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Diffstat (limited to 'portaudio/doc/src/tutorial/blocking_read_write.dox')
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diff --git a/portaudio/doc/src/tutorial/blocking_read_write.dox b/portaudio/doc/src/tutorial/blocking_read_write.dox deleted file mode 100644 index 8905ee3..0000000 --- a/portaudio/doc/src/tutorial/blocking_read_write.dox +++ /dev/null @@ -1,68 +0,0 @@ -/** @page blocking_read_write Blocking Read/Write Functions -@ingroup tutorial - -PortAudio V19 adds a huge advance over previous versions with a feature called Blocking I/O. Although it may have lower performance that the callback method described earlier in this tutorial, blocking I/O is easier to understand and is, in some cases, more compatible with third party systems than the callback method. Most people starting audio programming also find Blocking I/O easier to learn. - -Blocking I/O works in much the same way as the callback method except that instead of providing a function to provide (or consume) audio data, you must feed data to (or consume data from) PortAudio at regular intervals, usually inside a loop. The example below, excepted from patest_read_write_wire.c, shows how to open the default device, and pass data from its input to its output for a set period of time. Note that we use the default high latency values to help avoid underruns since we are usually reading and writing audio data from a relatively low priority thread, and there is usually extra buffering required to make blocking I/O work. - -Note that not all API's implement Blocking I/O at this point, so for maximum portability or performance, you'll still want to use callbacks. - -@code - /* -- initialize PortAudio -- */ - err = Pa_Initialize(); - if( err != paNoError ) goto error; - - /* -- setup input and output -- */ - inputParameters.device = Pa_GetDefaultInputDevice(); /* default input device */ - inputParameters.channelCount = NUM_CHANNELS; - inputParameters.sampleFormat = PA_SAMPLE_TYPE; - inputParameters.suggestedLatency = Pa_GetDeviceInfo( inputParameters.device )->defaultHighInputLatency ; - inputParameters.hostApiSpecificStreamInfo = NULL; - - outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */ - outputParameters.channelCount = NUM_CHANNELS; - outputParameters.sampleFormat = PA_SAMPLE_TYPE; - outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultHighOutputLatency; - outputParameters.hostApiSpecificStreamInfo = NULL; - - /* -- setup stream -- */ - err = Pa_OpenStream( - &stream, - &inputParameters, - &outputParameters, - SAMPLE_RATE, - FRAMES_PER_BUFFER, - paClipOff, /* we won't output out of range samples so don't bother clipping them */ - NULL, /* no callback, use blocking API */ - NULL ); /* no callback, so no callback userData */ - if( err != paNoError ) goto error; - - /* -- start stream -- */ - err = Pa_StartStream( stream ); - if( err != paNoError ) goto error; - printf("Wire on. Will run one minute.\n"); fflush(stdout); - - /* -- Here's the loop where we pass data from input to output -- */ - for( i=0; i<(60*SAMPLE_RATE)/FRAMES_PER_BUFFER; ++i ) - { - err = Pa_WriteStream( stream, sampleBlock, FRAMES_PER_BUFFER ); - if( err ) goto xrun; - err = Pa_ReadStream( stream, sampleBlock, FRAMES_PER_BUFFER ); - if( err ) goto xrun; - } - /* -- Now we stop the stream -- */ - err = Pa_StopStream( stream ); - if( err != paNoError ) goto error; - - /* -- don't forget to cleanup! -- */ - err = Pa_CloseStream( stream ); - if( err != paNoError ) goto error; - - Pa_Terminate(); - return 0; -@endcode - - -Previous: \ref querying_devices | Next: \ref exploring - -*/
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