add initial structure

1 files changed, 190 insertions, 0 deletions

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 <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. */
+}