Imported Debian version 2.4.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / ac3_parser.c
CommitLineData
2ba45a60
DM
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 "libavutil/channel_layout.h"
24#include "parser.h"
25#include "ac3_parser.h"
26#include "aac_ac3_parser.h"
27#include "get_bits.h"
28
29
30#define AC3_HEADER_SIZE 7
31
32
33static const uint8_t eac3_blocks[4] = {
34 1, 2, 3, 6
35};
36
37/**
38 * Table for center mix levels
39 * reference: Section 5.4.2.4 cmixlev
40 */
41static const uint8_t center_levels[4] = { 4, 5, 6, 5 };
42
43/**
44 * Table for surround mix levels
45 * reference: Section 5.4.2.5 surmixlev
46 */
47static const uint8_t surround_levels[4] = { 4, 6, 7, 6 };
48
49
50int avpriv_ac3_parse_header2(GetBitContext *gbc, AC3HeaderInfo **phdr)
51{
52 int frame_size_code;
53 AC3HeaderInfo *hdr;
54
55 if (!*phdr)
56 *phdr = av_mallocz(sizeof(AC3HeaderInfo));
57 if (!*phdr)
58 return AVERROR(ENOMEM);
59 hdr = *phdr;
60
61 memset(hdr, 0, sizeof(*hdr));
62
63 hdr->sync_word = get_bits(gbc, 16);
64 if(hdr->sync_word != 0x0B77)
65 return AAC_AC3_PARSE_ERROR_SYNC;
66
67 /* read ahead to bsid to distinguish between AC-3 and E-AC-3 */
68 hdr->bitstream_id = show_bits_long(gbc, 29) & 0x1F;
69 if(hdr->bitstream_id > 16)
70 return AAC_AC3_PARSE_ERROR_BSID;
71
72 hdr->num_blocks = 6;
73
74 /* set default mix levels */
75 hdr->center_mix_level = 5; // -4.5dB
76 hdr->surround_mix_level = 6; // -6.0dB
77
78 /* set default dolby surround mode */
79 hdr->dolby_surround_mode = AC3_DSURMOD_NOTINDICATED;
80
81 if(hdr->bitstream_id <= 10) {
82 /* Normal AC-3 */
83 hdr->crc1 = get_bits(gbc, 16);
84 hdr->sr_code = get_bits(gbc, 2);
85 if(hdr->sr_code == 3)
86 return AAC_AC3_PARSE_ERROR_SAMPLE_RATE;
87
88 frame_size_code = get_bits(gbc, 6);
89 if(frame_size_code > 37)
90 return AAC_AC3_PARSE_ERROR_FRAME_SIZE;
91
92 skip_bits(gbc, 5); // skip bsid, already got it
93
94 hdr->bitstream_mode = get_bits(gbc, 3);
95 hdr->channel_mode = get_bits(gbc, 3);
96
97 if(hdr->channel_mode == AC3_CHMODE_STEREO) {
98 hdr->dolby_surround_mode = get_bits(gbc, 2);
99 } else {
100 if((hdr->channel_mode & 1) && hdr->channel_mode != AC3_CHMODE_MONO)
101 hdr-> center_mix_level = center_levels[get_bits(gbc, 2)];
102 if(hdr->channel_mode & 4)
103 hdr->surround_mix_level = surround_levels[get_bits(gbc, 2)];
104 }
105 hdr->lfe_on = get_bits1(gbc);
106
107 hdr->sr_shift = FFMAX(hdr->bitstream_id, 8) - 8;
108 hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code] >> hdr->sr_shift;
109 hdr->bit_rate = (ff_ac3_bitrate_tab[frame_size_code>>1] * 1000) >> hdr->sr_shift;
110 hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
111 hdr->frame_size = ff_ac3_frame_size_tab[frame_size_code][hdr->sr_code] * 2;
112 hdr->frame_type = EAC3_FRAME_TYPE_AC3_CONVERT; //EAC3_FRAME_TYPE_INDEPENDENT;
113 hdr->substreamid = 0;
114 } else {
115 /* Enhanced AC-3 */
116 hdr->crc1 = 0;
117 hdr->frame_type = get_bits(gbc, 2);
118 if(hdr->frame_type == EAC3_FRAME_TYPE_RESERVED)
