1 /*
2 * The simplest AC-3 encoder
3 * Copyright (c) 2000 Fabrice Bellard
4 * Copyright (c) 2006-2010 Justin Ruggles <justin.ruggles@gmail.com>
5 * Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24 /**
25 * @file
26 * The simplest AC-3 encoder.
27 */
28
29 #include <stdint.h>
30
31 #include "libavutil/attributes.h"
32 #include "libavutil/avassert.h"
33 #include "libavutil/avstring.h"
34 #include "libavutil/channel_layout.h"
35 #include "libavutil/crc.h"
36 #include "libavutil/internal.h"
37 #include "libavutil/mem_internal.h"
38 #include "libavutil/opt.h"
39 #include "libavutil/thread.h"
40 #include "avcodec.h"
41 #include "internal.h"
42 #include "me_cmp.h"
43 #include "put_bits.h"
44 #include "audiodsp.h"
45 #include "ac3dsp.h"
46 #include "ac3.h"
47 #include "fft.h"
48 #include "ac3enc.h"
49 #include "eac3enc.h"
50
51 typedef struct AC3Mant {
52 int16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr; ///< mantissa pointers for bap=1,2,4
53 int mant1_cnt, mant2_cnt, mant4_cnt; ///< mantissa counts for bap=1,2,4
54 } AC3Mant;
55
56 #define CMIXLEV_NUM_OPTIONS 3
57 static const float cmixlev_options[CMIXLEV_NUM_OPTIONS] = {
58 LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB
59 };
60
61 #define SURMIXLEV_NUM_OPTIONS 3
62 static const float surmixlev_options[SURMIXLEV_NUM_OPTIONS] = {
63 LEVEL_MINUS_3DB, LEVEL_MINUS_6DB, LEVEL_ZERO
64 };
65
66 #define EXTMIXLEV_NUM_OPTIONS 8
67 static const float extmixlev_options[EXTMIXLEV_NUM_OPTIONS] = {
68 LEVEL_PLUS_3DB, LEVEL_PLUS_1POINT5DB, LEVEL_ONE, LEVEL_MINUS_1POINT5DB,
69 LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB, LEVEL_ZERO
70 };
71
72 /* The first two options apply only to the AC-3 encoders;
73 * the rest is also valid for EAC-3. When modifying it,
74 * it might be necessary to adapt said offset in eac3enc.c. */
75 #define OFFSET(param) offsetof(AC3EncodeContext, options.param)
76 #define AC3ENC_PARAM (AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM)
77 const AVOption ff_ac3_enc_options[] = {
78 /* AC-3 downmix levels */
79 {"center_mixlev", "Center Mix Level", OFFSET(center_mix_level), AV_OPT_TYPE_FLOAT, {.dbl = LEVEL_MINUS_4POINT5DB }, 0.0, 1.0, AC3ENC_PARAM},
80 {"surround_mixlev", "Surround Mix Level", OFFSET(surround_mix_level), AV_OPT_TYPE_FLOAT, {.dbl = LEVEL_MINUS_6DB }, 0.0, 1.0, AC3ENC_PARAM},
81 /* audio production information */
82 {"mixing_level", "Mixing Level", OFFSET(mixing_level), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_NONE }, AC3ENC_OPT_NONE, 111, AC3ENC_PARAM},
83 {"room_type", "Room Type", OFFSET(room_type), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_NONE }, AC3ENC_OPT_NONE, AC3ENC_OPT_SMALL_ROOM, AC3ENC_PARAM, "room_type"},
84 {"notindicated", "Not Indicated (default)", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_NOT_INDICATED }, INT_MIN, INT_MAX, AC3ENC_PARAM, "room_type"},
85 {"large", "Large Room", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_LARGE_ROOM }, INT_MIN, INT_MAX, AC3ENC_PARAM, "room_type"},
86 {"small", "Small Room", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_SMALL_ROOM }, INT_MIN, INT_MAX, AC3ENC_PARAM, "room_type"},
87 /* Metadata Options */
88 {"per_frame_metadata", "Allow Changing Metadata Per-Frame", OFFSET(allow_per_frame_metadata), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, AC3ENC_PARAM},
89 {"copyright", "Copyright Bit", OFFSET(copyright), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_NONE }, AC3ENC_OPT_NONE, 1, AC3ENC_PARAM},
90 {"dialnorm", "Dialogue Level (dB)", OFFSET(dialogue_level), AV_OPT_TYPE_INT, {.i64 = -31 }, -31, -1, AC3ENC_PARAM},
91 {"dsur_mode", "Dolby Surround Mode", OFFSET(dolby_surround_mode), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_NONE }, AC3ENC_OPT_NONE, AC3ENC_OPT_MODE_ON, AC3ENC_PARAM, "dsur_mode"},
92 {"notindicated", "Not Indicated (default)", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_NOT_INDICATED }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsur_mode"},
93 {"on", "Dolby Surround Encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_MODE_ON }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsur_mode"},
94 {"off", "Not Dolby Surround Encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_MODE_OFF }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsur_mode"},
95 {"original", "Original Bit Stream", OFFSET(original), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_NONE }, AC3ENC_OPT_NONE, 1, AC3ENC_PARAM},
96 /* extended bitstream information */
97 {"dmix_mode", "Preferred Stereo Downmix Mode", OFFSET(preferred_stereo_downmix), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_NONE }, AC3ENC_OPT_NONE, AC3ENC_OPT_DOWNMIX_DPLII, AC3ENC_PARAM, "dmix_mode"},
98 {"notindicated", "Not Indicated (default)", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_NOT_INDICATED }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dmix_mode"},
99 {"ltrt", "Lt/Rt Downmix Preferred", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_DOWNMIX_LTRT }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dmix_mode"},
100 {"loro", "Lo/Ro Downmix Preferred", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_DOWNMIX_LORO }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dmix_mode"},
101 {"dplii", "Dolby Pro Logic II Downmix Preferred", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_DOWNMIX_DPLII }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dmix_mode"},
102 {"ltrt_cmixlev", "Lt/Rt Center Mix Level", OFFSET(ltrt_center_mix_level), AV_OPT_TYPE_FLOAT, {.dbl = -1.0 }, -1.0, 2.0, AC3ENC_PARAM},
103 {"ltrt_surmixlev", "Lt/Rt Surround Mix Level", OFFSET(ltrt_surround_mix_level), AV_OPT_TYPE_FLOAT, {.dbl = -1.0 }, -1.0, 2.0, AC3ENC_PARAM},
104 {"loro_cmixlev", "Lo/Ro Center Mix Level", OFFSET(loro_center_mix_level), AV_OPT_TYPE_FLOAT, {.dbl = -1.0 }, -1.0, 2.0, AC3ENC_PARAM},
105 {"loro_surmixlev", "Lo/Ro Surround Mix Level", OFFSET(loro_surround_mix_level), AV_OPT_TYPE_FLOAT, {.dbl = -1.0 }, -1.0, 2.0, AC3ENC_PARAM},
106 {"dsurex_mode", "Dolby Surround EX Mode", OFFSET(dolby_surround_ex_mode), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_NONE }, AC3ENC_OPT_NONE, AC3ENC_OPT_DSUREX_DPLIIZ, AC3ENC_PARAM, "dsurex_mode"},
107 {"notindicated", "Not Indicated (default)", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_NOT_INDICATED }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
108 {"on", "Dolby Surround EX Encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_MODE_ON }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
109 {"off", "Not Dolby Surround EX Encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_MODE_OFF }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
110 {"dpliiz", "Dolby Pro Logic IIz-encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_DSUREX_DPLIIZ }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
111 {"dheadphone_mode", "Dolby Headphone Mode", OFFSET(dolby_headphone_mode), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_NONE }, AC3ENC_OPT_NONE, AC3ENC_OPT_MODE_ON, AC3ENC_PARAM, "dheadphone_mode"},
112 {"notindicated", "Not Indicated (default)", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_NOT_INDICATED }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dheadphone_mode"},
113 {"on", "Dolby Headphone Encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_MODE_ON }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dheadphone_mode"},
114 {"off", "Not Dolby Headphone Encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_MODE_OFF }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dheadphone_mode"},
115 {"ad_conv_type", "A/D Converter Type", OFFSET(ad_converter_type), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_NONE }, AC3ENC_OPT_NONE, AC3ENC_OPT_ADCONV_HDCD, AC3ENC_PARAM, "ad_conv_type"},
116 {"standard", "Standard (default)", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_ADCONV_STANDARD }, INT_MIN, INT_MAX, AC3ENC_PARAM, "ad_conv_type"},
117 {"hdcd", "HDCD", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_ADCONV_HDCD }, INT_MIN, INT_MAX, AC3ENC_PARAM, "ad_conv_type"},
118 /* Other Encoding Options */
119 {"stereo_rematrixing", "Stereo Rematrixing", OFFSET(stereo_rematrixing), AV_OPT_TYPE_BOOL, {.i64 = 1 }, 0, 1, AC3ENC_PARAM},
120 {"channel_coupling", "Channel Coupling", OFFSET(channel_coupling), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_AUTO }, AC3ENC_OPT_AUTO, AC3ENC_OPT_ON, AC3ENC_PARAM, "channel_coupling"},
121 {"auto", "Selected by the Encoder", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_AUTO }, INT_MIN, INT_MAX, AC3ENC_PARAM, "channel_coupling"},
122 {"cpl_start_band", "Coupling Start Band", OFFSET(cpl_start), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_AUTO }, AC3ENC_OPT_AUTO, 15, AC3ENC_PARAM, "cpl_start_band"},
123 {"auto", "Selected by the Encoder", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_AUTO }, INT_MIN, INT_MAX, AC3ENC_PARAM, "cpl_start_band"},
124 {NULL}
125 };
126
127 const AVCodecDefault ff_ac3_enc_defaults[] = {
128 { "b", "0" },
129 { NULL }
130 };
131
132 /**
133 * LUT for number of exponent groups.
134 * exponent_group_tab[coupling][exponent strategy-1][number of coefficients]
135 */
136 static uint8_t exponent_group_tab[2][3][256];
137
138
139 /**
140 * List of supported channel layouts.
141 */
142 const uint64_t ff_ac3_channel_layouts[19] = {
143 AV_CH_LAYOUT_MONO,
144 AV_CH_LAYOUT_STEREO,
145 AV_CH_LAYOUT_2_1,
146 AV_CH_LAYOUT_SURROUND,
147 AV_CH_LAYOUT_2_2,
148 AV_CH_LAYOUT_QUAD,
149 AV_CH_LAYOUT_4POINT0,
150 AV_CH_LAYOUT_5POINT0,
151 AV_CH_LAYOUT_5POINT0_BACK,
152 (AV_CH_LAYOUT_MONO | AV_CH_LOW_FREQUENCY),
153 (AV_CH_LAYOUT_STEREO | AV_CH_LOW_FREQUENCY),
154 (AV_CH_LAYOUT_2_1 | AV_CH_LOW_FREQUENCY),
155 (AV_CH_LAYOUT_SURROUND | AV_CH_LOW_FREQUENCY),
156 (AV_CH_LAYOUT_2_2 | AV_CH_LOW_FREQUENCY),
157 (AV_CH_LAYOUT_QUAD | AV_CH_LOW_FREQUENCY),
158 (AV_CH_LAYOUT_4POINT0 | AV_CH_LOW_FREQUENCY),
159 AV_CH_LAYOUT_5POINT1,
160 AV_CH_LAYOUT_5POINT1_BACK,
161 0
162 };
163
164 /**
165 * Table to remap channels from SMPTE order to AC-3 order.
166 * [channel_mode][lfe][ch]
167 */
168 static const uint8_t ac3_enc_channel_map[8][2][6] = {
169 COMMON_CHANNEL_MAP
170 { { 0, 1, 2, 3, }, { 0, 1, 3, 4, 2, } },
171 { { 0, 2, 1, 3, 4, }, { 0, 2, 1, 4, 5, 3 } },
172 };
173
174 /**
175 * LUT to select the bandwidth code based on the bit rate, sample rate, and
176 * number of full-bandwidth channels.
177 * bandwidth_tab[fbw_channels-1][sample rate code][bit rate code]
178 */
179 static const uint8_t ac3_bandwidth_tab[5][3][19] = {
180 // 32 40 48 56 64 80 96 112 128 160 192 224 256 320 384 448 512 576 640
181
182 { { 0, 0, 0, 12, 16, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
183 { 0, 0, 0, 16, 20, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
184 { 0, 0, 0, 32, 40, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
185
186 { { 0, 0, 0, 0, 0, 0, 0, 20, 24, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
187 { 0, 0, 0, 0, 0, 0, 4, 24, 28, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
188 { 0, 0, 0, 0, 0, 0, 20, 44, 52, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
189
190 { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 24, 32, 40, 48, 48, 48, 48, 48, 48 },
191 { 0, 0, 0, 0, 0, 0, 0, 0, 4, 20, 28, 36, 44, 56, 56, 56, 56, 56, 56 },
192 { 0, 0, 0, 0, 0, 0, 0, 0, 20, 40, 48, 60, 60, 60, 60, 60, 60, 60, 60 } },
193
194 { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 24, 32, 48, 48, 48, 48, 48, 48 },
195 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 28, 36, 56, 56, 56, 56, 56, 56 },
196 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 32, 48, 60, 60, 60, 60, 60, 60, 60 } },
197
198 { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 20, 32, 40, 48, 48, 48, 48 },
199 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 24, 36, 44, 56, 56, 56, 56 },
200 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 28, 44, 60, 60, 60, 60, 60, 60 } }
201 };
202
203
204 /**
205 * LUT to select the coupling start band based on the bit rate, sample rate, and
206 * number of full-bandwidth channels. -1 = coupling off
207 * ac3_coupling_start_tab[channel_mode-2][sample rate code][bit rate code]
208 *
209 * TODO: more testing for optimal parameters.
