483 lines
		
	
	
		
			18 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			483 lines
		
	
	
		
			18 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
|   | /** @file paqa_latency.c
 | ||
|  |     @ingroup qa_src | ||
|  |     @brief Test latency estimates. | ||
|  |     @author Ross Bencina <rossb@audiomulch.com> | ||
|  |     @author Phil Burk <philburk@softsynth.com> | ||
|  | */ | ||
|  | /*
 | ||
|  |  * $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 <math.h>
 | ||
|  | #include "portaudio.h"
 | ||
|  | #include "loopback/src/qa_tools.h"
 | ||
|  | 
 | ||
|  | #define NUM_SECONDS   (5)
 | ||
|  | #define SAMPLE_RATE   (44100)
 | ||
|  | #define FRAMES_PER_BUFFER  (64)
 | ||
|  | 
 | ||
|  | #ifndef M_PI
 | ||
|  | #define M_PI  (3.14159265)
 | ||
|  | #endif
 | ||
|  | 
 | ||
|  | #define TABLE_SIZE   (200)
 | ||
|  | typedef struct | ||
|  | { | ||
|  |     float sine[TABLE_SIZE]; | ||
|  |     int left_phase; | ||
|  |     int right_phase; | ||
|  |     char message[20]; | ||
|  |     unsigned long minFramesPerBuffer; | ||
|  |     unsigned long maxFramesPerBuffer; | ||
|  |     int callbackCount; | ||
|  |     PaTime minDeltaDacTime; | ||
|  |     PaTime maxDeltaDacTime; | ||
|  |     PaStreamCallbackTimeInfo previousTimeInfo; | ||
|  | } | ||
|  | paTestData; | ||
|  | 
 | ||
|  | /* Used to tally the results of the QA tests. */ | ||
|  | int g_testsPassed = 0; | ||
|  | int g_testsFailed = 0; | ||
|  | 
 | ||
|  | /* 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; | ||
|  | 
 | ||
|  |     (void) timeInfo; /* Prevent unused variable warnings. */ | ||
|  |     (void) statusFlags; | ||
|  |     (void) inputBuffer; | ||
|  | 
 | ||
|  |     if( data->minFramesPerBuffer > framesPerBuffer ) | ||
|  |     { | ||
|  |         data->minFramesPerBuffer = framesPerBuffer; | ||
|  |     } | ||
|  |     if( data->maxFramesPerBuffer < framesPerBuffer ) | ||
|  |     { | ||
|  |         data->maxFramesPerBuffer = framesPerBuffer; | ||
|  |     } | ||
|  | 
 | ||
|  |     /* Measure min and max output time stamp delta. */ | ||
|  |     if( data->callbackCount > 0 ) | ||
|  |     { | ||
|  |         PaTime delta = timeInfo->outputBufferDacTime - data->previousTimeInfo.outputBufferDacTime; | ||
|  |         if( data->minDeltaDacTime > delta ) | ||
|  |         { | ||
|  |             data->minDeltaDacTime = delta; | ||
|  |         } | ||
|  |         if( data->maxDeltaDacTime < delta ) | ||
|  |         { | ||
|  |             data->maxDeltaDacTime = delta; | ||
|  |         } | ||
|  |     } | ||
|  |     data->previousTimeInfo = *timeInfo; | ||
|  | 
 | ||
|  |     for( i=0; i<framesPerBuffer; i++ ) | ||
|  |     { | ||
|  |         *out++ = data->sine[data->left_phase];  /* left */ | ||
|  |         *out++ = data->sine[data->right_phase];  /* right */ | ||
|  |         data->left_phase += 1; | ||
|  |         if( data->left_phase >= TABLE_SIZE ) data->left_phase -= TABLE_SIZE; | ||
|  |         data->right_phase += 3; /* higher pitch so we can distinguish left and right. */ | ||
|  |         if( data->right_phase >= TABLE_SIZE ) data->right_phase -= TABLE_SIZE; | ||
|  |     } | ||
|  | 
 | ||
|  |     data->callbackCount += 1; | ||
|  |     return paContinue; | ||
|  | } | ||
|  | 
 | ||
|  | PaError paqaCheckLatency( PaStreamParameters *outputParamsPtr, | ||
|  |                          paTestData *dataPtr, double sampleRate, unsigned long framesPerBuffer ) | ||
|  | { | ||
|  |     PaError err; | ||
