doc/html/recording.html

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  12 <h1><a class="anchor" name="recording">Recording</a></h1>Using <a class="el" href="classRtAudio.html">RtAudio</a> for audio input is almost identical to the way it is used for playback. Here's the blocking playback example rewritten for recording:<p>
  13 <div class="fragment"><pre class="fragment"><span class="preprocessor">#include "<a class="code" href="RtAudio_8h.html">RtAudio.h</a>"</span>
  14 <span class="preprocessor">#include &lt;iostream&gt;</span>
  15
  16 <span class="keywordtype">int</span> record( <span class="keywordtype">void</span> *outputBuffer, <span class="keywordtype">void</span> *inputBuffer, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> nBufferFrames,
  17          <span class="keywordtype">double</span> streamTime, <a class="code" href="RtAudio_8h.html#a12">RtAudioStreamStatus</a> status, <span class="keywordtype">void</span> *userData )
  18 {
  19   <span class="keywordflow">if</span> ( status )
  20     std::cout &lt;&lt; <span class="stringliteral">"Stream overflow detected!"</span> &lt;&lt; std::endl;
  21
  22   <span class="comment">// Do something with the data in the "inputBuffer" buffer.</span>
  23
  24   <span class="keywordflow">return</span> 0;
  25 }
  26
  27 <span class="keywordtype">int</span> main()
  28 {
  29   <a class="code" href="classRtAudio.html">RtAudio</a> adc;
  30   <span class="keywordflow">if</span> ( adc.<a class="code" href="classRtAudio.html#a3">getDeviceCount</a>() &lt; 1 ) {
  31     std::cout &lt;&lt; <span class="stringliteral">"\nNo audio devices found!\n"</span>;
  32     exit( 0 );
  33   }
  34
  35   <a class="code" href="structRtAudio_1_1StreamParameters.html">RtAudio::StreamParameters</a> parameters;
  36   parameters.<a class="code" href="structRtAudio_1_1StreamParameters.html#o0">deviceId</a> = adc.<a class="code" href="classRtAudio.html#a6">getDefaultInputDevice</a>();
  37   parameters.<a class="code" href="structRtAudio_1_1StreamParameters.html#o1">nChannels</a> = 2;
  38   parameters.<a class="code" href="structRtAudio_1_1StreamParameters.html#o2">firstChannel</a> = 0;
  39   <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> sampleRate = 44100;
  40   <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> bufferFrames = 256; <span class="comment">// 256 sample frames</span>
  41
  42   <span class="keywordflow">try</span> {
  43     adc.<a class="code" href="classRtAudio.html#a7">openStream</a>( NULL, &amp;parameters, RTAUDIO_SINT16,
  44                     sampleRate, &amp;bufferFrames, &amp;record );
  45     adc.<a class="code" href="classRtAudio.html#a9">startStream</a>();
  46   }
  47   <span class="keywordflow">catch</span> ( <a class="code" href="classRtError.html">RtError</a>&amp; e ) {
  48     e.<a class="code" href="classRtError.html#a2">printMessage</a>();
  49     exit( 0 );
  50   }
  51
  52   <span class="keywordtype">char</span> input;
  53   std::cout &lt;&lt; <span class="stringliteral">"\nRecording ... press &lt;enter&gt; to quit.\n"</span>;
  54   std::cin.get( input );
  55
  56   <span class="keywordflow">try</span> {
  57     <span class="comment">// Stop the stream</span>
  58     adc.<a class="code" href="classRtAudio.html#a10">stopStream</a>();
  59   }
  60   <span class="keywordflow">catch</span> (<a class="code" href="classRtError.html">RtError</a>&amp; e) {
  61     e.<a class="code" href="classRtError.html#a2">printMessage</a>();
  62   }
  63
  64   <span class="keywordflow">if</span> ( adc.<a class="code" href="classRtAudio.html#a12">isStreamOpen</a>() ) adc.<a class="code" href="classRtAudio.html#a8">closeStream</a>();
  65
  66   <span class="keywordflow">return</span> 0;
  67 }
  68 </pre></div><p>
  69 In this example, we pass the address of the stream parameter structure as the second argument of the <a class="el" href="classRtAudio.html#a7">RtAudio::openStream()</a> function and pass a NULL value for the output stream parameters. In this example, the <em>record()</em> callback function performs no specific operations. <HR>
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