210 * multi-channel tests at 44.1kHz and 32kHz.
211 */
212 static const int8_t ac3_coupling_start_tab[6][3][19] = {
213 // 32 40 48 56 64 80 96 112 128 160 192 224 256 320 384 448 512 576 640
214
215 // 2/0
216 { { 0, 0, 0, 0, 0, 0, 0, 1, 1, 7, 8, 11, 12, -1, -1, -1, -1, -1, -1 },
217 { 0, 0, 0, 0, 0, 0, 1, 3, 5, 7, 10, 12, 13, -1, -1, -1, -1, -1, -1 },
218 { 0, 0, 0, 0, 1, 2, 2, 9, 13, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
219
220 // 3/0
221 { { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
222 { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
223 { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
224
225 // 2/1 - untested
226 { { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
227 { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
228 { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
229
230 // 3/1
231 { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
232 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
233 { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
234
235 // 2/2 - untested
236 { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
237 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
238 { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
239
240 // 3/2
241 { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 8, 11, 12, 12, -1, -1 },
242 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 8, 11, 12, 12, -1, -1 },
243 { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
244 };
245
246
247 /**
248 * Adjust the frame size to make the average bit rate match the target bit rate.
249 * This is only needed for 11025, 22050, and 44100 sample rates or any E-AC-3.
250 *
251 * @param s AC-3 encoder private context
252 */
ff_ac3_adjust_frame_size(AC3EncodeContext * s)253 void ff_ac3_adjust_frame_size(AC3EncodeContext *s)
254 {
255 while (s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
256 s->bits_written -= s->bit_rate;
257 s->samples_written -= s->sample_rate;
258 }
259 s->frame_size = s->frame_size_min +
260 2 * (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
261 s->bits_written += s->frame_size * 8;
262 s->samples_written += AC3_BLOCK_SIZE * s->num_blocks;
263 }
264
265
266 /**
267 * Set the initial coupling strategy parameters prior to coupling analysis.
268 *
269 * @param s AC-3 encoder private context
270 */
ff_ac3_compute_coupling_strategy(AC3EncodeContext * s)271 void ff_ac3_compute_coupling_strategy(AC3EncodeContext *s)
272 {
273 int blk, ch;
274 int got_cpl_snr;
275 int num_cpl_blocks;
276
277 /* set coupling use flags for each block/channel */
278 /* TODO: turn coupling on/off and adjust start band based on bit usage */
279 for (blk = 0; blk < s->num_blocks; blk++) {
280 AC3Block *block = &s->blocks[blk];
281 for (ch = 1; ch <= s->fbw_channels; ch++)
282 block->channel_in_cpl[ch] = s->cpl_on;
283 }
284
285 /* enable coupling for each block if at least 2 channels have coupling
286 enabled for that block */
287 got_cpl_snr = 0;
288 num_cpl_blocks = 0;
289 for (blk = 0; blk < s->num_blocks; blk++) {
290 AC3Block *block = &s->blocks[blk];
291 block->num_cpl_channels = 0;
292 for (ch = 1; ch <= s->fbw_channels; ch++)
293 block->num_cpl_channels += block->channel_in_cpl[ch];
294 block->cpl_in_use = block->num_cpl_channels > 1;
295 num_cpl_blocks += block->cpl_in_use;
296 if (!block->cpl_in_use) {
297 block->num_cpl_channels = 0;
298 for (ch = 1; ch <= s->fbw_channels; ch++)
299 block->channel_in_cpl[ch] = 0;
300 }
301
302 block->new_cpl_strategy = !blk;
303 if (blk) {
304 for (ch = 1; ch <= s->fbw_channels; ch++) {
305 if (block->channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
306 block->new_cpl_strategy = 1;
307 break;
308 }
309 }
310 }
311 block->new_cpl_leak = block->new_cpl_strategy;
312
313 if (!blk || (block->cpl_in_use && !got_cpl_snr)) {
314 block->new_snr_offsets = 1;
315 if (block->cpl_in_use)
316 got_cpl_snr = 1;
317 } else {
318 block->new_snr_offsets = 0;
319 }
320 }
321 if (!num_cpl_blocks)
322 s->cpl_on = 0;
323
324 /* set bandwidth for each channel */
325 for (blk = 0; blk < s->num_blocks; blk++) {
326 AC3Block *block = &s->blocks[blk];
327 for (ch = 1; ch <= s->fbw_channels; ch++) {
328 if (block->channel_in_cpl[ch])
329 block->end_freq[ch] = s->start_freq[CPL_CH];
330 else
331 block->end_freq[ch] = s->bandwidth_code * 3 + 73;
332 }
333 }
334 }
335
336
337 /**
338 * Apply stereo rematrixing to coefficients based on rematrixing flags.
339 *
340 * @param s AC-3 encoder private context
341 */
ac3_apply_rematrixing(AC3EncodeContext * s)342 static void ac3_apply_rematrixing(AC3EncodeContext *s)
343 {
344 int nb_coefs;
345 int blk, bnd, i;
346 int start, end;
347 uint8_t *flags = NULL;
348
349 if (!s->rematrixing_enabled)
350 return;
351
352 for (blk = 0; blk < s->num_blocks; blk++) {
353 AC3Block *block = &s->blocks[blk];
354 if (block->new_rematrixing_strategy)
355 flags = block->rematrixing_flags;
356 nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);
357 for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {
358 if (flags[bnd]) {
359 start = ff_ac3_rematrix_band_tab[bnd];
360 end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
361 for (i = start; i < end; i++) {
362 int32_t lt = block->fixed_coef[1][i];
363 int32_t rt = block->fixed_coef[2][i];
364 block->fixed_coef[1][i] = (lt + rt) >> 1;
365 block->fixed_coef[2][i] = (lt - rt) >> 1;
366 }
367 }
368 }
369 }
370 }
371
372
373 /*
374 * Initialize exponent tables.
375 */
exponent_init(void)376 static av_cold void exponent_init(void)
377 {
378 int expstr, i, grpsize;
379
380 for (expstr = EXP_D15-1; expstr <= EXP_D45-1; expstr++) {
381 grpsize = 3 << expstr;
382 for (i = 12; i < 256; i++) {
383 exponent_group_tab[0][expstr][i] = (i + grpsize - 4) / grpsize;
384 exponent_group_tab[1][expstr][i] = (i ) / grpsize;
385 }
386 }
387 /* LFE */
388 exponent_group_tab[0][0][7] = 2;
389 }
390
391
392 /*
393 * Extract exponents from the MDCT coefficients.
394 */
extract_exponents(AC3EncodeContext * s)395 static void extract_exponents(AC3EncodeContext *s)
396 {
397 int ch = !s->cpl_on;
398 int chan_size = AC3_MAX_COEFS * s->num_blocks * (s->channels - ch + 1);
399 AC3Block *block = &s->blocks[0];
400
401 s->ac3dsp.extract_exponents(block->exp[ch], block->fixed_coef[ch], chan_size);
402 }
403
404
405 /**
406 * Exponent Difference Threshold.
407 * New exponents are sent if their SAD exceed this number.
408 */
409 #define EXP_DIFF_THRESHOLD 500
410
411 /**
412 * Table used to select exponent strategy based on exponent reuse block interval.
413 */
414 static const uint8_t exp_strategy_reuse_tab[4][6] = {
415 { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
416 { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
417 { EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
418 { EXP_D45, EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15 }
419 };
420
421 /*
422 * Calculate exponent strategies for all channels.
423 * Array arrangement is reversed to simplify the per-channel calculation.
424 */
compute_exp_strategy(AC3EncodeContext * s)425 static void compute_exp_strategy(AC3EncodeContext *s)
426 {
427 int ch, blk, blk1;
428
429 for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) {
430 uint8_t *exp_strategy = s->exp_strategy[ch];
431 uint8_t *exp = s->blocks[0].exp[ch];
432 int exp_diff;
433
434 /* estimate if the exponent variation & decide if they should be
435 reused in the next frame */
436 exp_strategy[0] = EXP_NEW;
437 exp += AC3_MAX_COEFS;
438 for (blk = 1; blk < s->num_blocks; blk++, exp += AC3_MAX_COEFS) {
439 if (ch == CPL_CH) {
440 if (!s->blocks[blk-1].cpl_in_use) {
441 exp_strategy[blk] = EXP_NEW;
442 continue;
443 } else if (!s->blocks[blk].cpl_in_use) {
444 exp_strategy[blk] = EXP_REUSE;
445 continue;
446 }
447 } else if (s->blocks[blk].channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
448 exp_strategy[blk] = EXP_NEW;
449 continue;
450 }
451 exp_diff = s->mecc.sad[0](NULL, exp, exp - AC3_MAX_COEFS, 16, 16);
452 exp_strategy[blk] = EXP_REUSE;
453 if (ch == CPL_CH && exp_diff > (EXP_DIFF_THRESHOLD * (s->blocks[blk].end_freq[ch] - s->start_freq[ch]) / AC3_MAX_COEFS))
454 exp_strategy[blk] = EXP_NEW;
455 else if (ch > CPL_CH && exp_diff > EXP_DIFF_THRESHOLD)
456 exp_strategy[blk] = EXP_NEW;
457 }
458
459 /* now select the encoding strategy type : if exponents are often
460 recoded, we use a coarse encoding */
461 blk = 0;
462 while (blk < s->num_blocks) {
463 blk1 = blk + 1;
464 while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE)
465 blk1++;
466 exp_strategy[blk] = exp_strategy_reuse_tab[s->num_blks_code][blk1-blk-1];
467 blk = blk1;
468 }
469 }
470 if (s->lfe_on) {
471 ch = s->lfe_channel;
472 s->exp_strategy[ch][0] = EXP_D15;
473 for (blk = 1; blk < s->num_blocks; blk++)
474 s->exp_strategy[ch][blk] = EXP_REUSE;
475 }
476
477 /* for E-AC-3, determine frame exponent strategy */
478 if (CONFIG_EAC3_ENCODER && s->eac3)
479 ff_eac3_get_frame_exp_strategy(s);
480 }
481
482
483 /**
484 * Update the exponents so that they are the ones the decoder will decode.
485 *
486 * @param[in,out] exp array of exponents for 1 block in 1 channel
487 * @param nb_exps number of exponents in active bandwidth
488 * @param exp_strategy exponent strategy for the block
489 * @param cpl indicates if the block is in the coupling channel
490 */
encode_exponents_blk_ch(uint8_t * exp,int nb_exps,int exp_strategy,int cpl)491 static void encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy,
492 int cpl)
493 {
494 int nb_groups, i, k;
495
496 nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_exps] * 3;
497
498 /* for each group, compute the minimum exponent */
499 switch(exp_strategy) {
500 case EXP_D25:
501 for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
502 uint8_t exp_min = exp[k];
503 if (exp[k+1] < exp_min)
504 exp_min = exp[k+1];
505 exp[i-cpl] = exp_min;
506 k += 2;
507 }
508 break;
509 case EXP_D45:
510 for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
511 uint8_t exp_min = exp[k];
512 if (exp[k+1] < exp_min)
513 exp_min = exp[k+1];
514 if (exp[k+2] < exp_min)
515 exp_min = exp[k+2];
516 if (exp[k+3] < exp_min)
517 exp_min = exp[k+3];
518 exp[i-cpl] = exp_min;
519 k += 4;
520 }
521 break;
522 }
523
524 /* constraint for DC exponent */
525 if (!cpl && exp[0] > 15)
526 exp[0] = 15;
527
528 /* decrease the delta between each groups to within 2 so that they can be
529 differentially encoded */
530 for (i = 1; i <= nb_groups; i++)
531 exp[i] = FFMIN(exp[i], exp[i-1] + 2);
532 i--;
533 while (--i >= 0)
534 exp[i] = FFMIN(exp[i], exp[i+1] + 2);
535
536 if (cpl)
537 exp[-1] = exp[0] & ~1;
538
539 /* now we have the exponent values the decoder will see */
540 switch (exp_strategy) {
541 case EXP_D25:
542 for (i = nb_groups, k = (nb_groups * 2)-cpl; i > 0; i--) {
543 uint8_t exp1 = exp[i-cpl];
544 exp[k--] = exp1;
545 exp[k--] = exp1;
546 }
547 break;
548 case EXP_D45:
549 for (i = nb_groups, k = (nb_groups * 4)-cpl; i > 0; i--) {
550 exp[k] = exp[k-1] = exp[k-2] = exp[k-3] = exp[i-cpl];
551 k -= 4;
552 }
553 break;
554 }
555 }
556
557
558 /*
559 * Encode exponents from original extracted form to what the decoder will see.
560 * This copies and groups exponents based on exponent strategy and reduces
561 * deltas between adjacent exponent groups so that they can be differentially
562 * encoded.
563 */
encode_exponents(AC3EncodeContext * s)564 static void encode_exponents(AC3EncodeContext *s)
565 {
566 int blk, blk1, ch, cpl;
567 uint8_t *exp, *exp_strategy;
568 int nb_coefs, num_reuse_blocks;
569
570 for (ch = !s->cpl_on; ch <= s->channels; ch++) {
571 exp = s->blocks[0].exp[ch] + s->start_freq[ch];
572 exp_strategy = s->exp_strategy[ch];
573
574 cpl = (ch == CPL_CH);
575 blk = 0;
576 while (blk < s->num_blocks) {
577 AC3Block *block = &s->blocks[blk];
578 if (cpl && !block->cpl_in_use) {
579 exp += AC3_MAX_COEFS;
580 blk++;
581 continue;
582 }
583 nb_coefs = block->end_freq[ch] - s->start_freq[ch];
584 blk1 = blk + 1;
585
586 /* count the number of EXP_REUSE blocks after the current block
587 and set exponent reference block numbers */
588 s->exp_ref_block[ch][blk] = blk;
589 while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE) {
590 s->exp_ref_block[ch][blk1] = blk;
591 blk1++;
592 }
593 num_reuse_blocks = blk1 - blk - 1;
594
595 /* for the EXP_REUSE case we select the min of the exponents */
596 s->ac3dsp.ac3_exponent_min(exp-s->start_freq[ch], num_reuse_blocks,
597 AC3_MAX_COEFS);
598
599 encode_exponents_blk_ch(exp, nb_coefs, exp_strategy[blk], cpl);
600
601 exp += AC3_MAX_COEFS * (num_reuse_blocks + 1);
602 blk = blk1;
603 }
604 }
605
606 /* reference block numbers have been changed, so reset ref_bap_set */
607 s->ref_bap_set = 0;
608 }
609
610
611 /*
612 * Count exponent bits based on bandwidth, coupling, and exponent strategies.
