50 simultaneous clips sounds like a lot. i don't know if hap would help in this case but maybe. my recommendation to try first is to read all the clip frames into memory using either jit.matrixset or jit.movie @engine viddll loadram.

the clips should all be exported at the dimensions you expect them to be displayed at. i would implement this in javascript for the most ease and flexibility while experimenting.

Hi Rob. Thanks for your answer! I've no experience with javascript yet. ps: I'm working on a mac. Do I still use the viddll engine then?

if you're dealing with 50 videos to form a composition, they could probably be super super small? I would load the videos inside jit.movie objects in 50 instances of a [poly~ 50] and then you load your new "set" by loading a new poly~ with the message {patchername blablabla]

If I use poly~ , can all the files be different? (I have 50 unique movie clips)

sure, use thispoly~ to get the instance number and load different videos

I had this idea: instead of loading all 50 video per set / 150 video's total all at once, I can also use a movie file that has several clips edited behind each other. With the frame message I can play one clip in the movie, and change the frame count if I want to go to the next clip. I use one global qmetro object for timing.

Does this sound like a possible solution? I hope this method of playback is efficient. I think I'll use the VIDLL engine or HAP. note: all clips will have transparent (alphachannel) backgrounds. note2: the final patch will have about 50 movie players.

sure that could work too! you'll still need 50 jit.movie objects to play your 50 videos simultaneously, so that might only affect your loading time if you're dealing with a big and long video file, make sure you're using hap codec and playing from a ssd drive!

yeah, we have a SSD drive and HAP. I tested it with more video's before. That works good until it doesn't. (max crashed) but now I only have to load about 50 instead of 150 :) , so hopefully this will help. The video's play in a sequencer, so not all at once (but it can get fast and chaotic, when all buttons are pressed)

you could try the argument @unique 1 for your jit.movie objects and output in an openGl context (jit.world)