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Diffstat (limited to '3rdparty/portaudio/test/pa_minlat.c')
| -rw-r--r-- | 3rdparty/portaudio/test/pa_minlat.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/3rdparty/portaudio/test/pa_minlat.c b/3rdparty/portaudio/test/pa_minlat.c new file mode 100644 index 0000000..683b2bb --- /dev/null +++ b/3rdparty/portaudio/test/pa_minlat.c @@ -0,0 +1,205 @@ +/** @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 occurred while using the portaudio stream\n" ); + fprintf( stderr, "Error number: %d\n", err ); + fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) ); + return 1; +} |