613 */
count_exponent_bits(AC3EncodeContext * s)614 static int count_exponent_bits(AC3EncodeContext *s)
615 {
616 int blk, ch;
617 int nb_groups, bit_count;
618
619 bit_count = 0;
620 for (blk = 0; blk < s->num_blocks; blk++) {
621 AC3Block *block = &s->blocks[blk];
622 for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
623 int exp_strategy = s->exp_strategy[ch][blk];
624 int cpl = (ch == CPL_CH);
625 int nb_coefs = block->end_freq[ch] - s->start_freq[ch];
626
627 if (exp_strategy == EXP_REUSE)
628 continue;
629
630 nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_coefs];
631 bit_count += 4 + (nb_groups * 7);
632 }
633 }
634
635 return bit_count;
636 }
637
638
639 /**
640 * Group exponents.
641 * 3 delta-encoded exponents are in each 7-bit group. The number of groups
642 * varies depending on exponent strategy and bandwidth.
643 *
644 * @param s AC-3 encoder private context
645 */
ac3_group_exponents(AC3EncodeContext * s)646 static void ac3_group_exponents(AC3EncodeContext *s)
647 {
648 int blk, ch, i, cpl;
649 int group_size, nb_groups;
650 uint8_t *p;
651 int delta0, delta1, delta2;
652 int exp0, exp1;
653
654 for (blk = 0; blk < s->num_blocks; blk++) {
655 AC3Block *block = &s->blocks[blk];
656 for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
657 int exp_strategy = s->exp_strategy[ch][blk];
658 if (exp_strategy == EXP_REUSE)
659 continue;
660 cpl = (ch == CPL_CH);
661 group_size = exp_strategy + (exp_strategy == EXP_D45);
662 nb_groups = exponent_group_tab[cpl][exp_strategy-1][block->end_freq[ch]-s->start_freq[ch]];
663 p = block->exp[ch] + s->start_freq[ch] - cpl;
664
665 /* DC exponent */
666 exp1 = *p++;
667 block->grouped_exp[ch][0] = exp1;
668
669 /* remaining exponents are delta encoded */
670 for (i = 1; i <= nb_groups; i++) {
671 /* merge three delta in one code */
672 exp0 = exp1;
673 exp1 = p[0];
674 p += group_size;
675 delta0 = exp1 - exp0 + 2;
676 av_assert2(delta0 >= 0 && delta0 <= 4);
677
678 exp0 = exp1;
679 exp1 = p[0];
680 p += group_size;
681 delta1 = exp1 - exp0 + 2;
682 av_assert2(delta1 >= 0 && delta1 <= 4);
683
684 exp0 = exp1;
685 exp1 = p[0];
686 p += group_size;
687 delta2 = exp1 - exp0 + 2;
688 av_assert2(delta2 >= 0 && delta2 <= 4);
689
690 block->grouped_exp[ch][i] = ((delta0 * 5 + delta1) * 5) + delta2;
691 }
692 }
693 }
694 }
695
696
697 /**
698 * Calculate final exponents from the supplied MDCT coefficients and exponent shift.
699 * Extract exponents from MDCT coefficients, calculate exponent strategies,
700 * and encode final exponents.
701 *
702 * @param s AC-3 encoder private context
703 */
ac3_process_exponents(AC3EncodeContext * s)704 static void ac3_process_exponents(AC3EncodeContext *s)
705 {
706 extract_exponents(s);
707
708 compute_exp_strategy(s);
709
710 encode_exponents(s);
711
712 emms_c();
713 }
714
715
716 /*
717 * Count frame bits that are based solely on fixed parameters.
718 * This only has to be run once when the encoder is initialized.
719 */
count_frame_bits_fixed(AC3EncodeContext * s)720 static void count_frame_bits_fixed(AC3EncodeContext *s)
721 {
722 static const uint8_t frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
723 int blk;
724 int frame_bits;
725
726 /* assumptions:
727 * no dynamic range codes
728 * bit allocation parameters do not change between blocks
729 * no delta bit allocation
730 * no skipped data
731 * no auxiliary data
732 * no E-AC-3 metadata
733 */
734
735 /* header */
736 frame_bits = 16; /* sync info */
737 if (s->eac3) {
738 /* bitstream info header */
739 frame_bits += 35;
740 frame_bits += 1 + 1;
741 if (s->num_blocks != 0x6)
742 frame_bits++;
743 frame_bits++;
744 /* audio frame header */
745 if (s->num_blocks == 6)
746 frame_bits += 2;
747 frame_bits += 10;
748 /* exponent strategy */
749 if (s->use_frame_exp_strategy)
750 frame_bits += 5 * s->fbw_channels;
751 else
752 frame_bits += s->num_blocks * 2 * s->fbw_channels;
753 if (s->lfe_on)
754 frame_bits += s->num_blocks;
755 /* converter exponent strategy */
756 if (s->num_blks_code != 0x3)
757 frame_bits++;
758 else
759 frame_bits += s->fbw_channels * 5;
760 /* snr offsets */
761 frame_bits += 10;
762 /* block start info */
763 if (s->num_blocks != 1)
764 frame_bits++;
765 } else {
766 frame_bits += 49;
767 frame_bits += frame_bits_inc[s->channel_mode];
768 }
769
770 /* audio blocks */
771 for (blk = 0; blk < s->num_blocks; blk++) {
772 if (!s->eac3) {
773 /* block switch flags */
774 frame_bits += s->fbw_channels;
775
776 /* dither flags */
777 frame_bits += s->fbw_channels;
778 }
779
780 /* dynamic range */
781 frame_bits++;
782
783 /* spectral extension */
784 if (s->eac3)
785 frame_bits++;
786
787 if (!s->eac3) {
788 /* exponent strategy */
789 frame_bits += 2 * s->fbw_channels;
790 if (s->lfe_on)
791 frame_bits++;
792
793 /* bit allocation params */
794 frame_bits++;
795 if (!blk)
796 frame_bits += 2 + 2 + 2 + 2 + 3;
797 }
798
799 /* converter snr offset */
800 if (s->eac3)
801 frame_bits++;
802
803 if (!s->eac3) {
804 /* delta bit allocation */
805 frame_bits++;
806
807 /* skipped data */
808 frame_bits++;
809 }
810 }
811
812 /* auxiliary data */
813 frame_bits++;
814
815 /* CRC */
816 frame_bits += 1 + 16;
817
818 s->frame_bits_fixed = frame_bits;
819 }
820
821
822 /*
823 * Initialize bit allocation.
824 * Set default parameter codes and calculate parameter values.
825 */
bit_alloc_init(AC3EncodeContext * s)826 static av_cold void bit_alloc_init(AC3EncodeContext *s)
827 {
828 int ch;
829
830 /* init default parameters */
831 s->slow_decay_code = 2;
832 s->fast_decay_code = 1;
833 s->slow_gain_code = 1;
834 s->db_per_bit_code = s->eac3 ? 2 : 3;
835 s->floor_code = 7;
836 for (ch = 0; ch <= s->channels; ch++)
837 s->fast_gain_code[ch] = 4;
838
839 /* initial snr offset */
840 s->coarse_snr_offset = 40;
841
842 /* compute real values */
843 /* currently none of these values change during encoding, so we can just
844 set them once at initialization */
845 s->bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s->slow_decay_code] >> s->bit_alloc.sr_shift;
846 s->bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s->fast_decay_code] >> s->bit_alloc.sr_shift;
847 s->bit_alloc.slow_gain = ff_ac3_slow_gain_tab[s->slow_gain_code];
848 s->bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s->db_per_bit_code];
849 s->bit_alloc.floor = ff_ac3_floor_tab[s->floor_code];
850 s->bit_alloc.cpl_fast_leak = 0;
851 s->bit_alloc.cpl_slow_leak = 0;
852
853 count_frame_bits_fixed(s);
854 }
855
856
857 /*
858 * Count the bits used to encode the frame, minus exponents and mantissas.
859 * Bits based on fixed parameters have already been counted, so now we just
860 * have to add the bits based on parameters that change during encoding.
861 */
count_frame_bits(AC3EncodeContext * s)862 static void count_frame_bits(AC3EncodeContext *s)
863 {
864 AC3EncOptions *opt = &s->options;
865 int blk, ch;
866 int frame_bits = 0;
867
868 /* header */
869 if (s->eac3) {
870 if (opt->eac3_mixing_metadata) {
871 if (s->channel_mode > AC3_CHMODE_STEREO)
872 frame_bits += 2;
873 if (s->has_center)
874 frame_bits += 6;
875 if (s->has_surround)
876 frame_bits += 6;
877 frame_bits += s->lfe_on;
878 frame_bits += 1 + 1 + 2;
879 if (s->channel_mode < AC3_CHMODE_STEREO)
880 frame_bits++;
881 frame_bits++;
882 }
883 if (opt->eac3_info_metadata) {
884 frame_bits += 3 + 1 + 1;
885 if (s->channel_mode == AC3_CHMODE_STEREO)
886 frame_bits += 2 + 2;
887 if (s->channel_mode >= AC3_CHMODE_2F2R)
888 frame_bits += 2;
889 frame_bits++;
890 if (opt->audio_production_info)
891 frame_bits += 5 + 2 + 1;
892 frame_bits++;
893 }
894 /* coupling */
895 if (s->channel_mode > AC3_CHMODE_MONO) {
896 frame_bits++;
897 for (blk = 1; blk < s->num_blocks; blk++) {
898 AC3Block *block = &s->blocks[blk];
899 frame_bits++;
900 if (block->new_cpl_strategy)
901 frame_bits++;
902 }
903 }
904 /* coupling exponent strategy */
905 if (s->cpl_on) {
906 if (s->use_frame_exp_strategy) {
907 frame_bits += 5 * s->cpl_on;
908 } else {
909 for (blk = 0; blk < s->num_blocks; blk++)
910 frame_bits += 2 * s->blocks[blk].cpl_in_use;
911 }
912 }
913 } else {
914 if (opt->audio_production_info)
915 frame_bits += 7;
916 if (s->bitstream_id == 6) {
917 if (opt->extended_bsi_1)
918 frame_bits += 14;
919 if (opt->extended_bsi_2)
920 frame_bits += 14;
921 }
922 }
923
924 /* audio blocks */
925 for (blk = 0; blk < s->num_blocks; blk++) {
926 AC3Block *block = &s->blocks[blk];
927
928 /* coupling strategy */
929 if (!s->eac3)
930 frame_bits++;
931 if (block->new_cpl_strategy) {
932 if (!s->eac3)
933 frame_bits++;
934 if (block->cpl_in_use) {
935 if (s->eac3)
936 frame_bits++;
937 if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO)
938 frame_bits += s->fbw_channels;
939 if (s->channel_mode == AC3_CHMODE_STEREO)
940 frame_bits++;
941 frame_bits += 4 + 4;
942 if (s->eac3)
943 frame_bits++;
944 else
945 frame_bits += s->num_cpl_subbands - 1;
946 }
947 }
948
949 /* coupling coordinates */
950 if (block->cpl_in_use) {
951 for (ch = 1; ch <= s->fbw_channels; ch++) {
952 if (block->channel_in_cpl[ch]) {
953 if (!s->eac3 || block->new_cpl_coords[ch] != 2)
954 frame_bits++;
955 if (block->new_cpl_coords[ch]) {
956 frame_bits += 2;
957 frame_bits += (4 + 4) * s->num_cpl_bands;
958 }
959 }
960 }
961 }
962
963 /* stereo rematrixing */
964 if (s->channel_mode == AC3_CHMODE_STEREO) {
965 if (!s->eac3 || blk > 0)
966 frame_bits++;
967 if (s->blocks[blk].new_rematrixing_strategy)
968 frame_bits += block->num_rematrixing_bands;
969 }
970
971 /* bandwidth codes & gain range */
972 for (ch = 1; ch <= s->fbw_channels; ch++) {
973 if (s->exp_strategy[ch][blk] != EXP_REUSE) {
974 if (!block->channel_in_cpl[ch])
975 frame_bits += 6;
976 frame_bits += 2;
977 }
978 }
979
980 /* coupling exponent strategy */
981 if (!s->eac3 && block->cpl_in_use)
982 frame_bits += 2;
983
984 /* snr offsets and fast gain codes */
985 if (!s->eac3) {
986 frame_bits++;
987 if (block->new_snr_offsets)
988 frame_bits += 6 + (s->channels + block->cpl_in_use) * (4 + 3);
989 }
990
991 /* coupling leak info */
992 if (block->cpl_in_use) {
993 if (!s->eac3 || block->new_cpl_leak != 2)
994 frame_bits++;
995 if (block->new_cpl_leak)
996 frame_bits += 3 + 3;
997 }
998 }
999
1000 s->frame_bits = s->frame_bits_fixed + frame_bits;
1001 }
1002
1003
1004 /*
1005 * Calculate masking curve based on the final exponents.
1006 * Also calculate the power spectral densities to use in future calculations.
1007 */
bit_alloc_masking(AC3EncodeContext * s)1008 static void bit_alloc_masking(AC3EncodeContext *s)
1009 {
1010 int blk, ch;
1011
1012 for (blk = 0; blk < s->num_blocks; blk++) {
1013 AC3Block *block = &s->blocks[blk];
1014 for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1015 /* We only need psd and mask for calculating bap.