|  |     PaStream *stream; | ||
|  |     const PaStreamInfo* streamInfo; | ||
|  | 
 | ||
|  |     dataPtr->minFramesPerBuffer = 9999999; | ||
|  |     dataPtr->maxFramesPerBuffer = 0; | ||
|  |     dataPtr->minDeltaDacTime = 9999999.0; | ||
|  |     dataPtr->maxDeltaDacTime = 0.0; | ||
|  |     dataPtr->callbackCount = 0; | ||
|  | 
 | ||
|  |     printf("Stream parameter: suggestedOutputLatency = %g\n", outputParamsPtr->suggestedLatency ); | ||
|  |     if( framesPerBuffer == paFramesPerBufferUnspecified ){ | ||
|  |         printf("Stream parameter: user framesPerBuffer = paFramesPerBufferUnspecified\n" ); | ||
|  |     }else{ | ||
|  |         printf("Stream parameter: user framesPerBuffer = %lu\n", framesPerBuffer ); | ||
|  |     } | ||
|  |     err = Pa_OpenStream( | ||
|  |                         &stream, | ||
|  |                         NULL, /* no input */ | ||
|  |                         outputParamsPtr, | ||
|  |                         sampleRate, | ||
|  |                         framesPerBuffer, | ||
|  |                         paClipOff,      /* we won't output out of range samples so don't bother clipping them */ | ||
|  |                         patestCallback, | ||
|  |                         dataPtr ); | ||
|  |     if( err != paNoError ) goto error1; | ||
|  | 
 | ||
|  |     streamInfo = Pa_GetStreamInfo( stream ); | ||
|  |     printf("Stream info: inputLatency  = %g\n", streamInfo->inputLatency ); | ||
|  |     printf("Stream info: outputLatency = %g\n", streamInfo->outputLatency ); | ||
|  | 
 | ||
|  |     err = Pa_StartStream( stream ); | ||
|  |     if( err != paNoError ) goto error2; | ||
|  | 
 | ||
|  |     printf("Play for %d seconds.\n", NUM_SECONDS ); | ||
|  |     Pa_Sleep( NUM_SECONDS * 1000 ); | ||
|  | 
 | ||
|  |     printf("  minFramesPerBuffer = %4lu\n", dataPtr->minFramesPerBuffer ); | ||
|  |     printf("  maxFramesPerBuffer = %4lu\n", dataPtr->maxFramesPerBuffer ); | ||
|  |     printf("  minDeltaDacTime = %f\n", dataPtr->minDeltaDacTime ); | ||
|  |     printf("  maxDeltaDacTime = %f\n", dataPtr->maxDeltaDacTime ); | ||
|  | 
 | ||
|  |     err = Pa_StopStream( stream ); | ||
|  |     if( err != paNoError ) goto error2; | ||
|  | 
 | ||
|  |     err = Pa_CloseStream( stream ); | ||
|  |     Pa_Sleep( 1 * 1000 ); | ||
|  | 
 | ||
|  | 
 | ||
|  |     printf("-------------------------------------\n"); | ||
|  |     return err; | ||
|  | error2: | ||
|  |     Pa_CloseStream( stream ); | ||
|  | error1: | ||
|  |     printf("-------------------------------------\n"); | ||
|  |     return err; | ||
|  | } | ||
|  | 
 | ||
|  | 
 | ||
|  | /*******************************************************************/ | ||
|  | static int paqaNoopCallback( const void *inputBuffer, void *outputBuffer, | ||
|  |                           unsigned long framesPerBuffer, | ||
|  |                           const PaStreamCallbackTimeInfo* timeInfo, | ||
|  |                           PaStreamCallbackFlags statusFlags, | ||
|  |                           void *userData ) | ||
|  | { | ||
|  |     (void)inputBuffer; | ||
|  |     (void)outputBuffer; | ||
|  |     (void)framesPerBuffer; | ||
|  |     (void)timeInfo; | ||
|  |     (void)statusFlags; | ||
|  |     (void)userData; | ||
|  |     return paContinue; | ||
|  | } | ||
|  | 
 | ||
|  | /*******************************************************************/ | ||
|  | static int paqaCheckMultipleSuggested( PaDeviceIndex deviceIndex, int isInput ) | ||
