What is Puredata?
Pure Data is a computer music system installed on the computer music workstation. It's a graphical patcher language that is the third generation of patcher languages for digital synthesis and control. It's predecessors are Max/MSP and Max (without the MSP part).
How does it work?
That's a big subject. I'll leave that to the project docs.
I want it on my computer!
If you are new to puredata, you should install the Moscow Conservatory fork, which has nicer GUI objects for metering and control.
If your computer is a Raspberry Pi, you're in luck. Install a2jmidid to bridge the ALSA midi port to JACK, for easy patching fun!
You can have it on your computer! It's open source software that runs on Macs, PCs and Linuxes!
Is it good for live performance?
Yes. It's also good for building synthesizers. The version at Noisebridge is running on Windows, which kind of sucks because it didn't appear to have ASIO drivers. Then I found some more information and now it does have ASIO drivers. The audio settings are very important for good responsive live performance. I could only go down to 12 milliseconds of latency with a 64k buffer size at 44100 Hz. Do not check that "use callbacks" box. It literally breaks everything.
PD also does MIDI. Use the 828mkii driver for that. It's in the menu.
Audio Input and Output mapping
PD gives you individual inputs and outputs as patch points in the [dac~] and [adc~] objects. The 828 has a whopping 14 individually addressable inputs and outputs! Here's a tested table of how you refer to them by index number for the object (like [dac~ 1 2] produces an output object for 1 and 2) and what that means for the physical patch points labeled on the 828.
|Mic Preamp 1||Main Out L||1|
|Mic Preamp 2||Main Out R||2|
|Analog 1||Analog 1||3|
|Analog 2||Analog 2||4|
|Analog 3||Analog 3||5|
|Analog 4||Analog 4||6|
|Analog 5||Analog 5||7|
|Analog 6||Analog 6||8|
|Analog 7||Analog 7||9|
|Analog 8||Analog 8||10|
|S/PDIF L||S/PDIF L||11|
|S/PDIF R||S/PDIF R||12|
|Analog Return R||Headphone R||13|
|Analog Return L||Headphone L||14|