www.pudn.com > makewav.rar > wav.c

/* 
 * FAAD - Freeware Advanced Audio Decoder 
 * Copyright (C) 2001 Menno Bakker 
 * 
 * This library is free software; you can redistribute it and/or 
 * modify it under the terms of the GNU Lesser General Public 
 * License as published by the Free Software Foundation; either 
 * version 2.1 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 
 * Lesser General Public License for more details. 
 
 * You should have received a copy of the GNU Lesser General Public 
 * License along with this library; if not, write to the Free Software 
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
 * 
 * $Id: wav.c,v 1.4 2001/06/08 18:00:27 menno Exp $ 
 */ 
 
#include  
#include "wav.h" 
 
/* wav file writing */ 
 
/* Make an unfinished RIFF structure, with null values in the lengths */ 
int CreateWavHeader(FILE *file, int channels, int samplerate, int resolution) 
{ 
    int length; 
 
    /* Use a zero length for the chunk sizes for now, then modify when finished */ 
    WAVEAUDIOFORMAT format; 
 
    format.format_tag = 1; 
    format.channels = channels; 
    format.samplerate = samplerate; 
    format.bits_per_sample = resolution; 
    format.blockalign = channels * (resolution/8); 
    format.bytes_per_second = format.samplerate * format.blockalign; 
 
    fseek(file, 0, SEEK_SET); 
 
    fwrite("RIFF\0\0\0\0WAVEfmt ", sizeof(char), 16, file); /* Write RIFF, WAVE, and fmt  headers */ 
 
    length = 16; 
    fwrite(&length, 1, sizeof(long), file); /* Length of Format (always 16) */ 
    fwrite(&format, 1, sizeof(format), file); 
 
    fwrite("data\0\0\0\0", sizeof(char), 8, file); /* Write data chunk */ 
 
    return 0; 
} 
 
/* Update the RIFF structure with proper values. CreateWavHeader must be called first */ 
int UpdateWavHeader(FILE *file) 
{ 
    /*fpos_t*/int filelen, riff_length, data_length; 
 
    /* Get the length of the file */ 
 
    if(!file) 
        return -1; 
 
    fseek( file, 0, SEEK_END ); 
    filelen = ftell( file ); 
 
    if(filelen <= 0) 
        return -1; 
 
    riff_length = filelen - 8; 
    data_length = filelen - 44; 
 
    fseek(file, 4, SEEK_SET); 
    fwrite(&riff_length, 1, sizeof(long), file); 
 
    fseek(file, 40, SEEK_SET); 
    fwrite(&data_length, 1, sizeof(long), file); 
 
    /* reset file position for appending data */ 
    fseek(file, 0, SEEK_END); 
 
    return 0; 
}