Set the correct number of samples for E-AC-3 in the AC3 parser.
[libav.git] / libavcodec / ac3_parser.c
1 /*
2 * AC-3 parser
3 * Copyright (c) 2003 Fabrice Bellard
4 * Copyright (c) 2003 Michael Niedermayer
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 "parser.h"
24 #include "ac3_parser.h"
25 #include "aac_ac3_parser.h"
26 #include "bitstream.h"
27
28
29 #define AC3_HEADER_SIZE 7
30
31
32 static const uint8_t eac3_blocks[4] = {
33 1, 2, 3, 6
34 };
35
36
37 int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
38 {
39 int frame_size_code;
40
41 memset(hdr, 0, sizeof(*hdr));
42
43 hdr->sync_word = get_bits(gbc, 16);
44 if(hdr->sync_word != 0x0B77)
45 return AAC_AC3_PARSE_ERROR_SYNC;
46
47 /* read ahead to bsid to distinguish between AC-3 and E-AC-3 */
48 hdr->bitstream_id = show_bits_long(gbc, 29) & 0x1F;
49 if(hdr->bitstream_id > 16)
50 return AAC_AC3_PARSE_ERROR_BSID;
51
52 hdr->num_blocks = 6;
53
54 /* set default mix levels */
55 hdr->center_mix_level = 1; // -4.5dB
56 hdr->surround_mix_level = 1; // -6.0dB
57
58 if(hdr->bitstream_id <= 10) {
59 /* Normal AC-3 */
60 hdr->crc1 = get_bits(gbc, 16);
61 hdr->sr_code = get_bits(gbc, 2);
62 if(hdr->sr_code == 3)
63 return AAC_AC3_PARSE_ERROR_SAMPLE_RATE;
64
65 frame_size_code = get_bits(gbc, 6);
66 if(frame_size_code > 37)
67 return AAC_AC3_PARSE_ERROR_FRAME_SIZE;
68
69 skip_bits(gbc, 5); // skip bsid, already got it
70
71 skip_bits(gbc, 3); // skip bitstream mode
72 hdr->channel_mode = get_bits(gbc, 3);
73
74 if(hdr->channel_mode == AC3_CHMODE_STEREO) {
75 skip_bits(gbc, 2); // skip dsurmod
76 } else {
77 if((hdr->channel_mode & 1) && hdr->channel_mode != AC3_CHMODE_MONO)
78 hdr->center_mix_level = get_bits(gbc, 2);
79 if(hdr->channel_mode & 4)
80 hdr->surround_mix_level = get_bits(gbc, 2);
81 }
82 hdr->lfe_on = get_bits1(gbc);
83
84 hdr->sr_shift = FFMAX(hdr->bitstream_id, 8) - 8;
85 hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code] >> hdr->sr_shift;
86 hdr->bit_rate = (ff_ac3_bitrate_tab[frame_size_code>>1] * 1000) >> hdr->sr_shift;
87 hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
88 hdr->frame_size = ff_ac3_frame_size_tab[frame_size_code][hdr->sr_code] * 2;
89 hdr->frame_type = EAC3_FRAME_TYPE_AC3_CONVERT; //EAC3_FRAME_TYPE_INDEPENDENT;
90 hdr->substreamid = 0;
91 } else {
92 /* Enhanced AC-3 */
93 hdr->crc1 = 0;
94 hdr->frame_type = get_bits(gbc, 2);
95 if(hdr->frame_type == EAC3_FRAME_TYPE_RESERVED)
96 return AAC_AC3_PARSE_ERROR_FRAME_TYPE;
97
98 hdr->substreamid = get_bits(gbc, 3);
99
100 hdr->frame_size = (get_bits(gbc, 11) + 1) << 1;
101 if(hdr->frame_size < AC3_HEADER_SIZE)
102 return AAC_AC3_PARSE_ERROR_FRAME_SIZE;
103
104 hdr->sr_code = get_bits(gbc, 2);
105 if (hdr->sr_code == 3) {
106 int sr_code2 = get_bits(gbc, 2);
