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/test/patest_dither.c | 190 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 190 insertions(+) create mode 100644 portaudio/test/patest_dither.c (limited to 'portaudio/test/patest_dither.c') diff --git a/portaudio/test/patest_dither.c b/portaudio/test/patest_dither.c new file mode 100644 index 0000000..fc402dc --- /dev/null +++ b/portaudio/test/patest_dither.c @@ -0,0 +1,190 @@ +/** @file patest_dither.c + @ingroup test_src + @brief Attempt to hear difference between dithered and non-dithered signal. + + This only has an effect if the native format is 16 bit. + + @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 (5) +#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; + +/* 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; + + for( i=0; isine[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; +} + +/*****************************************************************************/ +/* + V18 version did not call Pa_Terminate() if Pa_Initialize() failed. + This V19 version ALWAYS calls Pa_Terminate(). PS. +*/ +PaError PlaySine( paTestData *data, PaStreamFlags flags, float amplitude ); +PaError PlaySine( paTestData *data, PaStreamFlags flags, float amplitude ) +{ + PaStream* stream; + PaStreamParameters outputParameters; + PaError err; + + data->left_phase = data->right_phase = 0; + data->amplitude = amplitude; + + err = Pa_Initialize(); + if (err != paNoError) + goto done; + + outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */ + if (outputParameters.device == paNoDevice) { + fprintf(stderr,"Error: No default output device.\n"); + goto done; + } + outputParameters.channelCount = 2; /* stereo output */ + outputParameters.hostApiSpecificStreamInfo = NULL; + outputParameters.sampleFormat = paFloat32; /* 32 bit floating point output. */ + /* When you change this, also */ + /* adapt the callback routine! */ + outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device ) + ->defaultLowOutputLatency; /* Low latency. */ + err = Pa_OpenStream( &stream, + NULL, /* No input. */ + &outputParameters, + SAMPLE_RATE, + 1024, /* frames per buffer */ + flags, + sineCallback, + (void*)data ); + if (err != paNoError) + goto done; + + err = Pa_StartStream( stream ); + if (err != paNoError) + goto done; + + Pa_Sleep( NUM_SECONDS * 1000 ); + printf("CPULoad = %8.6f\n", Pa_GetStreamCpuLoad(stream)); + + err = Pa_CloseStream( stream ); +done: + Pa_Sleep( 250 ); /* Just a small silence. */ + Pa_Terminate(); + return err; +} + + +/*******************************************************************/ +int main(void); +int main(void) +{ + PaError err; + paTestData DATA; + int i; + float amplitude = 4.0 / (1<<15); + + printf("PortAudio Test: output EXTREMELY QUIET sine wave with and without dithering.\n"); + /* initialise sinusoidal wavetable */ + for( i=0; i