Ciao fioj! (in venetian for "guys") I need your help!
The attached file is an alpha...deeply alpha...of my patch "v2MSy".
v2MSy is for video2MidiSynth: a patch that works in a similar way than MetaSynth (http://www.uisoftware.com/MetaSynth/index.php): converting pixels into MIDI signals. But while MetaSynth imports images only and outputs sounds, my patch works in real time with videos and webcam source outputting MIDI signals. This is how it works (please open my patch and click "help" red button, then enter [pd v2MSy], then [pd gemlist] then [pix_data000-127]...the problem is here!): gemwin's central y-axis (default is x=250) is divided into 128 points (default is [y[-[/ 500]-

• ), from 0 to 127 (that's the MIDI range); 128 [pix_data] objects analyze the 128 points of the gemwin's central y-axis and output 128 [noteout]s where all MIDI range is repeated 25 times par second but where every note is monitored outputting velocity changes 25 times par second. Velocity information is obtained analyzing the grey value of all 128 pixels in central y-axis. To do that, I use 128 [pix_data]s. We should obtain a chord repeted every 40ms made by all MIDI notes but that continuously changes in velocity. This is my idea to obtain a "score" from a video or from a webcam source...
  But when I try to output this result into a third part software (i.e. Ableton) by IAC driver, or MidiYoke or Jack...I only obtain a complete shit!
  Help me, please!
  Thanks

http://www.pdpatchrepo.info/hurleur/v2MSy_alpha03.pd.zip

Nobody wants help me?
'ndémo fioj! (c'mon guys!)
I try to upgrade the unsolved subpatch (the attached file), but it remains...unsolved!
Please help me to go on.

http://www.pdpatchrepo.info/hurleur/v2MSy_alpha04.pd.zip

I didn't actually run your patch as I don't have a virtual MIDI bus on the computer I'm using right now, and I don't know what you mean by "complete shit" (it's a good idea to say exactly what the problem is in a complicated patch like this, you'll get a quicker response), but looking at your [pd pix-data] abstractions, I noticed this at the bottom.

[t b f]
\
[pack 0 0]
|
[noteout]

So it looks like nothing's actually being sent to the [noteout] because [pack]'s hot outlet isn't receiving anything.

Edit: okay, that was the first patch you uploaded. That doesn't seem to be the case in the second one.

After looking at the helpfile for [pix_data], it says the range for x and y are 0-1. 250 for x and 2-127 for y are well out of that range. So perhaps scaling those values to within 0-1 will solve it?

No...in the patch I posted (I downloaded my attached file), every [pd pix-data] ends with:

[t b f]
| \
[pack 0 0]
|
[noteout]

perhaps one has this error (please say to me what [pd pix_data] has this error)

while...the range for x and y...(...)...AAAAAAAARGH...you are right! The range I used was wrong! I used 0-500 while the right range is 0-1!

Thanks Maelstrom!
I'll try again

P.S. you are right sayng that I would have had to describe better the resulting problem, but honestly I basically didn't understand what happened to ableton receiving the MIDI signals...It crashed but in a way that I can't explain (it simply seemed that 128 MIDI signals every 40ms were too many).

Oh, maybe I wasn't clear enough. The first patch you posted has that [noteout] problem in every [pd pix-data]. The second one does not.

As for the MIDI signals, according to the MIDI spec, MIDI can only transmit at something around 31250 bits per second, which comes out to about 1 message per millisecond. However, I'm not entirely clear if that means over the standard 5-pin DIN cable or in all cases. If it's in all cases, or if Live or Pd just chooses to conform to the 31250 bps standard, that could be the problem.

Finished! After your advice, Maelstrom, my patch seemed to work fine, but Ableton crashed receiving the MIDI flux (by IAC driver)...but...was an Ableton's problem! Infact, Logic Pro 8 receives the flux of 128 MIDI signals per 40ms and all works fine: Logic receives and writes the MIDI flux! Another question could be "why damn Ableton crashes my sweet little MIDI flux", but it will be another topic...