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 "codec_internal.h"
42 #include "config_components.h"
43 #include "encode.h"
44 #include "internal.h"
45 #include "me_cmp.h"
46 #include "put_bits.h"
47 #include "audiodsp.h"
48 #include "ac3dsp.h"
49 #include "ac3.h"
50 #include "ac3defs.h"
51 #include "ac3tab.h"
52 #include "fft.h"
53 #include "ac3enc.h"
54 #include "eac3enc.h"
55
56 typedef struct AC3Mant {
57 int16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr; ///< mantissa pointers for bap=1,2,4
58 int mant1_cnt, mant2_cnt, mant4_cnt; ///< mantissa counts for bap=1,2,4
59 } AC3Mant;
60
61 #define CMIXLEV_NUM_OPTIONS 3
62 static const float cmixlev_options[CMIXLEV_NUM_OPTIONS] = {
63 LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB
64 };
65
66 #define SURMIXLEV_NUM_OPTIONS 3
67 static const float surmixlev_options[SURMIXLEV_NUM_OPTIONS] = {
68 LEVEL_MINUS_3DB, LEVEL_MINUS_6DB, LEVEL_ZERO
69 };
70
71 #define EXTMIXLEV_NUM_OPTIONS 8
72 static const float extmixlev_options[EXTMIXLEV_NUM_OPTIONS] = {
73 LEVEL_PLUS_3DB, LEVEL_PLUS_1POINT5DB, LEVEL_ONE, LEVEL_MINUS_1POINT5DB,
74 LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB, LEVEL_ZERO
75 };
76
77 /* The first two options apply only to the AC-3 encoders;
78 * the rest is also valid for EAC-3. When modifying it,
79 * it might be necessary to adapt said offset in eac3enc.c. */
80 #define OFFSET(param) offsetof(AC3EncodeContext, options.param)
81 #define AC3ENC_PARAM (AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM)
82 const AVOption ff_ac3_enc_options[] = {
83 /* AC-3 downmix levels */
84 {"center_mixlev", "Center Mix Level", OFFSET(center_mix_level), AV_OPT_TYPE_FLOAT, {.dbl = LEVEL_MINUS_4POINT5DB }, 0.0, 1.0, AC3ENC_PARAM},
85 {"surround_mixlev", "Surround Mix Level", OFFSET(surround_mix_level), AV_OPT_TYPE_FLOAT, {.dbl = LEVEL_MINUS_6DB }, 0.0, 1.0, AC3ENC_PARAM},
86 /* audio production information */
87 {"mixing_level", "Mixing Level", OFFSET(mixing_level), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_NONE }, AC3ENC_OPT_NONE, 111, AC3ENC_PARAM},
88 {"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"},
89 {"notindicated", "Not Indicated (default)", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_NOT_INDICATED }, INT_MIN, INT_MAX, AC3ENC_PARAM, "room_type"},
90 {"large", "Large Room", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_LARGE_ROOM }, INT_MIN, INT_MAX, AC3ENC_PARAM, "room_type"},
91 {"small", "Small Room", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_SMALL_ROOM }, INT_MIN, INT_MAX, AC3ENC_PARAM, "room_type"},
92 /* Metadata Options */
93 {"per_frame_metadata", "Allow Changing Metadata Per-Frame", OFFSET(allow_per_frame_metadata), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, AC3ENC_PARAM},
94 {"copyright", "Copyright Bit", OFFSET(copyright), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_NONE }, AC3ENC_OPT_NONE, 1, AC3ENC_PARAM},
95 {"dialnorm", "Dialogue Level (dB)", OFFSET(dialogue_level), AV_OPT_TYPE_INT, {.i64 = -31 }, -31, -1, AC3ENC_PARAM},
96 {"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"},
97 {"notindicated", "Not Indicated (default)", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_NOT_INDICATED }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsur_mode"},
98 {"on", "Dolby Surround Encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_MODE_ON }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsur_mode"},
99 {"off", "Not Dolby Surround Encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_MODE_OFF }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsur_mode"},
100 {"original", "Original Bit Stream", OFFSET(original), AV_OPT_TYPE_INT, {.i64 = AC3ENC_OPT_NONE }, AC3ENC_OPT_NONE, 1, AC3ENC_PARAM},
101 /* extended bitstream information */
102 {"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"},
103 {"notindicated", "Not Indicated (default)", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_NOT_INDICATED }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dmix_mode"},
104 {"ltrt", "Lt/Rt Downmix Preferred", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_DOWNMIX_LTRT }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dmix_mode"},
105 {"loro", "Lo/Ro Downmix Preferred", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_DOWNMIX_LORO }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dmix_mode"},
106 {"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"},
107 {"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},
108 {"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},
109 {"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},
110 {"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},
111 {"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"},
112 {"notindicated", "Not Indicated (default)", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_NOT_INDICATED }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
113 {"on", "Dolby Surround EX Encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_MODE_ON }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
114 {"off", "Not Dolby Surround EX Encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_MODE_OFF }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
115 {"dpliiz", "Dolby Pro Logic IIz-encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_DSUREX_DPLIIZ }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
116 {"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"},
117 {"notindicated", "Not Indicated (default)", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_NOT_INDICATED }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dheadphone_mode"},
118 {"on", "Dolby Headphone Encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_MODE_ON }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dheadphone_mode"},
119 {"off", "Not Dolby Headphone Encoded", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_MODE_OFF }, INT_MIN, INT_MAX, AC3ENC_PARAM, "dheadphone_mode"},
120 {"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"},
121 {"standard", "Standard (default)", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_ADCONV_STANDARD }, INT_MIN, INT_MAX, AC3ENC_PARAM, "ad_conv_type"},
122 {"hdcd", "HDCD", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_ADCONV_HDCD }, INT_MIN, INT_MAX, AC3ENC_PARAM, "ad_conv_type"},
123 /* Other Encoding Options */
124 {"stereo_rematrixing", "Stereo Rematrixing", OFFSET(stereo_rematrixing), AV_OPT_TYPE_BOOL, {.i64 = 1 }, 0, 1, AC3ENC_PARAM},
125 {"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"},
126 {"auto", "Selected by the Encoder", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_AUTO }, INT_MIN, INT_MAX, AC3ENC_PARAM, "channel_coupling"},
127 {"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"},
128 {"auto", "Selected by the Encoder", 0, AV_OPT_TYPE_CONST, {.i64 = AC3ENC_OPT_AUTO }, INT_MIN, INT_MAX, AC3ENC_PARAM, "cpl_start_band"},
129 {NULL}
130 };
131
132 const AVClass ff_ac3enc_class = {
133 .class_name = "AC-3 Encoder",
134 .item_name = av_default_item_name,
135 .option = ff_ac3_enc_options,
136 .version = LIBAVUTIL_VERSION_INT,
137 };
138
139 const FFCodecDefault ff_ac3_enc_defaults[] = {
140 { "b", "0" },
141 { NULL }
142 };
143
144 /**
145 * LUT for number of exponent groups.
146 * exponent_group_tab[coupling][exponent strategy-1][number of coefficients]
147 */
148 static uint8_t exponent_group_tab[2][3][256];
149
150
151 /**
152 * List of supported channel layouts.
153 */
154 #if FF_API_OLD_CHANNEL_LAYOUT
155 const uint64_t ff_ac3_channel_layouts[19] = {
156 AV_CH_LAYOUT_MONO,
157 AV_CH_LAYOUT_STEREO,
158 AV_CH_LAYOUT_2_1,
159 AV_CH_LAYOUT_SURROUND,
160 AV_CH_LAYOUT_2_2,
161 AV_CH_LAYOUT_QUAD,
162 AV_CH_LAYOUT_4POINT0,
163 AV_CH_LAYOUT_5POINT0,
164 AV_CH_LAYOUT_5POINT0_BACK,
165 (AV_CH_LAYOUT_MONO | AV_CH_LOW_FREQUENCY),
166 (AV_CH_LAYOUT_STEREO | AV_CH_LOW_FREQUENCY),
167 (AV_CH_LAYOUT_2_1 | AV_CH_LOW_FREQUENCY),
168 (AV_CH_LAYOUT_SURROUND | AV_CH_LOW_FREQUENCY),
169 (AV_CH_LAYOUT_2_2 | AV_CH_LOW_FREQUENCY),
170 (AV_CH_LAYOUT_QUAD | AV_CH_LOW_FREQUENCY),
171 (AV_CH_LAYOUT_4POINT0 | AV_CH_LOW_FREQUENCY),
172 AV_CH_LAYOUT_5POINT1,
173 AV_CH_LAYOUT_5POINT1_BACK,
174 0
175 };
176 #endif
177
178 const AVChannelLayout ff_ac3_ch_layouts[19] = {
179 AV_CHANNEL_LAYOUT_MONO,
180 AV_CHANNEL_LAYOUT_STEREO,
181 AV_CHANNEL_LAYOUT_2_1,
182 AV_CHANNEL_LAYOUT_SURROUND,
183 AV_CHANNEL_LAYOUT_2_2,
184 AV_CHANNEL_LAYOUT_QUAD,
185 AV_CHANNEL_LAYOUT_4POINT0,
186 AV_CHANNEL_LAYOUT_5POINT0,
187 AV_CHANNEL_LAYOUT_5POINT0_BACK,
188 {
189 .nb_channels = 2,
190 .order = AV_CHANNEL_ORDER_NATIVE,
191 .u.mask = AV_CH_LAYOUT_MONO | AV_CH_LOW_FREQUENCY,
192 },
193 {
194 .nb_channels = 3,
195 .order = AV_CHANNEL_ORDER_NATIVE,
196 .u.mask = AV_CH_LAYOUT_STEREO | AV_CH_LOW_FREQUENCY,
197 },
198 {
199 .nb_channels = 4,
200 .order = AV_CHANNEL_ORDER_NATIVE,
201 .u.mask = AV_CH_LAYOUT_2_1 | AV_CH_LOW_FREQUENCY,
202 },
203 {
204 .nb_channels = 4,
205 .order = AV_CHANNEL_ORDER_NATIVE,
206 .u.mask = AV_CH_LAYOUT_SURROUND | AV_CH_LOW_FREQUENCY,
207 },
208 {
209 .nb_channels = 5,
210 .order = AV_CHANNEL_ORDER_NATIVE,
211 .u.mask = AV_CH_LAYOUT_4POINT0 | AV_CH_LOW_FREQUENCY,
212 },
213 AV_CHANNEL_LAYOUT_5POINT1,
214 AV_CHANNEL_LAYOUT_5POINT1_BACK,
215 { 0 },
216 };
217
218 /**
219 * Table to remap channels from SMPTE order to AC-3 order.
220 * [channel_mode][lfe][ch]
221 */
222 static const uint8_t ac3_enc_channel_map[8][2][6] = {
223 COMMON_CHANNEL_MAP
224 { { 0, 1, 2, 3, }, { 0, 1, 3, 4, 2, } },
225 { { 0, 2, 1, 3, 4, }, { 0, 2, 1, 4, 5, 3 } },
226 };
227
228 /**
229 * LUT to select the bandwidth code based on the bit rate, sample rate, and
230 * number of full-bandwidth channels.
231 * bandwidth_tab[fbw_channels-1][sample rate code][bit rate code]
232 */
233 static const uint8_t ac3_bandwidth_tab[5][3][19] = {
234 // 32 40 48 56 64 80 96 112 128 160 192 224 256 320 384 448 512 576 640
235
236 { { 0, 0, 0, 12, 16, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
237 { 0, 0, 0, 16, 20, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
238 { 0, 0, 0, 32, 40, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
239
240 { { 0, 0, 0, 0, 0, 0, 0, 20, 24, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
241 { 0, 0, 0, 0, 0, 0, 4, 24, 28, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
242 { 0, 0, 0, 0, 0, 0, 20, 44, 52, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
243
244 { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 24, 32, 40, 48, 48, 48, 48, 48, 48 },
245 { 0, 0, 0, 0, 0, 0, 0, 0, 4, 20, 28, 36, 44, 56, 56, 56, 56, 56, 56 },
246 { 0, 0, 0, 0, 0, 0, 0, 0, 20, 40, 48, 60, 60, 60, 60, 60, 60, 60, 60 } },
247
248 { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 24, 32, 48, 48, 48, 48, 48, 48 },
249 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 28, 36, 56, 56, 56, 56, 56, 56 },
250 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 32, 48, 60, 60, 60, 60, 60, 60, 60 } },
251
252 { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 20, 32, 40, 48, 48, 48, 48 },
253 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 24, 36, 44, 56, 56, 56, 56 },
254 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 28, 44, 60, 60, 60, 60, 60, 60 } }
255 };
256
257
258 /**
259 * LUT to select the coupling start band based on the bit rate, sample rate, and
260 * number of full-bandwidth channels. -1 = coupling off
261 * ac3_coupling_start_tab[channel_mode-2][sample rate code][bit rate code]
262 *
263 * TODO: more testing for optimal parameters.
264 * multi-channel tests at 44.1kHz and 32kHz.
265 */
266 static const int8_t ac3_coupling_start_tab[6][3][19] = {
267 // 32 40 48 56 64 80 96 112 128 160 192 224 256 320 384 448 512 576 640
268
269 // 2/0
270 { { 0, 0, 0, 0, 0, 0, 0, 1, 1, 7, 8, 11, 12, -1, -1, -1, -1, -1, -1 },
271 { 0, 0, 0, 0, 0, 0, 1, 3, 5, 7, 10, 12, 13, -1, -1, -1, -1, -1, -1 },
272 { 0, 0, 0, 0, 1, 2, 2, 9, 13, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
273
274 // 3/0
275 { { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
276 { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
277 { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
278
279 // 2/1 - untested
280 { { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
281 { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
282 { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
283
284 // 3/1
285 { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
286 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
287 { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
288
289 // 2/2 - untested
290 { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
291 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
292 { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
293
294 // 3/2
295 { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 8, 11, 12, 12, -1, -1 },
296 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 8, 11, 12, 12, -1, -1 },
297 { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
298 };
299
300
301 /**
302 * Adjust the frame size to make the average bit rate match the target bit rate.
