1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
|
/*
* E-AC-3 encoder
* Copyright (c) 2011 Justin Ruggles <justin.ruggles@gmail.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* E-AC-3 encoder
*/
#define AC3ENC_FLOAT 1
#include "libavutil/attributes.h"
#include "ac3enc.h"
#include "codec_internal.h"
#include "eac3enc.h"
#include "eac3_data.h"
static const AVClass eac3enc_class = {
.class_name = "E-AC-3 Encoder",
.item_name = av_default_item_name,
.option = &ff_ac3_enc_options[2], /* First two options are AC-3 only. */
.version = LIBAVUTIL_VERSION_INT,
};
/**
* LUT for finding a matching frame exponent strategy index from a set of
* exponent strategies for a single channel across all 6 blocks.
*/
static int8_t eac3_frame_expstr_index_tab[3][4][4][4][4][4];
av_cold void ff_eac3_exponent_init(void)
{
int i;
memset(eac3_frame_expstr_index_tab, -1, sizeof(eac3_frame_expstr_index_tab));
for (i = 0; i < 32; i++) {
eac3_frame_expstr_index_tab[ff_eac3_frm_expstr[i][0]-1]
[ff_eac3_frm_expstr[i][1]]
[ff_eac3_frm_expstr[i][2]]
[ff_eac3_frm_expstr[i][3]]
[ff_eac3_frm_expstr[i][4]]
[ff_eac3_frm_expstr[i][5]] = i;
}
}
void ff_eac3_get_frame_exp_strategy(AC3EncodeContext *s)
{
int ch;
if (s->num_blocks < 6) {
s->use_frame_exp_strategy = 0;
return;
}
s->use_frame_exp_strategy = 1;
for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) {
int expstr = eac3_frame_expstr_index_tab[s->exp_strategy[ch][0]-1]
[s->exp_strategy[ch][1]]
[s->exp_strategy[ch][2]]
[s->exp_strategy[ch][3]]
[s->exp_strategy[ch][4]]
[s->exp_strategy[ch][5]];
if (expstr < 0) {
s->use_frame_exp_strategy = 0;
break;
}
s->frame_exp_strategy[ch] = expstr;
}
}
void ff_eac3_set_cpl_states(AC3EncodeContext *s)
{
int ch, blk;
int first_cpl_coords[AC3_MAX_CHANNELS];
/* set first cpl coords */
for (ch = 1; ch <= s->fbw_channels; ch++)
first_cpl_coords[ch] = 1;
for (blk = 0; blk < s->num_blocks; blk++) {
AC3Block *block = &s->blocks[blk];
for (ch = 1; ch <= s->fbw_channels; ch++) {
if (block->channel_in_cpl[ch]) {
if (first_cpl_coords[ch]) {
block->new_cpl_coords[ch] = 2;
first_cpl_coords[ch] = 0;
}
} else {
first_cpl_coords[ch] = 1;
}
}
}
/* set first cpl leak */
for (blk = 0; blk < s->num_blocks; blk++) {
AC3Block *block = &s->blocks[blk];
if (block->cpl_in_use) {
block->new_cpl_leak = 2;
break;
}
}
}
void ff_eac3_output_frame_header(AC3EncodeContext *s)
{
int blk, ch;
AC3EncOptions *opt = &s->options;
put_bits(&s->pb, 16, 0x0b77); /* sync word */
/* BSI header */
put_bits(&s->pb, 2, 0); /* stream type = independent */
put_bits(&s->pb, 3, 0); /* substream id = 0 */
put_bits(&s->pb, 11, (s->frame_size / 2) - 1); /* frame size */
if (s->bit_alloc.sr_shift) {
put_bits(&s->pb, 2, 0x3); /* fscod2 */
put_bits(&s->pb, 2, s->bit_alloc.sr_code); /* sample rate code */
} else {
put_bits(&s->pb, 2, s->bit_alloc.sr_code); /* sample rate code */
put_bits(&s->pb, 2, s->num_blks_code); /* number of blocks */
}
put_bits(&s->pb, 3, s->channel_mode); /* audio coding mode */
put_bits(&s->pb, 1, s->lfe_on); /* LFE channel indicator */
put_bits(&s->pb, 5, s->bitstream_id); /* bitstream id (EAC3=16) */
put_bits(&s->pb, 5, -opt->dialogue_level); /* dialogue normalization level */
put_bits(&s->pb, 1, 0); /* no compression gain */
/* mixing metadata*/
put_bits(&s->pb, 1, opt->eac3_mixing_metadata);
if (opt->eac3_mixing_metadata) {
if (s->channel_mode > AC3_CHMODE_STEREO)
put_bits(&s->pb, 2, opt->preferred_stereo_downmix);
if (s->has_center) {
put_bits(&s->pb, 3, s->ltrt_center_mix_level);
put_bits(&s->pb, 3, s->loro_center_mix_level);
}
if (s->has_surround) {
put_bits(&s->pb, 3, s->ltrt_surround_mix_level);
put_bits(&s->pb, 3, s->loro_surround_mix_level);
}
if (s->lfe_on)
put_bits(&s->pb, 1, 0);
put_bits(&s->pb, 1, 0); /* no program scale */