107 if(sr_code2 == 3)
108 return AAC_AC3_PARSE_ERROR_SAMPLE_RATE;
109 hdr->sample_rate = ff_ac3_sample_rate_tab[sr_code2] / 2;
110 hdr->sr_shift = 1;
111 } else {
112 hdr->num_blocks = eac3_blocks[get_bits(gbc, 2)];
113 hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code];
114 hdr->sr_shift = 0;
115 }
116
117 hdr->channel_mode = get_bits(gbc, 3);
118 hdr->lfe_on = get_bits1(gbc);
119
120 hdr->bit_rate = (uint32_t)(8.0 * hdr->frame_size * hdr->sample_rate /
121 (hdr->num_blocks * 256.0));
122 hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
123 }
124
125 return 0;
126 }
127
128 int ff_ac3_parse_header_full(GetBitContext *gbc, AC3HeaderInfo *hdr){
129 int ret, i;
130 ret = ff_ac3_parse_header(gbc, hdr);
131 if(!ret){
132 if(hdr->bitstream_id>10){
133 /* Enhanced AC-3 */
134 skip_bits(gbc, 5); // skip bitstream id
135
136 /* skip dialog normalization and compression gain */
137 for (i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
138 skip_bits(gbc, 5); // skip dialog normalization
139 if (get_bits1(gbc)) {
140 skip_bits(gbc, 8); //skip Compression gain word
141 }
142 }
143 /* dependent stream channel map */
144 if (hdr->frame_type == EAC3_FRAME_TYPE_DEPENDENT && get_bits1(gbc)) {
145 hdr->channel_map = get_bits(gbc, 16); //custom channel map
146 return 0;
147 }
148 }
149 //default channel map based on acmod and lfeon
150 hdr->channel_map = ff_eac3_default_chmap[hdr->channel_mode];
151 if(hdr->lfe_on)
152 hdr->channel_map |= AC3_CHMAP_LFE;
153 }
154 return ret;
155 }
156
157 static int ac3_sync(uint64_t state, AACAC3ParseContext *hdr_info,
158 int *need_next_header, int *new_frame_start)
159 {
160 int err;
161 union {
162 uint64_t u64;
163 uint8_t u8[8];
164 } tmp = { be2me_64(state) };
165 AC3HeaderInfo hdr;
166 GetBitContext gbc;
167
168 init_get_bits(&gbc, tmp.u8+8-AC3_HEADER_SIZE, 54);
169 err = ff_ac3_parse_header(&gbc, &hdr);
170
171 if(err < 0)
172 return 0;
173
174 hdr_info->sample_rate = hdr.sample_rate;
175 hdr_info->bit_rate = hdr.bit_rate;
176 hdr_info->channels = hdr.channels;
177 hdr_info->samples = hdr.num_blocks * 256;
178 if(hdr.bitstream_id>10)
179 hdr_info->codec_id = CODEC_ID_EAC3;
180 else
181 hdr_info->codec_id = CODEC_ID_AC3;
182
183 *need_next_header = (hdr.frame_type != EAC3_FRAME_TYPE_AC3_CONVERT);
184 *new_frame_start = (hdr.frame_type != EAC3_FRAME_TYPE_DEPENDENT);
185 return hdr.frame_size;
186 }
187
188 static av_cold int ac3_parse_init(AVCodecParserContext *s1)
189 {
190 AACAC3ParseContext *s = s1->priv_data;
191 s->header_size = AC3_HEADER_SIZE;
192 s->sync = ac3_sync;
193 return 0;
194 }
195
196
197 AVCodecParser ac3_parser = {
198 { CODEC_ID_AC3, CODEC_ID_EAC3 },
199 sizeof(AACAC3ParseContext),
200 ac3_parse_init,
201 ff_aac_ac3_parse,
202 ff_parse_close,
203 };