303 * This is only needed for 11025, 22050, and 44100 sample rates or any E-AC-3.
304 *
305 * @param s AC-3 encoder private context
306 */
ff_ac3_adjust_frame_size(AC3EncodeContext *s)307 void ff_ac3_adjust_frame_size(AC3EncodeContext *s)
308 {
309 while (s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
310 s->bits_written -= s->bit_rate;
311 s->samples_written -= s->sample_rate;
312 }
313 s->frame_size = s->frame_size_min +
314 2 * (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
315 s->bits_written += s->frame_size * 8;
316 s->samples_written += AC3_BLOCK_SIZE * s->num_blocks;
317 }
318
319
320 /**
321 * Set the initial coupling strategy parameters prior to coupling analysis.
322 *
323 * @param s AC-3 encoder private context
324 */
ff_ac3_compute_coupling_strategy(AC3EncodeContext *s)325 void ff_ac3_compute_coupling_strategy(AC3EncodeContext *s)
326 {
327 int blk, ch;
328 int got_cpl_snr;
329 int num_cpl_blocks;
330
331 /* set coupling use flags for each block/channel */
332 /* TODO: turn coupling on/off and adjust start band based on bit usage */
333 for (blk = 0; blk < s->num_blocks; blk++) {
334 AC3Block *block = &s->blocks[blk];
335 for (ch = 1; ch <= s->fbw_channels; ch++)
336 block->channel_in_cpl[ch] = s->cpl_on;
337 }
338
339 /* enable coupling for each block if at least 2 channels have coupling
340 enabled for that block */
341 got_cpl_snr = 0;
342 num_cpl_blocks = 0;
343 for (blk = 0; blk < s->num_blocks; blk++) {
344 AC3Block *block = &s->blocks[blk];
345 block->num_cpl_channels = 0;
346 for (ch = 1; ch <= s->fbw_channels; ch++)
347 block->num_cpl_channels += block->channel_in_cpl[ch];
348 block->cpl_in_use = block->num_cpl_channels > 1;
349 num_cpl_blocks += block->cpl_in_use;
350 if (!block->cpl_in_use) {
351 block->num_cpl_channels = 0;
352 for (ch = 1; ch <= s->fbw_channels; ch++)
353 block->channel_in_cpl[ch] = 0;
354 }
355
356 block->new_cpl_strategy = !blk;
357 if (blk) {
358 for (ch = 1; ch <= s->fbw_channels; ch++) {
359 if (block->channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
360 block->new_cpl_strategy = 1;
361 break;
362 }
363 }
364 }
365 block->new_cpl_leak = block->new_cpl_strategy;
366
367 if (!blk || (block->cpl_in_use && !got_cpl_snr)) {
368 block->new_snr_offsets = 1;
369 if (block->cpl_in_use)
370 got_cpl_snr = 1;
371 } else {
372 block->new_snr_offsets = 0;
373 }
374 }
375 if (!num_cpl_blocks)
376 s->cpl_on = 0;
377
378 /* set bandwidth for each channel */
379 for (blk = 0; blk < s->num_blocks; blk++) {
380 AC3Block *block = &s->blocks[blk];
381 for (ch = 1; ch <= s->fbw_channels; ch++) {
382 if (block->channel_in_cpl[ch])
383 block->end_freq[ch] = s->start_freq[CPL_CH];
384 else
385 block->end_freq[ch] = s->bandwidth_code * 3 + 73;
386 }
387 }
388 }
389
390
391 /**
392 * Apply stereo rematrixing to coefficients based on rematrixing flags.
393 *
394 * @param s AC-3 encoder private context
395 */
ac3_apply_rematrixing(AC3EncodeContext *s)396 static void ac3_apply_rematrixing(AC3EncodeContext *s)
397 {
398 int nb_coefs;
399 int blk, bnd, i;
400 int start, end;
401 uint8_t *flags = NULL;
402
403 if (!s->rematrixing_enabled)
404 return;
405
406 for (blk = 0; blk < s->num_blocks; blk++) {
407 AC3Block *block = &s->blocks[blk];
408 if (block->new_rematrixing_strategy)
409 flags = block->rematrixing_flags;
410 nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);
411 for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {
412 if (flags[bnd]) {
413 start = ff_ac3_rematrix_band_tab[bnd];
414 end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
415 for (i = start; i < end; i++) {
416 int32_t lt = block->fixed_coef[1][i];
417 int32_t rt = block->fixed_coef[2][i];
418 block->fixed_coef[1][i] = (lt + rt) >> 1;
419 block->fixed_coef[2][i] = (lt - rt) >> 1;
420 }
421 }
422 }
423 }
424 }
425
426
427 /*
428 * Initialize exponent tables.
429 */
exponent_init(void)430 static av_cold void exponent_init(void)
431 {
432 int expstr, i, grpsize;
433
434 for (expstr = EXP_D15-1; expstr <= EXP_D45-1; expstr++) {
435 grpsize = 3 << expstr;
436 for (i = 12; i < 256; i++) {
437 exponent_group_tab[0][expstr][i] = (i + grpsize - 4) / grpsize;
438 exponent_group_tab[1][expstr][i] = (i ) / grpsize;
439 }
440 }
441 /* LFE */
442 exponent_group_tab[0][0][7] = 2;
443 }
444
445
446 /*
447 * Extract exponents from the MDCT coefficients.
448 */
extract_exponents(AC3EncodeContext *s)449 static void extract_exponents(AC3EncodeContext *s)
450 {
451 int ch = !s->cpl_on;
452 int chan_size = AC3_MAX_COEFS * s->num_blocks * (s->channels - ch + 1);
453 AC3Block *block = &s->blocks[0];
454
455 s->ac3dsp.extract_exponents(block->exp[ch], block->fixed_coef[ch], chan_size);
456 }
457
458
459 /**
460 * Exponent Difference Threshold.
461 * New exponents are sent if their SAD exceed this number.
462 */
463 #define EXP_DIFF_THRESHOLD 500
464
465 /**
466 * Table used to select exponent strategy based on exponent reuse block interval.
467 */
468 static const uint8_t exp_strategy_reuse_tab[4][6] = {
469 { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
470 { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
471 { EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
472 { EXP_D45, EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15 }
473 };
474
475 /*
476 * Calculate exponent strategies for all channels.
477 * Array arrangement is reversed to simplify the per-channel calculation.
478 */
compute_exp_strategy(AC3EncodeContext *s)479 static void compute_exp_strategy(AC3EncodeContext *s)
480 {
481 int ch, blk, blk1;
482
483 for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) {
484 uint8_t *exp_strategy = s->exp_strategy[ch];
485 uint8_t *exp = s->blocks[0].exp[ch];
486 int exp_diff;
487
488 /* estimate if the exponent variation & decide if they should be
489 reused in the next frame */
490 exp_strategy[0] = EXP_NEW;
491 exp += AC3_MAX_COEFS;
492 for (blk = 1; blk < s->num_blocks; blk++, exp += AC3_MAX_COEFS) {
493 if (ch == CPL_CH) {
494 if (!s->blocks[blk-1].cpl_in_use) {
495 exp_strategy[blk] = EXP_NEW;
496 continue;
497 } else if (!s->blocks[blk].cpl_in_use) {
498 exp_strategy[blk] = EXP_REUSE;
499 continue;
500 }
501 } else if (s->blocks[blk].channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
502 exp_strategy[blk] = EXP_NEW;
503 continue;
504 }
505 exp_diff = s->mecc.sad[0](NULL, exp, exp - AC3_MAX_COEFS, 16, 16);
506 exp_strategy[blk] = EXP_REUSE;
507 if (ch == CPL_CH && exp_diff > (EXP_DIFF_THRESHOLD * (s->blocks[blk].end_freq[ch] - s->start_freq[ch]) / AC3_MAX_COEFS))
508 exp_strategy[blk] = EXP_NEW;
509 else if (ch > CPL_CH && exp_diff > EXP_DIFF_THRESHOLD)
510 exp_strategy[blk] = EXP_NEW;
511 }
512
513 /* now select the encoding strategy type : if exponents are often
514 recoded, we use a coarse encoding */
515 blk = 0;
516 while (blk < s->num_blocks) {
517 blk1 = blk + 1;
518 while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE)
519 blk1++;
520 exp_strategy[blk] = exp_strategy_reuse_tab[s->num_blks_code][blk1-blk-1];
521 blk = blk1;
522 }
523 }
524 if (s->lfe_on) {
525 ch = s->lfe_channel;
526 s->exp_strategy[ch][0] = EXP_D15;
527 for (blk = 1; blk < s->num_blocks; blk++)
528 s->exp_strategy[ch][blk] = EXP_REUSE;
529 }
530
531 /* for E-AC-3, determine frame exponent strategy */
532 if (CONFIG_EAC3_ENCODER && s->eac3)
533 ff_eac3_get_frame_exp_strategy(s);
534 }
535
536
537 /**
538 * Update the exponents so that they are the ones the decoder will decode.
539 *
540 * @param[in,out] exp array of exponents for 1 block in 1 channel
541 * @param nb_exps number of exponents in active bandwidth
542 * @param exp_strategy exponent strategy for the block
543 * @param cpl indicates if the block is in the coupling channel
544 */
encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy, int cpl)545 static void encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy,
546 int cpl)
547 {
548 int nb_groups, i, k;
549
550 nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_exps] * 3;
551
552 /* for each group, compute the minimum exponent */
553 switch(exp_strategy) {
554 case EXP_D25:
555 for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
556 uint8_t exp_min = exp[k];
557 if (exp[k+1] < exp_min)
558 exp_min = exp[k+1];
559 exp[i-cpl] = exp_min;
560 k += 2;
561 }
562 break;
563 case EXP_D45:
564 for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
565 uint8_t exp_min = exp[k];
566 if (exp[k+1] < exp_min)
567 exp_min = exp[k+1];
568 if (exp[k+2] < exp_min)
569 exp_min = exp[k+2];
570 if (exp[k+3] < exp_min)
571 exp_min = exp[k+3];
572 exp[i-cpl] = exp_min;
573 k += 4;
574 }
575 break;
576 }
577
578 /* constraint for DC exponent */
579 if (!cpl && exp[0] > 15)
580 exp[0] = 15;
581
582 /* decrease the delta between each groups to within 2 so that they can be
583 differentially encoded */
584 for (i = 1; i <= nb_groups; i++)
585 exp[i] = FFMIN(exp[i], exp[i-1] + 2);
586 i--;
587 while (--i >= 0)
588 exp[i] = FFMIN(exp[i], exp[i+1] + 2);
589
590 if (cpl)
591 exp[-1] = exp[0] & ~1;
592
593 /* now we have the exponent values the decoder will see */
594 switch (exp_strategy) {
595 case EXP_D25:
596 for (i = nb_groups, k = (nb_groups * 2)-cpl; i > 0; i--) {
597 uint8_t exp1 = exp[i-cpl];
598 exp[k--] = exp1;
599 exp[k--] = exp1;
600 }
601 break;
602 case EXP_D45:
603 for (i = nb_groups, k = (nb_groups * 4)-cpl; i > 0; i--) {
604 exp[k] = exp[k-1] = exp[k-2] = exp[k-3] = exp[i-cpl];
605 k -= 4;
606 }
607 break;
608 }
609 }
610
611
612 /*
613 * Encode exponents from original extracted form to what the decoder will see.
614 * This copies and groups exponents based on exponent strategy and reduces
615 * deltas between adjacent exponent groups so that they can be differentially
616 * encoded.
617 */
encode_exponents(AC3EncodeContext *s)618 static void encode_exponents(AC3EncodeContext *s)
619 {
620 int blk, blk1, ch, cpl;
621 uint8_t *exp, *exp_strategy;
622 int nb_coefs, num_reuse_blocks;
623
624 for (ch = !s->cpl_on; ch <= s->channels; ch++) {
625 exp = s->blocks[0].exp[ch] + s->start_freq[ch];
626 exp_strategy = s->exp_strategy[ch];
627
628 cpl = (ch == CPL_CH);
629 blk = 0;
630 while (blk < s->num_blocks) {
631 AC3Block *block = &s->blocks[blk];
632 if (cpl && !block->cpl_in_use) {
633 exp += AC3_MAX_COEFS;
634 blk++;
635 continue;
636 }
637 nb_coefs = block->end_freq[ch] - s->start_freq[ch];
638 blk1 = blk + 1;
639
640 /* count the number of EXP_REUSE blocks after the current block
641 and set exponent reference block numbers */
642 s->exp_ref_block[ch][blk] = blk;
643 while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE) {
644 s->exp_ref_block[ch][blk1] = blk;
645 blk1++;
646 }
647 num_reuse_blocks = blk1 - blk - 1;
648
649 /* for the EXP_REUSE case we select the min of the exponents */
650 s->ac3dsp.ac3_exponent_min(exp-s->start_freq[ch], num_reuse_blocks,
651 AC3_MAX_COEFS);
652
653 encode_exponents_blk_ch(exp, nb_coefs, exp_strategy[blk], cpl);
654
655 exp += AC3_MAX_COEFS * (num_reuse_blocks + 1);
656 blk = blk1;
657 }
658 }
659
660 /* reference block numbers have been changed, so reset ref_bap_set */
661 s->ref_bap_set = 0;
662 }
663
664
665 /*
666 * Count exponent bits based on bandwidth, coupling, and exponent strategies.
