Fix ext_object_type.
[libav.git] / libavcodec / mpeg4audio.c
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1/*
2 * MPEG-4 Audio common code
3 * Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr>
107815de 4 * Copyright (c) 2009 Alex Converse <alex.converse@gmail.com>
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5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
9106a698 23#include "get_bits.h"
107815de 24#include "put_bits.h"
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25#include "mpeg4audio.h"
26
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27/**
28 * Parse MPEG-4 audio configuration for ALS object type.
29 * @param[in] gb bit reader context
30 * @param[in] c MPEG4AudioConfig structure to fill
31 * @return on success 0 is returned, otherwise a value < 0
32 */
33static int parse_config_ALS(GetBitContext *gb, MPEG4AudioConfig *c)
34{
6e44ba15 35 if (get_bits_left(gb) < 112)
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36 return -1;
37
38 if (get_bits_long(gb, 32) != MKBETAG('A','L','S','\0'))
39 return -1;
40
41 // override AudioSpecificConfig channel configuration and sample rate
42 // which are buggy in old ALS conformance files
43 c->sample_rate = get_bits_long(gb, 32);
44
45 // skip number of samples
46 skip_bits_long(gb, 32);
47
48 // read number of channels
49 c->chan_config = 0;
50 c->channels = get_bits(gb, 16) + 1;
51
52 return 0;
53}
54
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55const int ff_mpeg4audio_sample_rates[16] = {
56 96000, 88200, 64000, 48000, 44100, 32000,
57 24000, 22050, 16000, 12000, 11025, 8000, 7350
58};
59
60const uint8_t ff_mpeg4audio_channels[8] = {
61 0, 1, 2, 3, 4, 5, 6, 8
62};
63
64static inline int get_object_type(GetBitContext *gb)
65{
66 int object_type = get_bits(gb, 5);
0cc4701a 67 if (object_type == AOT_ESCAPE)
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68 object_type = 32 + get_bits(gb, 6);
69 return object_type;
70}
71
72static inline int get_sample_rate(GetBitContext *gb, int *index)
73{
74 *index = get_bits(gb, 4);
75 return *index == 0x0f ? get_bits(gb, 24) :
76 ff_mpeg4audio_sample_rates[*index];
77}
78
79int ff_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf, int buf_size)
80{
81 GetBitContext gb;
82 int specific_config_bitindex;
83
84 init_get_bits(&gb, buf, buf_size*8);
85 c->object_type = get_object_type(&gb);
86 c->sample_rate = get_sample_rate(&gb, &c->sampling_index);
87 c->chan_config = get_bits(&gb, 4);
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88 if (c->chan_config < FF_ARRAY_ELEMS(ff_mpeg4audio_channels))
89 c->channels = ff_mpeg4audio_channels[c->chan_config];
4d34bb19 90 c->sbr = -1;
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91 if (c->object_type == AOT_SBR || (c->object_type == AOT_PS &&
92 // check for W6132 Annex YYYY draft MP3onMP4
93 !(show_bits(&gb, 3) & 0x03 && !(show_bits(&gb, 9) & 0x3F)))) {
702b73bc 94 c->ext_object_type = AOT_SBR;
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95 c->sbr = 1;
96 c->ext_sample_rate = get_sample_rate(&gb, &c->ext_sampling_index);
97 c->object_type = get_object_type(&gb);
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98 if (c->object_type == AOT_ER_BSAC)
99 c->ext_chan_config = get_bits(&gb, 4);
44dff005 100 } else {
0cc4701a 101 c->ext_object_type = AOT_NULL;
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102 c->ext_sample_rate = 0;
103 }
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104 specific_config_bitindex = get_bits_count(&gb);
105
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106 if (c->object_type == AOT_ALS) {
107 skip_bits(&gb, 5);
108 if (show_bits_long(&gb, 24) != MKBETAG('\0','A','L','S'))
109 skip_bits_long(&gb, 24);
110
111 specific_config_bitindex = get_bits_count(&gb);
112
113 if (parse_config_ALS(&gb, c))
114 return -1;
115 }
116
b5fe06ab 117 if (c->ext_object_type != AOT_SBR) {
24026a2d 118 int bits_left = buf_size*8 - get_bits_count(&gb);
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119 for (; bits_left > 15; bits_left--) {
120 if (show_bits(&gb, 11) == 0x2b7) { // sync extension
121 get_bits(&gb, 11);
122 c->ext_object_type = get_object_type(&gb);
b5fe06ab 123 if (c->ext_object_type == AOT_SBR && (c->sbr = get_bits1(&gb)) == 1)
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124 c->ext_sample_rate = get_sample_rate(&gb, &c->ext_sampling_index);
125 break;
126 } else
127 get_bits1(&gb); // skip 1 bit
128 }
129 }
130 return specific_config_bitindex;
131}
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132
133static av_always_inline unsigned int copy_bits(PutBitContext *pb,
134 GetBitContext *gb,
135 int bits)
136{
137 unsigned int el = get_bits(gb, bits);
138 put_bits(pb, bits, el);
139 return el;
140}
141
142int ff_copy_pce_data(PutBitContext *pb, GetBitContext *gb)
143{
144 int five_bit_ch, four_bit_ch, comment_size, bits;
145 int offset = put_bits_count(pb);
146
147 copy_bits(pb, gb, 10); //Tag, Object Type, Frequency
148 five_bit_ch = copy_bits(pb, gb, 4); //Front
149 five_bit_ch += copy_bits(pb, gb, 4); //Side
150 five_bit_ch += copy_bits(pb, gb, 4); //Back
151 four_bit_ch = copy_bits(pb, gb, 2); //LFE
152 four_bit_ch += copy_bits(pb, gb, 3); //Data
153 five_bit_ch += copy_bits(pb, gb, 4); //Coupling
154 if (copy_bits(pb, gb, 1)) //Mono Mixdown
155 copy_bits(pb, gb, 4);
156 if (copy_bits(pb, gb, 1)) //Stereo Mixdown
157 copy_bits(pb, gb, 4);
158 if (copy_bits(pb, gb, 1)) //Matrix Mixdown
159 copy_bits(pb, gb, 3);
160 for (bits = five_bit_ch*5+four_bit_ch*4; bits > 16; bits -= 16)
161 copy_bits(pb, gb, 16);
162 if (bits)
163 copy_bits(pb, gb, bits);
164 align_put_bits(pb);
165 align_get_bits(gb);
166 comment_size = copy_bits(pb, gb, 8);
167 for (; comment_size > 0; comment_size--)
168 copy_bits(pb, gb, 8);
169
170 return put_bits_count(pb) - offset;
171}