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Diffstat (limited to 'portaudio/test/patest_latency.c')
| -rw-r--r-- | portaudio/test/patest_latency.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/portaudio/test/patest_latency.c b/portaudio/test/patest_latency.c new file mode 100644 index 0000000..7f622c1 --- /dev/null +++ b/portaudio/test/patest_latency.c @@ -0,0 +1,193 @@ +/** @file + @ingroup test_src + @brief Hear the latency caused by big buffers. + Play a sine wave and change frequency based on letter input. + @author Phil Burk <philburk@softsynth.com>, and Darren Gibbs +*/ +/* + * $Id$ + * + * 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 OUTPUT_DEVICE (Pa_GetDefaultOutputDevice()) +#define SAMPLE_RATE (44100) +#define FRAMES_PER_BUFFER (64) + +#define MIN_FREQ (100.0f) +#define CalcPhaseIncrement(freq) ((freq)/SAMPLE_RATE) +#ifndef M_PI +#define M_PI (3.14159265) +#endif +#define TABLE_SIZE (400) + +typedef struct +{ + float sine[TABLE_SIZE + 1]; /* add one for guard point for interpolation */ + float phase_increment; + float left_phase; + float right_phase; +} +paTestData; + +float LookupSine( paTestData *data, float phase ); +/* Convert phase between and 1.0 to sine value + * using linear interpolation. + */ +float LookupSine( paTestData *data, float phase ) +{ + float fIndex = phase*TABLE_SIZE; + int index = (int) fIndex; + float fract = fIndex - index; + float lo = data->sine[index]; + float hi = data->sine[index+1]; + float val = lo + fract*(hi-lo); + return val; +} + +/* 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 patestCallback( const void *inputBuffer, void *outputBuffer, + unsigned long framesPerBuffer, + const PaStreamCallbackTimeInfo* timeInfo, + PaStreamCallbackFlags statusFlags, + void *userData ) +{ + paTestData *data = (paTestData*)userData; + float *out = (float*)outputBuffer; + int i; + + (void) inputBuffer; /* Prevent unused variable warning. */ + + for( i=0; i<framesPerBuffer; i++ ) + { + *out++ = LookupSine(data, data->left_phase); /* left */ + *out++ = LookupSine(data, data->right_phase); /* right */ + data->left_phase += data->phase_increment; + if( data->left_phase >= 1.0f ) data->left_phase -= 1.0f; + data->right_phase += (data->phase_increment * 1.5f); /* fifth above */ + if( data->right_phase >= 1.0f ) data->right_phase -= 1.0f; + } + return 0; +} + +/*******************************************************************/ +int main(void); +int main(void) +{ + PaStream *stream; + PaStreamParameters outputParameters; + PaError err; + paTestData data; + int i; + int done = 0; + + printf("PortAudio Test: enter letter then hit ENTER.\n" ); + /* initialise sinusoidal wavetable */ + for( i=0; i<TABLE_SIZE; i++ ) + { + data.sine[i] = 0.90f * (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. ); + } + data.sine[TABLE_SIZE] = data.sine[0]; /* set guard point. */ + data.left_phase = data.right_phase = 0.0; + data.phase_increment = CalcPhaseIncrement(MIN_FREQ); + + err = Pa_Initialize(); + if( err != paNoError ) goto error; + printf("PortAudio Test: output device = %d\n", OUTPUT_DEVICE ); + + outputParameters.device = OUTPUT_DEVICE; + if (outputParameters.device == paNoDevice) { + fprintf(stderr,"Error: No default output device.\n"); + goto error; + } + outputParameters.channelCount = 2; /* stereo output */ + outputParameters.sampleFormat = paFloat32; /* 32 bit floating point output */ + outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency; + outputParameters.hostApiSpecificStreamInfo = NULL; + + printf("Requested output latency = %.4f seconds.\n", outputParameters.suggestedLatency ); + printf("%d frames per buffer.\n.", FRAMES_PER_BUFFER ); + + err = Pa_OpenStream( + &stream, + NULL, /* no input */ + &outputParameters, + SAMPLE_RATE, + FRAMES_PER_BUFFER, + paClipOff|paDitherOff, /* we won't output out of range samples so don't bother clipping them */ + patestCallback, + &data ); + if( err != paNoError ) goto error; + + err = Pa_StartStream( stream ); + if( err != paNoError ) goto error; + printf("Play ASCII keyboard. Hit 'q' to stop. (Use RETURN key on Mac)\n"); + fflush(stdout); + while ( !done ) + { + float freq; + int index; + char c; + do + { + c = getchar(); + } + while( c < ' '); /* Strip white space and control chars. */ + + if( c == 'q' ) done = 1; + index = c % 26; + freq = MIN_FREQ + (index * 40.0); + data.phase_increment = CalcPhaseIncrement(freq); + } + printf("Call Pa_StopStream()\n"); + err = Pa_StopStream( stream ); + if( err != paNoError ) goto error; + Pa_Terminate(); + printf("Test finished.\n"); + return err; +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 err; +} |