Björn - I'll give a good write-up of a practical implementation tomorrow when I'm in front of a computer. I've written a fair number of products with both portaudio and portmidi
Bjorn Roche <[email protected]> wrote: >My updated code is below. I no longer get the dropped note off message >(although I'm still unclear as to why I got that in the first place). >I started with code from Phil and Ross's sine wave generating code, so >hence the credits and license. > >Any suggestions for cleanup/correctness (especially if it isn't >obvious) please let me know. I am going to tinker a bit with the Dac/ >stream time issue tomorrow if I have time. > > bjorn > > >/** @file main.c > @brief Play a sine wave and a MIDI note every second for ten seconds. > @author Bjorn Roche > @author Ross Bencina <[email protected]> > @author Phil Burk <[email protected]> >*/ >/* > * This program demonstrates the synchronization of PortAudio and >PortMIDI. > * > * For more information see: http://www.portaudio.com/ > * and http://portmedia.sourceforge.net/ > * > * Copyright (c) Bjorn Roche, Ross Bencina and Phil Burk 2011 > * > * 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 <limits.h> >#include "src/portaudio.h" >#include "src/portmidi.h" > >#define NUM_SECONDS (10) >#define SAMPLE_RATE (44100) >#define FRAMES_PER_BUFFER (64) >//middle C (C4) >#define PITCH (261.63) >#define TONE_LENGTH (.5) > >#define MIDI_OUTPUT_BUFFER_SIZE (100) > >#ifndef M_PI >#define M_PI (3.14159265) >#endif > >PmTimestamp timeProc(void *timeData) { > PaStream *pas = (PaStream *) timeData ; > PaTime t = Pa_GetStreamTime( pas ); > return (PmTimestamp) (int64_t) ( t * 1000 + .5 ) ; >} > >typedef struct >{ > //this is used to mark when we've initialized the start time > int once; > PmTimestamp start; > PortMidiStream *midiStream; > //each on-off cycle is one iteration > int iterations; > // counts down the number of samples until we start the next tone > int countdown; > // counts down the number of samples in the current tone > int tonetime; >} >paTestData; > >/* 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; > unsigned long i; > > if( !data->once ) { > data->once = 1; > //initialize start time > data->start = (PmTimestamp) ( timeInfo->outputBufferDacTime * >1000 + .5 ); > } > > (void) timeInfo; /* Prevent unused variable warnings. */ > (void) statusFlags; > (void) inputBuffer; > > for( i=0; i<framesPerBuffer; i++ ) > { > if( data->countdown == SAMPLE_RATE ) { > if( data->iterations<NUM_SECONDS ) { > //Note: Priority inversions may make this unsafe to >call in PA Callback on ALSA (unconfirmed) > Pm_WriteShort( data->midiStream, > data->start + (data->iterations)*1000, > Pm_Message( 0x90, 0x3C, 0x60 ) ); > } > ++data->iterations; > data->tonetime = (int) (SAMPLE_RATE * TONE_LENGTH + .5 ) ; > } > if( data->tonetime > 0 && data->iterations-1<NUM_SECONDS ) { > int t = data->tonetime - (int) (SAMPLE_RATE * TONE_LENGTH >+ .5 ) ; > //play the tone on the left and right side: > *out++ = sin( 2. * M_PI * PITCH * t / SAMPLE_RATE ) ; > *out++ = sin( 2. * M_PI * PITCH * t / SAMPLE_RATE ) ; > } else { > if( data->tonetime == 0 && data- > >iterations-1<NUM_SECONDS ) { > Pm_WriteShort( data->midiStream, > data->start + (data->iterations-1)*1000+(int) >(1000*TONE_LENGTH+.5), > Pm_Message( 0x80, 0x3C, 0x00 ) ); > } > *out++ = 0; > *out++ = 0; > } > --data->tonetime; > > if( data->countdown == 0 ) > data->countdown = SAMPLE_RATE; //one second > else > --data->countdown; > } > > return paContinue; >} > >/* > * This routine is called by portaudio when playback is done. > */ >static void StreamFinished( void* userData ) >{ > //may want to send all-notes off here. > //paTestData *data = (paTestData *) userData; > printf( "Stream Completed." ); >} > >/*******************************************************************/ >int main(void); >int main(void) >{ > PaStreamParameters outputParameters; > PaStream *stream; > PaError paErr = paNoError; > PmError pmErr = pmNoError; > paTestData data; > PortMidiStream *midiStream; > PmDeviceID defaultPmDevice; > long latency1, latency2; > > printf("Sync Test: Opening Stream. SR = %d, BufSize = %d\n", >SAMPLE_RATE, FRAMES_PER_BUFFER); > > /* initialize countdown data */ > data.countdown = SAMPLE_RATE ; > data.tonetime = (int) (SAMPLE_RATE * TONE_LENGTH + .5 ) ; > data.once = 0; > data.iterations = 0; > > paErr = Pa_Initialize(); > if( paErr != paNoError ) goto error; > > pmErr = Pm_Initialize(); > if( pmErr != pmNoError ) goto error; > > /* > * Setup the Audio output stream > */ > outputParameters.device = Pa_GetDefaultOutputDevice(); /* default >audio output device */ > if (outputParameters.device == paNoDevice) { > fprintf(stderr,"Error: No default audio 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; > > paErr = Pa_OpenStream( > &stream, > NULL, /* no input */ > &outputParameters, > SAMPLE_RATE, > FRAMES_PER_BUFFER, > paClipOff, /* we won't output out of range samples >so don't bother clipping them */ > patestCallback, > &data ); > if( paErr != paNoError ) goto error; > > paErr = Pa_SetStreamFinishedCallback( stream, &StreamFinished ); > if( paErr != paNoError ) goto error; > > /* > * Setup the midi output stream > */ > defaultPmDevice = Pm_GetDefaultOutputDeviceID(); > if( defaultPmDevice == pmNoDevice ) { > fprintf( stderr, "Error: no portmidi default device found." ); > goto error; > } > // calculate latency > latency1 = (long) ( Pa_GetStreamInfo(stream)->outputLatency * >1000 + .5 ) ; > latency2 = (long) ( FRAMES_PER_BUFFER * 1000 * 2. / SAMPLE_RATE >+ .5 ) ; > if( latency1 == 0 || latency2 > latency1 ) > latency1 = latency2; > if( latency1 == 0 ) > latency1 = 10; > //actually open: > pmErr = Pm_OpenOutput( &midiStream, > defaultPmDevice, > NULL, > MIDI_OUTPUT_BUFFER_SIZE, > &timeProc, > stream, > latency1 ); > if( pmErr != pmNoError ) goto error; > data.midiStream = midiStream; > > /* > * start the audio stream > */ > paErr = Pa_StartStream( stream ); > if( paErr != paNoError ) goto error; > > printf("Play for %d seconds.\n", NUM_SECONDS ); > Pa_Sleep( NUM_SECONDS * 1000 ); > > paErr = Pa_StopStream( stream ); > if( paErr != paNoError ) goto error; > > paErr = Pa_CloseStream( stream ); > if( paErr != paNoError ) goto error; > > pmErr = Pm_Close( midiStream ); > if( pmErr != pmNoError ) goto error; > > Pa_Terminate(); > Pm_Terminate(); > printf("Test finished.\n"); > > return paErr; >error: > Pa_Terminate(); > if( paErr != paNoError ) { > fprintf( stderr, "An error occured while using the portaudio >stream\n" ); > fprintf( stderr, "PA Error number: %d\n", paErr ); > fprintf( stderr, "Error message: %s\n", >Pa_GetErrorText( paErr ) ); > } else { > fprintf( stderr, "An error occured while using PortMIDI\n" ); > fprintf( stderr, "PM Error number: %d\n", pmErr ); > fprintf( stderr, "Error message: %s\n", >Pa_GetErrorText( pmErr ) ); > } > return paErr; >} >_______________________________________________ >media_api mailing list >[email protected] >http://lists.create.ucsb.edu/mailman/listinfo/media_api _______________________________________________ media_api mailing list [email protected] http://lists.create.ucsb.edu/mailman/listinfo/media_api
