Video on Max slowed/sliced-like vs original file

Mar 1, 2013 at 11:38am

Video on Max slowed/sliced-like vs original file

Hello,

I would like to open a video file on a Max patch, and dynamically change its speed.

At first when I open my video (a turning piece), I see my piece not turning smoothly like in original files.
I tryed mp4, flv and avi format file for video, it’s always the same.

–> should I have the framerate, or other parameters of the original file, and explicitly pass them as messages to jit.pwindow object ?

Thanks a lot !

I put a copy of the simple patch here :

– Pasted Max Patch, click to expand. –
#66793
Mar 1, 2013 at 11:59am

not sure if I know what you mean by ‘turning smoothly’ …

codecs of choice for realtime are:
.Pro Res 422(LT)
.PhotoJPEG

the ones you name are not apt for realtime …
there are some post in the forum talking about this …

#240446
Mar 1, 2013 at 12:09pm

thanks for your reply !

By turning not smoothly, I mean I have the feeling some frames are missing… instead of seeing a continuous and slow rotation like in my original file, I see a quick rotation with some “steps” or “missing frames” effct

I will try the codecs you propose and check for the post in the forum and update this post

bye

#240447
Mar 1, 2013 at 1:02pm

does your (q)metro tempo match your movies’ framerate?

#240448
Mar 1, 2013 at 1:07pm

hello,

no, I did not make any sync. Just open the viedo file, play it and compare with the source using QuickTIme Player in parallel with Max.
Video flux is not constant, I can clearly see it on Max.

Could you explain me how I should do such a synchro ? (acutally I do not have a (q)metro on my pathc)

#240449
Mar 1, 2013 at 2:23pm

Ah ok, I never use that method. Try if you get the same issues with the plain jit.qt.movie object.

Btw, what’s the resolution, bit rate, frame rate and codec of your movies? Chances are you’re just overloading your CPU. What’s the CPU load when playing them?

#240450
Mar 1, 2013 at 2:40pm

@ctrlzjones :

I just tried converting the .mp4 into Photo-Jpg, .mov.
Looks like the result is better !
but for the beginning of the playing, maybe to some file size issue (file size : 340 Mo).

@dtr :
Resolution : 1920 x 1080
FPS : 25
22.69 Mbps
Codec : Photo – Jpeg (I get a .mov). The original file format is .flv. I convert .flv to .mov using MPEG StreamClip on Mac.
CPU and RAM looks okay (50 %) when playing Photo-Jpeg format.

For the plain jit.qt.movie object, yes I tried with it (currently this is the object I use).

Sorry I need to leave for a while, but I will be back tomorrow on the subject ; thanks again for your replies, that’s nice !

Have fun bye

#240451
Mar 1, 2013 at 6:06pm

> CPU and RAM looks okay (50 %) when playing Photo-Jpeg format.

Depends. Not sure if the playback process supports multi-thread/core processing. 50% on a dual-core CPU means 1 core is fully loaded, though you’d see the load being balanced over the 2 cores to lower CPU temperature. If the process is single-core only it couldn’t go over 50% to use both cores.

#240452
Oct 23, 2013 at 12:32pm

Hello,

Sorry for the late answer..;
Thank you DTR ! Yes you’re right.
We changed a bit the “specs” of the project, so I will come back on this subject later. I will let you know…

Thanks bye

#268932

You must be logged in to reply to this topic.