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ac3enc.h
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1 /*
2  * AC-3 encoder & E-AC-3 encoder common header
3  * Copyright (c) 2000 Fabrice Bellard
4  * Copyright (c) 2006-2010 Justin Ruggles <justin.ruggles@gmail.com>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * AC-3 encoder & E-AC-3 encoder common header
26  */
27 
28 #ifndef AVCODEC_AC3ENC_H
29 #define AVCODEC_AC3ENC_H
30 
31 #include <stdint.h>
32 
33 #include "libavutil/float_dsp.h"
34 
35 #include "ac3.h"
36 #include "ac3dsp.h"
37 #include "avcodec.h"
38 #include "fft.h"
39 #include "mathops.h"
40 #include "me_cmp.h"
41 #include "put_bits.h"
42 #include "audiodsp.h"
43 
44 #ifndef CONFIG_AC3ENC_FLOAT
45 #define CONFIG_AC3ENC_FLOAT 0
46 #endif
47 
48 #define OFFSET(param) offsetof(AC3EncodeContext, options.param)
49 #define AC3ENC_PARAM (AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM)
50 
51 #define AC3ENC_TYPE_AC3_FIXED 0
52 #define AC3ENC_TYPE_AC3 1
53 #define AC3ENC_TYPE_EAC3 2
54 
55 #if CONFIG_AC3ENC_FLOAT
56 #define AC3_NAME(x) ff_ac3_float_ ## x
57 #define MAC_COEF(d,a,b) ((d)+=(a)*(b))
58 #define COEF_MIN (-16777215.0/16777216.0)
59 #define COEF_MAX ( 16777215.0/16777216.0)
60 #define NEW_CPL_COORD_THRESHOLD 0.03
61 typedef float SampleType;
62 typedef float CoefType;
63 typedef float CoefSumType;
64 #else
65 #define AC3_NAME(x) ff_ac3_fixed_ ## x
66 #define MAC_COEF(d,a,b) MAC64(d,a,b)
67 #define COEF_MIN -16777215
68 #define COEF_MAX 16777215
69 #define NEW_CPL_COORD_THRESHOLD 503317
70 typedef int16_t SampleType;
71 typedef int32_t CoefType;
72 typedef int64_t CoefSumType;
73 #endif
74 
75 /* common option values */
76 #define AC3ENC_OPT_NONE -1
77 #define AC3ENC_OPT_AUTO -1
78 #define AC3ENC_OPT_OFF 0
79 #define AC3ENC_OPT_ON 1
80 #define AC3ENC_OPT_NOT_INDICATED 0
81 #define AC3ENC_OPT_MODE_ON 2
82 #define AC3ENC_OPT_MODE_OFF 1
83 #define AC3ENC_OPT_DSUREX_DPLIIZ 3
84 
85 /* specific option values */
86 #define AC3ENC_OPT_LARGE_ROOM 1
87 #define AC3ENC_OPT_SMALL_ROOM 2
88 #define AC3ENC_OPT_DOWNMIX_LTRT 1
89 #define AC3ENC_OPT_DOWNMIX_LORO 2
90 #define AC3ENC_OPT_DOWNMIX_DPLII 3 // reserved value in A/52, but used by encoders to indicate DPL2
91 #define AC3ENC_OPT_ADCONV_STANDARD 0
92 #define AC3ENC_OPT_ADCONV_HDCD 1
93 
94 
95 /**
96  * Encoding Options used by AVOption.
97  */
98 typedef struct AC3EncOptions {
99  /* AC-3 metadata options*/
100  int dialogue_level;
101  int bitstream_mode;
102  float center_mix_level;
103  float surround_mix_level;
104  int dolby_surround_mode;
105  int audio_production_info;
106  int mixing_level;
107  int room_type;
108  int copyright;
109  int original;
110  int extended_bsi_1;
111  int preferred_stereo_downmix;
112  float ltrt_center_mix_level;
113  float ltrt_surround_mix_level;
114  float loro_center_mix_level;
115  float loro_surround_mix_level;
116  int extended_bsi_2;
117  int dolby_surround_ex_mode;
118  int dolby_headphone_mode;
119  int ad_converter_type;
120  int eac3_mixing_metadata;
121  int eac3_info_metadata;
122 
123  /* other encoding options */
124  int allow_per_frame_metadata;
125  int stereo_rematrixing;
126  int channel_coupling;
127  int cpl_start;
128 } AC3EncOptions;
129 
130 /**
131  * Data for a single audio block.
