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Diffstat (limited to 'portaudio/test/patest_leftright.c')
| -rw-r--r-- | portaudio/test/patest_leftright.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/portaudio/test/patest_leftright.c b/portaudio/test/patest_leftright.c new file mode 100644 index 0000000..e61a351 --- /dev/null +++ b/portaudio/test/patest_leftright.c @@ -0,0 +1,185 @@ +/** @file patest_leftright.c + @ingroup test_src + @brief Play different tone sine waves that + alternate between left and right channel. + + The low tone should be on the left channel. + + @author Ross Bencina <rossb@audiomulch.com> + @author Phil Burk <philburk@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 <stdio.h> +#include <math.h> +#include "portaudio.h" + +#define NUM_SECONDS (8) +#define SAMPLE_RATE (44100) +#define FRAMES_PER_BUFFER (512) +#ifndef M_PI +#define M_PI (3.14159265) +#endif +#define TABLE_SIZE (200) +#define BALANCE_DELTA (0.001) + +typedef struct +{ + float sine[TABLE_SIZE]; + int left_phase; + int right_phase; + float targetBalance; // 0.0 = left, 1.0 = right + float currentBalance; +} 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 ) +{ + paTestData *data = (paTestData*)userData; + float *out = (float*)outputBuffer; + unsigned long i; + int finished = 0; + /* Prevent unused variable warnings. */ + (void) inputBuffer; + + for( i=0; i<framesPerBuffer; i++ ) + { + // Smoothly pan between left and right. + if( data->currentBalance < data->targetBalance ) + { + data->currentBalance += BALANCE_DELTA; + } + else if( data->currentBalance > data->targetBalance ) + { + data->currentBalance -= BALANCE_DELTA; + } + // Apply left/right balance. + *out++ = data->sine[data->left_phase] * (1.0f - data->currentBalance); /* left */ + *out++ = data->sine[data->right_phase] * data->currentBalance; /* right */ + + data->left_phase += 1; + if( data->left_phase >= TABLE_SIZE ) data->left_phase -= TABLE_SIZE; + data->right_phase += 3; /* higher pitch so we can distinguish left and right. */ + if( data->right_phase >= TABLE_SIZE ) data->right_phase -= TABLE_SIZE; + } + + return finished; +} + +/*******************************************************************/ +int main(void); +int main(void) +{ + PaStream *stream; + PaStreamParameters outputParameters; + PaError err; + paTestData data; + int i; + printf("Play different tone sine waves that alternate between left and right channel.\n"); + printf("The low tone should be on the left channel.\n"); + + /* initialise sinusoidal wavetable */ + for( i=0; i<TABLE_SIZE; i++ ) + { + data.sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. ); + } + data.left_phase = data.right_phase = 0; + data.currentBalance = 0.0; + data.targetBalance = 0.0; + + err = Pa_Initialize(); + if( err != paNoError ) goto error; + + outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */ + if (outputParameters.device == paNoDevice) { + fprintf(stderr,"Error: No default output device.\n"); + goto error; + } + outputParameters.channelCount = 2; /* stereo output */ + outputParameters.sampleFormat = paFloat32; /* 32 bit floating point output */ + outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency; + outputParameters.hostApiSpecificStreamInfo = NULL; + + err = Pa_OpenStream( &stream, + NULL, /* No input. */ + &outputParameters, /* As above. */ + SAMPLE_RATE, + FRAMES_PER_BUFFER, + paClipOff, /* we won't output out of range samples so don't bother clipping them */ + patestCallback, + &data ); + if( err != paNoError ) goto error; + + err = Pa_StartStream( stream ); + if( err != paNoError ) goto error; + + printf("Play for several seconds.\n"); + for( i=0; i<4; i++ ) + { + printf("Hear low sound on left side.\n"); + data.targetBalance = 0.01; + Pa_Sleep( 1000 ); + + printf("Hear high sound on right side.\n"); + data.targetBalance = 0.99; + Pa_Sleep( 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; +} |