Forums > Jitter

Keeping sync of Groove~ and jit.qt.movie when selecting new start points??


Joshua Batty
January 16, 2010 | 4:40 am

Hi, im having trouble with a patch of mine where i am syncing the playback of a jit.qt.movie to the sync output of groove~. This is working fine but what i cant seem to be able to do is jump around different start points in the buffer~ using waveform~ and keep the video synced.

As soon as you select at new start point in waveform the start and end point ratio is changed and that makes the sync coming out of groove~ ramp faster, therefore throwing the movie out of sync.

Does anyone know a way around this? been stuck on this for a while now.
i’ve included a patch below.

Thanks.

– Pasted Max Patch, click to expand. –

Joshua Batty
January 19, 2010 | 10:07 am

I’ve been going through the forums for the last few days and found this topic>


http://cycling74.com/forums/topic.php?id=13605">

Little Bear’s last post seemed to describe a way in which he managed to select different loop points for groove~ and the video looped relative to the sample position instead of speeding up.

Can someone please shine a little more light on how to do this. It seems as though loading the audio of a movie into msp is the way to go but by doing this i cant jump around to different parts of the movie and have it synced. couldn’t find any examples of people doing this which i find strange.

any help would be greatly appreciated.

Thanks,

Josh


Tim Lloyd
January 19, 2010 | 12:08 pm

Is this what you mean?

– Pasted Max Patch, click to expand. –

You need to scale the sync output of groove~ to the length of the loop. So if you select a new loopstart and loopend, you need to find the new loop length, and then add the loopstart value, resulting in a ramp that goes from the new loopstart to loopend in sync with groove~.


Tim Lloyd
January 19, 2010 | 12:12 pm

sorry, forgot to loadbang in crashtest.mov


Rob Ramirez
January 19, 2010 | 8:40 pm

the time attribute to quicktime movie is in quicktime units, not seconds, therefore the previous post will not work. also please note that 600 will not always be the proper timescale value.

search the forum for something like "sync groove~ jit.qt.movie" and you should find examples of how to do this.

as far as looppoints, you will have to either scale the sync out of your groove~ based on your loopstart/end, or manually control looping using >~, < ~, edge~, etc.


Tim Lloyd
January 19, 2010 | 9:03 pm

I see what you’re saying, after having read the reference, but it seemed to be working fine on my laptop when I made the patch. I’ll have a mess around with it.


Rob Ramirez
January 19, 2010 | 9:04 pm

anywho, i realize the forum search feature is not exactly up to par yet, so here is the patch i give my class to explain the qt timeunit stuff.

to sync with groove~, you basically just need to multiply the sync number (from 0 to 1) with the total number of frames, and use that with the frame message to qt.movie.

i usually keep my movie stopped when i’m controlling via the fame message and an audio signal.

– Pasted Max Patch, click to expand. –

Joshua Batty
January 21, 2010 | 9:26 am

sweet thanks for patches guys. What i ended up doing was using tim’s patch but adding a / object into prepend frame. its working as i expected now. thanks very much for all the replies, would never have figured this out on my own.

thanks

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