FFmpeg
aac.h
Go to the documentation of this file.
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"
36 #include "libavutil/float_dsp.h"
37 #include "libavutil/fixed_dsp.h"
38 #include "libavutil/mem_internal.h"
39 #include "avcodec.h"
40 #if !USE_FIXED
41 #include "mdct15.h"
42 #endif
43 #include "fft.h"
44 #include "mpeg4audio.h"
45 #include "sbr.h"
46 
47 #include <stdint.h>
48 
49 #define MAX_CHANNELS 64
50 #define MAX_ELEM_ID 16
51 
52 #define TNS_MAX_ORDER 20
53 #define MAX_LTP_LONG_SFB 40
54 
55 #define CLIP_AVOIDANCE_FACTOR 0.95f
56 
66 };
67 
73  EXT_SBR_DATA = 0xd,
75 };
76 
82 };
83 
84 enum BandType {
85  ZERO_BT = 0, ///< Scalefactors and spectral data are all zero.
86  FIRST_PAIR_BT = 5, ///< This and later band types encode two values (rather than four) with one code word.
87  ESC_BT = 11, ///< Spectral data are coded with an escape sequence.
88  RESERVED_BT = 12, ///< Band types following are encoded differently from others.
89  NOISE_BT = 13, ///< Spectral data are scaled white noise not coded in the bitstream.
90  INTENSITY_BT2 = 14, ///< Scalefactor data are intensity stereo positions (out of phase).
91  INTENSITY_BT = 15, ///< Scalefactor data are intensity stereo positions (in phase).
92 };
93 
94 #define IS_CODEBOOK_UNSIGNED(x) (((x) - 1) & 10)
95 
103 };
104 
105 /**
106  * The point during decoding at which channel coupling is applied.
107  */
112 };
113 
114 /**
115  * Output configuration status
116  */
117 enum OCStatus {
118  OC_NONE, ///< Output unconfigured
119  OC_TRIAL_PCE, ///< Output configuration under trial specified by an inband PCE
120  OC_TRIAL_FRAME, ///< Output configuration under trial specified by a frame header
121  OC_GLOBAL_HDR, ///< Output configuration set in a global header but not yet locked
122  OC_LOCKED, ///< Output configuration locked in place
123 };
124 
125 typedef struct OutputConfiguration {
127  uint8_t layout_map[MAX_ELEM_ID*4][3];
132 
133 /**
134  * Predictor State
135  */
136 typedef struct PredictorState {
146 
147 #define MAX_PREDICTORS 672
148 
149 #define SCALE_DIV_512 36 ///< scalefactor difference that corresponds to scale difference in 512 times
150 #define SCALE_ONE_POS 140 ///< scalefactor index that corresponds to scale=1.0
151 #define SCALE_MAX_POS 255 ///< scalefactor index maximum value
152 #define SCALE_MAX_DIFF 60 ///< maximum scalefactor difference allowed by standard
153 #define SCALE_DIFF_ZERO 60 ///< codebook index corresponding to zero scalefactor indices difference
154 
155 #define POW_SF2_ZERO 200 ///< ff_aac_pow2sf_tab index corresponding to pow(2, 0);
156 
157 #define NOISE_PRE 256 ///< preamble for NOISE_BT, put in bitstream with the first noise band
158 #define NOISE_PRE_BITS 9 ///< length of preamble
159 #define NOISE_OFFSET 90 ///< subtracted from global gain, used as offset for the preamble
160 
161 /**
162  * Long Term Prediction
163  */
164 typedef struct LongTermPrediction {
165  int8_t present;
166  int16_t lag;
167  int coef_idx;
171 
172 /**
173  * Individual Channel Stream
174  */
175 typedef struct IndividualChannelStream {
176  uint8_t max_sfb; ///< number of scalefactor bands per group
178  uint8_t use_kb_window[2]; ///< If set, use Kaiser-Bessel window, otherwise use a sine window.
180  uint8_t group_len[8];
182  const uint16_t *swb_offset; ///< table of offsets to the lowest spectral coefficient of a scalefactor band, sfb, for a particular window
183  const uint8_t *swb_sizes; ///< table of scalefactor band sizes for a particular window
184  int num_swb; ///< number of scalefactor window bands
190  int predictor_reset_count[31]; ///< used by encoder to count prediction resets
191  uint8_t prediction_used[41];
192  uint8_t window_clipping[8]; ///< set if a certain window is near clipping
193  float clip_avoidance_factor; ///< set if any window is near clipping to the necessary atennuation factor to avoid it
195 
196 /**
197  * Temporal Noise Shaping
198  */
199 typedef struct TemporalNoiseShaping {
200  int present;
201  int n_filt[8];
202  int length[8][4];
203  int direction[8][4];
204  int order[8][4];
208 
209 /**
210  * Dynamic Range Control - decoded from the bitstream but not processed further.
211  */
212 typedef struct DynamicRangeControl {
213  int pce_instance_tag; ///< Indicates with which program the DRC info is associated.
214  int dyn_rng_sgn[17]; ///< DRC sign information; 0 - positive, 1 - negative
215  int dyn_rng_ctl[17]; ///< DRC magnitude information
216  int exclude_mask[MAX_CHANNELS]; ///< Channels to be excluded from DRC processing.
217  int band_incr; ///< Number of DRC bands greater than 1 having DRC info.
218  int interpolation_scheme; ///< Indicates the interpolation scheme used in the SBR QMF domain.
