Playing many movies at once

Core Library Questions

drlandy

in Core Library Questions • 7 months ago

I would like to play many videos at once (10+). I'm currently creating a list of Movie objects and looping them, then mapping as textures to quads -- but this brings my sketch application to a crawl. Is there a better library to use than the default Movie? Is there an optimization I could do to improve performance?

(I've seen this question asked before e.g. here https://forum.processing.org/topic/play-multiple-videos, but I just wanted to check-in to see if there is new information)

Replies(4)

akiersky

Re: Playing many movies at once

7 months ago

Hi drlandy,

This should, conceptually, work. it depends on a lot of factors:

size and compression of your videos
quality and speed of your graphics card, cpu and ram
version of processing
usage of threads
quality of code

If you are using one of the processing betas, the built in movie class has enveloped much of GSVideo, the previous defacto standard (imo) for playing video in processing, and should be sufficient to play multiple videos.

Ideally each of the videos would be sized to the correct scale they are being used in your sketch and compressed in h264 at the lowest bitrate possible to get a reasonable quality (this will vary a bit depending on the size of each of the videos and the amount of motion and colors. I've found that for full hd, I can get away with around 1000kbps)

Graphics card cpu and ram; a good test would be to pull up all 10 videos in your default player (quicktime?) and see if your computer can even handle playing them all at the same time. If it can't, it's likely that processing won't do much better.

Now usage of threads and quality of code kind of go hand in hand in this case. Ideally you could set up each video to play independently in it's own class that would extend thread. This way each video can load frames and the reading and drawing part is done on a thread separate from all the other videos. I posted my example, that I found to be most efficient at handling video loading and viewing here although it does not use threading. Ill leave that part to you :)

Hopefully this gets you started, post some code and details about your specs and that could help narrow down what your problem may be.

good luck!

drlandy

Re: Playing many movies at once

7 months ago

I'm able to play the same 10 videos at once using C/OpenGL/ffmpeg so I don't think my computer hardware is the issue.

Threading sounds interesting, but I'm not very familar with Thread in processing. Can I draw to the screen from a thread?

I'm running processing 2.0b8, my code which I guess is naive is below:

import processing.video.*;

import java.util.*;

ArrayList<Movie> movieList = new ArrayList<Movie>();

String mfiles[] = {

"/Users/drlandy/Movies/file1.mpg",

"/Users/drlandy/Movies/file2.ts",

"/Users/drlandy/Movies/file3.ts",

"/Users/drlandy/Movies/file4.ts",

"/Users/drlandy/Movies/file5.ts"

};

void setup() {

size(displayWidth, displayHeight, OPENGL);

for (String movFile : mfiles) {

Movie movie = new Movie(this, movFile);

movie.loop();

movieList.add(movie);

}

textureMode(NORMAL);

}

boolean sketchFullScreen() {

return true;

}

void draw() {

background(0);

for (int i =0; i<5; i++) {

pushMatrix();

float yPos = 150 + 240*(i/10);

float xPos = 150 + 240*(i%10);

translate(xPos, yPos,0);

scale(120, 120);

beginShape(QUADS);

texture(movieList.get(i));

vertex(-1,-1, 1,0,0); vertex( 1,-1, 1,1,0); vertex( 1, 1, 1,1,1); vertex(-1, 1, 1,0,1);

endShape();

popMatrix();

}

void movieEvent(Movie m) {

m.read();

}

akiersky

Re: Playing many movies at once

7 months ago

hi drlandy,

That looks like a good start, how many videos can you successfully play with what you have?

I would start by taking a look at the link that I put in my last post and using an external class to hold each of your movies. You'll want to modify that class to extend thread, here's some great info about using threads. Then you can do all the movie frame grabbing and drawing to your vertex-drawn frame to a PGraphics. Your draw loop on your main sketch will be simply responsible for grabbing and positioning each PGraphic on the stage.

im away from my computer right now or I'd post some code. I hope that makes sense.

good luck!

drlandy

Re: Playing many movies at once

7 months ago

Thanks ak, I appreciate your help!

Right now I'm actually playing 4 videos textured to 10 quads, and it can be a bit laggy at time. Beyond five videos seems to degrade more for me with the above code.

One question I have is regarding creating the Movie objects. Should these be created & local to the Threads? Do I need (/can/should I?) create separate PApplet to pass to as the first parameter to the Movie constructor? (My concern is that otherwise will the Movie read method calls in movieEvent callback would serialize if I just have all threads callback to the main applet?)

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