|  | { | ||
|  |     int i; | ||
|  |     int numLoops = 10; | ||
|  |     PaError err; | ||
|  |     PaStream *stream; | ||
|  |     PaStreamParameters streamParameters; | ||
|  |     const PaStreamInfo* streamInfo; | ||
|  |     double lowLatency; | ||
|  |     double highLatency; | ||
|  |     double finalLatency; | ||
|  |     double sampleRate = SAMPLE_RATE; | ||
|  |     const PaDeviceInfo *pdi = Pa_GetDeviceInfo( deviceIndex ); | ||
|  |     double previousLatency = 0.0; | ||
|  |     int numChannels = 1; | ||
|  |     float toleranceRatio = 1.0; | ||
|  | 
 | ||
|  |     printf("------------------------ paqaCheckMultipleSuggested - %s\n", | ||
|  |            (isInput ? "INPUT" : "OUTPUT") ); | ||
|  |     if( isInput ) | ||
|  |     { | ||
|  |         lowLatency = pdi->defaultLowInputLatency; | ||
|  |         highLatency = pdi->defaultHighInputLatency; | ||
|  |         numChannels = (pdi->maxInputChannels < 2) ? 1 : 2; | ||
|  |     } | ||
|  |     else | ||
|  |     { | ||
|  |         lowLatency = pdi->defaultLowOutputLatency; | ||
|  |         highLatency = pdi->defaultHighOutputLatency; | ||
|  |         numChannels = (pdi->maxOutputChannels < 2) ? 1 : 2; | ||
|  |     } | ||
|  |     streamParameters.channelCount = numChannels; | ||
|  |     streamParameters.device = deviceIndex; | ||
|  |     streamParameters.hostApiSpecificStreamInfo = NULL; | ||
|  |     streamParameters.sampleFormat = paFloat32; | ||
|  |     sampleRate = pdi->defaultSampleRate; | ||
|  | 
 | ||
|  |     printf(" lowLatency  = %g\n", lowLatency ); | ||
|  |     printf(" highLatency = %g\n", highLatency ); | ||
|  |     printf(" numChannels = %d\n", numChannels ); | ||
|  |     printf(" sampleRate  = %g\n", sampleRate ); | ||
|  | 
 | ||
|  |     if( (highLatency - lowLatency) < 0.001 ) | ||
|  |     { | ||
|  |         numLoops = 1; | ||
|  |     } | ||
|  | 
 | ||
|  |     for( i=0; i<numLoops; i++ ) | ||
|  |     { | ||
|  |         if( numLoops == 1 ) | ||
|  |             streamParameters.suggestedLatency = lowLatency; | ||
|  |         else | ||
|  |             streamParameters.suggestedLatency = lowLatency + ((highLatency - lowLatency) * i /(numLoops - 1)); | ||
|  | 
 | ||
|  |         printf("   suggestedLatency[%d] = %6.4f\n", i, streamParameters.suggestedLatency ); | ||
|  | 
 | ||
|  |         err = Pa_OpenStream( | ||
|  |                             &stream, | ||
|  |                             (isInput ? &streamParameters : NULL), | ||
|  |                             (isInput ? NULL : &streamParameters), | ||
|  |                             sampleRate, | ||
|  |                             paFramesPerBufferUnspecified, | ||
|  |                             paClipOff,      /* we won't output out of range samples so don't bother clipping them */ | ||
|  |                             paqaNoopCallback, | ||
|  |                             NULL ); | ||
|  |         if( err != paNoError ) goto error; | ||
|  | 
 | ||
|  |         streamInfo = Pa_GetStreamInfo( stream ); | ||
|  | 
 | ||
|  |         err = Pa_CloseStream( stream ); | ||
|  | 
 | ||
|  |         if( isInput ) | ||
|  |         { | ||
|  |             finalLatency = streamInfo->inputLatency; | ||
|  |         } | ||
|  |         else | ||
|  |         { | ||
|  |             finalLatency = streamInfo->outputLatency; | ||
|  |         } | ||
|  |         printf("          finalLatency = %6.4f\n", finalLatency ); | ||
