Hi
I'm working on a project PD/Arduino.
I need to have multiple videos playing at the same time in the same gem window!
I've tried to put 4 videos at the same time from .mov files.
3 of them work properly... the 4th doesn't.
I'm mixing them with 3 [pix_mix]...
I actually need at least 10 layers at a time! Do you think this s possible!? and how!!!

Thanks!

10 videos mixed simultaneously would take a lot of processing power. No machine that I have access to would be able to handle it.

My guess is that your problem with [pix_mix] has to do with how it handles multiple texture units in OpenGL.

Theoretically, this could be done with OpenGL shaders (OpenGL has a maximum of 32 texture units, so you could assign each video to its own and then mix them) though it depends on what your graphics card supports. I know some cards won't support more than 8 texture units.

Each [pix_texture] object would need to be assigned a specific texture unit number using a [texunit 1( message, replacing 1 with whatever texture unit you are assigning.

Your fragment shader would probably look something like:

uniform sampler2DRect MyTex1;
uniform sampler2DRect MyTex2;
uniform sampler2DRect MyTex3;
uniform sampler2DRect MyTex4;
uniform sampler2DRect MyTex5;
uniform sampler2DRect MyTex6;
uniform sampler2DRect MyTex7;
uniform sampler2DRect MyTex8;
uniform sampler2DRect MyTex9;
uniform sampler2DRect MyTex10;

varying vec2 texcoord1;

void main (void)
{
vec4 color1 = texture2DRect(MyTex1, texcoord1);
vec4 color2 = texture2DRect(MyTex2, texcoord1);
vec4 color3 = texture2DRect(MyTex3, texcoord1);
vec4 color4 = texture2DRect(MyTex4, texcoord1);
vec4 color5 = texture2DRect(MyTex5, texcoord1);
vec4 color6 = texture2DRect(MyTex6, texcoord1);
vec4 color7 = texture2DRect(MyTex7, texcoord1);
vec4 color8 = texture2DRect(MyTex8, texcoord1);
vec4 color9 = texture2DRect(MyTex9, texcoord1);
vec4 color10 = texture2DRect(MyTex10, texcoord1);

gl_FragColor = (color1 + color2 + color3 + color4 + color5 + color6 + color7 + color8 + color9 + color10) / 10.;
}

--

I haven't tested this with more than 2 videos before, but I will give it a shot and post my results.

Attached is what I got so far.
I got the IDing idea of the texture units... however, this... I don't have a clue of what you're talking about!

"Your fragment shader would probably look something like:

uniform sampler2DRect MyTex1;
uniform sampler2DRect MyTex2;
uniform sampler2DRect MyTex3;
uniform sampler2DRect MyTex4;
uniform sampler2DRect MyTex5;
uniform sampler2DRect MyTex6;
uniform sampler2DRect MyTex7;
uniform sampler2DRect MyTex8;
uniform sampler2DRect MyTex9;
uniform sampler2DRect MyTex10;

varying vec2 texcoord1;

void main (void)
{
vec4 color1 = texture2DRect(MyTex1, texcoord1);
vec4 color2 = texture2DRect(MyTex2, texcoord1);
vec4 color3 = texture2DRect(MyTex3, texcoord1);
vec4 color4 = texture2DRect(MyTex4, texcoord1);
vec4 color5 = texture2DRect(MyTex5, texcoord1);
vec4 color6 = texture2DRect(MyTex6, texcoord1);
vec4 color7 = texture2DRect(MyTex7, texcoord1);
vec4 color8 = texture2DRect(MyTex8, texcoord1);
vec4 color9 = texture2DRect(MyTex9, texcoord1);
vec4 color10 = texture2DRect(MyTex10, texcoord1);

gl_FragColor = (color1 + color2 + color3 + color4 + color5 + color6 + color7 + color8 + color9 + color10) / 10.;
}"

I have a NVIDIA GeForce 9400M... think it works??

http://www.pdpatchrepo.info/hurleur/pd02.pd

According to this chart, the GeForce 9400M only supports a maximum of 8 Texture Units:
http://developer.apple.com/graphicsimaging/opengl/capabilities/

I haven't examined the [pix_mix] source code, but this could be your problem.

Well... but if I can have at least 2 videos per texture unit than I can have up to 16... right? Or am I just saying a stupid thing!?

To be honest I barely know what I'm talking about when it comes to OpenGL, so I may be completely wrong.

I downloaded the GEM source, so I'll take a look and try to figure what [pix_mix] is actually doing. I'm at work right now so it may be a while before I have some more downtime.

Thank you very much!

Alright, I'm not sure what's going on.. I just tested the same sort of setup as you have (chaining a bunch of [pix_mix] objects together) and was able to mix 11 different image files at the same time. The chart I referred to above says 8 max texture units for this graphics card, same as yours.

Can you test your patch with images before shifting to video?

Ok!
With still images (jpg) it doesn't make a big fuss with the 8 I've got! honestly I didn't try with more!...
Without images the sound works perfectly, no breaks, no matter how many layers!
So the problem is really the video.
It's rendering lots of video at a time! Got that! Agree...

next step: solve this!
Should I try different resolutions or compressions or anything that might occur to you to ease the render process?

I'd use mp4 files encoded with the xvid codec.

Smaller resolutions and lower bitrates will keep processing to a minimum.

--

That said, I just tried it with videos instead of images and I'm having the same experience with only 3 videos working. It's not a problem of processing power as my CPU is only running at 35%.

Have you tried the Pd-list? Iohannes or someone else better acquainted with GEM's inner workings may be able to help you out.

PD-List? What is that!?

got it... "that" is a used... lol how do I get to him!?

Pd-List is fantastic. Pretty much all the major developers are on it, so you can get answers straight from the source:

http://lists.puredata.info/listinfo/pd-list

You can also search the mailing list archives. Lots and lots of information from past discussions can be found there:

http://lists.puredata.info/pipermail/pd-list/

I'd start with the archive and if you can't find anything relevant to your problem shoot an e-mail to the list.

a way to play many different videos is to load them all in a shared pix_buffer object and play them with pix_buffer_read. hope it helps