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//+-------------------------------------------------------------------------
//
// Microsoft Windows
//
// Copyright (C) Microsoft Corporation, 1998 - 1999
//
// File: gen-wav.c
//
//--------------------------------------------------------------------------
#include "stdio.h"
#include "stdlib.h"
#include "windows.h"
// #include "ntddk.h"
//
// MAX is defined to prevent overflow errors
// floor( (0xffffffff - 54)/(4*44100) )
//
#define MAX_SECONDS 24347
#define SAMPLE_STEP 1
VOID__cdecl WriteIncreasingSawTooth( FILE * OutFile, ULONG32 NumberOfSeconds ){ ULONG32 i; ULONG32 currentSample = 0; ULONG32 samples = 44100 * NumberOfSeconds;
for ( i = 0; i < samples; i++ ) { putc( (currentSample >> 0) & 0xff, OutFile ); putc( (currentSample >> 8) & 0xff, OutFile ); putc( (currentSample >> 0) & 0xff, OutFile ); putc( (currentSample >> 8) & 0xff, OutFile );
currentSample += SAMPLE_STEP; }
}
VOID__cdecl WriteDecreasingSawTooth( FILE * OutFile, ULONG32 NumberOfSeconds ){ ULONG32 i; ULONG32 currentSample = 0; ULONG32 samples = 44100 * NumberOfSeconds;
for ( i = 0; i < samples; i++ ) { putc( (currentSample >> 0) & 0xff, OutFile ); putc( (currentSample >> 8) & 0xff, OutFile ); putc( (currentSample >> 0) & 0xff, OutFile ); putc( (currentSample >> 8) & 0xff, OutFile );
currentSample -= SAMPLE_STEP; }}
VOID__cdecl WriteTriangle( FILE * OutFile, ULONG32 NumberOfSeconds ){ ULONG32 i; ULONG32 samples = 44100 * NumberOfSeconds; ULONG32 increasing = TRUE; LONG32 currentSample = 0; LONG32 highestSample = 0x00007fff - SAMPLE_STEP + 1; LONG32 lowestSample = 0xffff8000 + SAMPLE_STEP - 1;
for ( i = 0; i < samples; i++ ) { putc( (currentSample >> 0) & 0xff, OutFile ); putc( (currentSample >> 8) & 0xff, OutFile ); putc( (currentSample >> 0) & 0xff, OutFile ); putc( (currentSample >> 8) & 0xff, OutFile );
if ( increasing == TRUE && currentSample >= highestSample ) { increasing = FALSE; } if ( increasing == FALSE && currentSample <= lowestSample ) { increasing = TRUE; } if ( increasing == TRUE ) { currentSample += SAMPLE_STEP; } else { currentSample -= SAMPLE_STEP; } }}
VOID__cdecl WriteHeader( FILE * OutFile, ULONG32 NumberOfSeconds ){ unsigned char header[] = { 0x52, 0x49, 0x46, 0x46, 0x00, 0x00, 0x00, 0x00, // 0- 7
0x57, 0x41, 0x56, 0x45, 0x66, 0x6D, 0x74, 0x20, // 8-15
0x12, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02, 0x00, // 16-23
0x44, 0xAC, 0x00, 0x00, 0x10, 0xB1, 0x02, 0x00, // 24-31
0x04, 0x00, 0x10, 0x00, 0x00, 0x00, 0x66, 0x61, // 32-39
0x63, 0x74, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, // 40-47
0x00, 0x00, 0x64, 0x61, 0x74, 0x61, 0x00, 0x00, // 48-55
0x00, 0x00 // 56-57 (length 58)
}; ULONG32 length; ULONG32 samples; ULONG32 other; ULONG32 i;
//
// setup the variable header info
//
// samples = 44100 * NumberOfSeconds
// other = (samples * 4) + 8
// length = other + 54
samples = 44100 * NumberOfSeconds + 1; // one extra sample?