1016 Since we currently do not calculate bap when exponent
1017 strategy is EXP_REUSE we do not need to calculate psd or mask. */
1018 if (s->exp_strategy[ch][blk] != EXP_REUSE) {
1019 ff_ac3_bit_alloc_calc_psd(block->exp[ch], s->start_freq[ch],
1020 block->end_freq[ch], block->psd[ch],
1021 block->band_psd[ch]);
1022 ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, block->band_psd[ch],
1023 s->start_freq[ch], block->end_freq[ch],
1024 ff_ac3_fast_gain_tab[s->fast_gain_code[ch]],
1025 ch == s->lfe_channel,
1026 DBA_NONE, 0, NULL, NULL, NULL,
1027 block->mask[ch]);
1028 }
1029 }
1030 }
1031 }
1032
1033
1034 /*
1035 * Ensure that bap for each block and channel point to the current bap_buffer.
1036 * They may have been switched during the bit allocation search.
1037 */
reset_block_bap(AC3EncodeContext * s)1038 static void reset_block_bap(AC3EncodeContext *s)
1039 {
1040 int blk, ch;
1041 uint8_t *ref_bap;
1042
1043 if (s->ref_bap[0][0] == s->bap_buffer && s->ref_bap_set)
1044 return;
1045
1046 ref_bap = s->bap_buffer;
1047 for (ch = 0; ch <= s->channels; ch++) {
1048 for (blk = 0; blk < s->num_blocks; blk++)
1049 s->ref_bap[ch][blk] = ref_bap + AC3_MAX_COEFS * s->exp_ref_block[ch][blk];
1050 ref_bap += AC3_MAX_COEFS * s->num_blocks;
1051 }
1052 s->ref_bap_set = 1;
1053 }
1054
1055
1056 /**
1057 * Initialize mantissa counts.
1058 * These are set so that they are padded to the next whole group size when bits
1059 * are counted in compute_mantissa_size.
1060 *
1061 * @param[in,out] mant_cnt running counts for each bap value for each block
1062 */
count_mantissa_bits_init(uint16_t mant_cnt[AC3_MAX_BLOCKS][16])1063 static void count_mantissa_bits_init(uint16_t mant_cnt[AC3_MAX_BLOCKS][16])
1064 {
1065 int blk;
1066
1067 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
1068 memset(mant_cnt[blk], 0, sizeof(mant_cnt[blk]));
1069 mant_cnt[blk][1] = mant_cnt[blk][2] = 2;
1070 mant_cnt[blk][4] = 1;
1071 }
1072 }
1073
1074
1075 /**
1076 * Update mantissa bit counts for all blocks in 1 channel in a given bandwidth
1077 * range.
1078 *
1079 * @param s AC-3 encoder private context
1080 * @param ch channel index
1081 * @param[in,out] mant_cnt running counts for each bap value for each block
1082 * @param start starting coefficient bin
1083 * @param end ending coefficient bin
1084 */
count_mantissa_bits_update_ch(AC3EncodeContext * s,int ch,uint16_t mant_cnt[AC3_MAX_BLOCKS][16],int start,int end)1085 static void count_mantissa_bits_update_ch(AC3EncodeContext *s, int ch,
1086 uint16_t mant_cnt[AC3_MAX_BLOCKS][16],
1087 int start, int end)
1088 {
1089 int blk;
1090
1091 for (blk = 0; blk < s->num_blocks; blk++) {
1092 AC3Block *block = &s->blocks[blk];
1093 if (ch == CPL_CH && !block->cpl_in_use)
1094 continue;
1095 s->ac3dsp.update_bap_counts(mant_cnt[blk],
1096 s->ref_bap[ch][blk] + start,
1097 FFMIN(end, block->end_freq[ch]) - start);
1098 }
1099 }
1100
1101
1102 /*
1103 * Count the number of mantissa bits in the frame based on the bap values.
1104 */
count_mantissa_bits(AC3EncodeContext * s)1105 static int count_mantissa_bits(AC3EncodeContext *s)
1106 {
1107 int ch, max_end_freq;
1108 LOCAL_ALIGNED_16(uint16_t, mant_cnt, [AC3_MAX_BLOCKS], [16]);
1109
1110 count_mantissa_bits_init(mant_cnt);
1111
1112 max_end_freq = s->bandwidth_code * 3 + 73;
1113 for (ch = !s->cpl_enabled; ch <= s->channels; ch++)
1114 count_mantissa_bits_update_ch(s, ch, mant_cnt, s->start_freq[ch],
1115 max_end_freq);
1116
1117 return s->ac3dsp.compute_mantissa_size(mant_cnt);
1118 }
1119
1120
1121 /**
1122 * Run the bit allocation with a given SNR offset.
1123 * This calculates the bit allocation pointers that will be used to determine
1124 * the quantization of each mantissa.
1125 *
1126 * @param s AC-3 encoder private context
1127 * @param snr_offset SNR offset, 0 to 1023
1128 * @return the number of bits needed for mantissas if the given SNR offset is
1129 * is used.
1130 */
bit_alloc(AC3EncodeContext * s,int snr_offset)1131 static int bit_alloc(AC3EncodeContext *s, int snr_offset)
1132 {
1133 int blk, ch;
1134
1135 snr_offset = (snr_offset - 240) * 4;
1136
1137 reset_block_bap(s);
1138 for (blk = 0; blk < s->num_blocks; blk++) {
1139 AC3Block *block = &s->blocks[blk];
1140
1141 for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1142 /* Currently the only bit allocation parameters which vary across
1143 blocks within a frame are the exponent values. We can take
1144 advantage of that by reusing the bit allocation pointers
1145 whenever we reuse exponents. */
1146 if (s->exp_strategy[ch][blk] != EXP_REUSE) {
1147 s->ac3dsp.bit_alloc_calc_bap(block->mask[ch], block->psd[ch],
1148 s->start_freq[ch], block->end_freq[ch],
1149 snr_offset, s->bit_alloc.floor,
1150 ff_ac3_bap_tab, s->ref_bap[ch][blk]);
1151 }
1152 }
1153 }
1154 return count_mantissa_bits(s);
1155 }
1156
1157
1158 /*
1159 * Constant bitrate bit allocation search.
1160 * Find the largest SNR offset that will allow data to fit in the frame.
1161 */
cbr_bit_allocation(AC3EncodeContext * s)1162 static int cbr_bit_allocation(AC3EncodeContext *s)
1163 {
1164 int ch;
1165 int bits_left;
1166 int snr_offset, snr_incr;
1167
1168 bits_left = 8 * s->frame_size - (s->frame_bits + s->exponent_bits);
1169 if (bits_left < 0)
1170 return AVERROR(EINVAL);
1171
1172 snr_offset = s->coarse_snr_offset << 4;
1173
1174 /* if previous frame SNR offset was 1023, check if current frame can also
1175 use SNR offset of 1023. if so, skip the search. */
1176 if ((snr_offset | s->fine_snr_offset[1]) == 1023) {
1177 if (bit_alloc(s, 1023) <= bits_left)
1178 return 0;
1179 }
1180
1181 while (snr_offset >= 0 &&
1182 bit_alloc(s, snr_offset) > bits_left) {
1183 snr_offset -= 64;
1184 }
1185 if (snr_offset < 0)
1186 return AVERROR(EINVAL);
1187
1188 FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1189 for (snr_incr = 64; snr_incr > 0; snr_incr >>= 2) {
1190 while (snr_offset + snr_incr <= 1023 &&
1191 bit_alloc(s, snr_offset + snr_incr) <= bits_left) {
1192 snr_offset += snr_incr;
1193 FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1194 }
1195 }
1196 FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1197 reset_block_bap(s);
1198
1199 s->coarse_snr_offset = snr_offset >> 4;
1200 for (ch = !s->cpl_on; ch <= s->channels; ch++)
1201 s->fine_snr_offset[ch] = snr_offset & 0xF;
1202
1203 return 0;
1204 }
1205
1206
1207 /*
1208 * Perform bit allocation search.
1209 * Finds the SNR offset value that maximizes quality and fits in the specified
1210 * frame size. Output is the SNR offset and a set of bit allocation pointers
1211 * used to quantize the mantissas.
1212 */
ac3_compute_bit_allocation(AC3EncodeContext * s)1213 static int ac3_compute_bit_allocation(AC3EncodeContext *s)
1214 {
1215 count_frame_bits(s);
1216
1217 s->exponent_bits = count_exponent_bits(s);
1218
1219 bit_alloc_masking(s);
1220
1221 return cbr_bit_allocation(s);
1222 }
1223
1224
1225 /**
1226 * Symmetric quantization on 'levels' levels.
1227 *
1228 * @param c unquantized coefficient
1229 * @param e exponent
1230 * @param levels number of quantization levels
1231 * @return quantized coefficient
1232 */
sym_quant(int c,int e,int levels)1233 static inline int sym_quant(int c, int e, int levels)
1234 {
1235 int v = (((levels * c) >> (24 - e)) + levels) >> 1;
1236 av_assert2(v >= 0 && v < levels);
1237 return v;
1238 }
1239
1240
1241 /**
1242 * Asymmetric quantization on 2^qbits levels.
1243 *
1244 * @param c unquantized coefficient
1245 * @param e exponent
1246 * @param qbits number of quantization bits
1247 * @return quantized coefficient
1248 */
asym_quant(int c,int e,int qbits)1249 static inline int asym_quant(int c, int e, int qbits)
1250 {
1251 int m;
1252
1253 c = (((c * (1<<e)) >> (24 - qbits)) + 1) >> 1;
1254 m = (1 << (qbits-1));
1255 if (c >= m)
1256 c = m - 1;
1257 av_assert2(c >= -m);
1258 return c;
1259 }
1260
1261
1262 /**
1263 * Quantize a set of mantissas for a single channel in a single block.
1264 *
1265 * @param s Mantissa count context
1266 * @param fixed_coef unquantized fixed-point coefficients
1267 * @param exp exponents
1268 * @param bap bit allocation pointer indices
1269 * @param[out] qmant quantized coefficients
1270 * @param start_freq starting coefficient bin
1271 * @param end_freq ending coefficient bin
1272 */
quantize_mantissas_blk_ch(AC3Mant * s,int32_t * fixed_coef,uint8_t * exp,uint8_t * bap,int16_t * qmant,int start_freq,int end_freq)1273 static void quantize_mantissas_blk_ch(AC3Mant *s, int32_t *fixed_coef,
1274 uint8_t *exp, uint8_t *bap,
1275 int16_t *qmant, int start_freq,
1276 int end_freq)
1277 {
1278 int i;
1279
1280 for (i = start_freq; i < end_freq; i++) {
1281 int c = fixed_coef[i];
1282 int e = exp[i];
1283 int v = bap[i];
1284 if (v)
1285 switch (v) {
1286 case 1:
1287 v = sym_quant(c, e, 3);
1288 switch (s->mant1_cnt) {
1289 case 0:
1290 s->qmant1_ptr = &qmant[i];
1291 v = 9 * v;
1292 s->mant1_cnt = 1;
1293 break;
1294 case 1:
1295 *s->qmant1_ptr += 3 * v;
1296 s->mant1_cnt = 2;
1297 v = 128;
1298 break;
1299 default:
1300 *s->qmant1_ptr += v;
1301 s->mant1_cnt = 0;
1302 v = 128;
1303 break;
1304 }
1305 break;
1306 case 2:
1307 v = sym_quant(c, e, 5);
1308 switch (s->mant2_cnt) {
1309 case 0:
1310 s->qmant2_ptr = &qmant[i];
1311 v = 25 * v;
1312 s->mant2_cnt = 1;
1313 break;
1314 case 1:
1315 *s->qmant2_ptr += 5 * v;
1316 s->mant2_cnt = 2;
1317 v = 128;
1318 break;
1319 default:
1320 *s->qmant2_ptr += v;
1321 s->mant2_cnt = 0;
1322 v = 128;
1323 break;
1324 }
1325 break;
1326 case 3:
1327 v = sym_quant(c, e, 7);
1328 break;
1329 case 4:
1330 v = sym_quant(c, e, 11);
1331 switch (s->mant4_cnt) {
1332 case 0:
1333 s->qmant4_ptr = &qmant[i];
1334 v = 11 * v;
1335 s->mant4_cnt = 1;
1336 break;
1337 default:
1338 *s->qmant4_ptr += v;
1339 s->mant4_cnt = 0;
1340 v = 128;
1341 break;
1342 }
1343 break;
1344 case 5:
1345 v = sym_quant(c, e, 15);
1346 break;
1347 case 14:
1348 v = asym_quant(c, e, 14);
1349 break;
1350 case 15:
1351 v = asym_quant(c, e, 16);
1352 break;
1353 default:
1354 v = asym_quant(c, e, v - 1);
1355 break;
1356 }
1357 qmant[i] = v;
1358 }
1359 }
1360
1361
1362 /**
1363 * Quantize mantissas using coefficients, exponents, and bit allocation pointers.
1364 *
1365 * @param s AC-3 encoder private context
1366 */
ac3_quantize_mantissas(AC3EncodeContext * s)1367 static void ac3_quantize_mantissas(AC3EncodeContext *s)
1368 {
1369 int blk, ch, ch0=0, got_cpl;
1370
1371 for (blk = 0; blk < s->num_blocks; blk++) {
1372 AC3Block *block = &s->blocks[blk];
1373 AC3Mant m = { 0 };
1374
1375 got_cpl = !block->cpl_in_use;
1376 for (ch = 1; ch <= s->channels; ch++) {
1377 if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
1378 ch0 = ch - 1;
1379 ch = CPL_CH;
1380 got_cpl = 1;
1381 }
1382 quantize_mantissas_blk_ch(&m, block->fixed_coef[ch],
1383 s->blocks[s->exp_ref_block[ch][blk]].exp[ch],
1384 s->ref_bap[ch][blk], block->qmant[ch],
1385 s->start_freq[ch], block->end_freq[ch]);
1386 if (ch == CPL_CH)
1387 ch = ch0;
1388 }
1389 }
1390 }
1391
1392
1393 /*
1394 * Write the AC-3 frame header to the output bitstream.