667 */
count_exponent_bits(AC3EncodeContext *s)668 static int count_exponent_bits(AC3EncodeContext *s)
669 {
670 int blk, ch;
671 int nb_groups, bit_count;
672
673 bit_count = 0;
674 for (blk = 0; blk < s->num_blocks; blk++) {
675 AC3Block *block = &s->blocks[blk];
676 for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
677 int exp_strategy = s->exp_strategy[ch][blk];
678 int cpl = (ch == CPL_CH);
679 int nb_coefs = block->end_freq[ch] - s->start_freq[ch];
680
681 if (exp_strategy == EXP_REUSE)
682 continue;
683
684 nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_coefs];
685 bit_count += 4 + (nb_groups * 7);
686 }
687 }
688
689 return bit_count;
690 }
691
692
693 /**
694 * Group exponents.
695 * 3 delta-encoded exponents are in each 7-bit group. The number of groups
696 * varies depending on exponent strategy and bandwidth.
697 *
698 * @param s AC-3 encoder private context
699 */
ac3_group_exponents(AC3EncodeContext *s)700 static void ac3_group_exponents(AC3EncodeContext *s)
701 {
702 int blk, ch, i, cpl;
703 int group_size, nb_groups;
704 uint8_t *p;
705 int delta0, delta1, delta2;
706 int exp0, exp1;
707
708 for (blk = 0; blk < s->num_blocks; blk++) {
709 AC3Block *block = &s->blocks[blk];
710 for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
711 int exp_strategy = s->exp_strategy[ch][blk];
712 if (exp_strategy == EXP_REUSE)
713 continue;
714 cpl = (ch == CPL_CH);
715 group_size = exp_strategy + (exp_strategy == EXP_D45);
716 nb_groups = exponent_group_tab[cpl][exp_strategy-1][block->end_freq[ch]-s->start_freq[ch]];
717 p = block->exp[ch] + s->start_freq[ch] - cpl;
718
719 /* DC exponent */
720 exp1 = *p++;
721 block->grouped_exp[ch][0] = exp1;
722
723 /* remaining exponents are delta encoded */
724 for (i = 1; i <= nb_groups; i++) {
725 /* merge three delta in one code */
726 exp0 = exp1;
727 exp1 = p[0];
728 p += group_size;
729 delta0 = exp1 - exp0 + 2;
730 av_assert2(delta0 >= 0 && delta0 <= 4);
731
732 exp0 = exp1;
733 exp1 = p[0];
734 p += group_size;
735 delta1 = exp1 - exp0 + 2;
736 av_assert2(delta1 >= 0 && delta1 <= 4);
737
738 exp0 = exp1;
739 exp1 = p[0];
740 p += group_size;
741 delta2 = exp1 - exp0 + 2;
742 av_assert2(delta2 >= 0 && delta2 <= 4);
743
744 block->grouped_exp[ch][i] = ((delta0 * 5 + delta1) * 5) + delta2;
745 }
746 }
747 }
748 }
749
750
751 /**
752 * Calculate final exponents from the supplied MDCT coefficients and exponent shift.
753 * Extract exponents from MDCT coefficients, calculate exponent strategies,
754 * and encode final exponents.
755 *
756 * @param s AC-3 encoder private context
757 */
ac3_process_exponents(AC3EncodeContext *s)758 static void ac3_process_exponents(AC3EncodeContext *s)
759 {
760 extract_exponents(s);
761
762 compute_exp_strategy(s);
763
764 encode_exponents(s);
765
766 emms_c();
767 }
768
769
770 /*
771 * Count frame bits that are based solely on fixed parameters.
772 * This only has to be run once when the encoder is initialized.
773 */
count_frame_bits_fixed(AC3EncodeContext *s)774 static void count_frame_bits_fixed(AC3EncodeContext *s)
775 {
776 static const uint8_t frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
777 int blk;
778 int frame_bits;
779
780 /* assumptions:
781 * no dynamic range codes
782 * bit allocation parameters do not change between blocks
783 * no delta bit allocation
784 * no skipped data
785 * no auxiliary data
786 * no E-AC-3 metadata
787 */
788
789 /* header */
790 frame_bits = 16; /* sync info */
791 if (s->eac3) {
792 /* bitstream info header */
793 frame_bits += 35;
794 frame_bits += 1 + 1;
795 if (s->num_blocks != 0x6)
796 frame_bits++;
797 frame_bits++;
798 /* audio frame header */
799 if (s->num_blocks == 6)
800 frame_bits += 2;
801 frame_bits += 10;
802 /* exponent strategy */
803 if (s->use_frame_exp_strategy)
804 frame_bits += 5 * s->fbw_channels;
805 else
806 frame_bits += s->num_blocks * 2 * s->fbw_channels;
807 if (s->lfe_on)
808 frame_bits += s->num_blocks;
809 /* converter exponent strategy */
810 if (s->num_blks_code != 0x3)
811 frame_bits++;
812 else
813 frame_bits += s->fbw_channels * 5;
814 /* snr offsets */
815 frame_bits += 10;
816 /* block start info */
817 if (s->num_blocks != 1)
818 frame_bits++;
819 } else {
820 frame_bits += 49;
821 frame_bits += frame_bits_inc[s->channel_mode];
822 }
823
824 /* audio blocks */
825 for (blk = 0; blk < s->num_blocks; blk++) {
826 if (!s->eac3) {
827 /* block switch flags */
828 frame_bits += s->fbw_channels;
829
830 /* dither flags */
831 frame_bits += s->fbw_channels;
832 }
833
834 /* dynamic range */
835 frame_bits++;
836
837 /* spectral extension */
838 if (s->eac3)
839 frame_bits++;
840
841 /* coupling strategy exists: cplstre */
842 if (!s->eac3)
843 frame_bits++;
844
845 if (!s->eac3) {
846 /* exponent strategy */
847 frame_bits += 2 * s->fbw_channels;
848 if (s->lfe_on)
849 frame_bits++;
850
851 /* bit allocation params */
852 frame_bits++;
853 if (!blk)
854 frame_bits += 2 + 2 + 2 + 2 + 3;
855 }
856
857 /* snroffste for AC-3, convsnroffste for E-AC-3 */
858 frame_bits++;
859
860 if (!s->eac3) {
861 /* delta bit allocation */
862 frame_bits++;
863
864 /* skipped data */
865 frame_bits++;
866 }
867 }
868
869 /* auxiliary data */
870 frame_bits++;
871
872 /* CRC */
873 frame_bits += 1 + 16;
874
875 s->frame_bits_fixed = frame_bits;
876 }
877
878
879 /*
880 * Initialize bit allocation.
881 * Set default parameter codes and calculate parameter values.
882 */
bit_alloc_init(AC3EncodeContext *s)883 static av_cold void bit_alloc_init(AC3EncodeContext *s)
884 {
885 int ch;
886
887 /* init default parameters */
888 s->slow_decay_code = 2;
889 s->fast_decay_code = 1;
890 s->slow_gain_code = 1;
891 s->db_per_bit_code = s->eac3 ? 2 : 3;
892 s->floor_code = 7;
893 for (ch = 0; ch <= s->channels; ch++)
894 s->fast_gain_code[ch] = 4;
895
896 /* initial snr offset */
897 s->coarse_snr_offset = 40;
898
899 /* compute real values */
900 /* currently none of these values change during encoding, so we can just
901 set them once at initialization */
902 s->bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s->slow_decay_code] >> s->bit_alloc.sr_shift;
903 s->bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s->fast_decay_code] >> s->bit_alloc.sr_shift;
904 s->bit_alloc.slow_gain = ff_ac3_slow_gain_tab[s->slow_gain_code];
905 s->bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s->db_per_bit_code];
906 s->bit_alloc.floor = ff_ac3_floor_tab[s->floor_code];
907 s->bit_alloc.cpl_fast_leak = 0;
908 s->bit_alloc.cpl_slow_leak = 0;
909
910 count_frame_bits_fixed(s);
911 }
912
913
914 /*
915 * Count the bits used to encode the frame, minus exponents and mantissas.
916 * Bits based on fixed parameters have already been counted, so now we just
917 * have to add the bits based on parameters that change during encoding.
918 */
count_frame_bits(AC3EncodeContext *s)919 static void count_frame_bits(AC3EncodeContext *s)
920 {
921 AC3EncOptions *opt = &s->options;
922 int blk, ch;
923 int frame_bits = 0;
924
925 /* header */
926 if (s->eac3) {
927 if (opt->eac3_mixing_metadata) {
928 if (s->channel_mode > AC3_CHMODE_STEREO)
929 frame_bits += 2;
930 if (s->has_center)
931 frame_bits += 6;
932 if (s->has_surround)
933 frame_bits += 6;
934 frame_bits += s->lfe_on;
935 frame_bits += 1 + 1 + 2;
936 if (s->channel_mode < AC3_CHMODE_STEREO)
937 frame_bits++;
938 frame_bits++;
939 }
940 if (opt->eac3_info_metadata) {
941 frame_bits += 3 + 1 + 1;
942 if (s->channel_mode == AC3_CHMODE_STEREO)
943 frame_bits += 2 + 2;
944 if (s->channel_mode >= AC3_CHMODE_2F2R)
945 frame_bits += 2;
946 frame_bits++;
947 if (opt->audio_production_info)
948 frame_bits += 5 + 2 + 1;
949 frame_bits++;
950 }
951 /* coupling */
952 if (s->channel_mode > AC3_CHMODE_MONO) {
953 frame_bits++;
954 for (blk = 1; blk < s->num_blocks; blk++) {
955 AC3Block *block = &s->blocks[blk];
956 frame_bits++;
957 if (block->new_cpl_strategy)
958 frame_bits++;
959 }
960 }
961 /* coupling exponent strategy */
962 if (s->cpl_on) {
963 if (s->use_frame_exp_strategy) {
964 frame_bits += 5;
965 } else {
966 for (blk = 0; blk < s->num_blocks; blk++)
967 frame_bits += 2 * s->blocks[blk].cpl_in_use;
968 }
969 }
970 } else {
971 if (opt->audio_production_info)
972 frame_bits += 7;
973 if (s->bitstream_id == 6) {
974 if (opt->extended_bsi_1)
975 frame_bits += 14;
976 if (opt->extended_bsi_2)
977 frame_bits += 14;
978 }
979 }
980
981 /* audio blocks */
982 for (blk = 0; blk < s->num_blocks; blk++) {
983 AC3Block *block = &s->blocks[blk];
984
985 /* coupling strategy */
986 if (block->new_cpl_strategy) {
987 if (!s->eac3)
988 frame_bits++;
989 if (block->cpl_in_use) {
990 if (s->eac3)
991 frame_bits++;
992 if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO)
993 frame_bits += s->fbw_channels;
994 if (s->channel_mode == AC3_CHMODE_STEREO)
995 frame_bits++;
996 frame_bits += 4 + 4;
997 if (s->eac3)
998 frame_bits++;
999 else
1000 frame_bits += s->num_cpl_subbands - 1;
1001 }
1002 }
1003
1004 /* coupling coordinates */
1005 if (block->cpl_in_use) {
1006 for (ch = 1; ch <= s->fbw_channels; ch++) {
1007 if (block->channel_in_cpl[ch]) {
1008 if (!s->eac3 || block->new_cpl_coords[ch] != 2)
1009 frame_bits++;
1010 if (block->new_cpl_coords[ch]) {
1011 frame_bits += 2;
1012 frame_bits += (4 + 4) * s->num_cpl_bands;
1013 }
1014 }
1015 }
1016 }
1017
1018 /* stereo rematrixing */
1019 if (s->channel_mode == AC3_CHMODE_STEREO) {
1020 if (!s->eac3 || blk > 0)
1021 frame_bits++;
1022 if (s->blocks[blk].new_rematrixing_strategy)
1023 frame_bits += block->num_rematrixing_bands;
1024 }
1025
1026 /* bandwidth codes & gain range */
1027 for (ch = 1; ch <= s->fbw_channels; ch++) {
1028 if (s->exp_strategy[ch][blk] != EXP_REUSE) {
1029 if (!block->channel_in_cpl[ch])
1030 frame_bits += 6;
1031 frame_bits += 2;
1032 }
1033 }
1034
1035 /* coupling exponent strategy */
1036 if (!s->eac3 && block->cpl_in_use)
1037 frame_bits += 2;
1038
1039 /* snr offsets and fast gain codes */
1040 if (!s->eac3) {
1041 if (block->new_snr_offsets)
1042 frame_bits += 6 + (s->channels + block->cpl_in_use) * (4 + 3);
1043 }
1044
1045 /* coupling leak info */
1046 if (block->cpl_in_use) {
1047 if (!s->eac3 || block->new_cpl_leak != 2)
1048 frame_bits++;
1049 if (block->new_cpl_leak)
1050 frame_bits += 3 + 3;
1051 }
1052 }
1053
1054 s->frame_bits = s->frame_bits_fixed + frame_bits;
1055 }
1056
1057
1058 /*
1059 * Calculate masking curve based on the final exponents.
1060 * Also calculate the power spectral densities to use in future calculations.
1061 */
bit_alloc_masking(AC3EncodeContext *s)1062 static void bit_alloc_masking(AC3EncodeContext *s)
1063 {
1064 int blk, ch;
1065
1066 for (blk = 0; blk < s->num_blocks; blk++) {
1067 AC3Block *block = &s->blocks[blk];
1068 for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1069 /* We only need psd and mask for calculating bap.