|  |         /* For the default low & high latency values, expect quite close; for other requested
 | ||
|  |          * values, at worst the next power-of-2 may result (eg 513 -> 1024) */ | ||
|  |         toleranceRatio = ( (i == 0) || (i == ( numLoops - 1 )) ) ? 0.1 : 1.0; | ||
|  |         QA_ASSERT_CLOSE( "final latency should be close to suggested latency", | ||
|  |                         streamParameters.suggestedLatency, finalLatency, (streamParameters.suggestedLatency * toleranceRatio) ); | ||
|  |         if( i == 0 ) | ||
|  |         { | ||
|  |             previousLatency = finalLatency; | ||
|  |         } | ||
|  |     } | ||
|  | 
 | ||
|  |     if( numLoops > 1 ) | ||
|  |     { | ||
|  |         QA_ASSERT_TRUE( " final latency should increase with suggested latency", (finalLatency > previousLatency) ); | ||
|  |     } | ||
|  | 
 | ||
|  |     return 0; | ||
|  | error: | ||
|  |     return -1; | ||
|  | } | ||
|  | 
 | ||
|  | /*******************************************************************/ | ||
|  | static int paqaVerifySuggestedLatency( void ) | ||
|  | { | ||
|  |     PaDeviceIndex id; | ||
|  |     int result = 0; | ||
|  |     const PaDeviceInfo *pdi; | ||
|  |     int numDevices = Pa_GetDeviceCount(); | ||
|  | 
 | ||
|  |     printf("\n ------------------------ paqaVerifySuggestedLatency\n"); | ||
|  |     for( id=0; id<numDevices; id++ )            /* Iterate through all devices. */ | ||
|  |     { | ||
|  |         pdi = Pa_GetDeviceInfo( id ); | ||
|  |         printf("\nUsing device #%d: '%s' (%s)\n", id, pdi->name, Pa_GetHostApiInfo(pdi->hostApi)->name); | ||
|  |         if( pdi->maxOutputChannels > 0 ) | ||
|  |         { | ||
|  |             if( paqaCheckMultipleSuggested( id, 0 ) < 0 ) | ||
|  |             { | ||
|  |                 printf("OUTPUT CHECK FAILED !!! #%d: '%s'\n", id, pdi->name); | ||
|  |                 result -= 1; | ||
|  |             } | ||
|  |         } | ||
|  |         if( pdi->maxInputChannels > 0 ) | ||
|  |         { | ||
|  |             if( paqaCheckMultipleSuggested( id, 1 ) < 0 ) | ||
|  |             { | ||
|  |                 printf("INPUT CHECK FAILED !!! #%d: '%s'\n", id, pdi->name); | ||
|  |                 result -= 1; | ||
|  |             } | ||
|  |         } | ||
|  |     } | ||
|  |     return result; | ||
|  | } | ||
|  | 
 | ||
|  | /*******************************************************************/ | ||
|  | static int paqaVerifyDeviceInfoLatency( void ) | ||
|  | { | ||
|  |     PaDeviceIndex id; | ||
|  |     const PaDeviceInfo *pdi; | ||
|  |     int numDevices = Pa_GetDeviceCount(); | ||
|  | 
 | ||
|  |     printf("\n ------------------------ paqaVerifyDeviceInfoLatency\n"); | ||
|  |     for( id=0; id<numDevices; id++ ) /* Iterate through all devices. */ | ||
|  |     { | ||
|  |         pdi = Pa_GetDeviceInfo( id ); | ||
|  |         printf("Using device #%d: '%s' (%s)\n", id, pdi->name, Pa_GetHostApiInfo(pdi->hostApi)->name); | ||
|  |         if( pdi->maxOutputChannels > 0 ) | ||
|  |         { | ||
|  |             printf("  Output defaultLowOutputLatency  = %f seconds\n", pdi->defaultLowOutputLatency); | ||
|  |             printf("  Output defaultHighOutputLatency = %f seconds\n", pdi->defaultHighOutputLatency); | ||
|  |             QA_ASSERT_TRUE( "defaultLowOutputLatency should be > 0", (pdi->defaultLowOutputLatency > 0.0) ); | ||
|  |             QA_ASSERT_TRUE( "defaultHighOutputLatency should be > 0", (pdi->defaultHighOutputLatency > 0.0) ); | ||