1395 */
ac3_output_frame_header(AC3EncodeContext * s)1396 static void ac3_output_frame_header(AC3EncodeContext *s)
1397 {
1398 AC3EncOptions *opt = &s->options;
1399
1400 put_bits(&s->pb, 16, 0x0b77); /* frame header */
1401 put_bits(&s->pb, 16, 0); /* crc1: will be filled later */
1402 put_bits(&s->pb, 2, s->bit_alloc.sr_code);
1403 put_bits(&s->pb, 6, s->frame_size_code + (s->frame_size - s->frame_size_min) / 2);
1404 put_bits(&s->pb, 5, s->bitstream_id);
1405 put_bits(&s->pb, 3, s->bitstream_mode);
1406 put_bits(&s->pb, 3, s->channel_mode);
1407 if ((s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO)
1408 put_bits(&s->pb, 2, s->center_mix_level);
1409 if (s->channel_mode & 0x04)
1410 put_bits(&s->pb, 2, s->surround_mix_level);
1411 if (s->channel_mode == AC3_CHMODE_STEREO)
1412 put_bits(&s->pb, 2, opt->dolby_surround_mode);
1413 put_bits(&s->pb, 1, s->lfe_on); /* LFE */
1414 put_bits(&s->pb, 5, -opt->dialogue_level);
1415 put_bits(&s->pb, 1, 0); /* no compression control word */
1416 put_bits(&s->pb, 1, 0); /* no lang code */
1417 put_bits(&s->pb, 1, opt->audio_production_info);
1418 if (opt->audio_production_info) {
1419 put_bits(&s->pb, 5, opt->mixing_level - 80);
1420 put_bits(&s->pb, 2, opt->room_type);
1421 }
1422 put_bits(&s->pb, 1, opt->copyright);
1423 put_bits(&s->pb, 1, opt->original);
1424 if (s->bitstream_id == 6) {
1425 /* alternate bit stream syntax */
1426 put_bits(&s->pb, 1, opt->extended_bsi_1);
1427 if (opt->extended_bsi_1) {
1428 put_bits(&s->pb, 2, opt->preferred_stereo_downmix);
1429 put_bits(&s->pb, 3, s->ltrt_center_mix_level);
1430 put_bits(&s->pb, 3, s->ltrt_surround_mix_level);
1431 put_bits(&s->pb, 3, s->loro_center_mix_level);
1432 put_bits(&s->pb, 3, s->loro_surround_mix_level);
1433 }
1434 put_bits(&s->pb, 1, opt->extended_bsi_2);
1435 if (opt->extended_bsi_2) {
1436 put_bits(&s->pb, 2, opt->dolby_surround_ex_mode);
1437 put_bits(&s->pb, 2, opt->dolby_headphone_mode);
1438 put_bits(&s->pb, 1, opt->ad_converter_type);
1439 put_bits(&s->pb, 9, 0); /* xbsi2 and encinfo : reserved */
1440 }
1441 } else {
1442 put_bits(&s->pb, 1, 0); /* no time code 1 */
1443 put_bits(&s->pb, 1, 0); /* no time code 2 */
1444 }
1445 put_bits(&s->pb, 1, 0); /* no additional bit stream info */
1446 }
1447
1448
1449 /*
1450 * Write one audio block to the output bitstream.
1451 */
output_audio_block(AC3EncodeContext * s,int blk)1452 static void output_audio_block(AC3EncodeContext *s, int blk)
1453 {
1454 int ch, i, baie, bnd, got_cpl, av_uninit(ch0);
1455 AC3Block *block = &s->blocks[blk];
1456
1457 /* block switching */
1458 if (!s->eac3) {
1459 for (ch = 0; ch < s->fbw_channels; ch++)
1460 put_bits(&s->pb, 1, 0);
1461 }
1462
1463 /* dither flags */
1464 if (!s->eac3) {
1465 for (ch = 0; ch < s->fbw_channels; ch++)
1466 put_bits(&s->pb, 1, 1);
1467 }
1468
1469 /* dynamic range codes */
1470 put_bits(&s->pb, 1, 0);
1471
1472 /* spectral extension */
1473 if (s->eac3)
1474 put_bits(&s->pb, 1, 0);
1475
1476 /* channel coupling */
1477 if (!s->eac3)
1478 put_bits(&s->pb, 1, block->new_cpl_strategy);
1479 if (block->new_cpl_strategy) {
1480 if (!s->eac3)
1481 put_bits(&s->pb, 1, block->cpl_in_use);
1482 if (block->cpl_in_use) {
1483 int start_sub, end_sub;
1484 if (s->eac3)
1485 put_bits(&s->pb, 1, 0); /* enhanced coupling */
1486 if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO) {
1487 for (ch = 1; ch <= s->fbw_channels; ch++)
1488 put_bits(&s->pb, 1, block->channel_in_cpl[ch]);
1489 }
1490 if (s->channel_mode == AC3_CHMODE_STEREO)
1491 put_bits(&s->pb, 1, 0); /* phase flags in use */
1492 start_sub = (s->start_freq[CPL_CH] - 37) / 12;
1493 end_sub = (s->cpl_end_freq - 37) / 12;
1494 put_bits(&s->pb, 4, start_sub);
1495 put_bits(&s->pb, 4, end_sub - 3);
1496 /* coupling band structure */
1497 if (s->eac3) {
1498 put_bits(&s->pb, 1, 0); /* use default */
1499 } else {
1500 for (bnd = start_sub+1; bnd < end_sub; bnd++)
1501 put_bits(&s->pb, 1, ff_eac3_default_cpl_band_struct[bnd]);
1502 }
1503 }
1504 }
1505
1506 /* coupling coordinates */
1507 if (block->cpl_in_use) {
1508 for (ch = 1; ch <= s->fbw_channels; ch++) {
1509 if (block->channel_in_cpl[ch]) {
1510 if (!s->eac3 || block->new_cpl_coords[ch] != 2)
1511 put_bits(&s->pb, 1, block->new_cpl_coords[ch]);
1512 if (block->new_cpl_coords[ch]) {
1513 put_bits(&s->pb, 2, block->cpl_master_exp[ch]);
1514 for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
1515 put_bits(&s->pb, 4, block->cpl_coord_exp [ch][bnd]);
1516 put_bits(&s->pb, 4, block->cpl_coord_mant[ch][bnd]);
1517 }
1518 }
1519 }
1520 }
1521 }
1522
1523 /* stereo rematrixing */
1524 if (s->channel_mode == AC3_CHMODE_STEREO) {
1525 if (!s->eac3 || blk > 0)
1526 put_bits(&s->pb, 1, block->new_rematrixing_strategy);
1527 if (block->new_rematrixing_strategy) {
1528 /* rematrixing flags */
1529 for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++)
1530 put_bits(&s->pb, 1, block->rematrixing_flags[bnd]);
1531 }
1532 }
1533
1534 /* exponent strategy */
1535 if (!s->eac3) {
1536 for (ch = !block->cpl_in_use; ch <= s->fbw_channels; ch++)
1537 put_bits(&s->pb, 2, s->exp_strategy[ch][blk]);
1538 if (s->lfe_on)
1539 put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]);
1540 }
1541
1542 /* bandwidth */
1543 for (ch = 1; ch <= s->fbw_channels; ch++) {
1544 if (s->exp_strategy[ch][blk] != EXP_REUSE && !block->channel_in_cpl[ch])
1545 put_bits(&s->pb, 6, s->bandwidth_code);
1546 }
1547
1548 /* exponents */
1549 for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1550 int nb_groups;
1551 int cpl = (ch == CPL_CH);
1552
1553 if (s->exp_strategy[ch][blk] == EXP_REUSE)
1554 continue;
1555
1556 /* DC exponent */
1557 put_bits(&s->pb, 4, block->grouped_exp[ch][0] >> cpl);
1558
1559 /* exponent groups */
1560 nb_groups = exponent_group_tab[cpl][s->exp_strategy[ch][blk]-1][block->end_freq[ch]-s->start_freq[ch]];
1561 for (i = 1; i <= nb_groups; i++)
1562 put_bits(&s->pb, 7, block->grouped_exp[ch][i]);
1563
1564 /* gain range info */
1565 if (ch != s->lfe_channel && !cpl)
1566 put_bits(&s->pb, 2, 0);
1567 }
1568
1569 /* bit allocation info */
1570 if (!s->eac3) {
1571 baie = (blk == 0);
1572 put_bits(&s->pb, 1, baie);
1573 if (baie) {
1574 put_bits(&s->pb, 2, s->slow_decay_code);
1575 put_bits(&s->pb, 2, s->fast_decay_code);
1576 put_bits(&s->pb, 2, s->slow_gain_code);
1577 put_bits(&s->pb, 2, s->db_per_bit_code);
1578 put_bits(&s->pb, 3, s->floor_code);
1579 }
1580 }
1581
1582 /* snr offset */
1583 if (!s->eac3) {
1584 put_bits(&s->pb, 1, block->new_snr_offsets);
1585 if (block->new_snr_offsets) {
1586 put_bits(&s->pb, 6, s->coarse_snr_offset);
1587 for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1588 put_bits(&s->pb, 4, s->fine_snr_offset[ch]);
1589 put_bits(&s->pb, 3, s->fast_gain_code[ch]);
1590 }
1591 }
1592 } else {
1593 put_bits(&s->pb, 1, 0); /* no converter snr offset */
1594 }
1595
1596 /* coupling leak */
1597 if (block->cpl_in_use) {
1598 if (!s->eac3 || block->new_cpl_leak != 2)
1599 put_bits(&s->pb, 1, block->new_cpl_leak);
1600 if (block->new_cpl_leak) {
1601 put_bits(&s->pb, 3, s->bit_alloc.cpl_fast_leak);
1602 put_bits(&s->pb, 3, s->bit_alloc.cpl_slow_leak);
1603 }
1604 }
1605
1606 if (!s->eac3) {
1607 put_bits(&s->pb, 1, 0); /* no delta bit allocation */
1608 put_bits(&s->pb, 1, 0); /* no data to skip */
1609 }
1610
1611 /* mantissas */
1612 got_cpl = !block->cpl_in_use;
1613 for (ch = 1; ch <= s->channels; ch++) {
1614 int b, q;
1615
1616 if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
1617 ch0 = ch - 1;
1618 ch = CPL_CH;
1619 got_cpl = 1;
1620 }
1621 for (i = s->start_freq[ch]; i < block->end_freq[ch]; i++) {
1622 q = block->qmant[ch][i];
1623 b = s->ref_bap[ch][blk][i];
1624 switch (b) {
1625 case 0: break;
1626 case 1: if (q != 128) put_bits (&s->pb, 5, q); break;
1627 case 2: if (q != 128) put_bits (&s->pb, 7, q); break;
1628 case 3: put_sbits(&s->pb, 3, q); break;
1629 case 4: if (q != 128) put_bits (&s->pb, 7, q); break;
1630 case 14: put_sbits(&s->pb, 14, q); break;
1631 case 15: put_sbits(&s->pb, 16, q); break;
1632 default: put_sbits(&s->pb, b-1, q); break;
1633 }
1634 }
1635 if (ch == CPL_CH)
1636 ch = ch0;
1637 }
1638 }
1639
1640
1641 /** CRC-16 Polynomial */
1642 #define CRC16_POLY ((1 << 0) | (1 << 2) | (1 << 15) | (1 << 16))
1643
1644
mul_poly(unsigned int a,unsigned int b,unsigned int poly)1645 static unsigned int mul_poly(unsigned int a, unsigned int b, unsigned int poly)
1646 {
1647 unsigned int c;
1648
1649 c = 0;
1650 while (a) {
1651 if (a & 1)
1652 c ^= b;
1653 a = a >> 1;
1654 b = b << 1;
1655 if (b & (1 << 16))
1656 b ^= poly;
1657 }
1658 return c;
1659 }
1660
1661
pow_poly(unsigned int a,unsigned int n,unsigned int poly)1662 static unsigned int pow_poly(unsigned int a, unsigned int n, unsigned int poly)
1663 {
1664 unsigned int r;
1665 r = 1;
1666 while (n) {
1667 if (n & 1)
1668 r = mul_poly(r, a, poly);
1669 a = mul_poly(a, a, poly);
1670 n >>= 1;
1671 }
1672 return r;
1673 }
1674
1675
1676 /*
1677 * Fill the end of the frame with 0's and compute the two CRCs.
1678 */
output_frame_end(AC3EncodeContext * s)1679 static void output_frame_end(AC3EncodeContext *s)
1680 {
1681 const AVCRC *crc_ctx = av_crc_get_table(AV_CRC_16_ANSI);
1682 int frame_size_58, pad_bytes, crc1, crc2_partial, crc2, crc_inv;
1683 uint8_t *frame;
1684
1685 frame_size_58 = ((s->frame_size >> 2) + (s->frame_size >> 4)) << 1;
1686
1687 /* pad the remainder of the frame with zeros */
1688 av_assert2(s->frame_size * 8 - put_bits_count(&s->pb) >= 18);
1689 flush_put_bits(&s->pb);
1690 frame = s->pb.buf;
1691 pad_bytes = s->frame_size - (put_bits_ptr(&s->pb) - frame) - 2;
1692 av_assert2(pad_bytes >= 0);
1693 if (pad_bytes > 0)
1694 memset(put_bits_ptr(&s->pb), 0, pad_bytes);
1695
1696 if (s->eac3) {
1697 /* compute crc2 */
1698 crc2_partial = av_crc(crc_ctx, 0, frame + 2, s->frame_size - 5);
1699 } else {
1700 /* compute crc1 */
1701 /* this is not so easy because it is at the beginning of the data... */
1702 crc1 = av_bswap16(av_crc(crc_ctx, 0, frame + 4, frame_size_58 - 4));
1703 crc_inv = s->crc_inv[s->frame_size > s->frame_size_min];
1704 crc1 = mul_poly(crc_inv, crc1, CRC16_POLY);
1705 AV_WB16(frame + 2, crc1);
1706
1707 /* compute crc2 */
1708 crc2_partial = av_crc(crc_ctx, 0, frame + frame_size_58,
1709 s->frame_size - frame_size_58 - 3);
1710 }
1711 crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1712 /* ensure crc2 does not match sync word by flipping crcrsv bit if needed */
1713 if (crc2 == 0x770B) {
1714 frame[s->frame_size - 3] ^= 0x1;
1715 crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1716 }
1717 crc2 = av_bswap16(crc2);
1718 AV_WB16(frame + s->frame_size - 2, crc2);
1719 }
1720
1721
1722 /**
1723 * Write the frame to the output bitstream.