put_bits(&s->pb, 1, 0); /* no ext program scale */
put_bits(&s->pb, 2, 0); /* no mixing parameters */
if (s->channel_mode < AC3_CHMODE_STEREO)
put_bits(&s->pb, 1, 0); /* no pan info */
put_bits(&s->pb, 1, 0); /* no frame mix config info */
}
/* info metadata*/
put_bits(&s->pb, 1, opt->eac3_info_metadata);
if (opt->eac3_info_metadata) {
put_bits(&s->pb, 3, s->bitstream_mode);
put_bits(&s->pb, 1, opt->copyright);
put_bits(&s->pb, 1, opt->original);
if (s->channel_mode == AC3_CHMODE_STEREO) {
put_bits(&s->pb, 2, opt->dolby_surround_mode);
put_bits(&s->pb, 2, opt->dolby_headphone_mode);
}
if (s->channel_mode >= AC3_CHMODE_2F2R)
put_bits(&s->pb, 2, opt->dolby_surround_ex_mode);
put_bits(&s->pb, 1, opt->audio_production_info);
if (opt->audio_production_info) {
put_bits(&s->pb, 5, opt->mixing_level - 80);
put_bits(&s->pb, 2, opt->room_type);
put_bits(&s->pb, 1, opt->ad_converter_type);
}
put_bits(&s->pb, 1, 0);
}
if (s->num_blocks != 6)
put_bits(&s->pb, 1, !(s->avctx->frame_num % 6)); /* converter sync flag */
put_bits(&s->pb, 1, 0); /* no additional bit stream info */
/* frame header */
if (s->num_blocks == 6) {
put_bits(&s->pb, 1, !s->use_frame_exp_strategy); /* exponent strategy syntax */
put_bits(&s->pb, 1, 0); /* aht enabled = no */
}
put_bits(&s->pb, 2, 0); /* snr offset strategy = 1 */
put_bits(&s->pb, 1, 0); /* transient pre-noise processing enabled = no */
put_bits(&s->pb, 1, 0); /* block switch syntax enabled = no */
put_bits(&s->pb, 1, 0); /* dither flag syntax enabled = no */
put_bits(&s->pb, 1, 0); /* bit allocation model syntax enabled = no */
put_bits(&s->pb, 1, 0); /* fast gain codes enabled = no */
put_bits(&s->pb, 1, 0); /* dba syntax enabled = no */
put_bits(&s->pb, 1, 0); /* skip field syntax enabled = no */
put_bits(&s->pb, 1, 0); /* spx enabled = no */
/* coupling strategy use flags */
if (s->channel_mode > AC3_CHMODE_MONO) {
put_bits(&s->pb, 1, s->blocks[0].cpl_in_use);
for (blk = 1; blk < s->num_blocks; blk++) {
AC3Block *block = &s->blocks[blk];
put_bits(&s->pb, 1, block->new_cpl_strategy);
if (block->new_cpl_strategy)
put_bits(&s->pb, 1, block->cpl_in_use);
}
}
/* exponent strategy */
if (s->use_frame_exp_strategy) {
for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++)
put_bits(&s->pb, 5, s->frame_exp_strategy[ch]);
} else {
for (blk = 0; blk < s->num_blocks; blk++)
for (ch = !s->blocks[blk].cpl_in_use; ch <= s->fbw_channels; ch++)
put_bits(&s->pb, 2, s->exp_strategy[ch][blk]);
}
if (s->lfe_on) {
for (blk = 0; blk < s->num_blocks; blk++)
put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]);
}
/* E-AC-3 to AC-3 converter exponent strategy (not optional when num blocks == 6) */
if (s->num_blocks != 6) {
put_bits(&s->pb, 1, 0);
} else {
for (ch = 1; ch <= s->fbw_channels; ch++) {
if (s->use_frame_exp_strategy)
put_bits(&s->pb, 5, s->frame_exp_strategy[ch]);
else
put_bits(&s->pb, 5, 0);
}
}
/* snr offsets */
put_bits(&s->pb, 6, s->coarse_snr_offset);
put_bits(&s->pb, 4, s->fine_snr_offset[1]);
/* block start info */
if (s->num_blocks > 1)
put_bits(&s->pb, 1, 0);
}
const FFCodec ff_eac3_encoder = {
.p.name = "eac3",
CODEC_LONG_NAME("ATSC A/52 E-AC-3"),
.p.type = AVMEDIA_TYPE_AUDIO,
.p.id = AV_CODEC_ID_EAC3,
.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
.priv_data_size = sizeof(AC3EncodeContext),
.init = ff_ac3_float_encode_init,
FF_CODEC_ENCODE_CB(ff_ac3_float_encode_frame),
.close = ff_ac3_encode_close,
.p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP,
AV_SAMPLE_FMT_NONE },
.p.priv_class = &eac3enc_class,
.p.supported_samplerates = ff_ac3_sample_rate_tab,
CODEC_OLD_CHANNEL_LAYOUTS_ARRAY(ff_ac3_channel_layouts)
.p.ch_layouts = ff_ac3_ch_layouts,
.defaults = ff_ac3_enc_defaults,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
};
|