other = ((44100 * NumberOfSeconds + 1) * 4) + 4; length = (((44100 * NumberOfSeconds + 1) * 4) + 4) + 50;
//
// Fill it in
//
header[4] = (length >> 0) & 0xff; header[5] = (length >> 8) & 0xff; header[6] = (length >> 16) & 0xff; header[7] = (length >> 24) & 0xff;
header[46] = (samples >> 0) & 0xff; header[47] = (samples >> 8) & 0xff; header[48] = (samples >> 16) & 0xff; header[49] = (samples >> 24) & 0xff;
header[54] = (other >> 0) & 0xff; header[55] = (other >> 8) & 0xff; header[56] = (other >> 16) & 0xff; header[57] = (other >> 24) & 0xff;
for ( i = 0; i < sizeof(header); i++ ) { fprintf( OutFile, "%c", header[i] ); }}
/* 02b3c146
The header to a WAV file is as follows:
52 49 46 46 XX XX XX XX-57 41 56 45 66 6D 74 2012 00 00 00 01 00 02 00-44 AC 00 00 10 B1 02 0004 00 10 00 00 00 66 61-63 74 04 00 00 00 YY YYYY YY 64 61 74 61 ZZ ZZ-ZZ ZZ
XX XX XX XX YY YY YY YY ZZ ZZ ZZ ZZ-------------------------------------------------------------- 1 = 46 b1 02 00 44 ac 00 00 14 b1 02 00 (0x2b110* +4) 2 = 56 62 05 00 88 58 01 00 24 62 05 00 (0x2b110* +4)267 = 46 c1 b3 02 44 f0 ac 00 14 c1 b3 02 (0x2b110* +4)
X = (length - 4) in reverse-byte order (eight is number of bytes including this part of the struct)Y = number of samples (0xac44 == 44100 == 1 second)Z = (# of seconds) * 0x02b1
*/
VOID__inline WriteFooter( FILE * OutFile ){ printf( "writing the footer\n" ); putc( 0x50, OutFile ); putc( 0xB5, OutFile ); putc( 0x50, OutFile ); putc( 0xB5, OutFile ); putc( 0x00, OutFile ); putc( 0x00, OutFile ); putc( 0x00, OutFile ); putc( 0x00, OutFile );}
VOID__cdecl main( int Argc, char ** Argv ){ FILE * outFile; ULONG32 seconds; ULONG32 wavType = 1; CHAR fileName[256];
if ( Argc > 1 ) {
//
// try to get number seconds they want audio
//
seconds = atoi( Argv[1] );
if ( Argc > 2 ) {
//
// get the type of wavform
//
wavType = atoi( Argv[2] );
}
}
if ( Argc < 2 || Argc > 3 || strcmp(Argv[1], "-?") == 0 || strcmp(Argv[1], "-h") == 0 || seconds > MAX_SECONDS || wavType < 1 || wavType > 3 ) {
//
// give usage help
//
printf( "\nUsage: %s seconds [wavtype]\n" "\tseconds must be a positive integer\n" "\tless than %d (prevents overflow)\n" "\twavtype can be one of three integers:\n" "\t\t1: increasing sawtooth (default)\n" "\t\t2: decreasing sawtooth\n" "\t\t3: triangular wav\n" "\n" , Argv[0] , MAX_SECONDS ); exit(1); } switch( wavType ) { case 1: sprintf( fileName, "increase-%d.wav", seconds ); printf( "Requesting %d seconds of increasing sawtooth wav output\n", seconds ); outFile = fopen( fileName, "wb" ); WriteHeader( outFile, seconds ); WriteIncreasingSawTooth( outFile, seconds ); WriteFooter( outFile ); break; case 2: sprintf( fileName, "decrease-%d.wav", seconds ); printf( "Requesting %d seconds of decreasing sawtooth wav output\n", seconds ); outFile = fopen( fileName, "wb" ); WriteHeader( outFile, seconds ); WriteDecreasingSawTooth( outFile, seconds ); WriteFooter( outFile ); break; case 3: sprintf( fileName, "triangle-%d.wav", seconds ); printf( "Requesting %d seconds of triangle wav output\n", seconds ); outFile = fopen( fileName, "wb" ); WriteHeader( outFile, seconds ); WriteTriangle( outFile, seconds ); WriteFooter( outFile ); break; default: break;
} exit(0);}
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