1724 *
1725 * @param s AC-3 encoder private context
1726 * @param frame output data buffer
1727 */
ac3_output_frame(AC3EncodeContext * s,unsigned char * frame)1728 static void ac3_output_frame(AC3EncodeContext *s, unsigned char *frame)
1729 {
1730 int blk;
1731
1732 init_put_bits(&s->pb, frame, s->frame_size);
1733
1734 s->output_frame_header(s);
1735
1736 for (blk = 0; blk < s->num_blocks; blk++)
1737 output_audio_block(s, blk);
1738
1739 output_frame_end(s);
1740 }
1741
ff_ac3_encode_frame_common_end(AVCodecContext * avctx,AVPacket * avpkt,const AVFrame * frame,int * got_packet_ptr)1742 int ff_ac3_encode_frame_common_end(AVCodecContext *avctx, AVPacket *avpkt,
1743 const AVFrame *frame, int *got_packet_ptr)
1744 {
1745 AC3EncodeContext *const s = avctx->priv_data;
1746 int ret;
1747
1748 ac3_apply_rematrixing(s);
1749
1750 ac3_process_exponents(s);
1751
1752 ret = ac3_compute_bit_allocation(s);
1753 if (ret) {
1754 av_log(avctx, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n");
1755 return ret;
1756 }
1757
1758 ac3_group_exponents(s);
1759
1760 ac3_quantize_mantissas(s);
1761
1762 if ((ret = ff_alloc_packet2(avctx, avpkt, s->frame_size, 0)) < 0)
1763 return ret;
1764 ac3_output_frame(s, avpkt->data);
1765
1766 if (frame->pts != AV_NOPTS_VALUE)
1767 avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->initial_padding);
1768
1769 *got_packet_ptr = 1;
1770 return 0;
1771 }
1772
dprint_options(AC3EncodeContext * s)1773 static void dprint_options(AC3EncodeContext *s)
1774 {
1775 #ifdef DEBUG
1776 AVCodecContext *avctx = s->avctx;
1777 AC3EncOptions *opt = &s->options;
1778 char strbuf[32];
1779
1780 switch (s->bitstream_id) {
1781 case 6: av_strlcpy(strbuf, "AC-3 (alt syntax)", 32); break;
1782 case 8: av_strlcpy(strbuf, "AC-3 (standard)", 32); break;
1783 case 9: av_strlcpy(strbuf, "AC-3 (dnet half-rate)", 32); break;
1784 case 10: av_strlcpy(strbuf, "AC-3 (dnet quater-rate)", 32); break;
1785 case 16: av_strlcpy(strbuf, "E-AC-3 (enhanced)", 32); break;
1786 default: snprintf(strbuf, 32, "ERROR");
1787 }
1788 ff_dlog(avctx, "bitstream_id: %s (%d)\n", strbuf, s->bitstream_id);
1789 ff_dlog(avctx, "sample_fmt: %s\n", av_get_sample_fmt_name(avctx->sample_fmt));
1790 av_get_channel_layout_string(strbuf, 32, s->channels, avctx->channel_layout);
1791 ff_dlog(avctx, "channel_layout: %s\n", strbuf);
1792 ff_dlog(avctx, "sample_rate: %d\n", s->sample_rate);
1793 ff_dlog(avctx, "bit_rate: %d\n", s->bit_rate);
1794 ff_dlog(avctx, "blocks/frame: %d (code=%d)\n", s->num_blocks, s->num_blks_code);
1795 if (s->cutoff)
1796 ff_dlog(avctx, "cutoff: %d\n", s->cutoff);
1797
1798 ff_dlog(avctx, "per_frame_metadata: %s\n",
1799 opt->allow_per_frame_metadata?"on":"off");
1800 if (s->has_center)
1801 ff_dlog(avctx, "center_mixlev: %0.3f (%d)\n", opt->center_mix_level,
1802 s->center_mix_level);
1803 else
1804 ff_dlog(avctx, "center_mixlev: {not written}\n");
1805 if (s->has_surround)
1806 ff_dlog(avctx, "surround_mixlev: %0.3f (%d)\n", opt->surround_mix_level,
1807 s->surround_mix_level);
1808 else
1809 ff_dlog(avctx, "surround_mixlev: {not written}\n");
1810 if (opt->audio_production_info) {
1811 ff_dlog(avctx, "mixing_level: %ddB\n", opt->mixing_level);
1812 switch (opt->room_type) {
1813 case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1814 case AC3ENC_OPT_LARGE_ROOM: av_strlcpy(strbuf, "large", 32); break;
1815 case AC3ENC_OPT_SMALL_ROOM: av_strlcpy(strbuf, "small", 32); break;
1816 default: snprintf(strbuf, 32, "ERROR (%d)", opt->room_type);
1817 }
1818 ff_dlog(avctx, "room_type: %s\n", strbuf);
1819 } else {
1820 ff_dlog(avctx, "mixing_level: {not written}\n");
1821 ff_dlog(avctx, "room_type: {not written}\n");
1822 }
1823 ff_dlog(avctx, "copyright: %s\n", opt->copyright?"on":"off");
1824 ff_dlog(avctx, "dialnorm: %ddB\n", opt->dialogue_level);
1825 if (s->channel_mode == AC3_CHMODE_STEREO) {
1826 switch (opt->dolby_surround_mode) {
1827 case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1828 case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1829 case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1830 default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_mode);
1831 }
1832 ff_dlog(avctx, "dsur_mode: %s\n", strbuf);
1833 } else {
1834 ff_dlog(avctx, "dsur_mode: {not written}\n");
1835 }
1836 ff_dlog(avctx, "original: %s\n", opt->original?"on":"off");
1837
1838 if (s->bitstream_id == 6) {
1839 if (opt->extended_bsi_1) {
1840 switch (opt->preferred_stereo_downmix) {
1841 case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1842 case AC3ENC_OPT_DOWNMIX_LTRT: av_strlcpy(strbuf, "ltrt", 32); break;
1843 case AC3ENC_OPT_DOWNMIX_LORO: av_strlcpy(strbuf, "loro", 32); break;
1844 default: snprintf(strbuf, 32, "ERROR (%d)", opt->preferred_stereo_downmix);
1845 }
1846 ff_dlog(avctx, "dmix_mode: %s\n", strbuf);
1847 ff_dlog(avctx, "ltrt_cmixlev: %0.3f (%d)\n",
1848 opt->ltrt_center_mix_level, s->ltrt_center_mix_level);
1849 ff_dlog(avctx, "ltrt_surmixlev: %0.3f (%d)\n",
1850 opt->ltrt_surround_mix_level, s->ltrt_surround_mix_level);
1851 ff_dlog(avctx, "loro_cmixlev: %0.3f (%d)\n",
1852 opt->loro_center_mix_level, s->loro_center_mix_level);
1853 ff_dlog(avctx, "loro_surmixlev: %0.3f (%d)\n",
1854 opt->loro_surround_mix_level, s->loro_surround_mix_level);
1855 } else {
1856 ff_dlog(avctx, "extended bitstream info 1: {not written}\n");
1857 }
1858 if (opt->extended_bsi_2) {
1859 switch (opt->dolby_surround_ex_mode) {
1860 case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1861 case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1862 case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1863 default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_ex_mode);
1864 }
1865 ff_dlog(avctx, "dsurex_mode: %s\n", strbuf);
1866 switch (opt->dolby_headphone_mode) {
1867 case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1868 case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1869 case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1870 default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_headphone_mode);
1871 }
1872 ff_dlog(avctx, "dheadphone_mode: %s\n", strbuf);
1873
1874 switch (opt->ad_converter_type) {
1875 case AC3ENC_OPT_ADCONV_STANDARD: av_strlcpy(strbuf, "standard", 32); break;
1876 case AC3ENC_OPT_ADCONV_HDCD: av_strlcpy(strbuf, "hdcd", 32); break;
1877 default: snprintf(strbuf, 32, "ERROR (%d)", opt->ad_converter_type);
1878 }
1879 ff_dlog(avctx, "ad_conv_type: %s\n", strbuf);
1880 } else {
1881 ff_dlog(avctx, "extended bitstream info 2: {not written}\n");
1882 }
1883 }
1884 #endif
1885 }
1886
1887
1888 #define FLT_OPTION_THRESHOLD 0.01
1889
validate_float_option(float v,const float * v_list,int v_list_size)1890 static int validate_float_option(float v, const float *v_list, int v_list_size)
1891 {
1892 int i;
1893
1894 for (i = 0; i < v_list_size; i++) {
1895 if (v < (v_list[i] + FLT_OPTION_THRESHOLD) &&
1896 v > (v_list[i] - FLT_OPTION_THRESHOLD))
1897 break;
1898 }
1899 if (i == v_list_size)
1900 return AVERROR(EINVAL);
1901
1902 return i;
1903 }
1904
1905
validate_mix_level(void * log_ctx,const char * opt_name,float * opt_param,const float * list,int list_size,int default_value,int min_value,int * ctx_param)1906 static void validate_mix_level(void *log_ctx, const char *opt_name,
1907 float *opt_param, const float *list,
1908 int list_size, int default_value, int min_value,
1909 int *ctx_param)
1910 {
1911 int mixlev = validate_float_option(*opt_param, list, list_size);
1912 if (mixlev < min_value) {
1913 mixlev = default_value;
1914 if (*opt_param >= 0.0) {
1915 av_log(log_ctx, AV_LOG_WARNING, "requested %s is not valid. using "
1916 "default value: %0.3f\n", opt_name, list[mixlev]);
1917 }
1918 }
1919 *opt_param = list[mixlev];
1920 *ctx_param = mixlev;
1921 }
1922
1923
1924 /**
1925 * Validate metadata options as set by AVOption system.
1926 * These values can optionally be changed per-frame.