1070 Since we currently do not calculate bap when exponent
1071 strategy is EXP_REUSE we do not need to calculate psd or mask. */
1072 if (s->exp_strategy[ch][blk] != EXP_REUSE) {
1073 ff_ac3_bit_alloc_calc_psd(block->exp[ch], s->start_freq[ch],
1074 block->end_freq[ch], block->psd[ch],
1075 block->band_psd[ch]);
1076 ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, block->band_psd[ch],
1077 s->start_freq[ch], block->end_freq[ch],
1078 ff_ac3_fast_gain_tab[s->fast_gain_code[ch]],
1079 ch == s->lfe_channel,
1080 DBA_NONE, 0, NULL, NULL, NULL,
1081 block->mask[ch]);
1082 }
1083 }
1084 }
1085 }
1086
1087
1088 /*
1089 * Ensure that bap for each block and channel point to the current bap_buffer.
1090 * They may have been switched during the bit allocation search.
1091 */
reset_block_bap(AC3EncodeContext *s)1092 static void reset_block_bap(AC3EncodeContext *s)
1093 {
1094 int blk, ch;
1095 uint8_t *ref_bap;
1096
1097 if (s->ref_bap[0][0] == s->bap_buffer && s->ref_bap_set)
1098 return;
1099
1100 ref_bap = s->bap_buffer;
1101 for (ch = 0; ch <= s->channels; ch++) {
1102 for (blk = 0; blk < s->num_blocks; blk++)
1103 s->ref_bap[ch][blk] = ref_bap + AC3_MAX_COEFS * s->exp_ref_block[ch][blk];
1104 ref_bap += AC3_MAX_COEFS * s->num_blocks;
1105 }
1106 s->ref_bap_set = 1;
1107 }
1108
1109
1110 /**
1111 * Initialize mantissa counts.
1112 * These are set so that they are padded to the next whole group size when bits
1113 * are counted in compute_mantissa_size.
1114 *
1115 * @param[in,out] mant_cnt running counts for each bap value for each block
1116 */
count_mantissa_bits_init(uint16_t mant_cnt[AC3_MAX_BLOCKS][16])1117 static void count_mantissa_bits_init(uint16_t mant_cnt[AC3_MAX_BLOCKS][16])
1118 {
1119 int blk;
1120
1121 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
1122 memset(mant_cnt[blk], 0, sizeof(mant_cnt[blk]));
1123 mant_cnt[blk][1] = mant_cnt[blk][2] = 2;
1124 mant_cnt[blk][4] = 1;
1125 }
1126 }
1127
1128
1129 /**
1130 * Update mantissa bit counts for all blocks in 1 channel in a given bandwidth
1131 * range.
1132 *
1133 * @param s AC-3 encoder private context
1134 * @param ch channel index
1135 * @param[in,out] mant_cnt running counts for each bap value for each block
1136 * @param start starting coefficient bin
1137 * @param end ending coefficient bin
1138 */
count_mantissa_bits_update_ch(AC3EncodeContext *s, int ch, uint16_t mant_cnt[AC3_MAX_BLOCKS][16], int start, int end)1139 static void count_mantissa_bits_update_ch(AC3EncodeContext *s, int ch,
1140 uint16_t mant_cnt[AC3_MAX_BLOCKS][16],
1141 int start, int end)
1142 {
1143 int blk;
1144
1145 for (blk = 0; blk < s->num_blocks; blk++) {
1146 AC3Block *block = &s->blocks[blk];
1147 if (ch == CPL_CH && !block->cpl_in_use)
1148 continue;
1149 s->ac3dsp.update_bap_counts(mant_cnt[blk],
1150 s->ref_bap[ch][blk] + start,
1151 FFMIN(end, block->end_freq[ch]) - start);
1152 }
1153 }
1154
1155
1156 /*
1157 * Count the number of mantissa bits in the frame based on the bap values.
1158 */
count_mantissa_bits(AC3EncodeContext *s)1159 static int count_mantissa_bits(AC3EncodeContext *s)
1160 {
1161 int ch, max_end_freq;
1162 LOCAL_ALIGNED_16(uint16_t, mant_cnt, [AC3_MAX_BLOCKS], [16]);
1163
1164 count_mantissa_bits_init(mant_cnt);
1165
1166 max_end_freq = s->bandwidth_code * 3 + 73;
1167 for (ch = !s->cpl_enabled; ch <= s->channels; ch++)
1168 count_mantissa_bits_update_ch(s, ch, mant_cnt, s->start_freq[ch],
1169 max_end_freq);
1170
1171 return s->ac3dsp.compute_mantissa_size(mant_cnt);
1172 }
1173
1174
1175 /**
1176 * Run the bit allocation with a given SNR offset.
1177 * This calculates the bit allocation pointers that will be used to determine
1178 * the quantization of each mantissa.
1179 *
1180 * @param s AC-3 encoder private context
1181 * @param snr_offset SNR offset, 0 to 1023
1182 * @return the number of bits needed for mantissas if the given SNR offset is
1183 * is used.
1184 */
bit_alloc(AC3EncodeContext *s, int snr_offset)1185 static int bit_alloc(AC3EncodeContext *s, int snr_offset)
1186 {
1187 int blk, ch;
1188
1189 snr_offset = (snr_offset - 240) * 4;
1190
1191 reset_block_bap(s);
1192 for (blk = 0; blk < s->num_blocks; blk++) {
1193 AC3Block *block = &s->blocks[blk];
1194
1195 for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1196 /* Currently the only bit allocation parameters which vary across
1197 blocks within a frame are the exponent values. We can take
1198 advantage of that by reusing the bit allocation pointers
1199 whenever we reuse exponents. */
1200 if (s->exp_strategy[ch][blk] != EXP_REUSE) {
1201 s->ac3dsp.bit_alloc_calc_bap(block->mask[ch], block->psd[ch],
1202 s->start_freq[ch], block->end_freq[ch],
1203 snr_offset, s->bit_alloc.floor,
1204 ff_ac3_bap_tab, s->ref_bap[ch][blk]);
1205 }
1206 }
1207 }
1208 return count_mantissa_bits(s);
1209 }
1210
1211
1212 /*
1213 * Constant bitrate bit allocation search.
1214 * Find the largest SNR offset that will allow data to fit in the frame.
1215 */
cbr_bit_allocation(AC3EncodeContext *s)1216 static int cbr_bit_allocation(AC3EncodeContext *s)
1217 {
1218 int ch;
1219 int bits_left;
1220 int snr_offset, snr_incr;
1221
1222 bits_left = 8 * s->frame_size - (s->frame_bits + s->exponent_bits);
1223 if (bits_left < 0)
1224 return AVERROR(EINVAL);
1225
1226 snr_offset = s->coarse_snr_offset << 4;
1227
1228 /* if previous frame SNR offset was 1023, check if current frame can also
1229 use SNR offset of 1023. if so, skip the search. */
1230 if ((snr_offset | s->fine_snr_offset[1]) == 1023) {
1231 if (bit_alloc(s, 1023) <= bits_left)
1232 return 0;
1233 }
1234
1235 while (snr_offset >= 0 &&
1236 bit_alloc(s, snr_offset) > bits_left) {
1237 snr_offset -= 64;
1238 }
1239 if (snr_offset < 0)
1240 return AVERROR(EINVAL);
1241
1242 FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1243 for (snr_incr = 64; snr_incr > 0; snr_incr >>= 2) {
1244 while (snr_offset + snr_incr <= 1023 &&
1245 bit_alloc(s, snr_offset + snr_incr) <= bits_left) {
1246 snr_offset += snr_incr;
1247 FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1248 }
1249 }
1250 FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1251 reset_block_bap(s);
1252
1253 s->coarse_snr_offset = snr_offset >> 4;
1254 for (ch = !s->cpl_on; ch <= s->channels; ch++)
1255 s->fine_snr_offset[ch] = snr_offset & 0xF;
1256
1257 return 0;
1258 }
1259
1260
1261 /*
1262 * Perform bit allocation search.
1263 * Finds the SNR offset value that maximizes quality and fits in the specified
1264 * frame size. Output is the SNR offset and a set of bit allocation pointers
1265 * used to quantize the mantissas.
1266 */
ac3_compute_bit_allocation(AC3EncodeContext *s)1267 static int ac3_compute_bit_allocation(AC3EncodeContext *s)
1268 {
1269 count_frame_bits(s);
1270
1271 s->exponent_bits = count_exponent_bits(s);
1272
1273 bit_alloc_masking(s);
1274
1275 return cbr_bit_allocation(s);
1276 }
1277
1278
1279 /**
1280 * Symmetric quantization on 'levels' levels.
1281 *
1282 * @param c unquantized coefficient
1283 * @param e exponent
1284 * @param levels number of quantization levels
1285 * @return quantized coefficient
1286 */
sym_quant(int c, int e, int levels)1287 static inline int sym_quant(int c, int e, int levels)
1288 {
1289 int v = (((levels * c) >> (24 - e)) + levels) >> 1;
1290 av_assert2(v >= 0 && v < levels);
1291 return v;
1292 }
1293
1294
1295 /**
1296 * Asymmetric quantization on 2^qbits levels.
1297 *
1298 * @param c unquantized coefficient
1299 * @param e exponent
1300 * @param qbits number of quantization bits
1301 * @return quantized coefficient
1302 */
asym_quant(int c, int e, int qbits)1303 static inline int asym_quant(int c, int e, int qbits)
1304 {
1305 int m;
1306
1307 c = (((c * (1<<e)) >> (24 - qbits)) + 1) >> 1;
1308 m = (1 << (qbits-1));
1309 if (c >= m)
1310 c = m - 1;
1311 av_assert2(c >= -m);
1312 return c;
1313 }
1314
1315
1316 /**
1317 * Quantize a set of mantissas for a single channel in a single block.
1318 *
1319 * @param s Mantissa count context
1320 * @param fixed_coef unquantized fixed-point coefficients
1321 * @param exp exponents
1322 * @param bap bit allocation pointer indices
1323 * @param[out] qmant quantized coefficients
1324 * @param start_freq starting coefficient bin
1325 * @param end_freq ending coefficient bin
1326 */
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)1327 static void quantize_mantissas_blk_ch(AC3Mant *s, int32_t *fixed_coef,
1328 uint8_t *exp, uint8_t *bap,
1329 int16_t *qmant, int start_freq,
1330 int end_freq)
1331 {
1332 int i;
1333
1334 for (i = start_freq; i < end_freq; i++) {
1335 int c = fixed_coef[i];
1336 int e = exp[i];
1337 int v = bap[i];
1338 switch (v) {
1339 case 0:
1340 break;
1341 case 1:
1342 v = sym_quant(c, e, 3);
1343 switch (s->mant1_cnt) {
1344 case 0:
1345 s->qmant1_ptr = &qmant[i];
1346 v = 9 * v;
1347 s->mant1_cnt = 1;
1348 break;
1349 case 1:
1350 *s->qmant1_ptr += 3 * v;
1351 s->mant1_cnt = 2;
1352 v = 128;
1353 break;
1354 default:
1355 *s->qmant1_ptr += v;
1356 s->mant1_cnt = 0;
1357 v = 128;
1358 break;
1359 }
1360 break;
1361 case 2:
1362 v = sym_quant(c, e, 5);
1363 switch (s->mant2_cnt) {
1364 case 0:
1365 s->qmant2_ptr = &qmant[i];
1366 v = 25 * v;
1367 s->mant2_cnt = 1;
1368 break;
1369 case 1:
1370 *s->qmant2_ptr += 5 * v;
1371 s->mant2_cnt = 2;
1372 v = 128;
1373 break;
1374 default:
1375 *s->qmant2_ptr += v;
1376 s->mant2_cnt = 0;
1377 v = 128;
1378 break;
1379 }
1380 break;
1381 case 3:
1382 v = sym_quant(c, e, 7);
1383 break;
1384 case 4:
1385 v = sym_quant(c, e, 11);
1386 switch (s->mant4_cnt) {
1387 case 0:
1388 s->qmant4_ptr = &qmant[i];
1389 v = 11 * v;
1390 s->mant4_cnt = 1;
1391 break;
1392 default:
1393 *s->qmant4_ptr += v;
1394 s->mant4_cnt = 0;
1395 v = 128;
1396 break;
1397 }
1398 break;
1399 case 5:
1400 v = sym_quant(c, e, 15);
1401 break;
1402 case 14:
1403 v = asym_quant(c, e, 14);
1404 break;
1405 case 15:
1406 v = asym_quant(c, e, 16);
1407 break;
1408 default:
1409 v = asym_quant(c, e, v - 1);
1410 break;
1411 }
1412 qmant[i] = v;
1413 }
1414 }
1415
1416
1417 /**
1418 * Quantize mantissas using coefficients, exponents, and bit allocation pointers.
1419 *
1420 * @param s AC-3 encoder private context
1421 */
ac3_quantize_mantissas(AC3EncodeContext *s)1422 static void ac3_quantize_mantissas(AC3EncodeContext *s)
1423 {
1424 int blk, ch, ch0=0, got_cpl;
1425
1426 for (blk = 0; blk < s->num_blocks; blk++) {
1427 AC3Block *block = &s->blocks[blk];
1428 AC3Mant m = { 0 };
1429
1430 got_cpl = !block->cpl_in_use;
1431 for (ch = 1; ch <= s->channels; ch++) {
1432 if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
1433 ch0 = ch - 1;
1434 ch = CPL_CH;
1435 got_cpl = 1;
1436 }
1437 quantize_mantissas_blk_ch(&m, block->fixed_coef[ch],
1438 s->blocks[s->exp_ref_block[ch][blk]].exp[ch],
1439 s->ref_bap[ch][blk], block->qmant[ch],
1440 s->start_freq[ch], block->end_freq[ch]);
1441 if (ch == CPL_CH)
1442 ch = ch0;
1443 }
1444 }
1445 }
1446
1447
1448 /*
1449 * Write the AC-3 frame header to the output bitstream.