|  |             QA_ASSERT_TRUE( "defaultHighOutputLatency should be >= Low", (pdi->defaultHighOutputLatency >= pdi->defaultLowOutputLatency) ); | ||
|  |         } | ||
|  |         if( pdi->maxInputChannels > 0 ) | ||
|  |         { | ||
|  |             printf("  Input defaultLowInputLatency  = %f seconds\n", pdi->defaultLowInputLatency); | ||
|  |             printf("  Input defaultHighInputLatency = %f seconds\n", pdi->defaultHighInputLatency); | ||
|  |             QA_ASSERT_TRUE( "defaultLowInputLatency should be > 0", (pdi->defaultLowInputLatency > 0.0) ); | ||
|  |             QA_ASSERT_TRUE( "defaultHighInputLatency should be > 0", (pdi->defaultHighInputLatency > 0.0) ); | ||
|  |             QA_ASSERT_TRUE( "defaultHighInputLatency should be >= Low", (pdi->defaultHighInputLatency >= pdi->defaultLowInputLatency) ); | ||
|  |         } | ||
|  |     } | ||
|  |     return 0; | ||
|  | error: | ||
|  |     return -1; | ||
|  | } | ||
|  | 
 | ||
|  | 
 | ||
|  | 
 | ||
|  | /*******************************************************************/ | ||
|  | int main(void); | ||
|  | int main(void) | ||
|  | { | ||
|  |     PaStreamParameters outputParameters; | ||
|  |     PaError err; | ||
|  |     paTestData data; | ||
|  |     const PaDeviceInfo *deviceInfo; | ||
|  |     int i; | ||
|  |     int framesPerBuffer; | ||
|  |     double sampleRate = SAMPLE_RATE; | ||
|  | 
 | ||
|  |     printf("\nPortAudio QA: investigate output latency.\n"); | ||
|  | 
 | ||
|  |     /* initialise sinusoidal wavetable */ | ||
|  |     for( i=0; i<TABLE_SIZE; i++ ) | ||
|  |     { | ||
|  |         data.sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. ); | ||
|  |     } | ||
|  |     data.left_phase = data.right_phase = 0; | ||
|  | 
 | ||
|  |     err = Pa_Initialize(); | ||
|  |     if( err != paNoError ) goto error; | ||
|  | 
 | ||
|  |     /* Run self tests. */ | ||
|  |     if( paqaVerifyDeviceInfoLatency() < 0 ) goto error; | ||
|  | 
 | ||
|  |     if( paqaVerifySuggestedLatency() < 0 ) goto error; | ||
|  | 
 | ||
|  |     outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */ | ||
|  |     if (outputParameters.device == paNoDevice) { | ||
|  |         fprintf(stderr,"Error: No default output device.\n"); | ||
|  |         goto error; | ||
|  |     } | ||
|  | 
 | ||
|  |     printf("\n\nNow running Audio Output Tests...\n"); | ||
|  |     printf("-------------------------------------\n"); | ||
|  | 
 | ||
|  |     outputParameters.channelCount = 2;       /* stereo output */ | ||
|  |     outputParameters.sampleFormat = paFloat32; /* 32 bit floating point output */ | ||
|  |     deviceInfo = Pa_GetDeviceInfo( outputParameters.device ); | ||
|  |     printf("Using device #%d: '%s' (%s)\n", outputParameters.device, deviceInfo->name, Pa_GetHostApiInfo(deviceInfo->hostApi)->name); | ||
|  |     printf("Device info: defaultLowOutputLatency  = %f seconds\n", deviceInfo->defaultLowOutputLatency); | ||
|  |     printf("Device info: defaultHighOutputLatency = %f seconds\n", deviceInfo->defaultHighOutputLatency); | ||
|  |     sampleRate = deviceInfo->defaultSampleRate; | ||
|  |     printf("Sample Rate for following tests: %g\n", sampleRate); | ||
|  |     outputParameters.hostApiSpecificStreamInfo = NULL; | ||
|  |     printf("-------------------------------------\n"); | ||
|  | 
 | ||
|  |     // Try to use a small buffer that is smaller than we think the device can handle.
