aac: error cleanup
[paraslash.git] / aac_common.c
1 /*
2 * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
17 */
18 /*
19 * based in parts on libfaad, Copyright (C) 2003-2005 M. Bakker,
20 * Ahead Software AG
21 */
22
23 /** \file aac_ccomon.c common functions of aac_afh and aadcec */
24
25 #include "para.h"
26 #include "aac.h"
27 #include "error.h"
28
29 /**
30 * get a new libfaad decoder handle
31 *
32 */
33 NeAACDecHandle aac_open(void)
34 {
35 NeAACDecHandle h = NeAACDecOpen();
36 NeAACDecConfigurationPtr c = NeAACDecGetCurrentConfiguration(h);
37
38 c->defObjectType = LC;
39 c->outputFormat = FAAD_FMT_16BIT;
40 c->downMatrix = 0;
41 NeAACDecSetConfiguration(h, c);
42 return h;
43 };
44
45 static int aac_read_decoder_length(unsigned char *buf, int *description_len)
46 {
47 uint8_t b;
48 uint8_t numBytes = 0;
49 uint32_t length = 0;
50
51 do {
52 b = buf[numBytes];
53 numBytes++;
54 length = (length << 7) | (b & 0x7F);
55 } while
56 ((b & 0x80) && numBytes < 4);
57 *description_len = numBytes;
58 return length;
59 }
60
61 int aac_find_esds(unsigned char *buf, unsigned buflen, int *skip)
62 {
63 int i;
64
65 for (i = 0; i + 4 < buflen; i++) {
66 unsigned char *p = buf + i;
67 int decoder_length, description_len;
68
69 if (p[0] != 'e' || p[1] != 's' || p[2] != 'd' || p[3] != 's')
70 continue;
71 i += 8;
72 p = buf + i;
73 PARA_INFO_LOG("found esds@%d, next: %x\n", i, *p);
74 if (*p == 3)
75 i += 8;
76 else
77 i += 6;
78 p = buf + i;
79 PARA_INFO_LOG("next: %x\n", *p);
80 if (*p != 4)
81 continue;
82 i += 18;
83 p = buf + i;
84 PARA_INFO_LOG("next: %x\n", *p);
85 if (*p != 5)
86 continue;
87 i++;
88 p = buf + i;
89 decoder_length = aac_read_decoder_length(p, &description_len);
90 PARA_INFO_LOG("decoder length: %d\n", decoder_length);
91 i += description_len;
92 *skip = i;
93 return decoder_length;
94 }
95 return -E_ESDS;
96 }
97
98 unsigned aac_read_int32(unsigned char *buf)
99 {
100 uint8_t *d = (uint8_t*)buf;
101 return (d[0] << 24) | (d[1] << 16) | (d[2] << 8) | d[3];
102 }
103
104 /**
105 * search for the first entry in the stco table
106 *
107 * \param buf buffer to seach
108 * \param buflen length of \a buf
109 * \param skip Upon succesful return, this contains the number
110 * of bytes to skip from the input buffer.
111 *
112 * \return the position of the first entry in the table on success,
113 * -E_STCO on errors.
114 */
115
116 int aac_find_entry_point(unsigned char *buf, unsigned buflen, int *skip)
117 {
118 int i, ret;
119
120 for (i = 0; i + 20 < buflen; i++) {
121 unsigned char *p = buf + i;
122
123 if (p[0] != 's' || p[1] != 't' || p[2] != 'c' || p[3] != 'o')
124 continue;
125 PARA_INFO_LOG("found stco@%d\n", i);
126 i += 12;
127 ret = aac_read_int32(buf + i); /* first offset */
128 i += 4;
129 PARA_INFO_LOG("num entries: %d\n", ret);
130 *skip = i;
131 return ret;
132 }
133 PARA_WARNING_LOG("stco not found, buflen: %d\n", buflen);
134 return -E_STCO;
135 }
136