--- /dev/null
+/*\r
+ * $Id: $\r
+ * Portable Audio I/O Library\r
+ * Windows MME low level buffer parameters search\r
+ *\r
+ * Copyright (c) 2010 Ross Bencina\r
+ *\r
+ * Permission is hereby granted, free of charge, to any person obtaining\r
+ * a copy of this software and associated documentation files\r
+ * (the "Software"), to deal in the Software without restriction,\r
+ * including without limitation the rights to use, copy, modify, merge,\r
+ * publish, distribute, sublicense, and/or sell copies of the Software,\r
+ * and to permit persons to whom the Software is furnished to do so,\r
+ * subject to the following conditions:\r
+ *\r
+ * The above copyright notice and this permission notice shall be\r
+ * included in all copies or substantial portions of the Software.\r
+ *\r
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,\r
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF\r
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.\r
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR\r
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF\r
+ * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION\r
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
+ */\r
+\r
+/*\r
+ * The text above constitutes the entire PortAudio license; however, \r
+ * the PortAudio community also makes the following non-binding requests:\r
+ *\r
+ * Any person wishing to distribute modifications to the Software is\r
+ * requested to send the modifications to the original developer so that\r
+ * they can be incorporated into the canonical version. It is also \r
+ * requested that these non-binding requests be included along with the \r
+ * license above.\r
+ */\r
+\r
+#include <stdio.h>\r
+#include <math.h>\r
+\r
+#include <windows.h> /* required when using pa_win_wmme.h */\r
+#include <mmsystem.h> /* required when using pa_win_wmme.h */\r
+\r
+#include <conio.h> /* for _getch */\r
+\r
+\r
+#include "portaudio.h"\r
+#include "pa_win_wmme.h"\r
+\r
+\r
+#define SAMPLE_RATE (22050)\r
+\r
+#ifndef M_PI\r
+#define M_PI (3.14159265)\r
+#endif\r
+\r
+#define TABLE_SIZE (2048)\r
+\r
+#define CHANNEL_COUNT (2)\r
+\r
+\r
+typedef struct\r
+{\r
+ float sine[TABLE_SIZE];\r
+ double phase;\r
+}\r
+paTestData;\r
+\r
+static paTestData data;\r
+\r
+/* This routine will be called by the PortAudio engine when audio is needed.\r
+** It may called at interrupt level on some machines so don't do anything\r
+** that could mess up the system like calling malloc() or free().\r
+*/\r
+static int patestCallback( const void *inputBuffer, void *outputBuffer,\r
+ unsigned long framesPerBuffer,\r
+ const PaStreamCallbackTimeInfo* timeInfo,\r
+ PaStreamCallbackFlags statusFlags,\r
+ void *userData )\r
+{\r
+ paTestData *data = (paTestData*)userData;\r
+ float *out = (float*)outputBuffer;\r
+ unsigned long i,j;\r
+\r
+ (void) timeInfo; /* Prevent unused variable warnings. */\r
+ (void) statusFlags;\r
+ (void) inputBuffer;\r
+ \r
+ for( i=0; i<framesPerBuffer; i++ )\r
+ {\r
+ float x = data->sine[(int)data->phase];\r
+ data->phase += 20;\r
+ if( data->phase >= TABLE_SIZE ){\r
+ data->phase -= TABLE_SIZE;\r
+ }\r
+\r
+ for( j = 0; j < CHANNEL_COUNT; ++j ){\r
+ *out++ = x;\r
+ }\r
+ }\r
+ \r
+ return paContinue;\r
+}\r
+\r
+\r
+#define YES 1\r
+#define NO 0\r
+\r
+\r
+static int playUntilKeyPress( int deviceIndex, int framesPerUserBuffer, int framesPerWmmeBuffer, int wmmeBufferCount )\r
+{\r
+ PaStreamParameters outputParameters;\r
+ PaWinMmeStreamInfo wmmeStreamInfo;\r
+ PaStream *stream;\r
+ PaError err;\r
+ int c;\r
+\r
+ outputParameters.device = deviceIndex;\r
+ outputParameters.channelCount = CHANNEL_COUNT;\r
+ outputParameters.sampleFormat = paFloat32; /* 32 bit floating point processing */\r
+ outputParameters.suggestedLatency = 0; /*Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency;*/\r
+ outputParameters.hostApiSpecificStreamInfo = NULL;\r
+\r
+ wmmeStreamInfo.size = sizeof(PaWinMmeStreamInfo);\r
+ wmmeStreamInfo.hostApiType = paMME; \r
+ wmmeStreamInfo.version = 1;\r
+ wmmeStreamInfo.flags = paWinMmeUseLowLevelLatencyParameters | paWinMmeDontThrottleOverloadedProcessingThread;\r
+ wmmeStreamInfo.framesPerBuffer = framesPerWmmeBuffer;\r
+ wmmeStreamInfo.bufferCount = wmmeBufferCount;\r
+ outputParameters.hostApiSpecificStreamInfo = &wmmeStreamInfo;\r
