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Diffstat (limited to 'portaudio/test/patest_clip.c')
| -rw-r--r-- | portaudio/test/patest_clip.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/portaudio/test/patest_clip.c b/portaudio/test/patest_clip.c new file mode 100644 index 0000000..4580ed0 --- /dev/null +++ b/portaudio/test/patest_clip.c @@ -0,0 +1,186 @@ +/** @file patest_clip.c + @ingroup test_src + @brief Play a sine wave for several seconds at an amplitude + that would require clipping. + + @author Phil Burk http://www.softsynth.com +*/ +/* + * $Id: patest_clip.c 1097 2006-08-26 08:27:53Z rossb $ + * + * 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 (4) +#define SAMPLE_RATE (44100) +#ifndef M_PI +#define M_PI (3.14159265) +#endif +#define TABLE_SIZE (200) + +typedef struct paTestData +{ + float sine[TABLE_SIZE]; + float amplitude; + int left_phase; + int right_phase; +} +paTestData; + +PaError PlaySine( paTestData *data, unsigned long flags, float amplitude ); + +/* 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 sineCallback( const void *inputBuffer, void *outputBuffer, + unsigned long framesPerBuffer, + const PaStreamCallbackTimeInfo* timeInfo, + PaStreamCallbackFlags statusFlags, + void *userData ) +{ + paTestData *data = (paTestData*)userData; + float *out = (float*)outputBuffer; + float amplitude = data->amplitude; + unsigned int i; + (void) inputBuffer; /* Prevent "unused variable" warnings. */ + (void) timeInfo; + (void) statusFlags; + + for( i=0; i<framesPerBuffer; i++ ) + { + *out++ = amplitude * data->sine[data->left_phase]; /* left */ + *out++ = amplitude * data->sine[data->right_phase]; /* 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 0; +} +/*******************************************************************/ +int main(void); +int main(void) +{ + PaError err; + paTestData data; + int i; + + printf("PortAudio Test: output sine wave with and without clipping.\n"); + /* initialise sinusoidal wavetable */ + for( i=0; i<TABLE_SIZE; i++ ) + { + data.sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. ); + } + + printf("\nHalf amplitude. Should sound like sine wave.\n"); fflush(stdout); + err = PlaySine( &data, paClipOff | paDitherOff, 0.5f ); + if( err < 0 ) goto error; + + printf("\nFull amplitude. Should sound like sine wave.\n"); fflush(stdout); + err = PlaySine( &data, paClipOff | paDitherOff, 0.999f ); + if( err < 0 ) goto error; + + printf("\nOver range with clipping and dithering turned OFF. Should sound very nasty.\n"); + fflush(stdout); + err = PlaySine( &data, paClipOff | paDitherOff, 1.1f ); + if( err < 0 ) goto error; + + printf("\nOver range with clipping and dithering turned ON. Should sound smoother than previous.\n"); + fflush(stdout); + err = PlaySine( &data, paNoFlag, 1.1f ); + if( err < 0 ) goto error; + + printf("\nOver range with paClipOff but dithering ON.\n" + "That forces clipping ON so it should sound the same as previous.\n"); + fflush(stdout); + err = PlaySine( &data, paClipOff, 1.1f ); + if( err < 0 ) goto error; + + return 0; +error: + fprintf( stderr, "An error occured while using the portaudio stream\n" ); + fprintf( stderr, "Error number: %d\n", err ); + fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) ); + return 1; +} +/*****************************************************************************/ +PaError PlaySine( paTestData *data, unsigned long flags, float amplitude ) +{ + PaStreamParameters outputParameters; + PaStream *stream; + PaError err; + + data->left_phase = data->right_phase = 0; + data->amplitude = amplitude; + + err = Pa_Initialize(); + if( err != paNoError ) goto error; + + outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */ + 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, + SAMPLE_RATE, + 1024, + flags, + sineCallback, + data ); + if( err != paNoError ) goto error; + + err = Pa_StartStream( stream ); + if( err != paNoError ) goto error; + + Pa_Sleep( NUM_SECONDS * 1000 ); + printf("CPULoad = %8.6f\n", Pa_GetStreamCpuLoad( stream ) ); + + err = Pa_CloseStream( stream ); + if( err != paNoError ) goto error; + + Pa_Terminate(); + return paNoError; +error: + return err; +} |