1450 */
ac3_output_frame_header(AC3EncodeContext *s)1451 static void ac3_output_frame_header(AC3EncodeContext *s)
1452 {
1453 AC3EncOptions *opt = &s->options;
1454
1455 put_bits(&s->pb, 16, 0x0b77); /* frame header */
1456 put_bits(&s->pb, 16, 0); /* crc1: will be filled later */
1457 put_bits(&s->pb, 2, s->bit_alloc.sr_code);
1458 put_bits(&s->pb, 6, s->frame_size_code + (s->frame_size - s->frame_size_min) / 2);
1459 put_bits(&s->pb, 5, s->bitstream_id);
1460 put_bits(&s->pb, 3, s->bitstream_mode);
1461 put_bits(&s->pb, 3, s->channel_mode);
1462 if ((s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO)
1463 put_bits(&s->pb, 2, s->center_mix_level);
1464 if (s->channel_mode & 0x04)
1465 put_bits(&s->pb, 2, s->surround_mix_level);
1466 if (s->channel_mode == AC3_CHMODE_STEREO)
1467 put_bits(&s->pb, 2, opt->dolby_surround_mode);
1468 put_bits(&s->pb, 1, s->lfe_on); /* LFE */
1469 put_bits(&s->pb, 5, -opt->dialogue_level);
1470 put_bits(&s->pb, 1, 0); /* no compression control word */
1471 put_bits(&s->pb, 1, 0); /* no lang code */
1472 put_bits(&s->pb, 1, opt->audio_production_info);
1473 if (opt->audio_production_info) {
1474 put_bits(&s->pb, 5, opt->mixing_level - 80);
1475 put_bits(&s->pb, 2, opt->room_type);
1476 }
1477 put_bits(&s->pb, 1, opt->copyright);
1478 put_bits(&s->pb, 1, opt->original);
1479 if (s->bitstream_id == 6) {
1480 /* alternate bit stream syntax */
1481 put_bits(&s->pb, 1, opt->extended_bsi_1);
1482 if (opt->extended_bsi_1) {
1483 put_bits(&s->pb, 2, opt->preferred_stereo_downmix);
1484 put_bits(&s->pb, 3, s->ltrt_center_mix_level);
1485 put_bits(&s->pb, 3, s->ltrt_surround_mix_level);
1486 put_bits(&s->pb, 3, s->loro_center_mix_level);
1487 put_bits(&s->pb, 3, s->loro_surround_mix_level);
1488 }
1489 put_bits(&s->pb, 1, opt->extended_bsi_2);
1490 if (opt->extended_bsi_2) {
1491 put_bits(&s->pb, 2, opt->dolby_surround_ex_mode);
1492 put_bits(&s->pb, 2, opt->dolby_headphone_mode);
1493 put_bits(&s->pb, 1, opt->ad_converter_type);
1494 put_bits(&s->pb, 9, 0); /* xbsi2 and encinfo : reserved */
1495 }
1496 } else {
1497 put_bits(&s->pb, 1, 0); /* no time code 1 */
1498 put_bits(&s->pb, 1, 0); /* no time code 2 */
1499 }
1500 put_bits(&s->pb, 1, 0); /* no additional bit stream info */
1501 }
1502
1503
1504 /*
1505 * Write one audio block to the output bitstream.
1506 */
output_audio_block(AC3EncodeContext *s, int blk)1507 static void output_audio_block(AC3EncodeContext *s, int blk)
1508 {
1509 int ch, i, baie, bnd, got_cpl, av_uninit(ch0);
1510 AC3Block *block = &s->blocks[blk];
1511
1512 /* block switching */
1513 if (!s->eac3) {
1514 for (ch = 0; ch < s->fbw_channels; ch++)
1515 put_bits(&s->pb, 1, 0);
1516 }
1517
1518 /* dither flags */
1519 if (!s->eac3) {
1520 for (ch = 0; ch < s->fbw_channels; ch++)
1521 put_bits(&s->pb, 1, 1);
1522 }
1523
1524 /* dynamic range codes */
1525 put_bits(&s->pb, 1, 0);
1526
1527 /* spectral extension */
1528 if (s->eac3)
1529 put_bits(&s->pb, 1, 0);
1530
1531 /* channel coupling */
1532 if (!s->eac3)
1533 put_bits(&s->pb, 1, block->new_cpl_strategy);
1534 if (block->new_cpl_strategy) {
1535 if (!s->eac3)
1536 put_bits(&s->pb, 1, block->cpl_in_use);
1537 if (block->cpl_in_use) {
1538 int start_sub, end_sub;
1539 if (s->eac3)
1540 put_bits(&s->pb, 1, 0); /* enhanced coupling */
1541 if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO) {
1542 for (ch = 1; ch <= s->fbw_channels; ch++)
1543 put_bits(&s->pb, 1, block->channel_in_cpl[ch]);
1544 }
1545 if (s->channel_mode == AC3_CHMODE_STEREO)
1546 put_bits(&s->pb, 1, 0); /* phase flags in use */
1547 start_sub = (s->start_freq[CPL_CH] - 37) / 12;
1548 end_sub = (s->cpl_end_freq - 37) / 12;
1549 put_bits(&s->pb, 4, start_sub);
1550 put_bits(&s->pb, 4, end_sub - 3);
1551 /* coupling band structure */
1552 if (s->eac3) {
1553 put_bits(&s->pb, 1, 0); /* use default */
1554 } else {
1555 for (bnd = start_sub+1; bnd < end_sub; bnd++)
1556 put_bits(&s->pb, 1, ff_eac3_default_cpl_band_struct[bnd]);
1557 }
1558 }
1559 }
1560
1561 /* coupling coordinates */
1562 if (block->cpl_in_use) {
1563 for (ch = 1; ch <= s->fbw_channels; ch++) {
1564 if (block->channel_in_cpl[ch]) {
1565 if (!s->eac3 || block->new_cpl_coords[ch] != 2)
1566 put_bits(&s->pb, 1, block->new_cpl_coords[ch]);
1567 if (block->new_cpl_coords[ch]) {
1568 put_bits(&s->pb, 2, block->cpl_master_exp[ch]);
1569 for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
1570 put_bits(&s->pb, 4, block->cpl_coord_exp [ch][bnd]);
1571 put_bits(&s->pb, 4, block->cpl_coord_mant[ch][bnd]);
1572 }
1573 }
1574 }
1575 }
1576 }
1577
1578 /* stereo rematrixing */
1579 if (s->channel_mode == AC3_CHMODE_STEREO) {
1580 if (!s->eac3 || blk > 0)
1581 put_bits(&s->pb, 1, block->new_rematrixing_strategy);
1582 if (block->new_rematrixing_strategy) {
1583 /* rematrixing flags */
1584 for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++)
1585 put_bits(&s->pb, 1, block->rematrixing_flags[bnd]);
1586 }
1587 }
1588
1589 /* exponent strategy */
1590 if (!s->eac3) {
1591 for (ch = !block->cpl_in_use; ch <= s->fbw_channels; ch++)
1592 put_bits(&s->pb, 2, s->exp_strategy[ch][blk]);
1593 if (s->lfe_on)
1594 put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]);
1595 }
1596
1597 /* bandwidth */
1598 for (ch = 1; ch <= s->fbw_channels; ch++) {
1599 if (s->exp_strategy[ch][blk] != EXP_REUSE && !block->channel_in_cpl[ch])
1600 put_bits(&s->pb, 6, s->bandwidth_code);
1601 }
1602
1603 /* exponents */
1604 for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1605 int nb_groups;
1606 int cpl = (ch == CPL_CH);
1607
1608 if (s->exp_strategy[ch][blk] == EXP_REUSE)
1609 continue;
1610
1611 /* DC exponent */
1612 put_bits(&s->pb, 4, block->grouped_exp[ch][0] >> cpl);
1613
1614 /* exponent groups */
1615 nb_groups = exponent_group_tab[cpl][s->exp_strategy[ch][blk]-1][block->end_freq[ch]-s->start_freq[ch]];
1616 for (i = 1; i <= nb_groups; i++)
1617 put_bits(&s->pb, 7, block->grouped_exp[ch][i]);
1618
1619 /* gain range info */
1620 if (ch != s->lfe_channel && !cpl)
1621 put_bits(&s->pb, 2, 0);
1622 }
1623
1624 /* bit allocation info */
1625 if (!s->eac3) {
1626 baie = (blk == 0);
1627 put_bits(&s->pb, 1, baie);
1628 if (baie) {
1629 put_bits(&s->pb, 2, s->slow_decay_code);
1630 put_bits(&s->pb, 2, s->fast_decay_code);
1631 put_bits(&s->pb, 2, s->slow_gain_code);
1632 put_bits(&s->pb, 2, s->db_per_bit_code);
1633 put_bits(&s->pb, 3, s->floor_code);
1634 }
1635 }
1636
1637 /* snr offset */
1638 if (!s->eac3) {
1639 put_bits(&s->pb, 1, block->new_snr_offsets);
1640 if (block->new_snr_offsets) {
1641 put_bits(&s->pb, 6, s->coarse_snr_offset);
1642 for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1643 put_bits(&s->pb, 4, s->fine_snr_offset[ch]);
1644 put_bits(&s->pb, 3, s->fast_gain_code[ch]);
1645 }
1646 }
1647 } else {
1648 put_bits(&s->pb, 1, 0); /* no converter snr offset */
1649 }
1650
1651 /* coupling leak */
1652 if (block->cpl_in_use) {
1653 if (!s->eac3 || block->new_cpl_leak != 2)
1654 put_bits(&s->pb, 1, block->new_cpl_leak);
1655 if (block->new_cpl_leak) {
1656 put_bits(&s->pb, 3, s->bit_alloc.cpl_fast_leak);
1657 put_bits(&s->pb, 3, s->bit_alloc.cpl_slow_leak);
1658 }
1659 }
1660
1661 if (!s->eac3) {
1662 put_bits(&s->pb, 1, 0); /* no delta bit allocation */
1663 put_bits(&s->pb, 1, 0); /* no data to skip */
1664 }
1665
1666 /* mantissas */
1667 got_cpl = !block->cpl_in_use;
1668 for (ch = 1; ch <= s->channels; ch++) {
1669 int b, q;
1670
1671 if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
1672 ch0 = ch - 1;
1673 ch = CPL_CH;
1674 got_cpl = 1;
1675 }
1676 for (i = s->start_freq[ch]; i < block->end_freq[ch]; i++) {
1677 q = block->qmant[ch][i];
1678 b = s->ref_bap[ch][blk][i];
1679 switch (b) {
1680 case 0: break;
1681 case 1: if (q != 128) put_bits (&s->pb, 5, q); break;
1682 case 2: if (q != 128) put_bits (&s->pb, 7, q); break;
1683 case 3: put_sbits(&s->pb, 3, q); break;
1684 case 4: if (q != 128) put_bits (&s->pb, 7, q); break;
1685 case 14: put_sbits(&s->pb, 14, q); break;
1686 case 15: put_sbits(&s->pb, 16, q); break;
1687 default: put_sbits(&s->pb, b-1, q); break;
1688 }
1689 }
1690 if (ch == CPL_CH)
1691 ch = ch0;
1692 }
1693 }
1694
1695
1696 /** CRC-16 Polynomial */
1697 #define CRC16_POLY ((1 << 0) | (1 << 2) | (1 << 15) | (1 << 16))
1698
1699
mul_poly(unsigned int a, unsigned int b, unsigned int poly)1700 static unsigned int mul_poly(unsigned int a, unsigned int b, unsigned int poly)
1701 {
1702 unsigned int c;
1703
1704 c = 0;
1705 while (a) {
1706 if (a & 1)
1707 c ^= b;
1708 a = a >> 1;
1709 b = b << 1;
1710 if (b & (1 << 16))
1711 b ^= poly;
1712 }
1713 return c;
1714 }
1715
1716
pow_poly(unsigned int a, unsigned int n, unsigned int poly)1717 static unsigned int pow_poly(unsigned int a, unsigned int n, unsigned int poly)
1718 {
1719 unsigned int r;
1720 r = 1;
1721 while (n) {
1722 if (n & 1)
1723 r = mul_poly(r, a, poly);
1724 a = mul_poly(a, a, poly);
1725 n >>= 1;
1726 }
1727 return r;
1728 }
1729
1730
1731 /*
1732 * Fill the end of the frame with 0's and compute the two CRCs.
1733 */
output_frame_end(AC3EncodeContext *s)1734 static void output_frame_end(AC3EncodeContext *s)
1735 {
1736 const AVCRC *crc_ctx = av_crc_get_table(AV_CRC_16_ANSI);
1737 int frame_size_58, pad_bytes, crc1, crc2_partial, crc2, crc_inv;
1738 uint8_t *frame;
1739
1740 frame_size_58 = ((s->frame_size >> 2) + (s->frame_size >> 4)) << 1;
1741
1742 /* pad the remainder of the frame with zeros */
1743 av_assert2(s->frame_size * 8 - put_bits_count(&s->pb) >= 18);
1744 flush_put_bits(&s->pb);
1745 frame = s->pb.buf;
1746 pad_bytes = s->frame_size - (put_bits_ptr(&s->pb) - frame) - 2;
1747 av_assert2(pad_bytes >= 0);
1748 if (pad_bytes > 0)
1749 memset(put_bits_ptr(&s->pb), 0, pad_bytes);
1750
1751 if (s->eac3) {
1752 /* compute crc2 */
1753 crc2_partial = av_crc(crc_ctx, 0, frame + 2, s->frame_size - 5);
1754 } else {
1755 /* compute crc1 */
1756 /* this is not so easy because it is at the beginning of the data... */
1757 crc1 = av_bswap16(av_crc(crc_ctx, 0, frame + 4, frame_size_58 - 4));
1758 crc_inv = s->crc_inv[s->frame_size > s->frame_size_min];
1759 crc1 = mul_poly(crc_inv, crc1, CRC16_POLY);
1760 AV_WB16(frame + 2, crc1);
1761
1762 /* compute crc2 */
1763 crc2_partial = av_crc(crc_ctx, 0, frame + frame_size_58,
1764 s->frame_size - frame_size_58 - 3);
1765 }
1766 crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1767 /* ensure crc2 does not match sync word by flipping crcrsv bit if needed */
1768 if (crc2 == 0x770B) {
1769 frame[s->frame_size - 3] ^= 0x1;
1770 crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1771 }
1772 crc2 = av_bswap16(crc2);
1773 AV_WB16(frame + s->frame_size - 2, crc2);
1774 }
1775
1776
1777 /**
1778 * Write the frame to the output bitstream.