+\r
+ err = Pa_OpenStream(\r
+ &stream,\r
+ NULL, /* no input */\r
+ &outputParameters,\r
+ SAMPLE_RATE,\r
+ framesPerUserBuffer,\r
+ paClipOff | paPrimeOutputBuffersUsingStreamCallback, /* we won't output out of range samples so don't bother clipping them */\r
+ patestCallback,\r
+ &data );\r
+ if( err != paNoError ) goto error;\r
+\r
+ err = Pa_StartStream( stream );\r
+ if( err != paNoError ) goto error;\r
+\r
+\r
+ do{\r
+ printf( "Trying buffer size %d.\nIf it sounds smooth press 'y', if it sounds bad press 'n'\n", framesPerWmmeBuffer );\r
+ c = tolower(_getch());\r
+ }while( c != 'y' && c != 'n' );\r
+\r
+ err = Pa_AbortStream( stream );\r
+ if( err != paNoError ) goto error;\r
+\r
+ err = Pa_CloseStream( stream );\r
+ if( err != paNoError ) goto error;\r
+\r
+ return (c == 'y') ? YES : NO;\r
+\r
+error:\r
+ return err;\r
+}\r
+\r
+\r
+/*******************************************************************/\r
+int main(int argc, char* argv[])\r
+{\r
+ PaError err;\r
+ int i;\r
+ int deviceIndex;\r
+ int wmmeBufferCount, wmmeBufferSize, smallestWorkingBufferSize;\r
+ int min, max, mid;\r
+ int testResult;\r
+ FILE *resultsFp;\r
+ OSVERSIONINFO windowsVersion;\r
+\r
+ err = Pa_Initialize();\r
+ if( err != paNoError ) goto error;\r
+\r
+ /*\r
+ TODO: print an index of devices and ask the user to select one\r
+\r
+ */\r
+\r
+ deviceIndex = Pa_GetHostApiInfo( Pa_HostApiTypeIdToHostApiIndex( paMME ) )->defaultOutputDevice;\r
+ if( argc == 2 ){\r
+ sscanf( argv[1], "%d", &deviceIndex );\r
+ }\r
+\r
+ printf( "using device id %d (%s)\n", deviceIndex, Pa_GetDeviceInfo(deviceIndex)->name );\r
+\r
+ /* initialise sinusoidal wavetable */\r
+ for( i=0; i<TABLE_SIZE; i++ )\r
+ {\r
+ data.sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. );\r
+ }\r
+\r
+ data.phase = 0;\r
+\r
+\r
+ resultsFp = fopen( "results.txt", "at" );\r
+ fprintf( resultsFp, "*** WMME smallest working buffer sizes\n" );\r
+\r
+ memset( &windowsVersion, 0, sizeof(OSVERSIONINFO) );\r
+ windowsVersion.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);\r
+ GetVersionEx( &windowsVersion );\r
+\r
+ fprintf( resultsFp, "windows version: %d.%d.%d %S\n", windowsVersion.dwMajorVersion, windowsVersion.dwMinorVersion, windowsVersion.dwBuildNumber, windowsVersion.szCSDVersion );\r
+ fprintf( resultsFp, "audio device: %s\n", Pa_GetDeviceInfo( deviceIndex )->name );\r
+ \r
+\r
+ /*\r
+ TODO: test at 22050 44100, 48000, 96000, mono and stereo and surround\r
+\r
+ TODO: should be testing with 80% CPU load\r
+\r
+\r
+ another thing to try would be setting the timeBeginPeriod granularity to 1ms and see if it changes the behavior\r
+ */\r
+\r
+ printf( "testing with sample rate %f.\n", (float)SAMPLE_RATE );\r
+ fprintf( resultsFp, "sample rate: %f\n", (float)SAMPLE_RATE );\r
+ fprintf( resultsFp, "buffer count, smallest working size (frames)\n" );\r
+\r
+ for( wmmeBufferCount = 2; wmmeBufferCount < 13; ++wmmeBufferCount ){\r
+ \r
+ \r
+ printf( "testing with %d buffers...\n", wmmeBufferCount );\r
+\r
+ /*\r
+ Binary search after Niklaus Wirth\r
+ from http://en.wikipedia.org/wiki/Binary_search_algorithm#The_algorithm\r
+ */\r
+ min = 1;\r
+ max = 8192; /* we assume that this size works */\r
+ smallestWorkingBufferSize = 0;\r
+\r
+ do{\r
+ mid = min + ((max - min) / 2);\r
+\r
+ wmmeBufferSize = mid;\r
+ testResult = playUntilKeyPress( deviceIndex, wmmeBufferSize, wmmeBufferSize, wmmeBufferCount );\r
+\r
+ if( testResult == YES ){\r
+ max = mid - 1;\r
+ smallestWorkingBufferSize = wmmeBufferSize;\r
+ }else{\r
+ min = mid + 1;\r
+ }\r
+ \r
+ }while( (min <= max) && (testResult == YES || testResult == NO) );\r
+\r
+ printf( "smallest working buffer size for %d buffers is: %d\n", wmmeBufferCount, smallestWorkingBufferSize );\r
+\r
+ fprintf( resultsFp, "%d, %d\n", wmmeBufferCount, smallestWorkingBufferSize );\r
+ fflush( resultsFp );\r
+ }\r
+\r
+ fprintf( resultsFp, "###\n" );\r
+\r
+ fclose( resultsFp );\r
+ \r
+ Pa_Terminate();\r
+ printf("Test finished.\n");\r
+ \r
+ return err;\r
+error:\r
+ Pa_Terminate();\r
+ fprintf( stderr, "An error occured while using the portaudio stream\n" );\r
+ fprintf( stderr, "Error number: %d\n", err );\r
+ fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );\r
+ return err;\r
+}\r
+\r
projects / portaudio / commitdiff