Forums > Jitter

Need major help with some Jitter functions for Installation!


o.trickett
April 26, 2011 | 6:49 pm

Hi list, am trying to do some functions with jitter and am having major problems. Here is the patch

– Pasted Max Patch, click to expand. –

I want the movies to have random lengths, however when a clip (all 10s) is stopped abruptly there is an audio ‘click’. Any other ways to do this?

Each screen represents separate tv screens. Also any advice for trying to speed up the frame rate, when all 9 operations are running fps goes from like 25fps (one on) to like 4fps (all on)

Many Thanks!


o.trickett
April 26, 2011 | 6:50 pm

Sorry for extremely long code!


MIB
April 26, 2011 | 8:03 pm

to get around the audio click I would try using line object to ramp down the vol and then back up again. so something like: line -> vol 0. -> load next movie -> line -> vol 1.

all your metros are set to 40, which means at the very best you will get 25fps. set it to 33 and you will get 30 fps at the best. As you add more movies to be processed, you will need faster metros for the CPU to keep up, so experiment with the speed. Also, I suggest you use qmetro instead of metro, see the helpfile on why. It might also be worth experimenting with one master qmetro rather than 9 separate ones…
also get rid of the button object just after your metro. that might be helpful for debugging but it eats unnecessary resources for drawing. just go directly from qmetro to jit.qt.movie.


o.trickett
April 27, 2011 | 12:50 pm

Thanks for the help, have neatened my patch up and changed frame rates. I’m still a little confused over the line object though. I want the length of the ramp to be dictated by the random object generating numbers between 200ms and 10s. How do i patch this up?

Many Thanks


MIB
April 27, 2011 | 5:02 pm

many different ways. here is one:

– Pasted Max Patch, click to expand. –

o.trickett
April 27, 2011 | 10:48 pm

Ok i see, thanks a lot for the help, however i’m trying to have the ramp only effect the last few seconds of the clip. For example for a random time of say 9.0s i want it to be normal volume until say 8.95s when it will ramp down to 0 (to avoid the audio ‘click’), then return to normal volume for the next .mov. I tried to do this with a ‘-’ arguement with the random time but can’t get the line working.

Many Thanks


MIB
April 27, 2011 | 11:41 pm

another approach would be using bline rather than line (may make more sense in the first place).
have a look at the patch below. I calculate how many frames there are in the movie, then start ramping the volume to 0 once a certain frame has been reached (here 50) and then back to 1 starting with frame 0. This will make it also easier to randomize the ramp length…

– Pasted Max Patch, click to expand. –

o.trickett
May 8, 2011 | 5:03 pm

Sorry for late reply, been very busy with finals, etc. Above patch works brilliantly, except it reads the length for the movie clip itself, which is randomly chosen in the patch. So it reads the 10s clip, but not it’s varients, saying that they are all the same length. I tried to use the random time selection in the argument to figure out the frame count, but have been unsuccessful.
Also do you reckon it may be better to let MSP do this processing? ie use Spigot to take the audio out of jitter?

Many Thanks


MIB
May 8, 2011 | 7:19 pm

I always thought spigot was flakey, but then I haven’t really tried to work it out either…
Anyway, I think everything you need is in the patch above. Calculate the number of frames in your movie, then randomly choose a starting and endpoint within that number, rather than using bang to go through your movie use counter (or something like it) to move through your random frames using the "frame" message… voila! that is if I understand what you are saying…

Viewing 9 posts - 1 through 9 (of 9 total)