1779 *
1780 * @param s AC-3 encoder private context
1781 * @param frame output data buffer
1782 */
ac3_output_frame(AC3EncodeContext *s, unsigned char *frame)1783 static void ac3_output_frame(AC3EncodeContext *s, unsigned char *frame)
1784 {
1785 int blk;
1786
1787 init_put_bits(&s->pb, frame, s->frame_size);
1788
1789 s->output_frame_header(s);
1790
1791 for (blk = 0; blk < s->num_blocks; blk++)
1792 output_audio_block(s, blk);
1793
1794 output_frame_end(s);
1795 }
1796
ff_ac3_encode_frame_common_end(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)1797 int ff_ac3_encode_frame_common_end(AVCodecContext *avctx, AVPacket *avpkt,
1798 const AVFrame *frame, int *got_packet_ptr)
1799 {
1800 AC3EncodeContext *const s = avctx->priv_data;
1801 int ret;
1802
1803 ac3_apply_rematrixing(s);
1804
1805 ac3_process_exponents(s);
1806
1807 ret = ac3_compute_bit_allocation(s);
1808 if (ret) {
1809 av_log(avctx, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n");
1810 return ret;
1811 }
1812
1813 ac3_group_exponents(s);
1814
1815 ac3_quantize_mantissas(s);
1816
1817 ret = ff_get_encode_buffer(avctx, avpkt, s->frame_size, 0);
1818 if (ret < 0)
1819 return ret;
1820 ac3_output_frame(s, avpkt->data);
1821
1822 if (frame->pts != AV_NOPTS_VALUE)
1823 avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->initial_padding);
1824
1825 *got_packet_ptr = 1;
1826 return 0;
1827 }
1828
dprint_options(AC3EncodeContext *s)1829 static void dprint_options(AC3EncodeContext *s)
1830 {
1831 #ifdef DEBUG
1832 AVCodecContext *avctx = s->avctx;
1833 AC3EncOptions *opt = &s->options;
1834 char strbuf[32];
1835
1836 switch (s->bitstream_id) {
1837 case 6: av_strlcpy(strbuf, "AC-3 (alt syntax)", 32); break;
1838 case 8: av_strlcpy(strbuf, "AC-3 (standard)", 32); break;
1839 case 9: av_strlcpy(strbuf, "AC-3 (dnet half-rate)", 32); break;
1840 case 10: av_strlcpy(strbuf, "AC-3 (dnet quater-rate)", 32); break;
1841 case 16: av_strlcpy(strbuf, "E-AC-3 (enhanced)", 32); break;
1842 default: snprintf(strbuf, 32, "ERROR");
1843 }
1844 ff_dlog(avctx, "bitstream_id: %s (%d)\n", strbuf, s->bitstream_id);
1845 ff_dlog(avctx, "sample_fmt: %s\n", av_get_sample_fmt_name(avctx->sample_fmt));
1846 av_channel_layout_describe(&avctx->ch_layout, strbuf, sizeof(strbuf));
1847 ff_dlog(avctx, "channel_layout: %s\n", strbuf);
1848 ff_dlog(avctx, "sample_rate: %d\n", s->sample_rate);
1849 ff_dlog(avctx, "bit_rate: %d\n", s->bit_rate);
1850 ff_dlog(avctx, "blocks/frame: %d (code=%d)\n", s->num_blocks, s->num_blks_code);
1851 if (s->cutoff)
1852 ff_dlog(avctx, "cutoff: %d\n", s->cutoff);
1853
1854 ff_dlog(avctx, "per_frame_metadata: %s\n",
1855 opt->allow_per_frame_metadata?"on":"off");
1856 if (s->has_center)
1857 ff_dlog(avctx, "center_mixlev: %0.3f (%d)\n", opt->center_mix_level,
1858 s->center_mix_level);
1859 else
1860 ff_dlog(avctx, "center_mixlev: {not written}\n");
1861 if (s->has_surround)
1862 ff_dlog(avctx, "surround_mixlev: %0.3f (%d)\n", opt->surround_mix_level,
1863 s->surround_mix_level);
1864 else
1865 ff_dlog(avctx, "surround_mixlev: {not written}\n");
1866 if (opt->audio_production_info) {
1867 ff_dlog(avctx, "mixing_level: %ddB\n", opt->mixing_level);
1868 switch (opt->room_type) {
1869 case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1870 case AC3ENC_OPT_LARGE_ROOM: av_strlcpy(strbuf, "large", 32); break;
1871 case AC3ENC_OPT_SMALL_ROOM: av_strlcpy(strbuf, "small", 32); break;
1872 default: snprintf(strbuf, 32, "ERROR (%d)", opt->room_type);
1873 }
1874 ff_dlog(avctx, "room_type: %s\n", strbuf);
1875 } else {
1876 ff_dlog(avctx, "mixing_level: {not written}\n");
1877 ff_dlog(avctx, "room_type: {not written}\n");
1878 }
1879 ff_dlog(avctx, "copyright: %s\n", opt->copyright?"on":"off");
1880 ff_dlog(avctx, "dialnorm: %ddB\n", opt->dialogue_level);
1881 if (s->channel_mode == AC3_CHMODE_STEREO) {
1882 switch (opt->dolby_surround_mode) {
1883 case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1884 case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1885 case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1886 default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_mode);
1887 }
1888 ff_dlog(avctx, "dsur_mode: %s\n", strbuf);
1889 } else {
1890 ff_dlog(avctx, "dsur_mode: {not written}\n");
1891 }
1892 ff_dlog(avctx, "original: %s\n", opt->original?"on":"off");
1893
1894 if (s->bitstream_id == 6) {
1895 if (opt->extended_bsi_1) {
1896 switch (opt->preferred_stereo_downmix) {
1897 case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1898 case AC3ENC_OPT_DOWNMIX_LTRT: av_strlcpy(strbuf, "ltrt", 32); break;
1899 case AC3ENC_OPT_DOWNMIX_LORO: av_strlcpy(strbuf, "loro", 32); break;
1900 default: snprintf(strbuf, 32, "ERROR (%d)", opt->preferred_stereo_downmix);
1901 }
1902 ff_dlog(avctx, "dmix_mode: %s\n", strbuf);
1903 ff_dlog(avctx, "ltrt_cmixlev: %0.3f (%d)\n",
1904 opt->ltrt_center_mix_level, s->ltrt_center_mix_level);
1905 ff_dlog(avctx, "ltrt_surmixlev: %0.3f (%d)\n",
1906 opt->ltrt_surround_mix_level, s->ltrt_surround_mix_level);
1907 ff_dlog(avctx, "loro_cmixlev: %0.3f (%d)\n",
1908 opt->loro_center_mix_level, s->loro_center_mix_level);
1909 ff_dlog(avctx, "loro_surmixlev: %0.3f (%d)\n",
1910 opt->loro_surround_mix_level, s->loro_surround_mix_level);
1911 } else {
1912 ff_dlog(avctx, "extended bitstream info 1: {not written}\n");
1913 }
1914 if (opt->extended_bsi_2) {
1915 switch (opt->dolby_surround_ex_mode) {
1916 case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1917 case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1918 case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1919 default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_ex_mode);
1920 }
1921 ff_dlog(avctx, "dsurex_mode: %s\n", strbuf);
1922 switch (opt->dolby_headphone_mode) {
1923 case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1924 case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1925 case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1926 default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_headphone_mode);
1927 }
1928 ff_dlog(avctx, "dheadphone_mode: %s\n", strbuf);
1929
1930 switch (opt->ad_converter_type) {
1931 case AC3ENC_OPT_ADCONV_STANDARD: av_strlcpy(strbuf, "standard", 32); break;
1932 case AC3ENC_OPT_ADCONV_HDCD: av_strlcpy(strbuf, "hdcd", 32); break;
1933 default: snprintf(strbuf, 32, "ERROR (%d)", opt->ad_converter_type);
1934 }
1935 ff_dlog(avctx, "ad_conv_type: %s\n", strbuf);
1936 } else {
1937 ff_dlog(avctx, "extended bitstream info 2: {not written}\n");
1938 }
1939 }
1940 #endif
1941 }
1942
1943
1944 #define FLT_OPTION_THRESHOLD 0.01
1945
validate_float_option(float v, const float *v_list, int v_list_size)1946 static int validate_float_option(float v, const float *v_list, int v_list_size)
1947 {
1948 int i;
1949
1950 for (i = 0; i < v_list_size; i++) {
1951 if (v < (v_list[i] + FLT_OPTION_THRESHOLD) &&
1952 v > (v_list[i] - FLT_OPTION_THRESHOLD))
1953 break;
1954 }
1955 if (i == v_list_size)
1956 return AVERROR(EINVAL);
1957
1958 return i;
1959 }
1960
1961
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)1962 static void validate_mix_level(void *log_ctx, const char *opt_name,
1963 float *opt_param, const float *list,
1964 int list_size, int default_value, int min_value,
1965 int *ctx_param)
1966 {
1967 int mixlev = validate_float_option(*opt_param, list, list_size);
1968 if (mixlev < min_value) {
1969 mixlev = default_value;
1970 if (*opt_param >= 0.0) {
1971 av_log(log_ctx, AV_LOG_WARNING, "requested %s is not valid. using "
1972 "default value: %0.3f\n", opt_name, list[mixlev]);
1973 }
1974 }
1975 *opt_param = list[mixlev];
1976 *ctx_param = mixlev;
1977 }
1978
1979
1980 /**
1981 * Validate metadata options as set by AVOption system.
1982 * These values can optionally be changed per-frame.
