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https://github.com/cookiengineer/audacity
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87 lines
2.9 KiB
HTML
87 lines
2.9 KiB
HTML
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
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<html>
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
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<meta name="GENERATOR" content="Mozilla/4.77 [en]C-gatewaynet (Win98; U) [Netscape]">
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<meta name="Author" content="Phil Burk">
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<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.">
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<meta name="KeyWords" content="audio, tutorial, library, portable, open-source, DirectSound,sound, music, JSyn, synthesis,">
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<title>PortAudio Tutorial</title>
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</head>
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<body>
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<center><table COLS=1 WIDTH="100%" BGCOLOR="#FADA7A" >
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<tr>
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<td>
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<center>
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<h1>
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PortAudio Tutorial</h1></center>
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</td>
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</tr>
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</table></center>
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<h2>
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Overview of PortAudio</h2>
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<blockquote>PortAudio is a library that provides streaming audio input
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and output. It is a cross-platform API (Application Programming Interface)
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that works on Windows and Macintosh, and perhaps other platforms by the
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time you read this. This means that you can write a simple 'C' program
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to process or generate an audio signal, and that program can run on several
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different computers just by recompiling the source code.
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<p>Here are the steps to writing a PortAudio application:
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<ol>
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<li>
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Write a callback function that will be called by PortAudio when audio processing
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is needed.</li>
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<li>
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Initialize the PA library and open a stream for audio I/O.</li>
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<li>
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Start the stream. Your callback function will be now be called repeatedly
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by PA in the background.</li>
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<li>
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In your callback you can read audio data from the inputBuffer and/or write
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data to the outputBuffer.</li>
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<li>
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Stop the stream by returning 1 from your callback, or by calling a stop
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function.</li>
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<li>
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Close the stream and terminate the library.</li>
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</ol>
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</blockquote>
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<blockquote>There is also <a href="pa_tut_rw.html">another interface</a>
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provided that allows you to generate audio in the foreground. You then
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simply write data to the stream and the tool will not return until it is
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ready to accept more data. This interface is simpler to use but is usually
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not preferred for large applications because it requires that you launch
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a thread to perform the synthesis. Launching a thread may be difficult
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on non-multi-tasking systems such as the Macintosh prior to MacOS X.
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<p>Let's continue by building a simple application that will play a sawtooth
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wave.
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<p>Please select the page for the implementation you would like to use:
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<ul>
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<li>
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<a href="pa_tut_pc.html">Windows (WMME or DirectSound)</a></li>
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<li>
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<a href="pa_tut_mac.html">Macintosh SoundManager</a></li>
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<li>
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<a href="pa_tut_asio.html">ASIO on Windows or Macintosh</a></li>
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<li>
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<a href="pa_tut_oss.html">Unix OSS</a></li>
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</ul>
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</blockquote>
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<font size=+2><a href="http://www.portaudio.com/">home</a> |
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<a href="pa_tutorial.html">contents</a>
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| <a href="pa_tutorial.html">previous</a></font>
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</body>
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</html>
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