-static int find_sync_word(unsigned char *buf, int nBytes)
-{
- unsigned char *p, *pe;
-
- /* find byte-aligned syncword - need 12 (MPEG 1,2) or 11 (MPEG 2.5) matching bits */
- for (p = buf, pe = buf + nBytes - 4; p < pe; p++)
- {
- int pn;
- if (p[0] != 0xff) continue;
- pn = p[1];
- if ((pn & 0xf8) != 0xf8 || // currently must be MPEG1
- (pn & 6) == 0) { // invalid layer
- p++; continue;
- }
- pn = p[2];
- if ((pn & 0xf0) < 0x20 || (pn & 0xf0) == 0xf0 || // bitrates
- (pn & 0x0c) != 0) { // not 44kHz
- continue;
- }
-
- return p - buf;
- }
-
- return -1;
-}
-