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diff --git a/pd/portaudio_v18/docs/pa_tut_rw.html b/pd/portaudio_v18/docs/pa_tut_rw.html new file mode 100644 index 00000000..93c7b8bb --- /dev/null +++ b/pd/portaudio_v18/docs/pa_tut_rw.html @@ -0,0 +1,79 @@ +<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> +<html> +<head> + <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> + <meta name="GENERATOR" content="Mozilla/4.77 [en]C-gatewaynet (Win98; U) [Netscape]"> + <meta name="Author" content="Phil Burk"> + <meta name="Description" content="Tutorial for PortAudio, a cross platform, open-source, audio I/O library.It provides a very simple API for recording and/or playing sound using a simple callback function."> + <meta name="KeyWords" content="audio, tutorial, library, portable, open-source, DirectSound,sound, music, JSyn, synthesis,"> + <title>PortAudio Tutorial</title> +</head> +<body> + +<center><table COLS=1 WIDTH="100%" BGCOLOR="#FADA7A" > +<tr> +<td> +<center> +<h1> +PortAudio Tutorial</h1></center> +</td> +</tr> +</table></center> + +<h2> +Blocking Read/Write Functions</h2> + +<blockquote>[Note: These functions are not part of the official PortAudio +API. They are simply built on top of PortAudio as an extra utility. Also +note that they are under evaluation and their definition may change.] +<p>There are two fundamentally different ways to design an audio API. One +is to use callback functions the way we have already shown. The callback +function operates under an interrupt or background thread This leaves the +foreground application free to do other things while the audio just runs +in the background. But this can sometimes be awkward. +<p>So we have provided an alternative technique that lets a program generate +audio in the foreground and then just write it to the audio stream as if +it was a file. If there is not enough room in the audio buffer for more +data, then the write function will just block until more room is available. +This can make it very easy to write an audio example. To use this tool, +you must add the files "pablio/pablio.c" and "pablio/ringbuffer.c" to your +project. You must also: +<blockquote> +<pre>#include "pablio.h"</pre> +</blockquote> +Here is a short excerpt of a program that opens a stream for input and +output. It then reads a block of samples from input, and writes them to +output, in a loop. The complete example can be found in "pablio/test_rw.c". +<blockquote> +<pre> #define SAMPLES_PER_FRAME (2) + #define FRAMES_PER_BLOCK (1024) + SAMPLE samples[SAMPLES_PER_FRAME * FRAMES_PER_BLOCK]; + PaError err; + PABLIO_Stream *aStream; + +/* Open simplified blocking I/O layer on top of PortAudio. */ + err = OpenAudioStream( &rwbl, SAMPLE_RATE, paFloat32, + (PABLIO_READ_WRITE | PABLIO_STEREO) ); + if( err != paNoError ) goto error; + +/* Process samples in the foreground. */ + for( i=0; i<(NUM_SECONDS * SAMPLE_RATE); i++ ) + { + /* Read one block of data into sample array from audio input. */ + ReadAudioStream( aStream, samples, FRAMES_PER_BLOCK ); + /* + ** At this point you could process the data in samples array, + ** and write the result back to the same samples array. + */ + /* Write that same frame of data to output. */ + WriteAudioStream( aStream, samples, FRAMES_PER_BLOCK ); + } + + CloseAudioStream( aStream );</pre> +</blockquote> +</blockquote> +<font size=+2><a href="http://www.portaudio.com/">home</a> | +<a href="pa_tutorial.html">contents</a> +| <a href="pa_tut_devs.html">previous</a> | <a href="pa_tut_explore.html">next</a></font> +</body> +</html> |