record qt movie in realtime at 25 fps

Jun 22, 2006 at 5:02pm

record qt movie in realtime at 25 fps

Hi!

I?m capturing from DV FireWire Cam in MAX.

i use the jit.qt.record object. I use the realtime option. but I have the problem that the framerates of my captured movies are always different depending on how much cpu power is available for max.
but i need every movie at a framerate of 25fps.

i send this message to start the recording in jit.qt.record:

write /Users/spierala/Desktop/clip1.mov 25 dvpal

so why is max ignoring the 25 framerate in this message when I use the realtime option?

What I need is realtime at framerate 25.

I also tried to capture directly from the jit.qt.grab object, but I?m working with more cameras and I want to switch between them while recording… I can?t do that with the grab object.

so who can help me?
cheers
FLo

#26520
Jun 23, 2006 at 6:55am

What version of Jitter are you using? “realtime” mode has gotten a
rewrite for the next version of Jitter, and should be much more
reliable, FWIW. Note that decompression/recompression from/to DV is
not a cheap operation, and it’s likely that realtime mode is
dropping a lot of frames, in any case. You might consider recording
to a lighter compression format (PJPEG, Animation) and then
recompressing after you’re done.

jb

#79458
Jun 23, 2006 at 8:27am

Hi!

i?m using jitter 1.2.4

actually i get enough framerates 25. i can record dv pal at 29 fps.
but I want to limit it to 25.

if I deactivate the realtime option I get a 25 fps movie, but it?s not realtime.

cheers

flo

#79459
Jun 23, 2006 at 1:25pm

Jitter 1.2.x is not going to be updated for the new realtime mode in
Jitter 1.5.3. For Jitter 1.2.4, you may have to use non-realtime
mode, with a timing gate to ensure that only 1 frame every 40ms gets
to the jit.qt.record object.

jb

Am 23.06.2006 um 10:27 schrieb flo spier:

>
> Hi!
>
> i?m using jitter 1.2.4
>
> actually i get enough framerates 25. i can record dv pal at 29 fps.
> but I want to limit it to 25.
>
> if I deactivate the realtime option I get a 25 fps movie, but it?s
> not realtime.
>
> cheers
>
> flo

#79460

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