Replace 2010 in copyright message by 2011.
[paraslash.git] / aac_common.c
1 /*
2 * Copyright (C) 2006-2011 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6 /*
7 * based in parts on libfaad, Copyright (C) 2003-2005 M. Bakker,
8 * Ahead Software AG
9 */
10
11 /** \file aac_common.c common functions of aac_afh and aadcec */
12
13 #include "para.h"
14 #include "aac.h"
15 #include "error.h"
16
17 /**
18 * get a new libfaad decoder handle
19 *
20 */
21 NeAACDecHandle aac_open(void)
22 {
23 NeAACDecHandle h = NeAACDecOpen();
24 NeAACDecConfigurationPtr c = NeAACDecGetCurrentConfiguration(h);
25
26 c->defObjectType = LC;
27 c->outputFormat = FAAD_FMT_16BIT;
28 c->downMatrix = 0;
29 NeAACDecSetConfiguration(h, c);
30 return h;
31 }
32
33 static unsigned long aac_read_decoder_length(unsigned char *buf, int *description_len)
34 {
35 uint8_t b;
36 uint8_t numBytes = 0;
37 unsigned long length = 0;
38
39 do {
40 b = buf[numBytes];
41 numBytes++;
42 length = (length << 7) | (b & 0x7F);
43 } while
44 ((b & 0x80) && numBytes < 4);
45 *description_len = numBytes;
46 return length;
47 }
48
49 /**
50 * search for the position and the length of the decoder configuration
51 *
52 * \param buf buffer to seach
53 * \param buflen length of \a buf
54 * \param skip Upon succesful return, this contains the offset in \a buf where
55 * the decoder config starts.
56 * \param decoder_length result pointer that is filled in with the length of
57 * the decoder configuration on success.
58 *
59 * \return positive on success, negative on errors
60 */
61 int aac_find_esds(unsigned char *buf, size_t buflen, size_t *skip,
62 unsigned long *decoder_length)
63 {
64 size_t i;
65
66 for (i = 0; i + 4 < buflen; i++) {
67 unsigned char *p = buf + i;
68 int description_len;
69
70 if (p[0] != 'e' || p[1] != 's' || p[2] != 'd' || p[3] != 's')
71 continue;
72 i += 8;
73 p = buf + i;
74 PARA_INFO_LOG("found esds@%zu, next: %x\n", i, *p);
75 if (*p == 3)
76 i += 8;
77 else
78 i += 6;
79 p = buf + i;
80 PARA_INFO_LOG("next: %x\n", *p);
81 if (*p != 4)
82 continue;
83 i += 18;
84 p = buf + i;
85 PARA_INFO_LOG("next: %x\n", *p);
86 if (*p != 5)
87 continue;
88 i++;
89 p = buf + i;
90 *decoder_length = aac_read_decoder_length(p, &description_len);
91 PARA_INFO_LOG("decoder length: %lu\n", *decoder_length);
92 i += description_len;
93 *skip = i;
94 return 1;
95 }
96 return -E_ESDS;
97 }
98
99 /**
100 * search for the first entry in the stco table
101 *
102 * \param buf buffer to seach
103 * \param buflen length of \a buf
104 * \param skip Upon succesful return, this contains the number
105 * of bytes to skip from the input buffer.
106 *
107 * \return the position of the first entry in the table on success,
108 * -E_STCO on errors.
109 */
110 ssize_t aac_find_entry_point(unsigned char *buf, size_t buflen, size_t *skip)
111 {
112 ssize_t ret;
113 size_t i;
114
115 for (i = 0; i + 20 < buflen; i++) {
116 unsigned char *p = buf + i;
117
118 if (p[0] != 's' || p[1] != 't' || p[2] != 'c' || p[3] != 'o')
119 continue;
120 PARA_INFO_LOG("found stco@%zu\n", i);
121 i += 12;
122 ret = aac_read_int32(buf + i); /* first offset */
123 i += 4;
124 PARA_INFO_LOG("entry point: %zd\n", ret);
125 *skip = i;
126 return ret;
127 }
128 PARA_WARNING_LOG("stco not found, buflen: %zu\n", buflen);
129 return -E_STCO;
130 }