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/* ------------------------------------------------------------------
libofa -- the Open Fingerprint Architecture library
Public Domain (PD) 2006 MusicIP Corporation
No rights reserved.
-------------------------------------------------------------------*/
#include "protocol.h"
#ifdef WIN32
#include "io.h"
#endif
#include <fcntl.h>
static bool readBytes(int fd, unsigned char *buf, int size) {
int ct = 0;
while (ct < size) {
unsigned char tmp[4096];
int x = size - ct;
if (x > 4096)
x = 4096;
int n = read(fd, tmp, x);
if (n <= 0) {
return false;
}
for (int i = 0; i < n; ++i) {
buf[ct + i] = tmp[i];
}
ct += n;
}
return true;
}
// This method only supports PCM/uncompressed format, with a single fmt
// chunk followed by a single data chunk
AudioData* loadWaveFile(char *file) {
int srate = 0;
int channels = 0;
int fd = open(file, O_RDONLY | 0x8000);
if (fd == -1)
return 0;
if (lseek(fd, 0L, SEEK_SET) == -1L) {
close(fd);
return 0;
}
unsigned char hdr[36];
if (!readBytes(fd, hdr, 36)) {
close(fd);
return 0;
}
if (hdr[0] != 'R' || hdr[1] != 'I' || hdr[2] != 'F' || hdr[3] != 'F') {
close(fd);
return 0;
}
// Note: bytes 4 thru 7 contain the file size - 8 bytes
if (hdr[8] != 'W' || hdr[9] != 'A' || hdr[10] != 'V' || hdr[11] != 'E') {
close(fd);
return 0;
}
if (hdr[12] != 'f' || hdr[13] != 'm' || hdr[14] != 't' || hdr[15] != ' ') {
close(fd);
return 0;
}
long extraBytes = hdr[16] + (hdr[17] << 8) + (hdr[18] << 16) + (hdr[19] << 24) - 16;
int compression = hdr[20] + (hdr[21] << 8);
// Type 1 is PCM/Uncompressed
if (compression != 1) {
close(fd);
return 0;
}
channels = hdr[22] + (hdr[23] << 8);
// Only mono or stereo PCM is supported in this example
if (channels < 1 || channels > 2) {
close(fd);
return 0;
}
// Samples per second, independent of number of channels
srate = hdr[24] + (hdr[25] << 8) + (hdr[26] << 16) + (hdr[27] << 24);
// Bytes 28-31 contain the "average bytes per second", unneeded here
// Bytes 32-33 contain the number of bytes per sample (includes channels)
// Bytes 34-35 contain the number of bits per single sample
int bits = hdr[34] + (hdr[35] << 8);
// Supporting othe sample depths will require conversion
if (bits != 16) {
close(fd);
return 0;
}
// Skip past extra bytes, if any
if (lseek(fd, 36L + extraBytes, SEEK_SET) == -1L) {
close(fd);
return 0;
}
// Start reading the next frame. Only supported frame is the data block
unsigned char b[8];
if (!readBytes(fd, b, 8)) {
close(fd);
return 0;
}
// Do we have a fact block?
if (b[0] == 'f' && b[1] == 'a' && b[2] == 'c' && b[3] == 't') {
// Skip the fact block
if (lseek(fd, 36L + extraBytes + 12L, SEEK_SET) == -1L) {
close(fd);
return 0;
}
// Read the next frame
if (!readBytes(fd, b, 8)) {
close(fd);
return 0;
}
}
// Now look for the data block
if (b[0] != 'd' || b[1] != 'a' || b[2] != 't' || b[3] != 'a') {
close(fd);
return 0;
}
long bytes = b[4] + (b[5] << 8) + (b[6] << 16) + (b[7] << 24);
long ms = (bytes/2)/(srate/1000);
if ( channels == 2 ) ms /= 2;
// No need to read the whole file, just the first 135 seconds
int sampleSize = 135;
long bytesInNSecs = sampleSize * srate * 2 * channels;
bytes = bytes > bytesInNSecs ? bytesInNSecs : bytes;
unsigned char *samples = new unsigned char[bytes];
if (!readBytes(fd, samples, bytes)) {
delete[] samples;
close(fd);
return 0;
}
close(fd);
AudioData *data = new AudioData();
data->setData(samples, OFA_LITTLE_ENDIAN, bytes/2, srate,
channels == 2 ? 1 : 0, ms, "wav");
return data;
}
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