 | ||
|  |     // Try to force combining multiple user buffers into a host buffer.
 | ||
|  |     printf("------------- Try a very small buffer.\n"); | ||
|  |     framesPerBuffer = 9; | ||
|  |     outputParameters.suggestedLatency = deviceInfo->defaultLowOutputLatency; | ||
|  |     err = paqaCheckLatency( &outputParameters, &data, sampleRate, framesPerBuffer ); | ||
|  |     if( err != paNoError ) goto error; | ||
|  | 
 | ||
|  |     printf("------------- 64 frame buffer with 1.1 * defaultLow latency.\n"); | ||
|  |     framesPerBuffer = 64; | ||
|  |     outputParameters.suggestedLatency = deviceInfo->defaultLowOutputLatency * 1.1; | ||
|  |     err = paqaCheckLatency( &outputParameters, &data, sampleRate, framesPerBuffer ); | ||
|  |     if( err != paNoError ) goto error; | ||
|  | 
 | ||
|  |     // Try to create a huge buffer that is bigger than the allowed device maximum.
 | ||
|  |     printf("------------- Try a huge buffer.\n"); | ||
|  |     framesPerBuffer = 16*1024; | ||
|  |     outputParameters.suggestedLatency = ((double)framesPerBuffer) / sampleRate; // approximate
 | ||
|  |     err = paqaCheckLatency( &outputParameters, &data, sampleRate, framesPerBuffer ); | ||
|  |     if( err != paNoError ) goto error; | ||
|  | 
 | ||
|  |     printf("------------- Try suggestedLatency = 0.0\n"); | ||
|  |     outputParameters.suggestedLatency = 0.0; | ||
|  |     err = paqaCheckLatency( &outputParameters, &data, sampleRate, paFramesPerBufferUnspecified ); | ||
|  |     if( err != paNoError ) goto error; | ||
|  | 
 | ||
|  |     printf("------------- Try suggestedLatency = defaultLowOutputLatency\n"); | ||
|  |     outputParameters.suggestedLatency = deviceInfo->defaultLowOutputLatency; | ||
|  |     err = paqaCheckLatency( &outputParameters, &data, sampleRate, paFramesPerBufferUnspecified ); | ||
|  |     if( err != paNoError ) goto error; | ||
|  | 
 | ||
|  |     printf("------------- Try suggestedLatency = defaultHighOutputLatency\n"); | ||
|  |     outputParameters.suggestedLatency = deviceInfo->defaultHighOutputLatency; | ||
|  |     err = paqaCheckLatency( &outputParameters, &data, sampleRate, paFramesPerBufferUnspecified ); | ||
|  |     if( err != paNoError ) goto error; | ||
|  | 
 | ||
|  |     printf("------------- Try suggestedLatency = defaultHighOutputLatency * 4\n"); | ||
|  |     outputParameters.suggestedLatency = deviceInfo->defaultHighOutputLatency * 4; | ||
|  |     err = paqaCheckLatency( &outputParameters, &data, sampleRate, paFramesPerBufferUnspecified ); | ||
|  |     if( err != paNoError ) goto error; | ||
|  | 
 | ||
|  |     Pa_Terminate(); | ||
|  |     printf("SUCCESS - test finished.\n"); | ||
|  |     return err; | ||
|  | 
 | ||
|  | error: | ||
|  |     Pa_Terminate(); | ||
|  |     fprintf( stderr, "ERROR - test failed.\n" ); | ||
|  |     fprintf( stderr, "Error number: %d\n", err ); | ||
|  |     fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) ); | ||
|  |     return err; | ||
|  | } |