From 37c97e345d12f95dde44e1d1a4c2f2aadd4615bc Mon Sep 17 00:00:00 2001 From: sanine Date: Thu, 25 Aug 2022 14:54:53 -0500 Subject: add initial structure --- portaudio/examples/paex_saw.c | 133 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+) create mode 100644 portaudio/examples/paex_saw.c (limited to 'portaudio/examples/paex_saw.c') diff --git a/portaudio/examples/paex_saw.c b/portaudio/examples/paex_saw.c new file mode 100644 index 0000000..caec0b0 --- /dev/null +++ b/portaudio/examples/paex_saw.c @@ -0,0 +1,133 @@ +/** @file paex_saw.c + @ingroup examples_src + @brief Play a simple (aliasing) sawtooth wave. + @author Phil Burk http://www.softsynth.com +*/ +/* + * $Id$ + * + * This program uses the PortAudio Portable Audio Library. + * For more information see: http://www.portaudio.com + * Copyright (c) 1999-2000 Ross Bencina and Phil Burk + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files + * (the "Software"), to deal in the Software without restriction, + * including without limitation the rights to use, copy, modify, merge, + * publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, + * subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR + * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF + * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION + * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + +/* + * The text above constitutes the entire PortAudio license; however, + * the PortAudio community also makes the following non-binding requests: + * + * Any person wishing to distribute modifications to the Software is + * requested to send the modifications to the original developer so that + * they can be incorporated into the canonical version. It is also + * requested that these non-binding requests be included along with the + * license above. + */ + +#include +#include +#include "portaudio.h" +#define NUM_SECONDS (4) +#define SAMPLE_RATE (44100) + +typedef struct +{ + float left_phase; + float right_phase; +} +paTestData; + +/* This routine will be called by the PortAudio engine when audio is needed. +** It may called at interrupt level on some machines so don't do anything +** that could mess up the system like calling malloc() or free(). +*/ +static int patestCallback( const void *inputBuffer, void *outputBuffer, + unsigned long framesPerBuffer, + const PaStreamCallbackTimeInfo* timeInfo, + PaStreamCallbackFlags statusFlags, + void *userData ) +{ + /* Cast data passed through stream to our structure. */ + paTestData *data = (paTestData*)userData; + float *out = (float*)outputBuffer; + unsigned int i; + (void) inputBuffer; /* Prevent unused variable warning. */ + + for( i=0; ileft_phase; /* left */ + *out++ = data->right_phase; /* right */ + /* Generate simple sawtooth phaser that ranges between -1.0 and 1.0. */ + data->left_phase += 0.01f; + /* When signal reaches top, drop back down. */ + if( data->left_phase >= 1.0f ) data->left_phase -= 2.0f; + /* higher pitch so we can distinguish left and right. */ + data->right_phase += 0.03f; + if( data->right_phase >= 1.0f ) data->right_phase -= 2.0f; + } + return 0; +} + +/*******************************************************************/ +static paTestData data; +int main(void); +int main(void) +{ + PaStream *stream; + PaError err; + + printf("PortAudio Test: output sawtooth wave.\n"); + /* Initialize our data for use by callback. */ + data.left_phase = data.right_phase = 0.0; + /* Initialize library before making any other calls. */ + err = Pa_Initialize(); + if( err != paNoError ) goto error; + + /* 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 */ + patestCallback, + &data ); + if( err != paNoError ) goto error; + + err = Pa_StartStream( stream ); + if( err != paNoError ) goto error; + + /* Sleep for several seconds. */ + Pa_Sleep(NUM_SECONDS*1000); + + err = Pa_StopStream( stream ); + if( err != paNoError ) goto error; + err = Pa_CloseStream( stream ); + if( err != paNoError ) goto error; + Pa_Terminate(); + printf("Test finished.\n"); + return err; +error: + Pa_Terminate(); + fprintf( stderr, "An error occurred while using the portaudio stream\n" ); + fprintf( stderr, "Error number: %d\n", err ); + fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) ); + return err; +} -- cgit v1.2.1