The internal header libavutil/internal.h should not be used outside libavutil.
[libav.git] / libavcodec / aac.h
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 libavcodec/aac.h
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 #include "avcodec.h"
34 #include "dsputil.h"
35 #include "mpeg4audio.h"
36
37 #include <stdint.h>
38
39 #define AAC_INIT_VLC_STATIC(num, size) \
40 INIT_VLC_STATIC(&vlc_spectral[num], 6, ff_aac_spectral_sizes[num], \
41 ff_aac_spectral_bits[num], sizeof( ff_aac_spectral_bits[num][0]), sizeof( ff_aac_spectral_bits[num][0]), \
42 ff_aac_spectral_codes[num], sizeof(ff_aac_spectral_codes[num][0]), sizeof(ff_aac_spectral_codes[num][0]), \
43 size);
44
45 #define MAX_CHANNELS 64
46 #define MAX_ELEM_ID 16
47
48 #define TNS_MAX_ORDER 20
49
50 enum RawDataBlockType {
51 TYPE_SCE,
52 TYPE_CPE,
53 TYPE_CCE,
54 TYPE_LFE,
55 TYPE_DSE,
56 TYPE_PCE,
57 TYPE_FIL,
58 TYPE_END,
59 };
60
61 enum ExtensionPayloadID {
62 EXT_FILL,
63 EXT_FILL_DATA,
64 EXT_DATA_ELEMENT,
65 EXT_DYNAMIC_RANGE = 0xb,
66 EXT_SBR_DATA = 0xd,
67 EXT_SBR_DATA_CRC = 0xe,
68 };
69
70 enum WindowSequence {
71 ONLY_LONG_SEQUENCE,
72 LONG_START_SEQUENCE,
73 EIGHT_SHORT_SEQUENCE,
74 LONG_STOP_SEQUENCE,
75 };
76
77 enum BandType {
78 ZERO_BT = 0, ///< Scalefactors and spectral data are all zero.
79 FIRST_PAIR_BT = 5, ///< This and later band types encode two values (rather than four) with one code word.
80 ESC_BT = 11, ///< Spectral data are coded with an escape sequence.
81 NOISE_BT = 13, ///< Spectral data are scaled white noise not coded in the bitstream.
82 INTENSITY_BT2 = 14, ///< Scalefactor data are intensity stereo positions.
83 INTENSITY_BT = 15, ///< Scalefactor data are intensity stereo positions.
84 };
85
86 #define IS_CODEBOOK_UNSIGNED(x) ((x - 1) & 10)
87
88 enum ChannelPosition {
89 AAC_CHANNEL_FRONT = 1,
90 AAC_CHANNEL_SIDE = 2,
91 AAC_CHANNEL_BACK = 3,
92 AAC_CHANNEL_LFE = 4,
93 AAC_CHANNEL_CC = 5,
94 };
95
96 /**
97 * The point during decoding at which channel coupling is applied.
98 */
99 enum CouplingPoint {
100 BEFORE_TNS,
101 BETWEEN_TNS_AND_IMDCT,
102 AFTER_IMDCT = 3,
103 };
104
105 /**
106 * Predictor State
107 */
108 typedef struct {
109 float cor0;
110 float cor1;
111 float var0;
112 float var1;
113 float r0;
114 float r1;
115 } PredictorState;
116
117 #define MAX_PREDICTORS 672
118
119 /**
120 * Individual Channel Stream
121 */
122 typedef struct {
123 uint8_t max_sfb; ///< number of scalefactor bands per group
124 enum WindowSequence window_sequence[2];
125 uint8_t use_kb_window[2]; ///< If set, use Kaiser-Bessel window, otherwise use a sinus window.
126 int num_window_groups;
127 uint8_t group_len[8];
128 const uint16_t *swb_offset; ///< table of offsets to the lowest spectral coefficient of a scalefactor band, sfb, for a particular window
129 int num_swb; ///< number of scalefactor window bands
130 int num_windows;
131 int tns_max_bands;
132 int predictor_present;
133 int predictor_initialized;
134 int predictor_reset_group;
135 uint8_t prediction_used[41];
136 } IndividualChannelStream;
137
138 /**
139 * Temporal Noise Shaping
140 */
141 typedef struct {
142 int present;
143 int n_filt[8];
144 int length[8][4];
145 int direction[8][4];
146 int order[8][4];
147 float coef[8][4][TNS_MAX_ORDER];
148 } TemporalNoiseShaping;
149
150 /**
151 * Dynamic Range Control - decoded from the bitstream but not processed further.
