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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
55enum 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
66enum 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
75enum WindowSequence {
76 ONLY_LONG_SEQUENCE,
77 LONG_START_SEQUENCE,
78 EIGHT_SHORT_SEQUENCE,
79 LONG_STOP_SEQUENCE,
80};
81
82enum 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
94enum 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 */
106enum CouplingPoint {
107 BEFORE_TNS,
108 BETWEEN_TNS_AND_IMDCT,
109 AFTER_IMDCT = 3,
110};
111
112/**
113 * Output configuration status
114 */
115enum 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
123typedef 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 */
135typedef 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 */
163typedef 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 */
174typedef 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 */
198typedef 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 */
211typedef 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
224typedef 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 */
234typedef 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 */
248typedef 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 */
275typedef 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 */
293struct 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 *mdct480;
331 AVFloatDSPContext *fdsp;
332#endif /* USE_FIXED */
333 int random_state;
334 /** @} */
335
336 /**
337 * @name Members used for output
338 * @{
339 */
340 SingleChannelElement *output_element[MAX_CHANNELS]; ///< Points to each SingleChannelElement
341 /** @} */
342
343
344 /**
345 * @name Japanese DTV specific extension
346 * @{
347 */
348 int force_dmono_mode;///< 0->not dmono, 1->use first channel, 2->use second channel
349 int dmono_mode; ///< 0->not dmono, 1->use first channel, 2->use second channel
350 /** @} */
351
352 DECLARE_ALIGNED(32, INTFLOAT, temp)[128];
353
354 OutputConfiguration oc[2];
355 int warned_num_aac_frames;
356
357 /* aacdec functions pointers */
358 void (*imdct_and_windowing)(AACContext *ac, SingleChannelElement *sce);
359 void (*apply_ltp)(AACContext *ac, SingleChannelElement *sce);
360 void (*apply_tns)(INTFLOAT coef[1024], TemporalNoiseShaping *tns,
361 IndividualChannelStream *ics, int decode);
362 void (*windowing_and_mdct_ltp)(AACContext *ac, INTFLOAT *out,
363 INTFLOAT *in, IndividualChannelStream *ics);
364 void (*update_ltp)(AACContext *ac, SingleChannelElement *sce);
365 void (*vector_pow43)(int *coefs, int len);
366 void (*subband_scale)(int *dst, int *src, int scale, int offset, int len);
367
368};
369
370void ff_aacdec_init_mips(AACContext *c);
371
372#endif /* AVCODEC_AAC_H */
373
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