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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 
84 /* specific option values */
85 #define AC3ENC_OPT_LARGE_ROOM 1
86 #define AC3ENC_OPT_SMALL_ROOM 2
87 #define AC3ENC_OPT_DOWNMIX_LTRT 1
88 #define AC3ENC_OPT_DOWNMIX_LORO 2
89 #define AC3ENC_OPT_ADCONV_STANDARD 0
90 #define AC3ENC_OPT_ADCONV_HDCD 1
91 
92 
93 /**
94  * Encoding Options used by AVOption.
95  */
96 typedef struct AC3EncOptions {
97  /* AC-3 metadata options*/
98  int dialogue_level;
99  int bitstream_mode;
100  float center_mix_level;
101  float surround_mix_level;
102  int dolby_surround_mode;
103  int audio_production_info;
104  int mixing_level;
105  int room_type;
106  int copyright;
107  int original;
108  int extended_bsi_1;
109  int preferred_stereo_downmix;
110  float ltrt_center_mix_level;
111  float ltrt_surround_mix_level;
112  float loro_center_mix_level;
113  float loro_surround_mix_level;
114  int extended_bsi_2;
115  int dolby_surround_ex_mode;
116  int dolby_headphone_mode;
117  int ad_converter_type;
118  int eac3_mixing_metadata;
119  int eac3_info_metadata;
120 
121  /* other encoding options */
122  int allow_per_frame_metadata;
123  int stereo_rematrixing;
124  int channel_coupling;
125  int cpl_start;
126 } AC3EncOptions;
127 
128 /**
129  * Data for a single audio block.
130  */
131 typedef struct AC3Block {
132  CoefType **mdct_coef; ///< MDCT coefficients
133  int32_t **fixed_coef; ///< fixed-point MDCT coefficients
134  uint8_t **exp; ///< original exponents
135  uint8_t **grouped_exp; ///< grouped exponents
136  int16_t **psd; ///< psd per frequency bin
137  int16_t **band_psd; ///< psd per critical band
138  int16_t **mask; ///< masking curve
139  uint16_t **qmant; ///< quantized mantissas
140  uint8_t **cpl_coord_exp; ///< coupling coord exponents (cplcoexp)
141  uint8_t **cpl_coord_mant; ///< coupling coord mantissas (cplcomant)
142  uint8_t coeff_shift[AC3_MAX_CHANNELS]; ///< fixed-point coefficient shift values
143  uint8_t new_rematrixing_strategy; ///< send new rematrixing flags in this block
144  int num_rematrixing_bands; ///< number of rematrixing bands
145  uint8_t rematrixing_flags[4]; ///< rematrixing flags
146  int new_cpl_strategy; ///< send new coupling strategy
147  int cpl_in_use; ///< coupling in use for this block (cplinu)
148  uint8_t channel_in_cpl[AC3_MAX_CHANNELS]; ///< channel in coupling (chincpl)
149  int num_cpl_channels; ///< number of channels in coupling
150  uint8_t new_cpl_coords[AC3_MAX_CHANNELS]; ///< send new coupling coordinates (cplcoe)
151  uint8_t cpl_master_exp[AC3_MAX_CHANNELS]; ///< coupling coord master exponents (mstrcplco)
152  int new_snr_offsets; ///< send new SNR offsets
153  int new_cpl_leak; ///< send new coupling leak info
154  int end_freq[AC3_MAX_CHANNELS]; ///< end frequency bin (endmant)
155 } AC3Block;
156 
157 /**
158  * AC-3 encoder private context.
