tend to think it wouldn't be widely supported by players even if it is possible to create such a file. But what i *do* know is that the clusters containing the data have timestamps -no matter wether you use timecode files or just mux an AVI (that doesnt have timestamps, but an framerate). Of course this doesn't prohibit anyone (player settings, control tracks) from changing the timescale during playback.

[Haali]

If your audio tracks have different durations, then it's close to impossible, because timecodes and fps are tied with physical block interleave. If you change fps of an existing track, the interleave will be skewed, and some splitters won't be able to play file at all and others will do excessive seeking.

[Disabled]

Hmm, sad to hear that from you haali. I think you pretty know what youre saying, so I guess I'll stop searching for a possibility.
Then I have to reencode the audio.
Thanks for clearing that up.