132  */
133 typedef struct AC3Block {
134  CoefType **mdct_coef; ///< MDCT coefficients
135  int32_t **fixed_coef; ///< fixed-point MDCT coefficients
136  uint8_t **exp; ///< original exponents
137  uint8_t **grouped_exp; ///< grouped exponents
138  int16_t **psd; ///< psd per frequency bin
139  int16_t **band_psd; ///< psd per critical band
140  int16_t **mask; ///< masking curve
141  uint16_t **qmant; ///< quantized mantissas
142  uint8_t **cpl_coord_exp; ///< coupling coord exponents (cplcoexp)
143  uint8_t **cpl_coord_mant; ///< coupling coord mantissas (cplcomant)
144  uint8_t coeff_shift[AC3_MAX_CHANNELS]; ///< fixed-point coefficient shift values
145  uint8_t new_rematrixing_strategy; ///< send new rematrixing flags in this block
146  int num_rematrixing_bands; ///< number of rematrixing bands
147  uint8_t rematrixing_flags[4]; ///< rematrixing flags
148  int new_cpl_strategy; ///< send new coupling strategy
149  int cpl_in_use; ///< coupling in use for this block (cplinu)
150  uint8_t channel_in_cpl[AC3_MAX_CHANNELS]; ///< channel in coupling (chincpl)
151  int num_cpl_channels; ///< number of channels in coupling
152  uint8_t new_cpl_coords[AC3_MAX_CHANNELS]; ///< send new coupling coordinates (cplcoe)
153  uint8_t cpl_master_exp[AC3_MAX_CHANNELS]; ///< coupling coord master exponents (mstrcplco)
154  int new_snr_offsets; ///< send new SNR offsets
155  int new_cpl_leak; ///< send new coupling leak info
156  int end_freq[AC3_MAX_CHANNELS]; ///< end frequency bin (endmant)
157 } AC3Block;
158 
159 /**
160  * AC-3 encoder private context.
161  */
162 typedef struct AC3EncodeContext {
163  AVClass *av_class; ///< AVClass used for AVOption
164  AC3EncOptions options; ///< encoding options
165  AVCodecContext *avctx; ///< parent AVCodecContext
166  PutBitContext pb; ///< bitstream writer context
167  AudioDSPContext adsp;
168  AVFloatDSPContext *fdsp;
169  MECmpContext mecc;
170  AC3DSPContext ac3dsp; ///< AC-3 optimized functions
171  FFTContext mdct; ///< FFT context for MDCT calculation
172  const SampleType *mdct_window; ///< MDCT window function array
173 
174  AC3Block blocks[AC3_MAX_BLOCKS]; ///< per-block info
175 
176  int fixed_point; ///< indicates if fixed-point encoder is being used
177  int eac3; ///< indicates if this is E-AC-3 vs. AC-3
178  int bitstream_id; ///< bitstream id (bsid)
179  int bitstream_mode; ///< bitstream mode (bsmod)
180 
181  int bit_rate; ///< target bit rate, in bits-per-second
182  int sample_rate; ///< sampling frequency, in Hz
183 
184  int num_blks_code; ///< number of blocks code (numblkscod)
185  int num_blocks; ///< number of blocks per frame
186  int frame_size_min; ///< minimum frame size in case rounding is necessary
187  int frame_size; ///< current frame size in bytes
188  int frame_size_code; ///< frame size code (frmsizecod)
189  uint16_t crc_inv[2];
190  int64_t bits_written; ///< bit count (used to avg. bitrate)
191  int64_t samples_written; ///< sample count (used to avg. bitrate)
192 
193  int fbw_channels; ///< number of full-bandwidth channels (nfchans)
194  int channels; ///< total number of channels (nchans)
195  int lfe_on; ///< indicates if there is an LFE channel (lfeon)
196  int lfe_channel; ///< channel index of the LFE channel
197  int has_center; ///< indicates if there is a center channel
198  int has_surround; ///< indicates if there are one or more surround channels
199  int channel_mode; ///< channel mode (acmod)
200  const uint8_t *channel_map; ///< channel map used to reorder channels
201 
202  int center_mix_level; ///< center mix level code
203  int surround_mix_level; ///< surround mix level code
204  int ltrt_center_mix_level; ///< Lt/Rt center mix level code
205  int ltrt_surround_mix_level; ///< Lt/Rt surround mix level code
206  int loro_center_mix_level; ///< Lo/Ro center mix level code
207  int loro_surround_mix_level; ///< Lo/Ro surround mix level code
208 
209  int cutoff; ///< user-specified cutoff frequency, in Hz
210  int bandwidth_code; ///< bandwidth code (0 to 60) (chbwcod)
211  int start_freq[AC3_MAX_CHANNELS]; ///< start frequency bin (strtmant)
212  int cpl_end_freq; ///< coupling channel end frequency bin
213 
214  int cpl_on; ///< coupling turned on for this frame