1927 *
1928 * @param s AC-3 encoder private context
1929 */
ff_ac3_validate_metadata(AC3EncodeContext * s)1930 int ff_ac3_validate_metadata(AC3EncodeContext *s)
1931 {
1932 AVCodecContext *avctx = s->avctx;
1933 AC3EncOptions *opt = &s->options;
1934
1935 opt->audio_production_info = 0;
1936 opt->extended_bsi_1 = 0;
1937 opt->extended_bsi_2 = 0;
1938 opt->eac3_mixing_metadata = 0;
1939 opt->eac3_info_metadata = 0;
1940
1941 /* determine mixing metadata / xbsi1 use */
1942 if (s->channel_mode > AC3_CHMODE_STEREO && opt->preferred_stereo_downmix != AC3ENC_OPT_NONE) {
1943 opt->extended_bsi_1 = 1;
1944 opt->eac3_mixing_metadata = 1;
1945 }
1946 if (s->has_center &&
1947 (opt->ltrt_center_mix_level >= 0 || opt->loro_center_mix_level >= 0)) {
1948 opt->extended_bsi_1 = 1;
1949 opt->eac3_mixing_metadata = 1;
1950 }
1951 if (s->has_surround &&
1952 (opt->ltrt_surround_mix_level >= 0 || opt->loro_surround_mix_level >= 0)) {
1953 opt->extended_bsi_1 = 1;
1954 opt->eac3_mixing_metadata = 1;
1955 }
1956
1957 if (s->eac3) {
1958 /* determine info metadata use */
1959 if (avctx->audio_service_type != AV_AUDIO_SERVICE_TYPE_MAIN)
1960 opt->eac3_info_metadata = 1;
1961 if (opt->copyright != AC3ENC_OPT_NONE || opt->original != AC3ENC_OPT_NONE)
1962 opt->eac3_info_metadata = 1;
1963 if (s->channel_mode == AC3_CHMODE_STEREO &&
1964 (opt->dolby_headphone_mode != AC3ENC_OPT_NONE || opt->dolby_surround_mode != AC3ENC_OPT_NONE))
1965 opt->eac3_info_metadata = 1;
1966 if (s->channel_mode >= AC3_CHMODE_2F2R && opt->dolby_surround_ex_mode != AC3ENC_OPT_NONE)
1967 opt->eac3_info_metadata = 1;
1968 if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE ||
1969 opt->ad_converter_type != AC3ENC_OPT_NONE) {
1970 opt->audio_production_info = 1;
1971 opt->eac3_info_metadata = 1;
1972 }
1973 } else {
1974 /* determine audio production info use */
1975 if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE)
1976 opt->audio_production_info = 1;
1977
1978 /* determine xbsi2 use */
1979 if (s->channel_mode >= AC3_CHMODE_2F2R && opt->dolby_surround_ex_mode != AC3ENC_OPT_NONE)
1980 opt->extended_bsi_2 = 1;
1981 if (s->channel_mode == AC3_CHMODE_STEREO && opt->dolby_headphone_mode != AC3ENC_OPT_NONE)
1982 opt->extended_bsi_2 = 1;
1983 if (opt->ad_converter_type != AC3ENC_OPT_NONE)
1984 opt->extended_bsi_2 = 1;
1985 }
1986
1987 /* validate AC-3 mixing levels */
1988 if (!s->eac3) {
1989 if (s->has_center) {
1990 validate_mix_level(avctx, "center_mix_level", &opt->center_mix_level,
1991 cmixlev_options, CMIXLEV_NUM_OPTIONS, 1, 0,
1992 &s->center_mix_level);
1993 }
1994 if (s->has_surround) {
1995 validate_mix_level(avctx, "surround_mix_level", &opt->surround_mix_level,
1996 surmixlev_options, SURMIXLEV_NUM_OPTIONS, 1, 0,
1997 &s->surround_mix_level);
1998 }
1999 }
2000
2001 /* validate extended bsi 1 / mixing metadata */
2002 if (opt->extended_bsi_1 || opt->eac3_mixing_metadata) {
2003 /* default preferred stereo downmix */
2004 if (opt->preferred_stereo_downmix == AC3ENC_OPT_NONE)
2005 opt->preferred_stereo_downmix = AC3ENC_OPT_NOT_INDICATED;
2006 if (!s->eac3 || s->has_center) {
2007 /* validate Lt/Rt center mix level */
2008 validate_mix_level(avctx, "ltrt_center_mix_level",
2009 &opt->ltrt_center_mix_level, extmixlev_options,
2010 EXTMIXLEV_NUM_OPTIONS, 5, 0,
2011 &s->ltrt_center_mix_level);
2012 /* validate Lo/Ro center mix level */
2013 validate_mix_level(avctx, "loro_center_mix_level",
2014 &opt->loro_center_mix_level, extmixlev_options,
2015 EXTMIXLEV_NUM_OPTIONS, 5, 0,
2016 &s->loro_center_mix_level);
2017 }
2018 if (!s->eac3 || s->has_surround) {
2019 /* validate Lt/Rt surround mix level */
2020 validate_mix_level(avctx, "ltrt_surround_mix_level",
2021 &opt->ltrt_surround_mix_level, extmixlev_options,
2022 EXTMIXLEV_NUM_OPTIONS, 6, 3,
2023 &s->ltrt_surround_mix_level);
2024 /* validate Lo/Ro surround mix level */
2025 validate_mix_level(avctx, "loro_surround_mix_level",
2026 &opt->loro_surround_mix_level, extmixlev_options,
2027 EXTMIXLEV_NUM_OPTIONS, 6, 3,
2028 &s->loro_surround_mix_level);
2029 }
2030 }
2031
2032 /* validate audio service type / channels combination */
2033 if ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_KARAOKE &&
2034 avctx->channels == 1) ||
2035 ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_COMMENTARY ||
2036 avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_EMERGENCY ||
2037 avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_VOICE_OVER)
2038 && avctx->channels > 1)) {
2039 av_log(avctx, AV_LOG_ERROR, "invalid audio service type for the "
2040 "specified number of channels\n");
2041 return AVERROR(EINVAL);
2042 }
2043
2044 /* validate extended bsi 2 / info metadata */
2045 if (opt->extended_bsi_2 || opt->eac3_info_metadata) {
2046 /* default dolby headphone mode */
2047 if (opt->dolby_headphone_mode == AC3ENC_OPT_NONE)
2048 opt->dolby_headphone_mode = AC3ENC_OPT_NOT_INDICATED;
2049 /* default dolby surround ex mode */
2050 if (opt->dolby_surround_ex_mode == AC3ENC_OPT_NONE)
2051 opt->dolby_surround_ex_mode = AC3ENC_OPT_NOT_INDICATED;
2052 /* default A/D converter type */
2053 if (opt->ad_converter_type == AC3ENC_OPT_NONE)
2054 opt->ad_converter_type = AC3ENC_OPT_ADCONV_STANDARD;
2055 }
2056
2057 /* copyright & original defaults */
2058 if (!s->eac3 || opt->eac3_info_metadata) {
2059 /* default copyright */
2060 if (opt->copyright == AC3ENC_OPT_NONE)
2061 opt->copyright = AC3ENC_OPT_OFF;
2062 /* default original */
2063 if (opt->original == AC3ENC_OPT_NONE)
2064 opt->original = AC3ENC_OPT_ON;
2065 }
2066
2067 /* dolby surround mode default */
2068 if (!s->eac3 || opt->eac3_info_metadata) {
2069 if (opt->dolby_surround_mode == AC3ENC_OPT_NONE)
2070 opt->dolby_surround_mode = AC3ENC_OPT_NOT_INDICATED;
2071 }
2072
2073 /* validate audio production info */
2074 if (opt->audio_production_info) {
2075 if (opt->mixing_level == AC3ENC_OPT_NONE) {
2076 av_log(avctx, AV_LOG_ERROR, "mixing_level must be set if "
2077 "room_type is set\n");
2078 return AVERROR(EINVAL);
2079 }
2080 if (opt->mixing_level < 80) {
2081 av_log(avctx, AV_LOG_ERROR, "invalid mixing level. must be between "
2082 "80dB and 111dB\n");
2083 return AVERROR(EINVAL);
2084 }
2085 /* default room type */
2086 if (opt->room_type == AC3ENC_OPT_NONE)
2087 opt->room_type = AC3ENC_OPT_NOT_INDICATED;
2088 }
2089
2090 /* set bitstream id for alternate bitstream syntax */
2091 if (!s->eac3 && (opt->extended_bsi_1 || opt->extended_bsi_2)) {
2092 if (s->bitstream_id > 8 && s->bitstream_id < 11) {
2093 if (!s->warned_alternate_bitstream) {
2094 av_log(avctx, AV_LOG_WARNING, "alternate bitstream syntax is "
2095 "not compatible with reduced samplerates. writing of "
2096 "extended bitstream information will be disabled.\n");
2097 s->warned_alternate_bitstream = 1;
2098 }
2099 } else {
2100 s->bitstream_id = 6;
2101 }
2102 }
2103
2104 return 0;
2105 }
2106
2107
2108 /**
2109 * Finalize encoding and free any memory allocated by the encoder.
2110 *
2111 * @param avctx Codec context
2112 */
ff_ac3_encode_close(AVCodecContext * avctx)2113 av_cold int ff_ac3_encode_close(AVCodecContext *avctx)
2114 {
2115 int blk, ch;
2116 AC3EncodeContext *s = avctx->priv_data;
2117
2118 av_freep(&s->mdct_window);
2119 av_freep(&s->windowed_samples);
2120 if (s->planar_samples)
2121 for (ch = 0; ch < s->channels; ch++)
2122 av_freep(&s->planar_samples[ch]);
2123 av_freep(&s->planar_samples);
2124 av_freep(&s->bap_buffer);
2125 av_freep(&s->bap1_buffer);
2126 av_freep(&s->mdct_coef_buffer);
2127 av_freep(&s->fixed_coef_buffer);
2128 av_freep(&s->exp_buffer);
2129 av_freep(&s->grouped_exp_buffer);
2130 av_freep(&s->psd_buffer);
2131 av_freep(&s->band_psd_buffer);
2132 av_freep(&s->mask_buffer);
2133 av_freep(&s->qmant_buffer);
2134 av_freep(&s->cpl_coord_exp_buffer);
2135 av_freep(&s->cpl_coord_mant_buffer);
2136 av_freep(&s->fdsp);
2137 for (blk = 0; blk < s->num_blocks; blk++) {
2138 AC3Block *block = &s->blocks[blk];
2139 av_freep(&block->mdct_coef);
2140 av_freep(&block->fixed_coef);
2141 av_freep(&block->exp);
2142 av_freep(&block->grouped_exp);
2143 av_freep(&block->psd);
2144 av_freep(&block->band_psd);
2145 av_freep(&block->mask);
2146 av_freep(&block->qmant);
2147 av_freep(&block->cpl_coord_exp);
2148 av_freep(&block->cpl_coord_mant);
2149 }
2150
2151 s->mdct_end(s);
2152
2153 return 0;
2154 }
2155
2156
2157 /*
2158 * Set channel information during initialization.
2159 */
set_channel_info(AC3EncodeContext * s,int channels,uint64_t * channel_layout)2160 static av_cold int set_channel_info(AC3EncodeContext *s, int channels,
2161 uint64_t *channel_layout)
2162 {
2163 int ch_layout;
2164
2165 if (channels < 1 || channels > AC3_MAX_CHANNELS)
2166 return AVERROR(EINVAL);
2167 if (*channel_layout > 0x7FF)
2168 return AVERROR(EINVAL);
2169 ch_layout = *channel_layout;
2170 if (!ch_layout)
2171 ch_layout = av_get_default_channel_layout(channels);
2172
2173 s->lfe_on = !!(ch_layout & AV_CH_LOW_FREQUENCY);
2174 s->channels = channels;
2175 s->fbw_channels = channels - s->lfe_on;
2176 s->lfe_channel = s->lfe_on ? s->fbw_channels + 1 : -1;
2177 if (s->lfe_on)
2178 ch_layout -= AV_CH_LOW_FREQUENCY;
2179
2180 switch (ch_layout) {
2181 case AV_CH_LAYOUT_MONO: s->channel_mode = AC3_CHMODE_MONO; break;
2182 case AV_CH_LAYOUT_STEREO: s->channel_mode = AC3_CHMODE_STEREO; break;
2183 case AV_CH_LAYOUT_SURROUND: s->channel_mode = AC3_CHMODE_3F; break;
2184 case AV_CH_LAYOUT_2_1: s->channel_mode = AC3_CHMODE_2F1R; break;
2185 case AV_CH_LAYOUT_4POINT0: s->channel_mode = AC3_CHMODE_3F1R; break;
2186 case AV_CH_LAYOUT_QUAD:
2187 case AV_CH_LAYOUT_2_2: s->channel_mode = AC3_CHMODE_2F2R; break;
2188 case AV_CH_LAYOUT_5POINT0:
2189 case AV_CH_LAYOUT_5POINT0_BACK: s->channel_mode = AC3_CHMODE_3F2R; break;
2190 default:
2191 return AVERROR(EINVAL);
2192 }
2193 s->has_center = (s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO;
2194 s->has_surround = s->channel_mode & 0x04;
2195
2196 s->channel_map = ac3_enc_channel_map[s->channel_mode][s->lfe_on];
2197 *channel_layout = ch_layout;
2198 if (s->lfe_on)
2199 *channel_layout |= AV_CH_LOW_FREQUENCY;
2200
2201 return 0;
2202 }
2203
2204
validate_options(AC3EncodeContext * s)2205 static av_cold int validate_options(AC3EncodeContext *s)
2206 {
2207 AVCodecContext *avctx = s->avctx;
2208 int i, ret, max_sr;
2209
2210 /* validate channel layout */
2211 if (!avctx->channel_layout) {
2212 av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The "
2213 "encoder will guess the layout, but it "
2214 "might be incorrect.\n");
2215 }
2216 ret = set_channel_info(s, avctx->channels, &avctx->channel_layout);
2217 if (ret) {
2218 av_log(avctx, AV_LOG_ERROR, "invalid channel layout\n");
2219 return ret;
2220 }
2221
2222 /* validate sample rate */
2223 /* note: max_sr could be changed from 2 to 5 for E-AC-3 once we find a
2224 decoder that supports half sample rate so we can validate that
2225 the generated files are correct. */
2226 max_sr = s->eac3 ? 2 : 8;
2227 for (i = 0; i <= max_sr; i++) {
2228 if ((ff_ac3_sample_rate_tab[i % 3] >> (i / 3)) == avctx->sample_rate)
2229 break;
2230 }
2231 if (i > max_sr) {
2232 av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
2233 return AVERROR(EINVAL);
2234 }
2235 s->sample_rate = avctx->sample_rate;
2236 s->bit_alloc.sr_shift = i / 3;
2237 s->bit_alloc.sr_code = i % 3;
2238 s->bitstream_id = s->eac3 ? 16 : 8 + s->bit_alloc.sr_shift;
2239
2240 /* select a default bit rate if not set by the user */
2241 if (!avctx->bit_rate) {
2242 switch (s->fbw_channels) {
2243 case 1: avctx->bit_rate = 96000; break;
2244 case 2: avctx->bit_rate = 192000; break;
2245 case 3: avctx->bit_rate = 320000; break;
2246 case 4: avctx->bit_rate = 384000; break;
2247 case 5: avctx->bit_rate = 448000; break;
2248 }
2249 }
2250
2251 /* validate bit rate */
2252 if (s->eac3) {
2253 int max_br, min_br, wpf, min_br_code;
2254 int num_blks_code, num_blocks, frame_samples;
2255 long long min_br_dist;
2256
2257 /* calculate min/max bitrate */
2258 /* TODO: More testing with 3 and 2 blocks. All E-AC-3 samples I've
2259 found use either 6 blocks or 1 block, even though 2 or 3 blocks
2260 would work as far as the bit rate is concerned. */
2261 for (num_blks_code = 3; num_blks_code >= 0; num_blks_code--) {
2262 num_blocks = ((int[]){ 1, 2, 3, 6 })[num_blks_code];
2263 frame_samples = AC3_BLOCK_SIZE * num_blocks;
2264 max_br = 2048 * s->sample_rate / frame_samples * 16;
2265 min_br = ((s->sample_rate + (frame_samples-1)) / frame_samples) * 16;
2266 if (avctx->bit_rate <= max_br)
2267 break;
2268 }
2269 if (avctx->bit_rate < min_br || avctx->bit_rate > max_br) {
2270 av_log(avctx, AV_LOG_ERROR, "invalid bit rate. must be %d to %d "
2271 "for this sample rate\n", min_br, max_br);
2272 return AVERROR(EINVAL);
2273 }
2274 s->num_blks_code = num_blks_code;
2275 s->num_blocks = num_blocks;
2276
2277 /* calculate words-per-frame for the selected bitrate */
2278 wpf = (avctx->bit_rate / 16) * frame_samples / s->sample_rate;
2279 av_assert1(wpf > 0 && wpf <= 2048);
2280
2281 /* find the closest AC-3 bitrate code to the selected bitrate.
