/* * $Id: patest_sync.c,v 1.1.1.1 2003-05-09 16:03:56 ggeiger Exp $ * patest_sync.c * Test time stamping and synchronization of audio and video. * A high latency is used so we can hear the difference in time. * Random durations are used so we know we are hearing the right beep * and not the one before or after. * * Sequence of events: * Foreground requests a beep. * Background randomly schedules a beep. * Foreground waits for the beep to be heard based on PaUtil_GetTime(). * Foreground outputs video (printf) in sync with audio. * Repeat. * * 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 #include #include "portaudio.h" #include "pa_util.h" #define NUM_BEEPS (6) #define SAMPLE_RATE (44100) #define SAMPLE_PERIOD (1.0/44100.0) #define FRAMES_PER_BUFFER (256) #define BEEP_DURATION (400) #define LATENCY_MSEC (2000) #define SLEEP_MSEC (10) #define TIMEOUT_MSEC (15000) #define STATE_BKG_IDLE (0) #define STATE_BKG_PENDING (1) #define STATE_BKG_BEEPING (2) typedef struct { float left_phase; float right_phase; int state; int requestBeep; /* Set by foreground, cleared by background. */ PaTime beepTime; int beepCount; double latency; /* For debugging. */ } paTestData; static unsigned long GenerateRandomNumber( void ); /************************************************************/ /* Calculate pseudo-random 32 bit number based on linear congruential method. */ static unsigned long GenerateRandomNumber( void ) { static unsigned long randSeed = 99887766; /* Change this for different random sequences. */ randSeed = (randSeed * 196314165) + 907633515; return randSeed; } /* 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( void *inputBuffer, void *outputBuffer, unsigned long framesPerBuffer, const PaStreamCallbackTimeInfo *timeInfo, PaStreamCallbackFlags statusFlags, void *userData ) { /* Cast data passed through stream to our structure. */ paTestData *data = (paTestData*)userData; float *out = (float*)outputBuffer; unsigned int i; (void) inputBuffer; data->latency = timeInfo->outputBufferDacTime - timeInfo->currentTime; for( i=0; istate ) { case STATE_BKG_IDLE: /* Schedule beep at some random time in the future. */ if( data->requestBeep ) { int random = GenerateRandomNumber() >> 14; data->beepTime = timeInfo->outputBufferDacTime + (( (double)(random + SAMPLE_RATE)) * SAMPLE_PERIOD ); data->state = STATE_BKG_PENDING; } *out++ = 0.0; /* left */ *out++ = 0.0; /* right */ break; case STATE_BKG_PENDING: if( (timeInfo->outputBufferDacTime + (i*SAMPLE_PERIOD)) >= data->beepTime ) { data->state = STATE_BKG_BEEPING; data->beepCount = BEEP_DURATION; data->left_phase = data->right_phase = 0.0; } *out++ = 0.0; /* left */ *out++ = 0.0; /* right */ break; case STATE_BKG_BEEPING: if( data->beepCount <= 0 ) { data->state = STATE_BKG_IDLE; data->requestBeep = 0; *out++ = 0.0; /* left */ *out++ = 0.0; /* right */ } else { /* Play sawtooth wave. */ *out++ = data->left_phase; /* left */ *out++ = data->right_phase; /* right */ /* Generate simple sawtooth phaser that ranges between -1.0 and 1.0. */ data->left_phase += 0.01f; /* When signal reaches top, drop back down. */ if( data->left_phase >= 1.0f ) data->left_phase -= 2.0f; /* higher pitch so we can distinguish left and right. */ data->right_phase += 0.03f; if( data->right_phase >= 1.0f ) data->right_phase -= 2.0f; } data->beepCount -= 1; break; default: data->state = STATE_BKG_IDLE; break; } } return 0; } /*******************************************************************/ int main(void); int main(void) { PaStream *stream; PaError err; paTestData DATA; int i, timeout; PaTime previousTime; PaStreamParameters outputParameters; printf("PortAudio Test: you should see BEEP at the same time you hear it.\n"); printf("Wait for a few seconds random delay between BEEPs.\n"); printf("BEEP %d times.\n", NUM_BEEPS ); /* Initialize our DATA for use by callback. */ DATA.left_phase = DATA.right_phase = 0.0; DATA.state = STATE_BKG_IDLE; DATA.requestBeep = 0; /* Initialize library before making any other calls. */ err = Pa_Initialize(); if( err != paNoError ) goto error; outputParameters.device = Pa_GetDefaultOutputDevice(); outputParameters.channelCount = 2; outputParameters.hostApiSpecificStreamInfo = NULL; outputParameters.sampleFormat = paFloat32; outputParameters.suggestedLatency = (double)LATENCY_MSEC / 1000; /* Open an audio I/O stream. */ err = Pa_OpenStream( &stream, NULL, /* no input */ &outputParameters, SAMPLE_RATE, FRAMES_PER_BUFFER, /* frames per buffer */ paClipOff, /* 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("started\n"); fflush(stdout); previousTime = Pa_GetStreamTime( stream ); for( i=0; i 0 ) ) Pa_Sleep(SLEEP_MSEC); if( timeout <= 0 ) { fprintf( stderr, "Timed out waiting for background to acknowledge request.\n" ); goto error; } printf("calc beep for %9.3f, latency = %6.3f\n", DATA.beepTime, DATA.latency ); fflush(stdout); /* Wait for scheduled beep time. */ timeout = TIMEOUT_MSEC + (10000/SLEEP_MSEC); while( (Pa_GetStreamTime( stream ) < DATA.beepTime) && (timeout-- > 0 ) ) { Pa_Sleep(SLEEP_MSEC); } if( timeout <= 0 ) { fprintf( stderr, "Timed out waiting for time. Now = %9.3f, Beep for %9.3f.\n", PaUtil_GetTime(), DATA.beepTime ); goto error; } /* Beep should be sounding now so print synchronized BEEP. */ printf("hear \"BEEP\" at %9.3f, delta = %9.3f\n", Pa_GetStreamTime( stream ), (DATA.beepTime - previousTime) ); fflush(stdout); previousTime = DATA.beepTime; } err = Pa_StopStream( stream ); if( err != paNoError ) goto error; err = Pa_CloseStream( stream ); if( err != paNoError ) goto error; Pa_Terminate(); printf("Test finished.\n"); return err; 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 err; }