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 */
fprintf(stderr, "Microsoft RIFF, ");
if(!checkString(config.wave.file,"WAVE")) ERROR("Input not WAVE audio");
fprintf(stderr, "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");
fprintf(stderr, "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");
fprintf(stderr, "%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;
fprintf(stderr, "Length: %2ld:%2ld:%2ld\n", (config.wave.length/3600),
(config.wave.length/60)%60,
(config.wave.length%60));
return true;
}
static int
parse_wave_header(FILE *sf)
{
fmt_chunk_data wave_info;
int is_wav = 0;
long data_length = 0, file_length, subSize = 0;
int loop_sanity = 0;
memset(&wave_info, 0, sizeof(wave_info));
file_length = Read32BitsHighLow(sf);
if (Read32BitsHighLow(sf) != WAV_ID_WAVE)
return 0;
for (loop_sanity = 0; loop_sanity < 20; ++loop_sanity) {
u_int type = Read32BitsHighLow(sf);
if (type == WAV_ID_FMT) {
subSize = Read32BitsLowHigh(sf);
if (subSize < 16) {
/*fprintf(stderr,
"'fmt' chunk too short (only %ld bytes)!", subSize); */
return 0;
}
wave_info.format_tag = Read16BitsLowHigh(sf);
subSize -= 2;
wave_info.channels = Read16BitsLowHigh(sf);
subSize -= 2;
wave_info.samples_per_sec = Read32BitsLowHigh(sf);
subSize -= 4;
wave_info.avg_bytes_per_sec = Read32BitsLowHigh(sf);
subSize -= 4;
wave_info.block_align = Read16BitsLowHigh(sf);
subSize -= 2;
wave_info.bits_per_sample = Read16BitsLowHigh(sf);
subSize -= 2;
/* fprintf(stderr, " skipping %d bytes\n", subSize); */
if (subSize > 0) {
if (fskip(sf, (long)subSize, SEEK_CUR) != 0 )
return 0;
};
} else if (type == WAV_ID_DATA) {
subSize = Read32BitsLowHigh(sf);
data_length = subSize;
is_wav = 1;
/* We've found the audio data. Read no further! */
break;
} else {
subSize = Read32BitsLowHigh(sf);
if (fskip(sf, (long) subSize, SEEK_CUR) != 0 ) return 0;
}
}
if (is_wav) {
/* make sure the header is sane */
wave_check("name", &wave_info);
num_channels = wave_info.channels;
samp_freq = wave_info.samples_per_sec;
num_samples = data_length / (wave_info.channels * wave_info.bits_per_sample / 8);
}
return is_wav;
}
