1 /* 2 * AAC definitions and structures 3 * Copyright (c) 2005-2006 Oded Shimon ( ods15 ods15 dyndns org ) 4 * Copyright (c) 2006-2007 Maxim Gavrilov ( maxim.gavrilov 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 * AAC definitions and structures 26 * @author Oded Shimon ( ods15 ods15 dyndns org ) 27 * @author Maxim Gavrilov ( maxim.gavrilov gmail com ) 28 */ 29 30 #ifndef AVCODEC_AAC_H 31 #define AVCODEC_AAC_H 32 33 34 #include "aac_defines.h" 35 #include "libavutil/float_dsp.h" 36 #include "libavutil/fixed_dsp.h" 37 #include "avcodec.h" 38 #if !USE_FIXED 39 #include "mdct15.h" 40 #endif 41 #include "fft.h" 42 #include "mpeg4audio.h" 43 #include "sbr.h" 44 45 #include <stdint.h> 46 47 #define MAX_CHANNELS 64 48 #define MAX_ELEM_ID 16 49 50 #define TNS_MAX_ORDER 20 51 #define MAX_LTP_LONG_SFB 40 52 53 #define CLIP_AVOIDANCE_FACTOR 0.95f 54 55 enum RawDataBlockType { 56 TYPE_SCE, 57 TYPE_CPE, 58 TYPE_CCE, 59 TYPE_LFE, 60 TYPE_DSE, 61 TYPE_PCE, 62 TYPE_FIL, 63 TYPE_END, 64 }; 65 66 enum ExtensionPayloadID { 67 EXT_FILL, 68 EXT_FILL_DATA, 69 EXT_DATA_ELEMENT, 70 EXT_DYNAMIC_RANGE = 0xb, 71 EXT_SBR_DATA = 0xd, 72 EXT_SBR_DATA_CRC = 0xe, 73 }; 74 75 enum WindowSequence { 76 ONLY_LONG_SEQUENCE, 77 LONG_START_SEQUENCE, 78 EIGHT_SHORT_SEQUENCE, 79 LONG_STOP_SEQUENCE, 80 }; 81 82 enum BandType { 83 ZERO_BT = 0, ///< Scalefactors and spectral data are all zero. 84 FIRST_PAIR_BT = 5, ///< This and later band types encode two values (rather than four) with one code word. 85 ESC_BT = 11, ///< Spectral data are coded with an escape sequence. 86 RESERVED_BT = 12, ///< Band types following are encoded differently from others. 87 NOISE_BT = 13, ///< Spectral data are scaled white noise not coded in the bitstream. 88 INTENSITY_BT2 = 14, ///< Scalefactor data are intensity stereo positions (out of phase). 89 INTENSITY_BT = 15, ///< Scalefactor data are intensity stereo positions (in phase). 90 }; 91 92 #define IS_CODEBOOK_UNSIGNED(x) (((x) - 1) & 10) 93 94 enum ChannelPosition { 95 AAC_CHANNEL_OFF = 0, 96 AAC_CHANNEL_FRONT = 1, 97 AAC_CHANNEL_SIDE = 2, 98 AAC_CHANNEL_BACK = 3, 99 AAC_CHANNEL_LFE = 4, 100 AAC_CHANNEL_CC = 5, 101 }; 102 103 /** 104 * The point during decoding at which channel coupling is applied. 105 */ 106 enum CouplingPoint { 107 BEFORE_TNS, 108 BETWEEN_TNS_AND_IMDCT, 109 AFTER_IMDCT = 3, 110 }; 111 112 /** 113 * Output configuration status 114 */ 115 enum OCStatus { 116 OC_NONE, ///< Output unconfigured 117 OC_TRIAL_PCE, ///< Output configuration under trial specified by an inband PCE 118 OC_TRIAL_FRAME, ///< Output configuration under trial specified by a frame header 119 OC_GLOBAL_HDR, ///< Output configuration set in a global header but not yet locked 120 OC_LOCKED, ///< Output configuration locked in place 121 }; 122 123 typedef struct OutputConfiguration { 124 MPEG4AudioConfig m4ac; 125 uint8_t layout_map[MAX_ELEM_ID*4][3]; 126 int layout_map_tags; 127 int channels; 128 uint64_t channel_layout; 129 enum OCStatus status; 130 } OutputConfiguration; 131 132 /** 133 * Predictor State 134 */ 135 typedef struct PredictorState { 136 AAC_FLOAT cor0; 137 AAC_FLOAT cor1; 138 AAC_FLOAT var0; 139 AAC_FLOAT var1; 140 AAC_FLOAT r0; 141 AAC_FLOAT r1; 142 AAC_FLOAT k1; 143 AAC_FLOAT x_est; 144 } PredictorState; 145 146 #define MAX_PREDICTORS 672 147 148 #define SCALE_DIV_512 36 ///< scalefactor difference that corresponds to scale difference in 512 times 149 #define SCALE_ONE_POS 140 ///< scalefactor index that corresponds to scale=1.0 150 #define SCALE_MAX_POS 255 ///< scalefactor index maximum value 151 #define SCALE_MAX_DIFF 60 ///< maximum scalefactor difference allowed by standard 152 #define SCALE_DIFF_ZERO 60 ///< codebook index corresponding to zero scalefactor indices difference 153 154 #define POW_SF2_ZERO 200 ///< ff_aac_pow2sf_tab index corresponding to pow(2, 0); 155 156 #define NOISE_PRE 256 ///< preamble for NOISE_BT, put in bitstream with the first noise band 157 #define NOISE_PRE_BITS 9 ///< length of preamble 158 #define NOISE_OFFSET 90 ///< subtracted from global gain, used as offset for the preamble 159 160 /** 161 * Long Term Prediction 162 */ 163 typedef struct LongTermPrediction { 164 int8_t present; 165 int16_t lag; 166 int coef_idx; 167 INTFLOAT coef; 168 int8_t used[MAX_LTP_LONG_SFB]; 169 } LongTermPrediction; 170 171 /** 172 * Individual Channel Stream 173 */ 174 typedef struct IndividualChannelStream { 175 uint8_t max_sfb; ///< number of scalefactor bands per group 176 enum WindowSequence window_sequence[2]; 177 uint8_t use_kb_window[2]; ///< If set, use Kaiser-Bessel window, otherwise use a sine window. 178 int num_window_groups; 179 uint8_t group_len[8]; 180 LongTermPrediction ltp; 181 const uint16_t *swb_offset; ///< table of offsets to the lowest spectral coefficient of a scalefactor band, sfb, for a particular window 182 const uint8_t *swb_sizes; ///< table of scalefactor band sizes for a particular window 183 int num_swb; ///< number of scalefactor window bands 184 int num_windows; 185 int tns_max_bands; 186 int predictor_present; 187 int predictor_initialized; 188 int predictor_reset_group; 189 int predictor_reset_count[31]; ///< used by encoder to count prediction resets 190 uint8_t prediction_used[41]; 191 uint8_t window_clipping[8]; ///< set if a certain window is near clipping 192 float clip_avoidance_factor; ///< set if any window is near clipping to the necessary atennuation factor to avoid it 193 } IndividualChannelStream; 194 195 /** 196 * Temporal Noise Shaping 197 */ 198 typedef struct TemporalNoiseShaping { 199 int present; 200 int n_filt[8]; 201 int length[8][4]; 202 int direction[8][4]; 203 int order[8][4]; 204 int coef_idx[8][4][TNS_MAX_ORDER]; 205 INTFLOAT coef[8][4][TNS_MAX_ORDER]; 206 } TemporalNoiseShaping; 207 208 /** 209 * Dynamic Range Control - decoded from the bitstream but not processed further. 210 */ 211 typedef struct DynamicRangeControl { 212 int pce_instance_tag; ///< Indicates with which program the DRC info is associated. 213 int dyn_rng_sgn[17]; ///< DRC sign information; 0 - positive, 1 - negative 214 int dyn_rng_ctl[17]; ///< DRC magnitude information 215 int exclude_mask[MAX_CHANNELS]; ///< Channels to be excluded from DRC processing. 216 int band_incr; ///< Number of DRC bands greater than 1 having DRC info. 217 int interpolation_scheme; ///< Indicates the interpolation scheme used in the SBR QMF domain. 218 int band_top[17]; ///< Indicates the top of the i-th DRC band in units of 4 spectral lines. 219 int prog_ref_level; /**< A reference level for the long-term program audio level for all 220 * channels combined. 221 */ 222 } DynamicRangeControl; 223 224 typedef struct Pulse { 225 int num_pulse; 226 int start; 227 int pos[4]; 228 int amp[4]; 229 } Pulse; 230 231 /** 232 * coupling parameters 233 */ 234 typedef struct ChannelCoupling { 235 enum CouplingPoint coupling_point; ///< The point during decoding at which coupling is applied. 236 int num_coupled; ///< number of target elements 237 enum RawDataBlockType type[8]; ///< Type of channel element to be coupled - SCE or CPE. 238 int id_select[8]; ///< element id 239 int ch_select[8]; /**< [0] shared list of gains; [1] list of gains for right channel; 240 * [2] list of gains for left channel; [3] lists of gains for both channels 241 */ 242 INTFLOAT gain[16][120]; 243 } ChannelCoupling; 244 245 /** 246 * Single Channel Element - used for both SCE and LFE elements. 