portaudio/test/patest_suggested_vs_streaminfo_latency.c

/** @file patest_suggested_vs_streaminfo_latency.c
    @ingroup test_src
    @brief Print suggested vs. PaStreamInfo reported actual latency
    @author Ross Bencina <[email protected]>

    Opens streams with a sequence of suggested latency values
    from 0 to 2 seconds in .5ms intervals and gathers the resulting actual
    latency values. Output a csv file and graph suggested vs. actual. Run
    with framesPerBuffer unspecified, powers of 2 and multiples of 50 and
    prime number buffer sizes.
*/
/*
 * $Id: patest_sine.c 1368 2008-03-01 00:38:27Z rossb $
 *
 * 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 <string.h>
#include <math.h>
#include "portaudio.h"

#define SAMPLE_RATE             (44100)
#define FRAMES_PER_BUFFER       2//(128)
#define NUM_CHANNELS            (2)

#define SUGGESTED_LATENCY_START_SECONDS     (0.0)
#define SUGGESTED_LATENCY_END_SECONDS       (2.0)
#define SUGGESTED_LATENCY_INCREMENT_SECONDS (0.0005) /* half a millisecond increments */


/* dummy callback. does nothing. never gets called */
static int patestCallback( const void *inputBuffer, void *outputBuffer,
                            unsigned long framesPerBuffer,
                            const PaStreamCallbackTimeInfo* timeInfo,
                            PaStreamCallbackFlags statusFlags,
                            void *userData )
{
    return paContinue;
}

/*******************************************************************/
static void usage()
{
    int i;
    const PaDeviceInfo *deviceInfo;
    const char *channelString;

    fprintf( stderr, "PortAudio suggested (requested) vs. resulting (reported) stream latency test\n" );
    fprintf( stderr, "Usage: x.exe input-device-index output-device-index sample-rate frames-per-buffer\n" );
    fprintf( stderr, "Use -1 for default device index, or use one of these:\n" );
    for( i=0; i < Pa_GetDeviceCount(); ++i ){
        deviceInfo = Pa_GetDeviceInfo(i);
        if( deviceInfo->maxInputChannels > 0 && deviceInfo->maxOutputChannels > 0 )
            channelString = "full-duplex";
        else if( deviceInfo->maxInputChannels > 0 )
            channelString = "input only";
        else
            channelString = "output only";

        fprintf( stderr, "%d (%s, %s, %s)\n", i, deviceInfo->name, Pa_GetHostApiInfo(deviceInfo->hostApi)->name, channelString );
    }
    Pa_Terminate();
    exit(-1);
}

int main( int argc, const char* argv[] );
int main( int argc, const char* argv[] )
{
    PaStreamParameters inputParameters, outputParameters;
    PaStream *stream;
    PaError err;
    PaTime suggestedLatency;
    const PaStreamInfo *streamInfo;
    const PaDeviceInfo *deviceInfo;
    float sampleRate = SAMPLE_RATE;
    int framesPerBuffer = FRAMES_PER_BUFFER;
    err = Pa_Initialize();
    if( err != paNoError ) goto error;

    if( argc > 1 && strcmp(argv[1],"-h") == 0 )
        usage();

    if( argc > 3 ){
        sampleRate = atoi(argv[3]);
    }

    if( argc > 4 ){
        framesPerBuffer = atoi(argv[4]);
    }

    printf("# sample rate=%f, frames per buffer=%d\n", (float)sampleRate, framesPerBuffer );

    inputParameters.device = -1;
    if( argc > 1 )
        inputParameters.device = atoi(argv[1]);
    if( inputParameters.device == -1 ){
        inputParameters.device = Pa_GetDefaultInputDevice();
        if (inputParameters.device == paNoDevice) {
            fprintf(stderr,"Error: No default input device available.\n");
            goto error;
        }
    }else{
        deviceInfo = Pa_GetDeviceInfo(inputParameters.device);
        if( !deviceInfo ){
            fprintf(stderr,"Error: Invalid input device index.\n");
            usage();
        }
        if( deviceInfo->maxInputChannels == 0 ){
            fprintf(stderr,"Error: Specified input device has no input channels (an output only device?).\n");
            usage();
        }
    }