159  */
160 typedef struct AC3EncodeContext {
161  AVClass *av_class; ///< AVClass used for AVOption
162  AC3EncOptions options; ///< encoding options
163  AVCodecContext *avctx; ///< parent AVCodecContext
164  PutBitContext pb; ///< bitstream writer context
165  AudioDSPContext adsp;
166  AVFloatDSPContext fdsp;
167  MECmpContext mecc;
168  AC3DSPContext ac3dsp; ///< AC-3 optimized functions
169  FFTContext mdct; ///< FFT context for MDCT calculation
170  const SampleType *mdct_window; ///< MDCT window function array
171 
172  AC3Block blocks[AC3_MAX_BLOCKS]; ///< per-block info
173 
174  int fixed_point; ///< indicates if fixed-point encoder is being used
175  int eac3; ///< indicates if this is E-AC-3 vs. AC-3
176  int bitstream_id; ///< bitstream id (bsid)
177  int bitstream_mode; ///< bitstream mode (bsmod)
178 
179  int bit_rate; ///< target bit rate, in bits-per-second
180  int sample_rate; ///< sampling frequency, in Hz
181 
182  int num_blks_code; ///< number of blocks code (numblkscod)
183  int num_blocks; ///< number of blocks per frame
184  int frame_size_min; ///< minimum frame size in case rounding is necessary
185  int frame_size; ///< current frame size in bytes
186  int frame_size_code; ///< frame size code (frmsizecod)
187  uint16_t crc_inv[2];
188  int64_t bits_written; ///< bit count (used to avg. bitrate)
189  int64_t samples_written; ///< sample count (used to avg. bitrate)
190 
191  int fbw_channels; ///< number of full-bandwidth channels (nfchans)
192  int channels; ///< total number of channels (nchans)
193  int lfe_on; ///< indicates if there is an LFE channel (lfeon)
194  int lfe_channel; ///< channel index of the LFE channel
195  int has_center; ///< indicates if there is a center channel
196  int has_surround; ///< indicates if there are one or more surround channels
197  int channel_mode; ///< channel mode (acmod)
198  const uint8_t *channel_map; ///< channel map used to reorder channels
199 
200  int center_mix_level; ///< center mix level code
201  int surround_mix_level; ///< surround mix level code
202  int ltrt_center_mix_level; ///< Lt/Rt center mix level code
203  int ltrt_surround_mix_level; ///< Lt/Rt surround mix level code
204  int loro_center_mix_level; ///< Lo/Ro center mix level code
205  int loro_surround_mix_level; ///< Lo/Ro surround mix level code
206 
207  int cutoff; ///< user-specified cutoff frequency, in Hz
208  int bandwidth_code; ///< bandwidth code (0 to 60) (chbwcod)
209  int start_freq[AC3_MAX_CHANNELS]; ///< start frequency bin (strtmant)
210  int cpl_end_freq; ///< coupling channel end frequency bin
211 
212  int cpl_on; ///< coupling turned on for this frame
213  int cpl_enabled; ///< coupling enabled for all frames
214  int num_cpl_subbands; ///< number of coupling subbands (ncplsubnd)
215  int num_cpl_bands; ///< number of coupling bands (ncplbnd)
216  uint8_t cpl_band_sizes[AC3_MAX_CPL_BANDS]; ///< number of coeffs in each coupling band
217 
218  int rematrixing_enabled; ///< stereo rematrixing enabled
219 
220  /* bitrate allocation control */
221  int slow_gain_code; ///< slow gain code (sgaincod)
222  int slow_decay_code; ///< slow decay code (sdcycod)
223  int fast_decay_code; ///< fast decay code (fdcycod)
224  int db_per_bit_code; ///< dB/bit code (dbpbcod)
225  int floor_code; ///< floor code (floorcod)
226  AC3BitAllocParameters bit_alloc; ///< bit allocation parameters
227  int coarse_snr_offset; ///< coarse SNR offsets (csnroffst)
