Forums > Jitter

error, jit.net.send: dropped a matrix

June 17, 2008 | 9:54 pm

Hi.
I am new to Max/jitter.

I am connecting 2 web cams over the network by using jit.net.send

Both computers can see each other but then i get an error.

error; jit.net.send: dropped a matrix
data is being input faster then it can sent.

Can someone help me how to fix this issues?

attaching a file

really appreciate some help here.

thanks

cujo


June 18, 2008 | 3:49 am

I get these all the time. It’s just a warning that the network isn’t quite keeping up with all the matrices/frames. If the result looks OK (not overly choppy) it’s nothing to worry about, plenty of frames can get dropped and the functionality still be totally fine—this happens all the time with online videos or in video chat programs.

Be sure you’re not using higher resolution than you need or are viewing on the screen (i.e. don’t send 640X480 into a 320X240 window). Also be sure you aren’t banging the matrices faster than you need (like trying to get 50 fps when our eyes don’t notice much change over 25-30, it’s a waste).

hth, CJ


June 18, 2008 | 4:23 am

Thanks a lot for your reply, really helpful.
The way i see the response, I got a message that i am viewing other computer, i can also see the other ip, but then one computer video freezes and other was really choppy.

Is this perhaps one computer i can using has standard webcam and on other i am using 3CCD digital camera?

and as you are suggesting i am having resolutions issues?

How i can control the video resolutions specially as you saying (i.e. don’t send 640X480 into a 320X240 window)?

Also pl tell me how to adjust matrices banging? IS this metro 2 or metro 100?

sorry for asking you basic questions.

cujo


June 18, 2008 | 4:35 am

Not sure about the camera. I’ve only used webcams and they work well. You set the resolution in the jit.qt.grab or jit.dx.grab (whichever you are using). I never set video metros less than 40 ms, which is 25 fps. Lots of the help files have metro 2, which seem to overload the processing sometimes and isn’t needed (that would technically be 500 fps). So try metro 40 on each, with 320X240, and see if maybe that helps the choppiness?

For the viewable windows, they should also be 320X240 or smaller, proportional is best. Larger sizes are OK but will slow things a bit and will start to look "jagged" (since the underlying resolution is the same). If the webcam has a 320X240 setting, and that’s a good size for you, probably want to set this too (that cuts incoming data by 75%, all before getting to Max itself).

–CJ


June 18, 2008 | 4:51 am

Thank a lot. I will work on it the way you suggested

i will make metro 40 on both computer and jit.qt.grab 320 240

let you know

Thanks again,


June 20, 2008 | 4:35 pm

Also, something that never seems to be mentioned and if useful for cpu
efficiency all over the place is throw away the alpha plane if you don’t
need it and then if you do add it back in at that point.


June 25, 2008 | 12:41 am

Hi.
sorry for the delay.
i did some more testing. Again both computer can see each other ip but one computer video freezes and others get huge delay.

This time i used metro 40

Any other thing i should test check?…

thanks

faisal


June 25, 2008 | 12:42 am

How i can do that?
Can you explain me more..
really appreciate it


July 8, 2008 | 2:15 pm

hi,

I’m a new user of Max/Msp too, and I just want to know how you suceed to use jit.net.recv and jit.net.send. Me, when I try to send a matrix (from video or webcam) or something else (message, number), the second computer don’t do anything.
The two computers are connected to a local server which is connected to the internet.
The two firewalls are off.

Any ideas?

Thanks in advance

jason


July 8, 2008 | 4:17 pm

now it works, just a problem of connection.
Sorry ^^

jason


July 24, 2008 | 3:00 pm

Hey.
sorry for been so late,
i have been doing testing and all..
it seems like everything is working.
so i am connecting 6 different location (web stream) through net/send/rece and then shuffling the locations them based on the time code.
Its working great, i am facing lag but right now for my installation project i can live with it.
Any further tips to reduce the lag will be great.

I am doing one real-time installation in south asian countries where inter speed is still some issues. My question is what is the lower band-witch i can use by using net/send

Is 256KPs which gives average speed of 126kbps will work?

or 512?

really appreciate if someone has experience will different band-witch and share some thoughts?

thx

fa


July 24, 2008 | 3:01 pm

Hey.
sorry for been so late,
i have been doing testing and all..
it seems like everything is working.
so i am connecting 6 different location (web stream) through net/send/rece and then shuffling the locations them based on the time code.
Its working great, i am facing lag but right now for my installation project i can live with it.
Any further tips to reduce the lag will be great.

I am doing one real-time installation in south asian countries where inter speed is still some issues. My question is what is the lower band-witch i can use by using net/send

Is 256KPs which gives average speed of 126kbps will work?

or 512?

really appreciate if someone has experience will different band-witch and share some thoughts?

thx

fa


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