152 */
153 typedef struct {
154 int pce_instance_tag; ///< Indicates with which program the DRC info is associated.
155 int dyn_rng_sgn[17]; ///< DRC sign information; 0 - positive, 1 - negative
156 int dyn_rng_ctl[17]; ///< DRC magnitude information
157 int exclude_mask[MAX_CHANNELS]; ///< Channels to be excluded from DRC processing.
158 int band_incr; ///< Number of DRC bands greater than 1 having DRC info.
159 int interpolation_scheme; ///< Indicates the interpolation scheme used in the SBR QMF domain.
160 int band_top[17]; ///< Indicates the top of the i-th DRC band in units of 4 spectral lines.
161 int prog_ref_level; /**< A reference level for the long-term program audio level for all
162 * channels combined.
163 */
164 } DynamicRangeControl;
165
166 typedef struct {
167 int num_pulse;
168 int pos[4];
169 int amp[4];
170 } Pulse;
171
172 /**
173 * coupling parameters
174 */
175 typedef struct {
176 enum CouplingPoint coupling_point; ///< The point during decoding at which coupling is applied.
177 int num_coupled; ///< number of target elements
178 enum RawDataBlockType type[8]; ///< Type of channel element to be coupled - SCE or CPE.
179 int id_select[8]; ///< element id
180 int ch_select[8]; /**< [0] shared list of gains; [1] list of gains for right channel;
181 * [2] list of gains for left channel; [3] lists of gains for both channels
182 */
183 float gain[16][120];
184 } ChannelCoupling;
185
186 /**
187 * Single Channel Element - used for both SCE and LFE elements.
188 */
189 typedef struct {
190 IndividualChannelStream ics;
191 TemporalNoiseShaping tns;
192 enum BandType band_type[120]; ///< band types
193 int band_type_run_end[120]; ///< band type run end points
194 float sf[120]; ///< scalefactors
195 DECLARE_ALIGNED_16(float, coeffs[1024]); ///< coefficients for IMDCT
196 DECLARE_ALIGNED_16(float, saved[512]); ///< overlap
197 DECLARE_ALIGNED_16(float, ret[1024]); ///< PCM output
198 PredictorState predictor_state[MAX_PREDICTORS];
199 } SingleChannelElement;
200
201 /**
202 * channel element - generic struct for SCE/CPE/CCE/LFE
203 */
204 typedef struct {
205 // CPE specific
206 uint8_t ms_mask[120]; ///< Set if mid/side stereo is used for each scalefactor window band
207 // shared
208 SingleChannelElement ch[2];
209 // CCE specific
210 ChannelCoupling coup;
211 } ChannelElement;
212
213 /**
214 * main AAC context
215 */
216 typedef struct {
217 AVCodecContext * avccontext;
218
219 MPEG4AudioConfig m4ac;
220
221 int is_saved; ///< Set if elements have stored overlap from previous frame.
222 DynamicRangeControl che_drc;
223
224 /**
225 * @defgroup elements Channel element related data.
226 * @{
227 */
228 enum ChannelPosition che_pos[4][MAX_ELEM_ID]; /**< channel element channel mapping with the
229 * first index as the first 4 raw data block types
230 */
231 ChannelElement * che[4][MAX_ELEM_ID];
232 ChannelElement * tag_che_map[4][MAX_ELEM_ID];
233 int tags_mapped;
234 /** @} */
235
236 /**
237 * @defgroup temporary aligned temporary buffers (We do not want to have these on the stack.)
238 * @{
239 */
240 DECLARE_ALIGNED_16(float, buf_mdct[1024]);
241 /** @} */
242
243 /**
244 * @defgroup tables Computed / set up during initialization.
245 * @{
246 */
247 MDCTContext mdct;
248 MDCTContext mdct_small;
249 DSPContext dsp;
250 int random_state;
251 /** @} */
252
253 /**
254 * @defgroup output Members used for output interleaving.
255 * @{
256 */
257 float *output_data[MAX_CHANNELS]; ///< Points to each element's 'ret' buffer (PCM output).
258 float add_bias; ///< offset for dsp.float_to_int16
259 float sf_scale; ///< Pre-scale for correct IMDCT and dsp.float_to_int16.
260 int sf_offset; ///< offset into pow2sf_tab as appropriate for dsp.float_to_int16
261 /** @} */
262
263 DECLARE_ALIGNED(16, float, temp[128]);
264 } AACContext;
265
266 #endif /* AVCODEC_AAC_H */