2282 this is needed for lookup tables for bandwidth and coupling
2283 parameter selection */
2284 min_br_code = -1;
2285 min_br_dist = INT64_MAX;
2286 for (i = 0; i < 19; i++) {
2287 long long br_dist = llabs(ff_ac3_bitrate_tab[i] * 1000 - avctx->bit_rate);
2288 if (br_dist < min_br_dist) {
2289 min_br_dist = br_dist;
2290 min_br_code = i;
2291 }
2292 }
2293
2294 /* make sure the minimum frame size is below the average frame size */
2295 s->frame_size_code = min_br_code << 1;
2296 while (wpf > 1 && wpf * s->sample_rate / AC3_FRAME_SIZE * 16 > avctx->bit_rate)
2297 wpf--;
2298 s->frame_size_min = 2 * wpf;
2299 } else {
2300 int best_br = 0, best_code = 0;
2301 long long best_diff = INT64_MAX;
2302 for (i = 0; i < 19; i++) {
2303 int br = (ff_ac3_bitrate_tab[i] >> s->bit_alloc.sr_shift) * 1000;
2304 long long diff = llabs(br - avctx->bit_rate);
2305 if (diff < best_diff) {
2306 best_br = br;
2307 best_code = i;
2308 best_diff = diff;
2309 }
2310 if (!best_diff)
2311 break;
2312 }
2313 avctx->bit_rate = best_br;
2314 s->frame_size_code = best_code << 1;
2315 s->frame_size_min = 2 * ff_ac3_frame_size_tab[s->frame_size_code][s->bit_alloc.sr_code];
2316 s->num_blks_code = 0x3;
2317 s->num_blocks = 6;
2318 }
2319 s->bit_rate = avctx->bit_rate;
2320 s->frame_size = s->frame_size_min;
2321
2322 /* validate cutoff */
2323 if (avctx->cutoff < 0) {
2324 av_log(avctx, AV_LOG_ERROR, "invalid cutoff frequency\n");
2325 return AVERROR(EINVAL);
2326 }
2327 s->cutoff = avctx->cutoff;
2328 if (s->cutoff > (s->sample_rate >> 1))
2329 s->cutoff = s->sample_rate >> 1;
2330
2331 ret = ff_ac3_validate_metadata(s);
2332 if (ret)
2333 return ret;
2334
2335 s->rematrixing_enabled = s->options.stereo_rematrixing &&
2336 (s->channel_mode == AC3_CHMODE_STEREO);
2337
2338 s->cpl_enabled = s->options.channel_coupling &&
2339 s->channel_mode >= AC3_CHMODE_STEREO;
2340
2341 return 0;
2342 }
2343
2344
2345 /*
2346 * Set bandwidth for all channels.
2347 * The user can optionally supply a cutoff frequency. Otherwise an appropriate
2348 * default value will be used.
2349 */
set_bandwidth(AC3EncodeContext * s)2350 static av_cold void set_bandwidth(AC3EncodeContext *s)
2351 {
2352 int blk, ch, av_uninit(cpl_start);
2353
2354 if (s->cutoff) {
2355 /* calculate bandwidth based on user-specified cutoff frequency */
2356 int fbw_coeffs;
2357 fbw_coeffs = s->cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
2358 s->bandwidth_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
2359 } else {
2360 /* use default bandwidth setting */
2361 s->bandwidth_code = ac3_bandwidth_tab[s->fbw_channels-1][s->bit_alloc.sr_code][s->frame_size_code/2];
2362 }
2363
2364 /* set number of coefficients for each channel */
2365 for (ch = 1; ch <= s->fbw_channels; ch++) {
2366 s->start_freq[ch] = 0;
2367 for (blk = 0; blk < s->num_blocks; blk++)
2368 s->blocks[blk].end_freq[ch] = s->bandwidth_code * 3 + 73;
2369 }
2370 /* LFE channel always has 7 coefs */
2371 if (s->lfe_on) {
2372 s->start_freq[s->lfe_channel] = 0;
2373 for (blk = 0; blk < s->num_blocks; blk++)
2374 s->blocks[blk].end_freq[ch] = 7;
2375 }
2376
2377 /* initialize coupling strategy */
2378 if (s->cpl_enabled) {
2379 if (s->options.cpl_start != AC3ENC_OPT_AUTO) {
2380 cpl_start = s->options.cpl_start;
2381 } else {
2382 cpl_start = ac3_coupling_start_tab[s->channel_mode-2][s->bit_alloc.sr_code][s->frame_size_code/2];
2383 if (cpl_start < 0) {
2384 if (s->options.channel_coupling == AC3ENC_OPT_AUTO)
2385 s->cpl_enabled = 0;
2386 else
2387 cpl_start = 15;
2388 }
2389 }
2390 }
2391 if (s->cpl_enabled) {
2392 int i, cpl_start_band, cpl_end_band;
2393 uint8_t *cpl_band_sizes = s->cpl_band_sizes;
2394
2395 cpl_end_band = s->bandwidth_code / 4 + 3;
2396 cpl_start_band = av_clip(cpl_start, 0, FFMIN(cpl_end_band-1, 15));
2397
2398 s->num_cpl_subbands = cpl_end_band - cpl_start_band;
2399
2400 s->num_cpl_bands = 1;
2401 *cpl_band_sizes = 12;
2402 for (i = cpl_start_band + 1; i < cpl_end_band; i++) {
2403 if (ff_eac3_default_cpl_band_struct[i]) {
2404 *cpl_band_sizes += 12;
2405 } else {
2406 s->num_cpl_bands++;
2407 cpl_band_sizes++;
2408 *cpl_band_sizes = 12;
2409 }
2410 }
2411
2412 s->start_freq[CPL_CH] = cpl_start_band * 12 + 37;
2413 s->cpl_end_freq = cpl_end_band * 12 + 37;
2414 for (blk = 0; blk < s->num_blocks; blk++)
2415 s->blocks[blk].end_freq[CPL_CH] = s->cpl_end_freq;
2416 }
2417 }
2418
2419
allocate_buffers(AC3EncodeContext * s)2420 static av_cold int allocate_buffers(AC3EncodeContext *s)
2421 {
2422 int blk, ch;
2423 int channels = s->channels + 1; /* includes coupling channel */
2424 int channel_blocks = channels * s->num_blocks;
2425 int total_coefs = AC3_MAX_COEFS * channel_blocks;
2426
2427 if (s->allocate_sample_buffers(s))
2428 return AVERROR(ENOMEM);
2429
2430 if (!FF_ALLOC_TYPED_ARRAY(s->bap_buffer, total_coefs) ||
2431 !FF_ALLOC_TYPED_ARRAY(s->bap1_buffer, total_coefs) ||
2432 !FF_ALLOCZ_TYPED_ARRAY(s->mdct_coef_buffer, total_coefs) ||
2433 !FF_ALLOC_TYPED_ARRAY(s->exp_buffer, total_coefs) ||
2434 !FF_ALLOC_TYPED_ARRAY(s->grouped_exp_buffer, channel_blocks * 128) ||
2435 !FF_ALLOC_TYPED_ARRAY(s->psd_buffer, total_coefs) ||
2436 !FF_ALLOC_TYPED_ARRAY(s->band_psd_buffer, channel_blocks * 64) ||
2437 !FF_ALLOC_TYPED_ARRAY(s->mask_buffer, channel_blocks * 64) ||
2438 !FF_ALLOC_TYPED_ARRAY(s->qmant_buffer, total_coefs))
2439 return AVERROR(ENOMEM);
2440
2441 if (s->cpl_enabled) {
2442 if (!FF_ALLOC_TYPED_ARRAY(s->cpl_coord_exp_buffer, channel_blocks * 16) ||
2443 !FF_ALLOC_TYPED_ARRAY(s->cpl_coord_mant_buffer, channel_blocks * 16))
2444 return AVERROR(ENOMEM);
2445 }
2446 for (blk = 0; blk < s->num_blocks; blk++) {
2447 AC3Block *block = &s->blocks[blk];
2448
2449 if (!FF_ALLOCZ_TYPED_ARRAY(block->mdct_coef, channels) ||
2450 !FF_ALLOCZ_TYPED_ARRAY(block->exp, channels) ||
2451 !FF_ALLOCZ_TYPED_ARRAY(block->grouped_exp, channels) ||
2452 !FF_ALLOCZ_TYPED_ARRAY(block->psd, channels) ||
2453 !FF_ALLOCZ_TYPED_ARRAY(block->band_psd, channels) ||
2454 !FF_ALLOCZ_TYPED_ARRAY(block->mask, channels) ||
2455 !FF_ALLOCZ_TYPED_ARRAY(block->qmant, channels))
2456 return AVERROR(ENOMEM);
2457
2458 if (s->cpl_enabled) {
2459 if (!FF_ALLOCZ_TYPED_ARRAY(block->cpl_coord_exp, channels) ||
2460 !FF_ALLOCZ_TYPED_ARRAY(block->cpl_coord_mant, channels))
2461 return AVERROR(ENOMEM);
2462 }
2463
2464 for (ch = 0; ch < channels; ch++) {
2465 /* arrangement: block, channel, coeff */
2466 block->grouped_exp[ch] = &s->grouped_exp_buffer[128 * (blk * channels + ch)];
2467 block->psd[ch] = &s->psd_buffer [AC3_MAX_COEFS * (blk * channels + ch)];
2468 block->band_psd[ch] = &s->band_psd_buffer [64 * (blk * channels + ch)];
2469 block->mask[ch] = &s->mask_buffer [64 * (blk * channels + ch)];
2470 block->qmant[ch] = &s->qmant_buffer [AC3_MAX_COEFS * (blk * channels + ch)];
2471 if (s->cpl_enabled) {
2472 block->cpl_coord_exp[ch] = &s->cpl_coord_exp_buffer [16 * (blk * channels + ch)];
2473 block->cpl_coord_mant[ch] = &s->cpl_coord_mant_buffer[16 * (blk * channels + ch)];
2474 }
2475
2476 /* arrangement: channel, block, coeff */
2477 block->exp[ch] = &s->exp_buffer [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2478 block->mdct_coef[ch] = &s->mdct_coef_buffer [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2479 }
2480 }
2481
2482 if (!s->fixed_point) {
2483 if (!FF_ALLOCZ_TYPED_ARRAY(s->fixed_coef_buffer, total_coefs))
2484 return AVERROR(ENOMEM);
2485 for (blk = 0; blk < s->num_blocks; blk++) {
2486 AC3Block *block = &s->blocks[blk];
2487 if (!FF_ALLOCZ_TYPED_ARRAY(block->fixed_coef, channels))
2488 return AVERROR(ENOMEM);
2489 for (ch = 0; ch < channels; ch++)
2490 block->fixed_coef[ch] = &s->fixed_coef_buffer[AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2491 }
2492 } else {
2493 for (blk = 0; blk < s->num_blocks; blk++) {
2494 AC3Block *block = &s->blocks[blk];
2495 if (!FF_ALLOCZ_TYPED_ARRAY(block->fixed_coef, channels))
2496 return AVERROR(ENOMEM);
2497 for (ch = 0; ch < channels; ch++)
2498 block->fixed_coef[ch] = (int32_t *)block->mdct_coef[ch];
2499 }
2500 }
2501
2502 return 0;
2503 }
2504
2505
ff_ac3_encode_init(AVCodecContext * avctx)2506 av_cold int ff_ac3_encode_init(AVCodecContext *avctx)
2507 {
2508 static AVOnce init_static_once = AV_ONCE_INIT;
2509 AC3EncodeContext *s = avctx->priv_data;
2510 int ret, frame_size_58;
2511
2512 s->avctx = avctx;
2513
2514 s->eac3 = avctx->codec_id == AV_CODEC_ID_EAC3;
2515
2516 ret = validate_options(s);
2517 if (ret)
2518 return ret;
2519
2520 avctx->frame_size = AC3_BLOCK_SIZE * s->num_blocks;
2521 avctx->initial_padding = AC3_BLOCK_SIZE;
2522
2523 s->bitstream_mode = avctx->audio_service_type;
2524 if (s->bitstream_mode == AV_AUDIO_SERVICE_TYPE_KARAOKE)
2525 s->bitstream_mode = 0x7;
2526
2527 s->bits_written = 0;
2528 s->samples_written = 0;
2529
2530 /* calculate crc_inv for both possible frame sizes */
2531 frame_size_58 = (( s->frame_size >> 2) + ( s->frame_size >> 4)) << 1;
2532 s->crc_inv[0] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2533 if (s->bit_alloc.sr_code == 1) {
2534 frame_size_58 = (((s->frame_size+2) >> 2) + ((s->frame_size+2) >> 4)) << 1;
2535 s->crc_inv[1] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2536 }
2537
2538 if (CONFIG_EAC3_ENCODER && s->eac3) {
2539 static AVOnce init_static_once_eac3 = AV_ONCE_INIT;
2540 ff_thread_once(&init_static_once_eac3, ff_eac3_exponent_init);
2541 s->output_frame_header = ff_eac3_output_frame_header;
2542 } else
2543 s->output_frame_header = ac3_output_frame_header;
2544
2545 set_bandwidth(s);
2546
2547 bit_alloc_init(s);
2548
2549 ret = s->mdct_init(s);
2550 if (ret)
2551 return ret;
2552
2553 ret = allocate_buffers(s);
2554 if (ret)
2555 return ret;
2556
2557 ff_audiodsp_init(&s->adsp);
2558 ff_me_cmp_init(&s->mecc, avctx);
2559 ff_ac3dsp_init(&s->ac3dsp, avctx->flags & AV_CODEC_FLAG_BITEXACT);
2560
2561 dprint_options(s);
2562
2563 ff_thread_once(&init_static_once, exponent_init);
2564
2565 return 0;
2566 }
2567