215  int cpl_enabled; ///< coupling enabled for all frames
216  int num_cpl_subbands; ///< number of coupling subbands (ncplsubnd)
217  int num_cpl_bands; ///< number of coupling bands (ncplbnd)
218  uint8_t cpl_band_sizes[AC3_MAX_CPL_BANDS]; ///< number of coeffs in each coupling band
219 
220  int rematrixing_enabled; ///< stereo rematrixing enabled
221 
222  /* bitrate allocation control */
223  int slow_gain_code; ///< slow gain code (sgaincod)
224  int slow_decay_code; ///< slow decay code (sdcycod)
225  int fast_decay_code; ///< fast decay code (fdcycod)
226  int db_per_bit_code; ///< dB/bit code (dbpbcod)
227  int floor_code; ///< floor code (floorcod)
228  AC3BitAllocParameters bit_alloc; ///< bit allocation parameters
229  int coarse_snr_offset; ///< coarse SNR offsets (csnroffst)
230  int fast_gain_code[AC3_MAX_CHANNELS]; ///< fast gain codes (signal-to-mask ratio) (fgaincod)
231  int fine_snr_offset[AC3_MAX_CHANNELS]; ///< fine SNR offsets (fsnroffst)
232  int frame_bits_fixed; ///< number of non-coefficient bits for fixed parameters
233  int frame_bits; ///< all frame bits except exponents and mantissas
234  int exponent_bits; ///< number of bits used for exponents
235 
236  SampleType *windowed_samples;
237  SampleType **planar_samples;
238  uint8_t *bap_buffer;
239  uint8_t *bap1_buffer;
240  CoefType *mdct_coef_buffer;
241  int32_t *fixed_coef_buffer;
242  uint8_t *exp_buffer;
243  uint8_t *grouped_exp_buffer;
244  int16_t *psd_buffer;
245  int16_t *band_psd_buffer;
246  int16_t *mask_buffer;
247  int16_t *qmant_buffer;
248  uint8_t *cpl_coord_exp_buffer;
249  uint8_t *cpl_coord_mant_buffer;
250 
251  uint8_t exp_strategy[AC3_MAX_CHANNELS][AC3_MAX_BLOCKS]; ///< exponent strategies
252  uint8_t frame_exp_strategy[AC3_MAX_CHANNELS]; ///< frame exp strategy index
253  int use_frame_exp_strategy; ///< indicates use of frame exp strategy
254  uint8_t exp_ref_block[AC3_MAX_CHANNELS][AC3_MAX_BLOCKS]; ///< reference blocks for EXP_REUSE
255  uint8_t *ref_bap [AC3_MAX_CHANNELS][AC3_MAX_BLOCKS]; ///< bit allocation pointers (bap)
256  int ref_bap_set; ///< indicates if ref_bap pointers have been set
257 
258  /* fixed vs. float function pointers */
259  void (*mdct_end)(struct AC3EncodeContext *s);
260  int (*mdct_init)(struct AC3EncodeContext *s);
261 
262  /* fixed vs. float templated function pointers */
263  int (*allocate_sample_buffers)(struct AC3EncodeContext *s);
264 
265  /* AC-3 vs. E-AC-3 function pointers */
266  void (*output_frame_header)(struct AC3EncodeContext *s);
267 } AC3EncodeContext;
268 
269 
270 extern const uint64_t ff_ac3_channel_layouts[19];
271 
272 int ff_ac3_encode_init(AVCodecContext *avctx);
273 int ff_ac3_float_encode_init(AVCodecContext *avctx);
274 
275 int ff_ac3_encode_close(AVCodecContext *avctx);
276 
277 int ff_ac3_validate_metadata(AC3EncodeContext *s);
278 
279 void ff_ac3_adjust_frame_size(AC3EncodeContext *s);
280 
281 void ff_ac3_compute_coupling_strategy(AC3EncodeContext *s);
282 
283 void ff_ac3_apply_rematrixing(AC3EncodeContext *s);
284 
285 void ff_ac3_process_exponents(AC3EncodeContext *s);
286 
287 int ff_ac3_compute_bit_allocation(AC3EncodeContext *s);
288 
289 void ff_ac3_group_exponents(AC3EncodeContext *s);
290 
291 void ff_ac3_quantize_mantissas(AC3EncodeContext *s);
292 
293 void ff_ac3_output_frame(AC3EncodeContext *s, unsigned char *frame);
294 
295 
296 /* prototypes for functions in ac3enc_fixed.c and ac3enc_float.c */
297 
298 void ff_ac3_fixed_mdct_end(AC3EncodeContext *s);
299 void ff_ac3_float_mdct_end(AC3EncodeContext *s);
300 
301 int ff_ac3_fixed_mdct_init(AC3EncodeContext *s);
302 int ff_ac3_float_mdct_init(AC3EncodeContext *s);
303 
304 
305 /* prototypes for functions in ac3enc_template.c */
306 
307 int ff_ac3_fixed_allocate_sample_buffers(AC3EncodeContext *s);
308 int ff_ac3_float_allocate_sample_buffers(AC3EncodeContext *s);
309 
310 int ff_ac3_fixed_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
311  const AVFrame *frame, int *got_packet_ptr);
312 int ff_ac3_float_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
313  const AVFrame *frame, int *got_packet_ptr);
314 
315 #endif /* AVCODEC_AC3ENC_H */
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