From c50ce0e0217ea07e2d450add2ab29cecea66fa96 Mon Sep 17 00:00:00 2001 From: Hans-Christoph Steiner Date: Mon, 28 Nov 2005 01:07:25 +0000 Subject: This commit was generated by cvs2svn to compensate for changes in r4059, which included commits to RCS files with non-trunk default branches. svn path=/trunk/externals/pdp/; revision=4060 --- doc/misc/overview.html | 102 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 doc/misc/overview.html (limited to 'doc/misc/overview.html') diff --git a/doc/misc/overview.html b/doc/misc/overview.html new file mode 100644 index 0000000..6eb0e70 --- /dev/null +++ b/doc/misc/overview.html @@ -0,0 +1,102 @@ + +Pure Data Packet + + +

Pure Data Packet

+ + +

Introduction

+ +

Pure Data Packet (PDP) is an extension library for the computer music +program Pure Data (PD), by Miller Puckette and +others. Its goal is to provide a way to use arbitrary data types (data +packets) as messages that can be passed around inside PD, along side the +standard PD numbers and symbol types. In short it puts any data object on +the same level as a float or a symbol. + +

PDP runs on Linux and OSX. The OSX version depends on Fink, which is not in the "point & +click" stage yet, so setting it up will require some efford. There is no +windows version. The reason for this is simple: i don't use windows myself. +Porting would require writing code for input/output and getting the +libraries PDP depends on to work. If anyone is willing to do this, just let +me know. PDP can run without X Window, using SDL. + +

Currently, PDP's focus is on images and video, but there is no reason it +should stay like that. There is limited support for matrix processing +included in the main library (like Jitter or Gridflow). There is an +extension library for 1D and 2D binary cellular automata, opengl rendering +(like Gem). Some plans include audio buffers (like Vasp), ascii packets, +text buffers, ... Finally there's a library that enables you to connect a +scheme interpreter (guile) to PD/PDP. For more image processing objects, +have a look at Yves Degoyon's PiDiP library. + +

Getting Started

+ +If you're used to working with PD, the the documentation and example +patches should be enough to get you started. Have a look at the README file +in the distribution to find out how to compile and setup. The file +doc/reference.txt contains a list of objects. If you have installed PDP +properly, you can just press the right mouse button on an object and select +help to get a help patch. If this doesn't work, look in the directory +doc/objects for a collection of help patches. The directory doc/examples +contains some more demos. The directory doc/objects contains two +abstractions that are used to setup the input and output in the help +patches. You might want to cut and connect some wires to use the +input/output setup that works for you. + +

Packets and Types

+ +

PDP is centered around the concept of packets and operations on +packets. There are several types of packets. The default type for most +objects is image/YCrCb/320x240. This is a single video +frame, encoded in the internal 16bit YUV format, measuring 320 by 240 +pixels. Another image type is the grayscale image +image/grey/320x240. Important notes: All image processing objects that +combine two or more packets need to be fed with the same packet types, i.e. +encoding (YCrCb/grey) and dimensions need to be the same. Image dimensions need to be a +multiple of 8x8. + +

The +bitmap/*/* type is another image representation type +supporting several encodings. I.e. bitmap/rgb/*, +bitmap/rgba/*, bitmap/yv12/*, ... + +This type cannot be processed directly by most of the image processing +objects, but it can be used to store in delay lines, or to send over the +network. It's main use is to support all kinds of input/output devices, and +opengl textures, without introducing too many conversions, but it can serve +as a space and bandwidth saver too (especially +bitmap/yv12/*). + +

One of the interesting +features in PD is the possibility of connecting everything with everything. +If you want to generalize this to all kinds of media objects, the complexity +of managing the different types starts to grow quite fast. Therefore PDP has +a type conversion system that can take care of most of the conversions +using the [pdp_convert] object. You can manually convert +packets to a certain type by specifying a type template as a creation +argument. I.e. [pdp_convert image/grey/*] will convert +any packet to a greyscale image. Most of the conversion will become +automatic later on. + +

An example: You can use the basic PDP library together with the +cellular automata library and the opengl rendering library to use a cellular +automaton as an input to a video processing chain. You can convert the +processed image to a texture that can be applied to a 3d object, which then +can be drawn to the screen, captured as a texture, converted back to an +image, which can then be converted to a sound, processed and converted back +to an image, etc... You get the point. The possibilities are endless. + + + +

Tom Schouten

+ + +Last modified: Thu Sep 25 20:51:44 CEST 2003 + + + -- cgit v1.2.1