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Diffstat (limited to '3rdparty/portaudio/doc/src/tutorial/open_default_stream.dox')
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diff --git a/3rdparty/portaudio/doc/src/tutorial/open_default_stream.dox b/3rdparty/portaudio/doc/src/tutorial/open_default_stream.dox new file mode 100644 index 0000000..7512d1e --- /dev/null +++ b/3rdparty/portaudio/doc/src/tutorial/open_default_stream.dox @@ -0,0 +1,48 @@ +/** @page open_default_stream Opening a Stream Using Defaults +@ingroup tutorial + +The next step is to open a stream, which is similar to opening a file. You can specify whether you want audio input and/or output, how many channels, the data format, sample rate, etc. Opening a ''default'' stream means opening the default input and output devices, which saves you the trouble of getting a list of devices and choosing one from the list. (We'll see how to do that later.) +@code +#define SAMPLE_RATE (44100) +static paTestData data; + +..... + + PaStream *stream; + PaError err; + + /* Open an audio I/O stream. */ + err = Pa_OpenDefaultStream( &stream, + 0, /* no input channels */ + 2, /* stereo output */ + paFloat32, /* 32 bit floating point output */ + SAMPLE_RATE, + 256, /* frames per buffer, i.e. the number + of sample frames that PortAudio will + request from the callback. Many apps + may want to use + paFramesPerBufferUnspecified, which + tells PortAudio to pick the best, + possibly changing, buffer size.*/ + patestCallback, /* this is your callback function */ + &data ); /*This is a pointer that will be passed to + your callback*/ + if( err != paNoError ) goto error; +@endcode + +The data structure and callback are described in \ref writing_a_callback. + +The above example opens the stream for writing, which is sufficient for playback. It is also possible to open a stream for reading, to do recording, or both reading and writing, for simultaneous recording and playback or even real-time audio processing. If you plan to do playback and recording at the same time, open only one stream with valid input and output parameters. + +There are some caveats to note about simultaneous read/write: + + - Some platforms can only open a read/write stream using the same device. + - Although multiple streams can be opened, it is difficult to synchronize them. + - Some platforms don't support opening multiple streams on the same device. + - Using multiple streams may not be as well tested as other features. + - The PortAudio library calls must be made from the same thread or synchronized by the user. + + +Previous: \ref initializing_portaudio | Next: \ref start_stop_abort + +*/
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