Forums > Jitter

Adding multiple matrices

Jul 22 2008 | 7:25 am

Hi –

I need to compile 8 smaller (40 x 30) video matrices in one 320 x 240 matrix. at the moment im doing this by [jit.op @op max] video_1 and video_2, then Video_12 and Video_3 then Video_123 and Video_4 etc.

i need to achieve this result much faster. is there a better more efficient way?



Jul 22 2008 | 8:58 am

Hmm i don’t understand your solution, won’t @op max just select the brightest source pixel out of the 2 video’s? Or do you input all matrixes of 320×240 size with only a small part actually used? That doesn’t sound too efficient…

[jit.glue] was designed to do this, but I don’t know how fast it is, something in the back of my mind tells me it’s not lightning-fast…try it anyway. GL.

Jul 22 2008 | 4:34 pm

Hi –

thanks for the reply. jit.glue does the job really nicely.

however now i have a strange problem: Im moving video around the larger screen according to an organized pattern. when i trigger each sequence with a bang (manually) it behaves really nicely, stepping through the sequence perfectly. However when i initiate the sequence using metro or tempo, elements often lag behind. when i tap ‘bang’ far faster than the tempo or metro are running i have no problems, but when either is connected, there is lag.

any idea what this could be?


Jul 22 2008 | 4:55 pm

it sounds like you the cpu can’t keep up.
this kind of thing is usually best achieved with opengl, for performance reasons. several different ways to approach this, the easiest probably being using a videoplane for each movie.

look at the transform_reset attribute, and then use scale and position attributes to place your screens.

also, what codec, size, settings, etc.

other than that, you’ll probably have to post a simple patch that demonstrates your problem

Jul 23 2008 | 11:49 am

hi rob –

thanks for your assistance. although it could be the cpu, im still curious why when i manually bang it through the sequence (faster than the metro or tempo speeds) it works fine, but when automated by using metro or temp, it lags.

Ive attached the patch if you have a chance to have a look.

Just load the 8 movies in and then next to the movie window you’ll see the large ‘bang’ with the metro and tempo connected.

thanks again.


Jul 23 2008 | 11:53 am

…forgot to tell you to put a pattern into the matrix control object.

Jul 23 2008 | 5:07 pm

why are all your qt.movies at 320 x 240 when they only need to be 1/8 that size? you can also try @unique 1 on your qt.movies.

other than that your patch worked as expected for me. didn’t see any "lag".

Viewing 7 posts - 1 through 7 (of 7 total)

Forums > Jitter