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| author | Guenter Geiger <ggeiger@users.sourceforge.net> | 2003-05-09 16:04:00 +0000 |
|---|---|---|
| committer | Guenter Geiger <ggeiger@users.sourceforge.net> | 2003-05-09 16:04:00 +0000 |
| commit | 9c0e19a3be2288db79e2502e5fa450c3e20a668d (patch) | |
| tree | ca97ce615e037a533304fc4660dcf372ca3b9cd6 /pd/portaudio/docs/pa_tut_devs.html | |
| parent | ef50dd62804d54af7da18d8bd8413c0dccd729b8 (diff) | |
This commit was generated by cvs2svn to compensate for changes in r610,
which included commits to RCS files with non-trunk default branches.
svn path=/trunk/; revision=611
Diffstat (limited to 'pd/portaudio/docs/pa_tut_devs.html')
| -rw-r--r-- | pd/portaudio/docs/pa_tut_devs.html | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/pd/portaudio/docs/pa_tut_devs.html b/pd/portaudio/docs/pa_tut_devs.html new file mode 100644 index 00000000..1756992c --- /dev/null +++ b/pd/portaudio/docs/pa_tut_devs.html @@ -0,0 +1,65 @@ +<!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/4.75 [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> +Querying for Available Devices</h2> + +<blockquote>There are often several different audio devices available in +a computer with different capabilities. They can differ in the sample rates +supported, bit widths, etc. PortAudio provides a simple way to query for +the available devices, and then pass the selected device to Pa_OpenStream(). +For an example, see the file "pa_tests/pa_devs.c". +<p>To determine the number of devices: +<blockquote> +<pre>numDevices = Pa_CountDevices();</pre> +</blockquote> +You can then query each device in turn by calling Pa_GetDeviceInfo() with +an index. +<blockquote> +<pre>for( i=0; i<numDevices; i++ ) { + pdi = Pa_GetDeviceInfo( i );</pre> +</blockquote> +It will return a pointer to a <tt>PaDeviceInfo</tt> structure which is +defined as: +<blockquote> +<pre>typedef struct{ + int structVersion; + const char *name; + int maxInputChannels; + int maxOutputChannels; +/* Number of discrete rates, or -1 if range supported. */ + int numSampleRates; +/* Array of supported sample rates, or {min,max} if range supported. */ + const double *sampleRates; + PaSampleFormat nativeSampleFormat; +}PaDeviceInfo;</pre> +</blockquote> +If the device supports a continuous range of sample rates, then numSampleRates +will equal -1, and the sampleRates array will have two values, the minimum +and maximum rate. +<p>The device information is allocated by Pa_Initialize() and freed by +Pa_Terminate() so you do not have to free() the structure returned by Pa_GetDeviceInfo().</blockquote> +<font size=+2><a href="http://www.portaudio.com/">home</a> | +<a href="pa_tutorial.html">contents</a> +| <a href="pa_tut_util.html">previous</a> | <a href="pa_tut_rw.html">next</a></font> +</body> +</html> |