1 /*
2 * Copyright (C) 2005 Nico Sabbi
3 *
4 * This file is part of MPlayer.
5 *
6 * MPlayer is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * MPlayer is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License along
17 * with MPlayer; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21 #include <stdint.h>
22 #include "aac_hdr.h"
23
24 /// \param srate (out) sample rate
25 /// \param num (out) number of audio frames in this ADTS frame
26 /// \return size of the ADTS frame in bytes
27 /// aac_parse_frames needs a buffer at least 8 bytes long
aac_parse_frame(uint8_t * buf,int * srate,int * num)28 int aac_parse_frame(uint8_t *buf, int *srate, int *num)
29 {
30 int i = 0, sr, fl = 0;
31 static const int srates[] = {96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000, 0, 0, 0};
32
33 if((buf[i] != 0xFF) || ((buf[i+1] & 0xF6) != 0xF0))
34 return 0;
35
36 sr = (buf[i+2] >> 2) & 0x0F;
37 if(sr > 11)
38 return 0;
39 *srate = srates[sr];
40
41 fl = ((buf[i+3] & 0x03) << 11) | (buf[i+4] << 3) | ((buf[i+5] >> 5) & 0x07);
42 *num = (buf[i+6] & 0x02) + 1;
43
44 return fl;
45 }
46