1 files changed, 156 insertions, 0 deletions
diff --git a/pd/portaudio/pa_tests/patest_clip.c b/pd/portaudio/pa_tests/patest_clip.c
new file mode 100644
index 00000000..c19bf3fe
--- /dev/null
+++ b/pd/portaudio/pa_tests/patest_clip.c
@@ -0,0 +1,156 @@
+/*
+ * $Id: patest_clip.c,v 1.1.1.1 2003-05-09 16:03:56 ggeiger Exp $
+ * patest_clip.c
+ * Play a sine wave using the Portable Audio api for several seconds
+ * at an amplitude that would require clipping.
+ *
+ * Author: Phil Burk  http://www.softsynth.com
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * 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.
+ *
+ */
+#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( void *inputBuffer, void *outputBuffer,
+                         unsigned long framesPerBuffer,
+                         PaTimestamp outTime, void *userData )
+{
+    paTestData *data = (paTestData*)userData;
+    float *out = (float*)outputBuffer;
+    float amplitude = data->amplitude;
+    unsigned int i;
+    (void) inputBuffer; /* Prevent "unused variable" warnings. */
+    (void) outTime;
+
+    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 )
+{
+    PortAudioStream *stream;
+    PaError err;
+    data->left_phase = data->right_phase = 0;
+    data->amplitude = amplitude;
+    err = Pa_Initialize();
+    if( err != paNoError ) goto error;
+    err = Pa_OpenStream(
+              &stream,
+              paNoDevice,/* default input device */
+              0,              /* no input */
+              paFloat32,  /* 32 bit floating point input */
+              NULL,
+              Pa_GetDefaultOutputDeviceID(), /* default output device */
+              2,              /* stereo output */
+              paFloat32,      /* 32 bit floating point output */
+              NULL,
+              SAMPLE_RATE,
+              1024,
+              0,              /* number of buffers, if zero then use default minimum */
+              flags,      /* we won't output out of range samples so don't bother clipping them */
+              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_GetCPULoad( stream ) );
+    err = Pa_CloseStream( stream );
+    if( err != paNoError ) goto error;
+    Pa_Terminate();
+    return paNoError;
+error:
+    return err;
+}