    inputParameters.channelCount = NUM_CHANNELS;
    inputParameters.sampleFormat = paFloat32; /* 32 bit floating point output */
    inputParameters.hostApiSpecificStreamInfo = NULL;

    deviceInfo = Pa_GetDeviceInfo(inputParameters.device);
    printf( "# using input device id %d (%s, %s)\n", inputParameters.device, deviceInfo->name, Pa_GetHostApiInfo(deviceInfo->hostApi)->name );


    outputParameters.device = -1;
    if( argc > 2 )
        outputParameters.device = atoi(argv[2]);
    if( outputParameters.device == -1 ){
        outputParameters.device = Pa_GetDefaultOutputDevice();
        if (outputParameters.device == paNoDevice) {
            fprintf(stderr,"Error: No default output device available.\n");
            goto error;
        }
    }else{
        deviceInfo = Pa_GetDeviceInfo(outputParameters.device);
        if( !deviceInfo ){
            fprintf(stderr,"Error: Invalid output device index.\n");
            usage();
        }
        if( deviceInfo->maxOutputChannels == 0 ){
            fprintf(stderr,"Error: Specified output device has no output channels (an input only device?).\n");
            usage();
        }
    }

    outputParameters.channelCount = NUM_CHANNELS;
    outputParameters.sampleFormat = paFloat32; /* 32 bit floating point output */
    outputParameters.hostApiSpecificStreamInfo = NULL;

    deviceInfo = Pa_GetDeviceInfo(outputParameters.device);
    printf( "# using output device id %d (%s, %s)\n", outputParameters.device, deviceInfo->name, Pa_GetHostApiInfo(deviceInfo->hostApi)->name );


    printf( "# suggested latency, half duplex PaStreamInfo::outputLatency, half duplex PaStreamInfo::inputLatency, full duplex PaStreamInfo::outputLatency, full duplex PaStreamInfo::inputLatency\n" );
    suggestedLatency = SUGGESTED_LATENCY_START_SECONDS;
    while( suggestedLatency <= SUGGESTED_LATENCY_END_SECONDS ){

        outputParameters.suggestedLatency = suggestedLatency;
        inputParameters.suggestedLatency = suggestedLatency;

        printf( "%f, ", suggestedLatency );

        /* ------------------------------ output ------------------------------ */

        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 */
                  patestCallback,
                  0 );
        if( err != paNoError ) goto error;

        streamInfo = Pa_GetStreamInfo( stream );

        printf( "%f,", streamInfo->outputLatency  );

        err = Pa_CloseStream( stream );
        if( err != paNoError ) goto error;

        /* ------------------------------ input ------------------------------ */

        err = Pa_OpenStream(
                  &stream,
                  &inputParameters,
                  NULL, /* no output */
                  sampleRate,
                  framesPerBuffer,
                  paClipOff,      /* we won't output out of range samples so don't bother clipping them */
                  patestCallback,
                  0 );
        if( err != paNoError ) goto error;

        streamInfo = Pa_GetStreamInfo( stream );

        printf( "%f,", streamInfo->inputLatency  );

        err = Pa_CloseStream( stream );
        if( err != paNoError ) goto error;

        /* ------------------------------ full duplex ------------------------------ */

        err = Pa_OpenStream(
                  &stream,
                  &inputParameters,
                  &outputParameters,
                  sampleRate,
                  framesPerBuffer,
                  paClipOff,      /* we won't output out of range samples so don't bother clipping them */
                  patestCallback,
                  0 );
        if( err != paNoError ) goto error;

        streamInfo = Pa_GetStreamInfo( stream );

        printf( "%f,%f", streamInfo->outputLatency, streamInfo->inputLatency );

        err = Pa_CloseStream( stream );
        if( err != paNoError ) goto error;

        /* ------------------------------------------------------------ */

        printf( "\n" );
        suggestedLatency += SUGGESTED_LATENCY_INCREMENT_SECONDS;
    }

    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;
}