Replace 5 with AOT_SBR when referring to the MPEG-4 audio object type.
[libav.git] / libavcodec / mpeg4audio.c
1 /*
2 * MPEG-4 Audio common code
3 * Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr>
4 * Copyright (c) 2009 Alex Converse <alex.converse@gmail.com>
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
23 #include "get_bits.h"
24 #include "put_bits.h"
25 #include "mpeg4audio.h"
26
27 const int ff_mpeg4audio_sample_rates[16] = {
28 96000, 88200, 64000, 48000, 44100, 32000,
29 24000, 22050, 16000, 12000, 11025, 8000, 7350
30 };
31
32 const uint8_t ff_mpeg4audio_channels[8] = {
33 0, 1, 2, 3, 4, 5, 6, 8
34 };
35
36 static inline int get_object_type(GetBitContext *gb)
37 {
38 int object_type = get_bits(gb, 5);
39 if (object_type == 31)
40 object_type = 32 + get_bits(gb, 6);
41 return object_type;
42 }
43
44 static inline int get_sample_rate(GetBitContext *gb, int *index)
45 {
46 *index = get_bits(gb, 4);
47 return *index == 0x0f ? get_bits(gb, 24) :
48 ff_mpeg4audio_sample_rates[*index];
49 }
50
51 int ff_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf, int buf_size)
52 {
53 GetBitContext gb;
54 int specific_config_bitindex;
55
56 init_get_bits(&gb, buf, buf_size*8);
57 c->object_type = get_object_type(&gb);
58 c->sample_rate = get_sample_rate(&gb, &c->sampling_index);
59 c->chan_config = get_bits(&gb, 4);
60 c->sbr = -1;
61 if (c->object_type == AOT_SBR) {
62 c->ext_object_type = c->object_type;
63 c->sbr = 1;
64 c->ext_sample_rate = get_sample_rate(&gb, &c->ext_sampling_index);
65 c->object_type = get_object_type(&gb);
66 if (c->object_type == AOT_ER_BSAC)
67 c->ext_chan_config = get_bits(&gb, 4);
68 } else {
69 c->ext_object_type = 0;
70 c->ext_sample_rate = 0;
71 }
72 specific_config_bitindex = get_bits_count(&gb);
73
74 if (c->ext_object_type != AOT_SBR) {
75 int bits_left = buf_size*8 - specific_config_bitindex;
76 for (; bits_left > 15; bits_left--) {
77 if (show_bits(&gb, 11) == 0x2b7) { // sync extension
78 get_bits(&gb, 11);
79 c->ext_object_type = get_object_type(&gb);
80 if (c->ext_object_type == AOT_SBR && (c->sbr = get_bits1(&gb)) == 1)
81 c->ext_sample_rate = get_sample_rate(&gb, &c->ext_sampling_index);
82 break;
83 } else
84 get_bits1(&gb); // skip 1 bit
85 }
86 }
87 return specific_config_bitindex;
88 }
89
90 static av_always_inline unsigned int copy_bits(PutBitContext *pb,
91 GetBitContext *gb,
92 int bits)
93 {
94 unsigned int el = get_bits(gb, bits);
95 put_bits(pb, bits, el);
96 return el;
97 }
98
99 int ff_copy_pce_data(PutBitContext *pb, GetBitContext *gb)
100 {
101 int five_bit_ch, four_bit_ch, comment_size, bits;
102 int offset = put_bits_count(pb);
103
104 copy_bits(pb, gb, 10); //Tag, Object Type, Frequency
105 five_bit_ch = copy_bits(pb, gb, 4); //Front
106 five_bit_ch += copy_bits(pb, gb, 4); //Side
107 five_bit_ch += copy_bits(pb, gb, 4); //Back
108 four_bit_ch = copy_bits(pb, gb, 2); //LFE
109 four_bit_ch += copy_bits(pb, gb, 3); //Data
110 five_bit_ch += copy_bits(pb, gb, 4); //Coupling
111 if (copy_bits(pb, gb, 1)) //Mono Mixdown
112 copy_bits(pb, gb, 4);
113 if (copy_bits(pb, gb, 1)) //Stereo Mixdown
114 copy_bits(pb, gb, 4);
115 if (copy_bits(pb, gb, 1)) //Matrix Mixdown
116 copy_bits(pb, gb, 3);
117 for (bits = five_bit_ch*5+four_bit_ch*4; bits > 16; bits -= 16)
118 copy_bits(pb, gb, 16);
119 if (bits)
120 copy_bits(pb, gb, bits);
121 align_put_bits(pb);
122 align_get_bits(gb);
123 comment_size = copy_bits(pb, gb, 8);
124 for (; comment_size > 0; comment_size--)
125 copy_bits(pb, gb, 8);
126
127 return put_bits_count(pb) - offset;
128 }