diff src/portaudio_20161030_catalina_patch/test/pa_minlat.c @ 162:d43aab368df9

Duplicate for patch testing
author Chris Cannam <cannam@all-day-breakfast.com>
date Wed, 30 Oct 2019 11:25:10 +0000
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/portaudio_20161030_catalina_patch/test/pa_minlat.c	Wed Oct 30 11:25:10 2019 +0000
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+/** @file pa_minlat.c
+	@ingroup test_src
+    @brief Experiment with different numbers of buffers to determine the
+	minimum latency for a computer.
+	@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 <stdlib.h>
+#include <math.h>
+#include <string.h>
+#include "portaudio.h"
+
+#ifndef M_PI
+#define M_PI  (3.14159265)
+#endif
+#define TWOPI (M_PI * 2.0)
+
+#define DEFAULT_BUFFER_SIZE   (32)
+
+typedef struct
+{
+    double left_phase;
+    double right_phase;
+}
+paTestData;
+
+/* Very simple synthesis routine to generate two sine waves. */
+static int paminlatCallback( const void *inputBuffer, void *outputBuffer,
+                             unsigned long framesPerBuffer,
+                             const PaStreamCallbackTimeInfo* timeInfo,
+                             PaStreamCallbackFlags statusFlags,
+                             void *userData )
+{
+    paTestData *data = (paTestData*)userData;
+    float *out = (float*)outputBuffer;
+    unsigned int i;
+    double left_phaseInc = 0.02;
+    double right_phaseInc = 0.06;
+
+    double left_phase = data->left_phase;
+    double right_phase = data->right_phase;
+
+    for( i=0; i<framesPerBuffer; i++ )
+    {
+        left_phase += left_phaseInc;
+        if( left_phase > TWOPI ) left_phase -= TWOPI;
+        *out++ = (float) sin( left_phase );
+
+        right_phase += right_phaseInc;
+        if( right_phase > TWOPI ) right_phase -= TWOPI;
+        *out++ = (float) sin( right_phase );
+    }
+
+    data->left_phase = left_phase;
+    data->right_phase = right_phase;
+    return 0;
+}
+
+int main( int argc, char **argv );
+int main( int argc, char **argv )
+{
+    PaStreamParameters outputParameters;
+    PaStream *stream;
+    PaError err;
+    paTestData data;
+    int    go;
+    int    outLatency = 0;
+    int    minLatency = DEFAULT_BUFFER_SIZE * 2;
+    int    framesPerBuffer;
+    double sampleRate = 44100.0;
+    char   str[256];
+	char  *line;
+
+    printf("pa_minlat - Determine minimum latency for your computer.\n");
+    printf("  usage:         pa_minlat {userBufferSize}\n");
+    printf("  for example:   pa_minlat 64\n");
+    printf("Adjust your stereo until you hear a smooth tone in each speaker.\n");
+    printf("Then try to find the smallest number of frames that still sounds smooth.\n");
+    printf("Note that the sound will stop momentarily when you change the number of buffers.\n");
+
+    /* Get bufferSize from command line. */
+    framesPerBuffer = ( argc > 1 ) ? atol( argv[1] ) : DEFAULT_BUFFER_SIZE;
+    printf("Frames per buffer = %d\n", framesPerBuffer );
+
+    data.left_phase = data.right_phase = 0.0;
+
+    err = Pa_Initialize();
+    if( err != paNoError ) goto error;
+
+    outLatency = sampleRate * 200.0 / 1000.0; /* 200 msec. */
+
+    /* Try different numBuffers in a loop. */
+    go = 1;
+    while( go )
+    {
+        outputParameters.device                    = Pa_GetDefaultOutputDevice(); /* Default output device. */
+        outputParameters.channelCount              = 2;                           /* Stereo output */
+        outputParameters.sampleFormat              = paFloat32;                   /* 32 bit floating point output. */
+        outputParameters.suggestedLatency          = (double)outLatency / sampleRate; /* In seconds. */
+        outputParameters.hostApiSpecificStreamInfo = NULL;
+        
+        printf("Latency = %d frames = %6.1f msec.\n", outLatency, outputParameters.suggestedLatency * 1000.0 );
+
+        err = Pa_OpenStream(
+                  &stream,
+                  NULL, /* no input */
+                  &outputParameters,
+                  sampleRate,
+                  framesPerBuffer,
+                  paClipOff,      /* we won't output out of range samples so don't bother clipping them */
+                  paminlatCallback,
+                  &data );
+        if( err != paNoError ) goto error;
+        if( stream == NULL ) goto error;
+
+        /* Start audio. */
+        err = Pa_StartStream( stream );
+        if( err != paNoError ) goto error;
+
+        /* Ask user for a new nlatency. */
+        printf("\nMove windows around to see if the sound glitches.\n");
+        printf("Latency now %d, enter new number of frames, or 'q' to quit: ", outLatency );
+        line = fgets( str, 256, stdin );
+		if( line == NULL )
+		{
+			go = 0;
+		}
+		else
+		{
+			{
+				/* Get rid of newline */
+				size_t l = strlen( str ) - 1;
+				if( str[ l ] == '\n')
+					str[ l ] = '\0';
+			}
+			
+			
+			if( str[0] == 'q' ) go = 0;
+			else
+			{
+				outLatency = atol( str );
+				if( outLatency < minLatency )
+				{
+					printf( "Latency below minimum of %d! Set to minimum!!!\n", minLatency );
+					outLatency = minLatency;
+				}
+			}
+			
+		}
+		/* Stop sound until ENTER hit. */
+        err = Pa_StopStream( stream );
+        if( err != paNoError ) goto error;
+        err = Pa_CloseStream( stream );
+        if( err != paNoError ) goto error;
+    }
+    printf("A good setting for latency would be somewhat higher than\n");
+    printf("the minimum latency that worked.\n");
+    printf("PortAudio: Test finished.\n");
+    Pa_Terminate();
+    return 0;
+error:
+    Pa_Terminate();
+    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;
+}