fix some signed warnings in aac and mp3 decoders
[paraslash.git] / aac_common.c
1 /*
2 * Copyright (C) 2006-2007 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_common.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 unsigned long aac_read_decoder_length(unsigned char *buf, int *description_len)
46 {
47 uint8_t b;
48 uint8_t numBytes = 0;
49 unsigned long 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 /**
62 * search for the position and the length of the decoder configuration
63 *
64 * \param buf buffer to seach
65 * \param buflen length of \a buf
66 * \param skip Upon succesful return, this contains the offset in \a buf where
67 * the decoder config starts.
68 * \param decoder_length result pointer that is filled in with the length of
69 * the decoder configuration on success.
70 *
71 * \return positive on success, negative on errors
72 */
73 int aac_find_esds(unsigned char *buf, size_t buflen, size_t *skip,
74 unsigned long *decoder_length)
75 {
76 size_t i;
77
78 for (i = 0; i + 4 < buflen; i++) {
79 unsigned char *p = buf + i;
80 int description_len;
81
82 if (p[0] != 'e' || p[1] != 's' || p[2] != 'd' || p[3] != 's')
83 continue;
84 i += 8;
85 p = buf + i;
86 PARA_INFO_LOG("found esds@%zu, next: %x\n", i, *p);
87 if (*p == 3)
88 i += 8;
89 else
90 i += 6;
91 p = buf + i;
92 PARA_INFO_LOG("next: %x\n", *p);
93 if (*p != 4)
94 continue;
95 i += 18;
96 p = buf + i;
97 PARA_INFO_LOG("next: %x\n", *p);
98 if (*p != 5)
99 continue;
100 i++;
101 p = buf + i;
102 *decoder_length = aac_read_decoder_length(p, &description_len);
103 PARA_INFO_LOG("decoder length: %lu\n", *decoder_length);
104 i += description_len;
105 *skip = i;
106 return 1;
107 }
108 return -E_ESDS;
109 }
110
111 /**
112 * search for the first entry in the stco table
113 *
114 * \param buf buffer to seach
115 * \param buflen length of \a buf
116 * \param skip Upon succesful return, this contains the number
117 * of bytes to skip from the input buffer.
118 *
119 * \return the position of the first entry in the table on success,
120 * -E_STCO on errors.
121 */
122 ssize_t aac_find_entry_point(unsigned char *buf, size_t buflen, size_t *skip)
123 {
124 ssize_t ret;
125 size_t i;
126
127 for (i = 0; i + 20 < buflen; i++) {
128 unsigned char *p = buf + i;
129
130 if (p[0] != 's' || p[1] != 't' || p[2] != 'c' || p[3] != 'o')
131 continue;
132 PARA_INFO_LOG("found stco@%zu\n", i);
133 i += 12;
134 ret = aac_read_int32(buf + i); /* first offset */
135 i += 4;
136 PARA_INFO_LOG("entry point: %zd\n", ret);
137 *skip = i;
138 return ret;
139 }
140 PARA_WARNING_LOG("stco not found, buflen: %zu\n", buflen);
141 return -E_STCO;
142 }