1983 *
1984 * @param s AC-3 encoder private context
1985 */
ff_ac3_validate_metadata(AC3EncodeContext *s)1986 int ff_ac3_validate_metadata(AC3EncodeContext *s)
1987 {
1988 AVCodecContext *avctx = s->avctx;
1989 AC3EncOptions *opt = &s->options;
1990
1991 opt->audio_production_info = 0;
1992 opt->extended_bsi_1 = 0;
1993 opt->extended_bsi_2 = 0;
1994 opt->eac3_mixing_metadata = 0;
1995 opt->eac3_info_metadata = 0;
1996
1997 /* determine mixing metadata / xbsi1 use */
1998 if (s->channel_mode > AC3_CHMODE_STEREO && opt->preferred_stereo_downmix != AC3ENC_OPT_NONE) {
1999 opt->extended_bsi_1 = 1;
2000 opt->eac3_mixing_metadata = 1;
2001 }
2002 if (s->has_center &&
2003 (opt->ltrt_center_mix_level >= 0 || opt->loro_center_mix_level >= 0)) {
2004 opt->extended_bsi_1 = 1;
2005 opt->eac3_mixing_metadata = 1;
2006 }
2007 if (s->has_surround &&
2008 (opt->ltrt_surround_mix_level >= 0 || opt->loro_surround_mix_level >= 0)) {
2009 opt->extended_bsi_1 = 1;
2010 opt->eac3_mixing_metadata = 1;
2011 }
2012
2013 if (s->eac3) {
2014 /* determine info metadata use */
2015 if (avctx->audio_service_type != AV_AUDIO_SERVICE_TYPE_MAIN)
2016 opt->eac3_info_metadata = 1;
2017 if (opt->copyright != AC3ENC_OPT_NONE || opt->original != AC3ENC_OPT_NONE)
2018 opt->eac3_info_metadata = 1;
2019 if (s->channel_mode == AC3_CHMODE_STEREO &&
2020 (opt->dolby_headphone_mode != AC3ENC_OPT_NONE || opt->dolby_surround_mode != AC3ENC_OPT_NONE))
2021 opt->eac3_info_metadata = 1;
2022 if (s->channel_mode >= AC3_CHMODE_2F2R && opt->dolby_surround_ex_mode != AC3ENC_OPT_NONE)
2023 opt->eac3_info_metadata = 1;
2024 if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE ||
2025 opt->ad_converter_type != AC3ENC_OPT_NONE) {
2026 opt->audio_production_info = 1;
2027 opt->eac3_info_metadata = 1;
2028 }
2029 } else {
2030 /* determine audio production info use */
2031 if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE)
2032 opt->audio_production_info = 1;
2033
2034 /* determine xbsi2 use */
2035 if (s->channel_mode >= AC3_CHMODE_2F2R && opt->dolby_surround_ex_mode != AC3ENC_OPT_NONE)
2036 opt->extended_bsi_2 = 1;
2037 if (s->channel_mode == AC3_CHMODE_STEREO && opt->dolby_headphone_mode != AC3ENC_OPT_NONE)
2038 opt->extended_bsi_2 = 1;
2039 if (opt->ad_converter_type != AC3ENC_OPT_NONE)
2040 opt->extended_bsi_2 = 1;
2041 }
2042
2043 /* validate AC-3 mixing levels */
2044 if (!s->eac3) {
2045 if (s->has_center) {
2046 validate_mix_level(avctx, "center_mix_level", &opt->center_mix_level,
2047 cmixlev_options, CMIXLEV_NUM_OPTIONS, 1, 0,
2048 &s->center_mix_level);
2049 }
2050 if (s->has_surround) {
2051 validate_mix_level(avctx, "surround_mix_level", &opt->surround_mix_level,
2052 surmixlev_options, SURMIXLEV_NUM_OPTIONS, 1, 0,
2053 &s->surround_mix_level);
2054 }
2055 }
2056
2057 /* validate extended bsi 1 / mixing metadata */
2058 if (opt->extended_bsi_1 || opt->eac3_mixing_metadata) {
2059 /* default preferred stereo downmix */
2060 if (opt->preferred_stereo_downmix == AC3ENC_OPT_NONE)
2061 opt->preferred_stereo_downmix = AC3ENC_OPT_NOT_INDICATED;
2062 if (!s->eac3 || s->has_center) {
2063 /* validate Lt/Rt center mix level */
2064 validate_mix_level(avctx, "ltrt_center_mix_level",
2065 &opt->ltrt_center_mix_level, extmixlev_options,
2066 EXTMIXLEV_NUM_OPTIONS, 5, 0,
2067 &s->ltrt_center_mix_level);
2068 /* validate Lo/Ro center mix level */
2069 validate_mix_level(avctx, "loro_center_mix_level",
2070 &opt->loro_center_mix_level, extmixlev_options,
2071 EXTMIXLEV_NUM_OPTIONS, 5, 0,
2072 &s->loro_center_mix_level);
2073 }
2074 if (!s->eac3 || s->has_surround) {
2075 /* validate Lt/Rt surround mix level */
2076 validate_mix_level(avctx, "ltrt_surround_mix_level",
2077 &opt->ltrt_surround_mix_level, extmixlev_options,
2078 EXTMIXLEV_NUM_OPTIONS, 6, 3,
2079 &s->ltrt_surround_mix_level);
2080 /* validate Lo/Ro surround mix level */
2081 validate_mix_level(avctx, "loro_surround_mix_level",
2082 &opt->loro_surround_mix_level, extmixlev_options,
2083 EXTMIXLEV_NUM_OPTIONS, 6, 3,
2084 &s->loro_surround_mix_level);
2085 }
2086 }
2087
2088 /* validate audio service type / channels combination */
2089 if ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_KARAOKE &&
2090 avctx->ch_layout.nb_channels == 1) ||
2091 ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_COMMENTARY ||
2092 avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_EMERGENCY ||
2093 avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_VOICE_OVER)
2094 && avctx->ch_layout.nb_channels > 1)) {
2095 av_log(avctx, AV_LOG_ERROR, "invalid audio service type for the "
2096 "specified number of channels\n");
2097 return AVERROR(EINVAL);
2098 }
2099
2100 /* validate extended bsi 2 / info metadata */
2101 if (opt->extended_bsi_2 || opt->eac3_info_metadata) {
2102 /* default dolby headphone mode */
2103 if (opt->dolby_headphone_mode == AC3ENC_OPT_NONE)
2104 opt->dolby_headphone_mode = AC3ENC_OPT_NOT_INDICATED;
2105 /* default dolby surround ex mode */
2106 if (opt->dolby_surround_ex_mode == AC3ENC_OPT_NONE)
2107 opt->dolby_surround_ex_mode = AC3ENC_OPT_NOT_INDICATED;
2108 /* default A/D converter type */
2109 if (opt->ad_converter_type == AC3ENC_OPT_NONE)
2110 opt->ad_converter_type = AC3ENC_OPT_ADCONV_STANDARD;
2111 }
2112
2113 /* copyright & original defaults */
2114 if (!s->eac3 || opt->eac3_info_metadata) {
2115 /* default copyright */
2116 if (opt->copyright == AC3ENC_OPT_NONE)
2117 opt->copyright = AC3ENC_OPT_OFF;
2118 /* default original */
2119 if (opt->original == AC3ENC_OPT_NONE)
2120 opt->original = AC3ENC_OPT_ON;
2121 }
2122
2123 /* dolby surround mode default */
2124 if (!s->eac3 || opt->eac3_info_metadata) {
2125 if (opt->dolby_surround_mode == AC3ENC_OPT_NONE)
2126 opt->dolby_surround_mode = AC3ENC_OPT_NOT_INDICATED;
2127 }
2128
2129 /* validate audio production info */
2130 if (opt->audio_production_info) {
2131 if (opt->mixing_level == AC3ENC_OPT_NONE) {
2132 av_log(avctx, AV_LOG_ERROR, "mixing_level must be set if "
2133 "room_type is set\n");
2134 return AVERROR(EINVAL);
2135 }
2136 if (opt->mixing_level < 80) {
2137 av_log(avctx, AV_LOG_ERROR, "invalid mixing level. must be between "
2138 "80dB and 111dB\n");
2139 return AVERROR(EINVAL);
2140 }
2141 /* default room type */
2142 if (opt->room_type == AC3ENC_OPT_NONE)
2143 opt->room_type = AC3ENC_OPT_NOT_INDICATED;
2144 }
2145
2146 /* set bitstream id for alternate bitstream syntax */
2147 if (!s->eac3 && (opt->extended_bsi_1 || opt->extended_bsi_2)) {
2148 if (s->bitstream_id > 8 && s->bitstream_id < 11) {
2149 if (!s->warned_alternate_bitstream) {
2150 av_log(avctx, AV_LOG_WARNING, "alternate bitstream syntax is "
2151 "not compatible with reduced samplerates. writing of "
2152 "extended bitstream information will be disabled.\n");
2153 s->warned_alternate_bitstream = 1;
2154 }
2155 } else {
2156 s->bitstream_id = 6;
2157 }
2158 }
2159
2160 return 0;
2161 }
2162
2163
2164 /**
2165 * Finalize encoding and free any memory allocated by the encoder.
2166 *
2167 * @param avctx Codec context
2168 */
ff_ac3_encode_close(AVCodecContext *avctx)2169 av_cold int ff_ac3_encode_close(AVCodecContext *avctx)
2170 {
2171 int blk, ch;
2172 AC3EncodeContext *s = avctx->priv_data;
2173
2174 av_freep(&s->mdct_window);
2175 av_freep(&s->windowed_samples);
2176 if (s->planar_samples)
2177 for (ch = 0; ch < s->channels; ch++)
2178 av_freep(&s->planar_samples[ch]);
2179 av_freep(&s->planar_samples);
2180 av_freep(&s->bap_buffer);
2181 av_freep(&s->bap1_buffer);
2182 av_freep(&s->mdct_coef_buffer);
2183 av_freep(&s->fixed_coef_buffer);
2184 av_freep(&s->exp_buffer);
2185 av_freep(&s->grouped_exp_buffer);
2186 av_freep(&s->psd_buffer);
2187 av_freep(&s->band_psd_buffer);
2188 av_freep(&s->mask_buffer);
2189 av_freep(&s->qmant_buffer);
2190 av_freep(&s->cpl_coord_exp_buffer);
2191 av_freep(&s->cpl_coord_mant_buffer);
2192 av_freep(&s->fdsp);
2193 for (blk = 0; blk < s->num_blocks; blk++) {
2194 AC3Block *block = &s->blocks[blk];
2195 av_freep(&block->mdct_coef);
2196 av_freep(&block->fixed_coef);
2197 av_freep(&block->exp);
2198 av_freep(&block->grouped_exp);
2199 av_freep(&block->psd);
2200 av_freep(&block->band_psd);
2201 av_freep(&block->mask);
2202 av_freep(&block->qmant);
2203 av_freep(&block->cpl_coord_exp);
2204 av_freep(&block->cpl_coord_mant);
2205 }
2206
2207 s->mdct_end(s);
2208
2209 return 0;
2210 }
2211
2212
2213 /*
2214 * Set channel information during initialization.
2215 */
set_channel_info(AVCodecContext *avctx)2216 static av_cold int set_channel_info(AVCodecContext *avctx)
2217 {
2218 AC3EncodeContext *s = avctx->priv_data;
2219 int channels = avctx->ch_layout.nb_channels;
2220 uint64_t mask = avctx->ch_layout.u.mask;
2221
2222 if (channels < 1 || channels > AC3_MAX_CHANNELS)
2223 return AVERROR(EINVAL);
2224 if (mask > 0x7FF)
2225 return AVERROR(EINVAL);
2226
2227 if (!mask)
2228 av_channel_layout_default(&avctx->ch_layout, channels);
2229 mask = avctx->ch_layout.u.mask;
2230
2231 s->lfe_on = !!(mask & AV_CH_LOW_FREQUENCY);
2232 s->channels = channels;
2233 s->fbw_channels = channels - s->lfe_on;
2234 s->lfe_channel = s->lfe_on ? s->fbw_channels + 1 : -1;
2235 if (s->lfe_on)
2236 mask -= AV_CH_LOW_FREQUENCY;
2237
2238 switch (mask) {
2239 case AV_CH_LAYOUT_MONO: s->channel_mode = AC3_CHMODE_MONO; break;
2240 case AV_CH_LAYOUT_STEREO: s->channel_mode = AC3_CHMODE_STEREO; break;
2241 case AV_CH_LAYOUT_SURROUND: s->channel_mode = AC3_CHMODE_3F; break;
2242 case AV_CH_LAYOUT_2_1: s->channel_mode = AC3_CHMODE_2F1R; break;
2243 case AV_CH_LAYOUT_4POINT0: s->channel_mode = AC3_CHMODE_3F1R; break;
2244 case AV_CH_LAYOUT_QUAD:
2245 case AV_CH_LAYOUT_2_2: s->channel_mode = AC3_CHMODE_2F2R; break;
2246 case AV_CH_LAYOUT_5POINT0:
2247 case AV_CH_LAYOUT_5POINT0_BACK: s->channel_mode = AC3_CHMODE_3F2R; break;
2248 default:
2249 return AVERROR(EINVAL);
2250 }
2251 s->has_center = (s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO;
2252 s->has_surround = s->channel_mode & 0x04;
2253
2254 s->channel_map = ac3_enc_channel_map[s->channel_mode][s->lfe_on];
2255 if (s->lfe_on)
2256 mask |= AV_CH_LOW_FREQUENCY;
2257 av_channel_layout_from_mask(&avctx->ch_layout, mask);
2258
2259 return 0;
2260 }
2261
2262
validate_options(AC3EncodeContext *s)2263 static av_cold int validate_options(AC3EncodeContext *s)
2264 {
2265 AVCodecContext *avctx = s->avctx;
2266 int i, ret, max_sr;
2267
2268 /* validate channel layout */
2269 if (!avctx->ch_layout.nb_channels) {
2270 av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The "
2271 "encoder will guess the layout, but it "
2272 "might be incorrect.\n");
2273 }
2274 ret = set_channel_info(avctx);
2275 if (ret) {
2276 av_log(avctx, AV_LOG_ERROR, "invalid channel layout\n");
2277 return ret;
2278 }
2279
2280 /* validate sample rate */
2281 /* note: max_sr could be changed from 2 to 5 for E-AC-3 once we find a
2282 decoder that supports half sample rate so we can validate that
2283 the generated files are correct. */
2284 max_sr = s->eac3 ? 2 : 8;
2285 for (i = 0; i <= max_sr; i++) {
2286 if ((ff_ac3_sample_rate_tab[i % 3] >> (i / 3)) == avctx->sample_rate)
2287 break;
2288 }
2289 if (i > max_sr) {
2290 av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
2291 return AVERROR(EINVAL);
2292 }
2293 s->sample_rate = avctx->sample_rate;
2294 s->bit_alloc.sr_shift = i / 3;
2295 s->bit_alloc.sr_code = i % 3;
2296 s->bitstream_id = s->eac3 ? 16 : 8 + s->bit_alloc.sr_shift;
2297
2298 /* select a default bit rate if not set by the user */
2299 if (!avctx->bit_rate) {
2300 switch (s->fbw_channels) {
2301 case 1: avctx->bit_rate = 96000; break;
2302 case 2: avctx->bit_rate = 192000; break;
2303 case 3: avctx->bit_rate = 320000; break;
2304 case 4: avctx->bit_rate = 384000; break;
2305 case 5: avctx->bit_rate = 448000; break;
2306 }
2307 }
2308
2309 /* validate bit rate */
2310 if (s->eac3) {
2311 int max_br, min_br, wpf, min_br_code;
2312 int num_blks_code, num_blocks, frame_samples;
2313 long long min_br_dist;
2314
2315 /* calculate min/max bitrate */
2316 /* TODO: More testing with 3 and 2 blocks. All E-AC-3 samples I've
2317 found use either 6 blocks or 1 block, even though 2 or 3 blocks
2318 would work as far as the bit rate is concerned. */
2319 for (num_blks_code = 3; num_blks_code >= 0; num_blks_code--) {
2320 num_blocks = ((int[]){ 1, 2, 3, 6 })[num_blks_code];
2321 frame_samples = AC3_BLOCK_SIZE * num_blocks;
2322 max_br = 2048 * s->sample_rate / frame_samples * 16;
2323 min_br = ((s->sample_rate + (frame_samples-1)) / frame_samples) * 16;
2324 if (avctx->bit_rate <= max_br)
2325 break;
2326 }
2327 if (avctx->bit_rate < min_br || avctx->bit_rate > max_br) {
2328 av_log(avctx, AV_LOG_ERROR, "invalid bit rate. must be %d to %d "
2329 "for this sample rate\n", min_br, max_br);
2330 return AVERROR(EINVAL);
2331 }
2332 s->num_blks_code = num_blks_code;
2333 s->num_blocks = num_blocks;
2334
2335 /* calculate words-per-frame for the selected bitrate */
2336 wpf = (avctx->bit_rate / 16) * frame_samples / s->sample_rate;
2337 av_assert1(wpf > 0 && wpf <= 2048);
2338
2339 /* find the closest AC-3 bitrate code to the selected bitrate.