228  int fast_gain_code[AC3_MAX_CHANNELS]; ///< fast gain codes (signal-to-mask ratio) (fgaincod)
229  int fine_snr_offset[AC3_MAX_CHANNELS]; ///< fine SNR offsets (fsnroffst)
230  int frame_bits_fixed; ///< number of non-coefficient bits for fixed parameters
231  int frame_bits; ///< all frame bits except exponents and mantissas
232  int exponent_bits; ///< number of bits used for exponents
233 
234  SampleType *windowed_samples;
235  SampleType **planar_samples;
236  uint8_t *bap_buffer;
237  uint8_t *bap1_buffer;
238  CoefType *mdct_coef_buffer;
239  int32_t *fixed_coef_buffer;
240  uint8_t *exp_buffer;
241  uint8_t *grouped_exp_buffer;
242  int16_t *psd_buffer;
243  int16_t *band_psd_buffer;
244  int16_t *mask_buffer;
245  int16_t *qmant_buffer;
246  uint8_t *cpl_coord_exp_buffer;
247  uint8_t *cpl_coord_mant_buffer;
248 
249  uint8_t exp_strategy[AC3_MAX_CHANNELS][AC3_MAX_BLOCKS]; ///< exponent strategies
250  uint8_t frame_exp_strategy[AC3_MAX_CHANNELS]; ///< frame exp strategy index
251  int use_frame_exp_strategy; ///< indicates use of frame exp strategy
252  uint8_t exp_ref_block[AC3_MAX_CHANNELS][AC3_MAX_BLOCKS]; ///< reference blocks for EXP_REUSE
253  uint8_t *ref_bap [AC3_MAX_CHANNELS][AC3_MAX_BLOCKS]; ///< bit allocation pointers (bap)
254  int ref_bap_set; ///< indicates if ref_bap pointers have been set
255 
256  /* fixed vs. float function pointers */
257  void (*mdct_end)(struct AC3EncodeContext *s);
258  int (*mdct_init)(struct AC3EncodeContext *s);
259 
260  /* fixed vs. float templated function pointers */
261  int (*allocate_sample_buffers)(struct AC3EncodeContext *s);
262 
263  /* AC-3 vs. E-AC-3 function pointers */
264  void (*output_frame_header)(struct AC3EncodeContext *s);
265 } AC3EncodeContext;
266 
267 
268 extern const uint64_t ff_ac3_channel_layouts[19];
269 
270 int ff_ac3_encode_init(AVCodecContext *avctx);
271 int ff_ac3_float_encode_init(AVCodecContext *avctx);
272 
273 int ff_ac3_encode_close(AVCodecContext *avctx);
274 
275 int ff_ac3_validate_metadata(AC3EncodeContext *s);
276 
277 void ff_ac3_adjust_frame_size(AC3EncodeContext *s);
278 
279 void ff_ac3_compute_coupling_strategy(AC3EncodeContext *s);
280 
281 void ff_ac3_apply_rematrixing(AC3EncodeContext *s);
282 
283 void ff_ac3_process_exponents(AC3EncodeContext *s);
284 
285 int ff_ac3_compute_bit_allocation(AC3EncodeContext *s);
286 
287 void ff_ac3_group_exponents(AC3EncodeContext *s);
288 
289 void ff_ac3_quantize_mantissas(AC3EncodeContext *s);
290 
291 void ff_ac3_output_frame(AC3EncodeContext *s, unsigned char *frame);
292 
293 
294 /* prototypes for functions in ac3enc_fixed.c and ac3enc_float.c */
295 
296 void ff_ac3_fixed_mdct_end(AC3EncodeContext *s);
297 void ff_ac3_float_mdct_end(AC3EncodeContext *s);
298 
299 int ff_ac3_fixed_mdct_init(AC3EncodeContext *s);
300 int ff_ac3_float_mdct_init(AC3EncodeContext *s);
301 
302 
303 /* prototypes for functions in ac3enc_template.c */
304 
305 int ff_ac3_fixed_allocate_sample_buffers(AC3EncodeContext *s);
306 int ff_ac3_float_allocate_sample_buffers(AC3EncodeContext *s);
307 
308 int ff_ac3_fixed_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
309  const AVFrame *frame, int *got_packet_ptr);
310 int ff_ac3_float_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
311  const AVFrame *frame, int *got_packet_ptr);
312 
313 #endif /* AVCODEC_AC3ENC_H */
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