www.pudn.com > shine.zip > wave.c

//    Shine is an MP3 encoder 
//    Copyright (C) 1999-2000  Gabriel Bouvigne 
// 
//    This library is free software; you can redistribute it and/or 
//    modify it under the terms of the GNU Library General Public 
//    License as published by the Free Software Foundation; either 
//    version 2 of the License, or (at your option) any later version. 
// 
//    This library is distributed in the hope that it will be useful, 
//    but WITHOUT ANY WARRANTY; without even the implied warranty of 
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
//    Library General Public License for more details. 
 
 
#include  
#include "portableio.h" 
 
#include "types.h" 
#include "error.h" 
#include "wave.h" 
 
static bool checkString(FILE *file,char *string) 
{ 
/*    char temp[1024]; 
    int  length = strlen(string); 
    if(fread(temp,1,length,file)!=length) ERROR("Premature EOF in input !?!"); 
    temp[length] = (char)0; 
    return !strcmp(temp,string);*/ 
 
     
 
	char temp[1024]; 
    int  length = strlen(string); 
	while (true) 
	{ 
		if(fread(temp,1,length,file)) 
		{ 
			temp[length] = (char)0; 
			if (!strcmp(temp,string)) 
				return !strcmp(temp,string); 
		} 
		if (temp[0]==EOF) 
			break; 
		fseek(file, -3, 1); 
	} 
	return 0; 
} 
 
 
void wave_close() 
{ 
    fclose(config.wave.file); 
} 
 
 
bool wave_open() 
{ 
    static char    *channel_mappings[] = {NULL,"mono","stereo"}; 
    unsigned short  wFormatTag; 
    unsigned long   dAvgBytesPerSec; 
    unsigned short  wBlockAlign; 
    long            filesize; 
    long            header_size; 
 
    if((config.wave.file = fopen(config.infile,"rb")) == NULL) ERROR("Unable to open file"); 
 
    if(!checkString(config.wave.file,"RIFF")) ERROR("Input not a MS-RIFF file"); 
    filesize = Read32BitsLowHigh(config.wave.file); /* complete wave chunk size */ 
    printf("Microsoft RIFF, "); 
 
    if(!checkString(config.wave.file,"WAVE")) ERROR("Input not WAVE audio"); 
    printf("WAVE audio, "); 
 
/* WAVE FMT format chunk */ 
    if(!checkString(config.wave.file,"fmt "))  ERROR("Can't find format chunk"); 
/* my total header size calculations don't work, so this is bogus... */ 
    header_size = Read32BitsLowHigh(config.wave.file); /* chunk size */ 
 
    wFormatTag = Read16BitsLowHigh(config.wave.file); 
    if(wFormatTag!=0x0001) ERROR("Unknown WAVE format"); 
    config.wave.type = WAVE_RIFF_PCM; 
 
    config.wave.channels   = Read16BitsLowHigh(config.wave.file); 
    config.wave.samplerate = Read32BitsLowHigh(config.wave.file); 
    dAvgBytesPerSec        = Read32BitsLowHigh(config.wave.file); 
    wBlockAlign            = Read16BitsLowHigh(config.wave.file); 
 
/* PCM specific */ 
    if(config.wave.channels>2) ERROR("More than 2 channels\n"); 
    printf("PCM, %s %ldHz ",  
           channel_mappings[config.wave.channels], config.wave.samplerate); 
    config.wave.bits       = Read16BitsLowHigh(config.wave.file); 
    if(config.wave.bits!=16) ERROR("NOT 16 Bit !!!\n"); 
    printf("%dbit, ", config.wave.bits); 
 
    if(!checkString(config.wave.file,"data")) ERROR("Can't find data chunk"); 
 
    header_size = ftell(config.wave.file); 
    fseek(config.wave.file, 0, SEEK_END); 
    filesize = ftell(config.wave.file); 
    fseek(config.wave.file, header_size, SEEK_SET); 
 
    config.wave.total_samples = (filesize-header_size)/(2*config.wave.channels); 
    config.wave.length = config.wave.total_samples/config.wave.samplerate; 
    printf("Length: %2ld:%2ld:%2ld\n", (config.wave.length/3600),  
                                       (config.wave.length/60)%60, 
                                       (config.wave.length%60));  
    return true; 
} 
 
static int read_samples(short *sample_buffer, 
                        int    frame_size) 
{ 
    int samples_read; 
 
    switch(config.wave.type) 
    { 
        default          : 
            ERROR("[read_samples], wave filetype not supported"); 
 
        case WAVE_RIFF_PCM : 
            samples_read = fread(sample_buffer,sizeof(short),frame_size, config.wave.file); 
     
            /* Microsoft PCM Samples are little-endian, */ 
            /* we must swap if this is a big-endian machine */ 
 
           if(config.byte_order==order_bigEndian)  
               SwapBytesInWords(sample_buffer,samples_read); 
 
           if(samples_read0)  
           { /* Pad sample with zero's */ 
               while(samples_read