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authorsanine <sanine.not@pm.me>2022-08-25 14:54:53 -0500
committersanine <sanine.not@pm.me>2022-08-25 14:54:53 -0500
commit37c97e345d12f95dde44e1d1a4c2f2aadd4615bc (patch)
treee1bb25bc855883062bdd7847ff2c04290f71c840 /portaudio/test/patest_dither.c
parent5634c7b04da619669f2f29f6798c03982be05180 (diff)
add initial structure
Diffstat (limited to 'portaudio/test/patest_dither.c')
-rw-r--r--portaudio/test/patest_dither.c190
1 files changed, 190 insertions, 0 deletions
diff --git a/portaudio/test/patest_dither.c b/portaudio/test/patest_dither.c
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+++ b/portaudio/test/patest_dither.c
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+/** @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 <stdio.h>
+#include <math.h>
+
+#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; 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;
+}
+
+/*****************************************************************************/
+/*
+ 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<TABLE_SIZE; i++ )
+ {
+ DATA.sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. );
+ }
+ printf("\nNo treatment..\n"); fflush(stdout);
+ err = PlaySine( &DATA, paClipOff | paDitherOff, amplitude );
+ if( err < 0 ) goto done;
+
+ printf("\nClip..\n");
+ fflush(stdout);
+ err = PlaySine( &DATA, paDitherOff, amplitude );
+ if( err < 0 ) goto done;
+
+ printf("\nClip and Dither..\n");
+ fflush(stdout);
+ err = PlaySine( &DATA, paNoFlag, amplitude );
+done:
+ if (err)
+ {
+ 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 ) );
+ err = 1; /* Though PlaySine() already called Pa_Terminate(), */
+ } /* we may still call Pa_GetErrorText(). */
+ else
+ printf("\n(Don't forget to turn the VOLUME DOWN after listening so carefully.)\n");
+ return err; /* 0 or 1. */
+}