2340 this is needed for lookup tables for bandwidth and coupling
2341 parameter selection */
2342 min_br_code = -1;
2343 min_br_dist = INT64_MAX;
2344 for (i = 0; i < 19; i++) {
2345 long long br_dist = llabs(ff_ac3_bitrate_tab[i] * 1000 - avctx->bit_rate);
2346 if (br_dist < min_br_dist) {
2347 min_br_dist = br_dist;
2348 min_br_code = i;
2349 }
2350 }
2351
2352 /* make sure the minimum frame size is below the average frame size */
2353 s->frame_size_code = min_br_code << 1;
2354 while (wpf > 1 && wpf * s->sample_rate / AC3_FRAME_SIZE * 16 > avctx->bit_rate)
2355 wpf--;
2356 s->frame_size_min = 2 * wpf;
2357 } else {
2358 int best_br = 0, best_code = 0;
2359 long long best_diff = INT64_MAX;
2360 for (i = 0; i < 19; i++) {
2361 int br = (ff_ac3_bitrate_tab[i] >> s->bit_alloc.sr_shift) * 1000;
2362 long long diff = llabs(br - avctx->bit_rate);
2363 if (diff < best_diff) {
2364 best_br = br;
2365 best_code = i;
2366 best_diff = diff;
2367 }
2368 if (!best_diff)
2369 break;
2370 }
2371 avctx->bit_rate = best_br;
2372 s->frame_size_code = best_code << 1;
2373 s->frame_size_min = 2 * ff_ac3_frame_size_tab[s->frame_size_code][s->bit_alloc.sr_code];
2374 s->num_blks_code = 0x3;
2375 s->num_blocks = 6;
2376 }
2377 s->bit_rate = avctx->bit_rate;
2378 s->frame_size = s->frame_size_min;
2379
2380 /* validate cutoff */
2381 if (avctx->cutoff < 0) {
2382 av_log(avctx, AV_LOG_ERROR, "invalid cutoff frequency\n");
2383 return AVERROR(EINVAL);
2384 }
2385 s->cutoff = avctx->cutoff;
2386 if (s->cutoff > (s->sample_rate >> 1))
2387 s->cutoff = s->sample_rate >> 1;
2388
2389 ret = ff_ac3_validate_metadata(s);
2390 if (ret)
2391 return ret;
2392
2393 s->rematrixing_enabled = s->options.stereo_rematrixing &&
2394 (s->channel_mode == AC3_CHMODE_STEREO);
2395
2396 s->cpl_enabled = s->options.channel_coupling &&
2397 s->channel_mode >= AC3_CHMODE_STEREO;
2398
2399 return 0;
2400 }
2401
2402
2403 /*
2404 * Set bandwidth for all channels.
2405 * The user can optionally supply a cutoff frequency. Otherwise an appropriate
2406 * default value will be used.
2407 */
set_bandwidth(AC3EncodeContext *s)2408 static av_cold void set_bandwidth(AC3EncodeContext *s)
2409 {
2410 int blk, ch, av_uninit(cpl_start);
2411
2412 if (s->cutoff) {
2413 /* calculate bandwidth based on user-specified cutoff frequency */
2414 int fbw_coeffs;
2415 fbw_coeffs = s->cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
2416 s->bandwidth_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
2417 } else {
2418 /* use default bandwidth setting */
2419 s->bandwidth_code = ac3_bandwidth_tab[s->fbw_channels-1][s->bit_alloc.sr_code][s->frame_size_code/2];
2420 }
2421
2422 /* set number of coefficients for each channel */
2423 for (ch = 1; ch <= s->fbw_channels; ch++) {
2424 s->start_freq[ch] = 0;
2425 for (blk = 0; blk < s->num_blocks; blk++)
2426 s->blocks[blk].end_freq[ch] = s->bandwidth_code * 3 + 73;
2427 }
2428 /* LFE channel always has 7 coefs */
2429 if (s->lfe_on) {
2430 s->start_freq[s->lfe_channel] = 0;
2431 for (blk = 0; blk < s->num_blocks; blk++)
2432 s->blocks[blk].end_freq[ch] = 7;
2433 }
2434
2435 /* initialize coupling strategy */
2436 if (s->cpl_enabled) {
2437 if (s->options.cpl_start != AC3ENC_OPT_AUTO) {
2438 cpl_start = s->options.cpl_start;
2439 } else {
2440 cpl_start = ac3_coupling_start_tab[s->channel_mode-2][s->bit_alloc.sr_code][s->frame_size_code/2];
2441 if (cpl_start < 0) {
2442 if (s->options.channel_coupling == AC3ENC_OPT_AUTO)
2443 s->cpl_enabled = 0;
2444 else
2445 cpl_start = 15;
2446 }
2447 }
2448 }
2449 if (s->cpl_enabled) {
2450 int i, cpl_start_band, cpl_end_band;
2451 uint8_t *cpl_band_sizes = s->cpl_band_sizes;
2452
2453 cpl_end_band = s->bandwidth_code / 4 + 3;
2454 cpl_start_band = av_clip(cpl_start, 0, FFMIN(cpl_end_band-1, 15));
2455
2456 s->num_cpl_subbands = cpl_end_band - cpl_start_band;
2457
2458 s->num_cpl_bands = 1;
2459 *cpl_band_sizes = 12;
2460 for (i = cpl_start_band + 1; i < cpl_end_band; i++) {
2461 if (ff_eac3_default_cpl_band_struct[i]) {
2462 *cpl_band_sizes += 12;
2463 } else {
2464 s->num_cpl_bands++;
2465 cpl_band_sizes++;
2466 *cpl_band_sizes = 12;
2467 }
2468 }
2469
2470 s->start_freq[CPL_CH] = cpl_start_band * 12 + 37;
2471 s->cpl_end_freq = cpl_end_band * 12 + 37;
2472 for (blk = 0; blk < s->num_blocks; blk++)
2473 s->blocks[blk].end_freq[CPL_CH] = s->cpl_end_freq;
2474 }
2475 }
2476
2477
allocate_buffers(AC3EncodeContext *s)2478 static av_cold int allocate_buffers(AC3EncodeContext *s)
2479 {
2480 int blk, ch;
2481 int channels = s->channels + 1; /* includes coupling channel */
2482 int channel_blocks = channels * s->num_blocks;
2483 int total_coefs = AC3_MAX_COEFS * channel_blocks;
2484
2485 if (s->allocate_sample_buffers(s))
2486 return AVERROR(ENOMEM);
2487
2488 if (!FF_ALLOC_TYPED_ARRAY(s->bap_buffer, total_coefs) ||
2489 !FF_ALLOC_TYPED_ARRAY(s->bap1_buffer, total_coefs) ||
2490 !FF_ALLOCZ_TYPED_ARRAY(s->mdct_coef_buffer, total_coefs) ||
2491 !FF_ALLOC_TYPED_ARRAY(s->exp_buffer, total_coefs) ||
2492 !FF_ALLOC_TYPED_ARRAY(s->grouped_exp_buffer, channel_blocks * 128) ||
2493 !FF_ALLOC_TYPED_ARRAY(s->psd_buffer, total_coefs) ||
2494 !FF_ALLOC_TYPED_ARRAY(s->band_psd_buffer, channel_blocks * 64) ||
2495 !FF_ALLOC_TYPED_ARRAY(s->mask_buffer, channel_blocks * 64) ||
2496 !FF_ALLOC_TYPED_ARRAY(s->qmant_buffer, total_coefs))
2497 return AVERROR(ENOMEM);
2498
2499 if (s->cpl_enabled) {
2500 if (!FF_ALLOC_TYPED_ARRAY(s->cpl_coord_exp_buffer, channel_blocks * 16) ||
2501 !FF_ALLOC_TYPED_ARRAY(s->cpl_coord_mant_buffer, channel_blocks * 16))
2502 return AVERROR(ENOMEM);
2503 }
2504 for (blk = 0; blk < s->num_blocks; blk++) {
2505 AC3Block *block = &s->blocks[blk];
2506
2507 if (!FF_ALLOCZ_TYPED_ARRAY(block->mdct_coef, channels) ||
2508 !FF_ALLOCZ_TYPED_ARRAY(block->exp, channels) ||
2509 !FF_ALLOCZ_TYPED_ARRAY(block->grouped_exp, channels) ||
2510 !FF_ALLOCZ_TYPED_ARRAY(block->psd, channels) ||
2511 !FF_ALLOCZ_TYPED_ARRAY(block->band_psd, channels) ||
2512 !FF_ALLOCZ_TYPED_ARRAY(block->mask, channels) ||
2513 !FF_ALLOCZ_TYPED_ARRAY(block->qmant, channels))
2514 return AVERROR(ENOMEM);
2515
2516 if (s->cpl_enabled) {
2517 if (!FF_ALLOCZ_TYPED_ARRAY(block->cpl_coord_exp, channels) ||
2518 !FF_ALLOCZ_TYPED_ARRAY(block->cpl_coord_mant, channels))
2519 return AVERROR(ENOMEM);
2520 }
2521
2522 for (ch = 0; ch < channels; ch++) {
2523 /* arrangement: block, channel, coeff */
2524 block->grouped_exp[ch] = &s->grouped_exp_buffer[128 * (blk * channels + ch)];
2525 block->psd[ch] = &s->psd_buffer [AC3_MAX_COEFS * (blk * channels + ch)];
2526 block->band_psd[ch] = &s->band_psd_buffer [64 * (blk * channels + ch)];
2527 block->mask[ch] = &s->mask_buffer [64 * (blk * channels + ch)];
2528 block->qmant[ch] = &s->qmant_buffer [AC3_MAX_COEFS * (blk * channels + ch)];
2529 if (s->cpl_enabled) {
2530 block->cpl_coord_exp[ch] = &s->cpl_coord_exp_buffer [16 * (blk * channels + ch)];
2531 block->cpl_coord_mant[ch] = &s->cpl_coord_mant_buffer[16 * (blk * channels + ch)];
2532 }
2533
2534 /* arrangement: channel, block, coeff */
2535 block->exp[ch] = &s->exp_buffer [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2536 block->mdct_coef[ch] = &s->mdct_coef_buffer [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2537 }
2538 }
2539
2540 if (!s->fixed_point) {
2541 if (!FF_ALLOCZ_TYPED_ARRAY(s->fixed_coef_buffer, total_coefs))
2542 return AVERROR(ENOMEM);
2543 for (blk = 0; blk < s->num_blocks; blk++) {
2544 AC3Block *block = &s->blocks[blk];
2545 if (!FF_ALLOCZ_TYPED_ARRAY(block->fixed_coef, channels))
2546 return AVERROR(ENOMEM);
2547 for (ch = 0; ch < channels; ch++)
2548 block->fixed_coef[ch] = &s->fixed_coef_buffer[AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2549 }
2550 } else {
2551 for (blk = 0; blk < s->num_blocks; blk++) {
2552 AC3Block *block = &s->blocks[blk];
2553 if (!FF_ALLOCZ_TYPED_ARRAY(block->fixed_coef, channels))
2554 return AVERROR(ENOMEM);
2555 for (ch = 0; ch < channels; ch++)
2556 block->fixed_coef[ch] = (int32_t *)block->mdct_coef[ch];
2557 }
2558 }
2559
2560 return 0;
2561 }
2562
2563
ff_ac3_encode_init(AVCodecContext *avctx)2564 av_cold int ff_ac3_encode_init(AVCodecContext *avctx)
2565 {
2566 static AVOnce init_static_once = AV_ONCE_INIT;
2567 AC3EncodeContext *s = avctx->priv_data;
2568 int ret, frame_size_58;
2569
2570 s->avctx = avctx;
2571
2572 s->eac3 = avctx->codec_id == AV_CODEC_ID_EAC3;
2573
2574 ret = validate_options(s);
2575 if (ret)
2576 return ret;
2577
2578 avctx->frame_size = AC3_BLOCK_SIZE * s->num_blocks;
2579 avctx->initial_padding = AC3_BLOCK_SIZE;
2580
2581 s->bitstream_mode = avctx->audio_service_type;
2582 if (s->bitstream_mode == AV_AUDIO_SERVICE_TYPE_KARAOKE)
2583 s->bitstream_mode = 0x7;
2584
2585 s->bits_written = 0;
2586 s->samples_written = 0;
2587
2588 /* calculate crc_inv for both possible frame sizes */
2589 frame_size_58 = (( s->frame_size >> 2) + ( s->frame_size >> 4)) << 1;
2590 s->crc_inv[0] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2591 if (s->bit_alloc.sr_code == 1) {
2592 frame_size_58 = (((s->frame_size+2) >> 2) + ((s->frame_size+2) >> 4)) << 1;
2593 s->crc_inv[1] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2594 }
2595
2596 if (CONFIG_EAC3_ENCODER && s->eac3) {
2597 static AVOnce init_static_once_eac3 = AV_ONCE_INIT;
2598 ff_thread_once(&init_static_once_eac3, ff_eac3_exponent_init);
2599 s->output_frame_header = ff_eac3_output_frame_header;
2600 } else
2601 s->output_frame_header = ac3_output_frame_header;
2602
2603 set_bandwidth(s);
2604
2605 bit_alloc_init(s);
2606
2607 ret = s->mdct_init(s);
2608 if (ret)
2609 return ret;
2610
2611 ret = allocate_buffers(s);
2612 if (ret)
2613 return ret;
2614
2615 ff_audiodsp_init(&s->adsp);
2616 ff_me_cmp_init(&s->mecc, avctx);
2617 ff_ac3dsp_init(&s->ac3dsp, avctx->flags & AV_CODEC_FLAG_BITEXACT);
2618
2619 dprint_options(s);
2620
2621 ff_thread_once(&init_static_once, exponent_init);
2622
2623 return 0;
2624 }
2625