247 */ 248 typedef struct SingleChannelElement { 249 IndividualChannelStream ics; 250 TemporalNoiseShaping tns; 251 Pulse pulse; 252 enum BandType band_type[128]; ///< band types 253 enum BandType band_alt[128]; ///< alternative band type (used by encoder) 254 int band_type_run_end[120]; ///< band type run end points 255 INTFLOAT sf[120]; ///< scalefactors 256 int sf_idx[128]; ///< scalefactor indices (used by encoder) 257 uint8_t zeroes[128]; ///< band is not coded (used by encoder) 258 uint8_t can_pns[128]; ///< band is allowed to PNS (informative) 259 float is_ener[128]; ///< Intensity stereo pos (used by encoder) 260 float pns_ener[128]; ///< Noise energy values (used by encoder) 261 DECLARE_ALIGNED(32, INTFLOAT, pcoeffs)[1024]; ///< coefficients for IMDCT, pristine 262 DECLARE_ALIGNED(32, INTFLOAT, coeffs)[1024]; ///< coefficients for IMDCT, maybe processed 263 DECLARE_ALIGNED(32, INTFLOAT, saved)[1536]; ///< overlap 264 DECLARE_ALIGNED(32, INTFLOAT, ret_buf)[2048]; ///< PCM output buffer 265 DECLARE_ALIGNED(16, INTFLOAT, ltp_state)[3072]; ///< time signal for LTP 266 DECLARE_ALIGNED(32, AAC_FLOAT, lcoeffs)[1024]; ///< MDCT of LTP coefficients (used by encoder) 267 DECLARE_ALIGNED(32, AAC_FLOAT, prcoeffs)[1024]; ///< Main prediction coefs (used by encoder) 268 PredictorState predictor_state[MAX_PREDICTORS]; 269 INTFLOAT *ret; ///< PCM output 270 } SingleChannelElement; 271 272 /** 273 * channel element - generic struct for SCE/CPE/CCE/LFE 274 */ 275 typedef struct ChannelElement { 276 int present; 277 // CPE specific 278 int common_window; ///< Set if channels share a common 'IndividualChannelStream' in bitstream. 279 int ms_mode; ///< Signals mid/side stereo flags coding mode (used by encoder) 280 uint8_t is_mode; ///< Set if any bands have been encoded using intensity stereo (used by encoder) 281 uint8_t ms_mask[128]; ///< Set if mid/side stereo is used for each scalefactor window band 282 uint8_t is_mask[128]; ///< Set if intensity stereo is used (used by encoder) 283 // shared 284 SingleChannelElement ch[2]; 285 // CCE specific 286 ChannelCoupling coup; 287 SpectralBandReplication sbr; 288 } ChannelElement; 289 290 /** 291 * main AAC context 292 */ 293 struct AACContext { 294 AVClass *class; 295 AVCodecContext *avctx; 296 AVFrame *frame; 297 298 int is_saved; ///< Set if elements have stored overlap from previous frame. 299 DynamicRangeControl che_drc; 300 301 /** 302 * @name Channel element related data 303 * @{ 304 */ 305 ChannelElement *che[4][MAX_ELEM_ID]; 306 ChannelElement *tag_che_map[4][MAX_ELEM_ID]; 307 int tags_mapped; 308 int warned_remapping_once; 309 /** @} */ 310 311 /** 312 * @name temporary aligned temporary buffers 313 * (We do not want to have these on the stack.) 314 * @{ 315 */ 316 DECLARE_ALIGNED(32, INTFLOAT, buf_mdct)[1024]; 317 /** @} */ 318 319 /** 320 * @name Computed / set up during initialization 321 * @{ 322 */ 323 FFTContext mdct; 324 FFTContext mdct_small; 325 FFTContext mdct_ld; 326 FFTContext mdct_ltp; 327 #if USE_FIXED 328 AVFixedDSPContext *fdsp; 329 #else 330 MDCT15Context *mdct120; 331 MDCT15Context *mdct480; 332 MDCT15Context *mdct960; 333 AVFloatDSPContext *fdsp; 334 #endif /* USE_FIXED */ 335 int random_state; 336 /** @} */ 337 338 /** 339 * @name Members used for output 340 * @{ 341 */ 342 SingleChannelElement *output_element[MAX_CHANNELS]; ///< Points to each SingleChannelElement 343 /** @} */ 344 345 346 /** 347 * @name Japanese DTV specific extension 348 * @{ 349 */ 350 int force_dmono_mode;///< 0->not dmono, 1->use first channel, 2->use second channel 351 int dmono_mode; ///< 0->not dmono, 1->use first channel, 2->use second channel 352 /** @} */ 353 354 DECLARE_ALIGNED(32, INTFLOAT, temp)[128]; 355 356 OutputConfiguration oc[2]; 357 int warned_num_aac_frames; 358 int warned_960_sbr; 359 unsigned warned_71_wide; 360 int warned_gain_control; 361 362 /* aacdec functions pointers */ 363 void (*imdct_and_windowing)(AACContext *ac, SingleChannelElement *sce); 364 void (*apply_ltp)(AACContext *ac, SingleChannelElement *sce); 365 void (*apply_tns)(INTFLOAT coef[1024], TemporalNoiseShaping *tns, 366 IndividualChannelStream *ics, int decode); 367 void (*windowing_and_mdct_ltp)(AACContext *ac, INTFLOAT *out, 368 INTFLOAT *in, IndividualChannelStream *ics); 369 void (*update_ltp)(AACContext *ac, SingleChannelElement *sce); 370 void (*vector_pow43)(int *coefs, int len); 371 void (*subband_scale)(int *dst, int *src, int scale, int offset, int len, void *log_context); 372 373 }; 374 375 void ff_aacdec_init_mips(AACContext *c); 376 377 #endif /* AVCODEC_AAC_H */ 378