| /** @file patest_sync.c |
| @ingroup test_src |
| @brief 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 |
| */ |
| /* |
| * $Id$ |
| * |
| * 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" |
| #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; |
| volatile 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( const 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; i<framesPerBuffer; i++ ) |
| { |
| switch( data->state ) |
| { |
| 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(); |
| if (outputParameters.device == paNoDevice) { |
| fprintf(stderr,"Error: No default output device.\n"); |
| goto error; |
| } |
| 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<NUM_BEEPS; i++ ) |
| { |
| /* Request a beep from background. */ |
| DATA.requestBeep = 1; |
| |
| /* Wait for background to acknowledge request. */ |
| timeout = TIMEOUT_MSEC; |
| while( (DATA.requestBeep == 1) && (timeout-- > 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; |
| } |