comparison README @ 37:27bab3a16c9a vampy2final

new branch Vampy2final

+
+ * VamPy is an API wrapper for Vamp. It allows for writing Vamp 
+	plugins in Python with or without Numpy support.
+
+WHAT IS IT FOR?
+	
+	This wrapper is for writing Vamp plugins in Python which 
+	can do the same as a native C++ plugin, plus a lot more if 
+	you're using advanced Python modules.
+
+	This may be an easier way to get into Vamp development.
+	You can use it for prototyping your plugin before writing 
+	it in C++.
+
+
+WHY PYTHON?
+
+	Python is a general purpose high level scripting language.
+	It is interpreted, so you don't need to compile your plugins.
+	It has very high level libraries. e.g. you can stream audio from your VamPy plugin (it works for me...)
+	Supports functional programming. 
+
+UPDATE IN THIS VERSION:
+
+	* Two-way Numpy Support
+	* Embedded extension module exposing Vamp defined names 
+		e.g. ParameterDescriptor. This allows easier porting to C++.
+	* Support RealTime time stamps
+	* Support byte compiled Python scripts (.pyc)
+	* Environment variables: VAMPY_COMPILED, VAMPY_EXTPATH
+	* Flags to control type conversion and error reporting for development
+	* Flexible type inference to take advantage of Python's loose typing
+	* Full error checking for all Python/C API calls
+	* Various optimisations and speed-ups
+
+PREVIOUS VAMPY README:
+
+HOW DOES IT WORK:
+
+	(1) Make sure you have Python installed.
+	(2) Compile the C++ source or ask me for a binary (MacOS).
+	(3) Copy the library in your Vamp plugin directory like any other Vamp plugins: 
+		eg. /Library/Audio/Plug-Ins/Vamp
+	(4) Write some python plugins and copy them to the same place.
+	(5) Each plugin must contain a single class with the same name as your script file.
+		e.g. PyZeroCrossing.py -> calss PyZeroCrossing
+		-Scripts with syntax errors in them are ignored.
+		-Scripts not having the same class as the filename are ignored. (Python is case sensitive!)
+		-Other unknown scripts are likely to cause a crash.  (Don't put other python scripts in your Vamp directory.)
+
+	
+COMPILING AND LINKING:
+
+	(1) make sure Python.h is included wherever it is on your machine 
+	(2) the plugin needs to be linked against the Python binary: e.g.: ld -lpython2.5
+
+	example on on MacOSX:
+	g++ -I../vamp-plugin-sdk -O2 -Wall -I/usr/include/python2.5   -c -o PyPlugin.o PyPlugin.cpp
+	g++ -I../vamp-plugin-sdk -O2 -Wall -I/usr/include/python2.5   -c -o PyPlugScanner.o PyPlugScanner.cpp
+	g++ -I../vamp-plugin-sdk -O2 -Wall -I/usr/include/python2.5   -c -o pyvamp-main.o pyvamp-main.cpp
+	g++ -I../vamp-plugin-sdk -O2 -Wall -I/usr/include/python2.5   -c -o Mutex.o Mutex.cpp
+	g++ -shared PyPlugin.o PyPlugScanner.o pyvamp-main.o Mutex.o -o vampy.dylib -L../vamp-plugin-sdk/vamp-sdk -lvamp-sdk -dynamiclib -lpython2.5 -lpthread
+
+	
+	(3) There is a Makefile that compiles this plugin by default.
+
+
+LIMITATIONS:
+
+	This is mainly a proof of concept. The implementation is not the most efficient, but using NumPy it's very reasonable.	
+	Only tested on MacOSX and Linux (by Chris), but in theory should work on other platforms with small fixes.	
+
+	Error checking is not yet fully complete.
+	You better not make a mistake in your Python script, although in most cases you can see what the problem is 
+	if you start the host (e.g. Sonic Visualiser) from a command line interface.
+	The wrapper plugin is quite verbose and outputs error messages.
+
+
+TODO:	* needs more complete error checking (almost done)
+	* needs correct implementation of Python threading (done)
+	* more efficient data conversion using the buffering interface or ctypes (done)
+	* Vamp 'programs' not implemented
+	* support multiple classes per script in scanner
+	* ensure proper cleanup, (host does a good job though)
+
+HISTORY:
+	added support for NumPy arrays in processN()
+	framecount is now passed also to legacy process() and fixed resulting bugs in the PyZeroCrossing plugin
+	added two examples which use Frequency Domain input in processN()
+