119 return AAC_AC3_PARSE_ERROR_FRAME_TYPE;
120
121 hdr->substreamid = get_bits(gbc, 3);
122
123 hdr->frame_size = (get_bits(gbc, 11) + 1) << 1;
124 if(hdr->frame_size < AC3_HEADER_SIZE)
125 return AAC_AC3_PARSE_ERROR_FRAME_SIZE;
126
127 hdr->sr_code = get_bits(gbc, 2);
128 if (hdr->sr_code == 3) {
129 int sr_code2 = get_bits(gbc, 2);
130 if(sr_code2 == 3)
131 return AAC_AC3_PARSE_ERROR_SAMPLE_RATE;
132 hdr->sample_rate = ff_ac3_sample_rate_tab[sr_code2] / 2;
133 hdr->sr_shift = 1;
134 } else {
135 hdr->num_blocks = eac3_blocks[get_bits(gbc, 2)];
136 hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code];
137 hdr->sr_shift = 0;
138 }
139
140 hdr->channel_mode = get_bits(gbc, 3);
141 hdr->lfe_on = get_bits1(gbc);
142
143 hdr->bit_rate = (uint32_t)(8.0 * hdr->frame_size * hdr->sample_rate /
144 (hdr->num_blocks * 256.0));
145 hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
146 }
147 hdr->channel_layout = avpriv_ac3_channel_layout_tab[hdr->channel_mode];
148 if (hdr->lfe_on)
149 hdr->channel_layout |= AV_CH_LOW_FREQUENCY;
150
151 return 0;
152}
153
154int avpriv_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
155{
156 AC3HeaderInfo tmp, *ptmp = &tmp;
157 int ret = avpriv_ac3_parse_header2(gbc, &ptmp);
158
159 memcpy(hdr, ptmp, ((intptr_t)&tmp.channel_layout) - ((intptr_t)&tmp) + sizeof(uint64_t));
160 return ret;
161}
162
163static int ac3_sync(uint64_t state, AACAC3ParseContext *hdr_info,
164 int *need_next_header, int *new_frame_start)
165{
166 int err;
167 union {
168 uint64_t u64;
169 uint8_t u8[8 + FF_INPUT_BUFFER_PADDING_SIZE];
170 } tmp = { av_be2ne64(state) };
171 AC3HeaderInfo hdr, *phdr = &hdr;
172 GetBitContext gbc;
173
174 init_get_bits(&gbc, tmp.u8+8-AC3_HEADER_SIZE, 54);
175 err = avpriv_ac3_parse_header2(&gbc, &phdr);
176
177 if(err < 0)
178 return 0;
179
180 hdr_info->sample_rate = hdr.sample_rate;
181 hdr_info->bit_rate = hdr.bit_rate;
182 hdr_info->channels = hdr.channels;
183 hdr_info->channel_layout = hdr.channel_layout;
184 hdr_info->samples = hdr.num_blocks * 256;
185 hdr_info->service_type = hdr.bitstream_mode;
186 if (hdr.bitstream_mode == 0x7 && hdr.channels > 1)
187 hdr_info->service_type = AV_AUDIO_SERVICE_TYPE_KARAOKE;
188 if(hdr.bitstream_id>10)
189 hdr_info->codec_id = AV_CODEC_ID_EAC3;
190 else if (hdr_info->codec_id == AV_CODEC_ID_NONE)
191 hdr_info->codec_id = AV_CODEC_ID_AC3;
192
193 *need_next_header = (hdr.frame_type != EAC3_FRAME_TYPE_AC3_CONVERT);
194 *new_frame_start = (hdr.frame_type != EAC3_FRAME_TYPE_DEPENDENT);
195 return hdr.frame_size;
196}
197
198static av_cold int ac3_parse_init(AVCodecParserContext *s1)
199{
200 AACAC3ParseContext *s = s1->priv_data;
201 s->header_size = AC3_HEADER_SIZE;
202 s->sync = ac3_sync;
203 return 0;
204}
205
206
207AVCodecParser ff_ac3_parser = {
208 .codec_ids = { AV_CODEC_ID_AC3, AV_CODEC_ID_EAC3 },
209 .priv_data_size = sizeof(AACAC3ParseContext),
210 .parser_init = ac3_parse_init,
211 .parser_parse = ff_aac_ac3_parse,
212 .parser_close = ff_parse_close,
213};