219  int band_top[17]; ///< Indicates the top of the i-th DRC band in units of 4 spectral lines.
220  int prog_ref_level; /**< A reference level for the long-term program audio level for all
221  * channels combined.
222  */
224 
225 typedef struct Pulse {
227  int start;
228  int pos[4];
229  int amp[4];
230 } Pulse;
231 
232 /**
233  * coupling parameters
234  */
235 typedef struct ChannelCoupling {
236  enum CouplingPoint coupling_point; ///< The point during decoding at which coupling is applied.
237  int num_coupled; ///< number of target elements
238  enum RawDataBlockType type[8]; ///< Type of channel element to be coupled - SCE or CPE.
239  int id_select[8]; ///< element id
240  int ch_select[8]; /**< [0] shared list of gains; [1] list of gains for right channel;
241  * [2] list of gains for left channel; [3] lists of gains for both channels
242  */
243  INTFLOAT gain[16][120];
245 
246 /**
247  * Single Channel Element - used for both SCE and LFE elements.
248  */
249 typedef struct SingleChannelElement {
253  enum BandType band_type[128]; ///< band types
254  enum BandType band_alt[128]; ///< alternative band type (used by encoder)
255  int band_type_run_end[120]; ///< band type run end points
256  INTFLOAT sf[120]; ///< scalefactors
257  int sf_idx[128]; ///< scalefactor indices (used by encoder)
258  uint8_t zeroes[128]; ///< band is not coded (used by encoder)
259  uint8_t can_pns[128]; ///< band is allowed to PNS (informative)
260  float is_ener[128]; ///< Intensity stereo pos (used by encoder)
261  float pns_ener[128]; ///< Noise energy values (used by encoder)
262  DECLARE_ALIGNED(32, INTFLOAT, pcoeffs)[1024]; ///< coefficients for IMDCT, pristine
263  DECLARE_ALIGNED(32, INTFLOAT, coeffs)[1024]; ///< coefficients for IMDCT, maybe processed
264  DECLARE_ALIGNED(32, INTFLOAT, saved)[1536]; ///< overlap
265  DECLARE_ALIGNED(32, INTFLOAT, ret_buf)[2048]; ///< PCM output buffer
266  DECLARE_ALIGNED(16, INTFLOAT, ltp_state)[3072]; ///< time signal for LTP
267  DECLARE_ALIGNED(32, AAC_FLOAT, lcoeffs)[1024]; ///< MDCT of LTP coefficients (used by encoder)
268  DECLARE_ALIGNED(32, AAC_FLOAT, prcoeffs)[1024]; ///< Main prediction coefs (used by encoder)
270  INTFLOAT *ret; ///< PCM output
272 
273 /**
274  * channel element - generic struct for SCE/CPE/CCE/LFE
275  */
276 typedef struct ChannelElement {
277  int present;
278  // CPE specific
279  int common_window; ///< Set if channels share a common 'IndividualChannelStream' in bitstream.
280  int ms_mode; ///< Signals mid/side stereo flags coding mode (used by encoder)
281  uint8_t is_mode; ///< Set if any bands have been encoded using intensity stereo (used by encoder)
282  uint8_t ms_mask[128]; ///< Set if mid/side stereo is used for each scalefactor window band
283  uint8_t is_mask[128]; ///< Set if intensity stereo is used (used by encoder)
284  // shared
286  // CCE specific
290 
294 };
295 
296 /**
297  * main AAC context
298  */
299 struct AACContext {
300  AVClass *class;
303 
304  int is_saved; ///< Set if elements have stored overlap from previous frame.
306 
307  /**
308  * @name Channel element related data
309  * @{
310  */
315  /** @} */
316 
317  /**
318  * @name temporary aligned temporary buffers
319  * (We do not want to have these on the stack.)
320  * @{
321  */
323  /** @} */
324 
325  /**
326  * @name Computed / set up during initialization
327  * @{
328  */
333 #if USE_FIXED
335 #else
340 #endif /* USE_FIXED */
342  /** @} */
343 
344  /**
345  * @name Members used for output
346  * @{
347  */
348  SingleChannelElement *output_element[MAX_CHANNELS]; ///< Points to each SingleChannelElement
349  /** @} */
350 
351 
352  /**
353  * @name Japanese DTV specific extension
354  * @{
355  */
356  int force_dmono_mode;///< 0->not dmono, 1->use first channel, 2->use second channel
357  int dmono_mode; ///< 0->not dmono, 1->use first channel, 2->use second channel
358  /** @} */
359 
361 
363 
367  unsigned warned_71_wide;
370 
371  /* aacdec functions pointers */
374  void (*apply_tns)(INTFLOAT coef[1024], TemporalNoiseShaping *tns,
375  IndividualChannelStream *ics, int decode);
379  void (*vector_pow43)(int *coefs, int len);
380  void (*subband_scale)(int *dst, int *src, int scale, int offset, int len, void *log_context);
381 
382 };
383 
385 
386 #endif /* AVCODEC_AAC_H */
ChannelCoupling::type
enum RawDataBlockType type[8]
Type of channel element to be coupled - SCE or CPE.
Definition: aac.h:238
MAX_ELEM_ID
#define MAX_ELEM_ID
Definition: aac.h:50
AAC_CHANNEL_BACK
@ AAC_CHANNEL_BACK
Definition: aac.h:100
CouplingPoint
CouplingPoint
The point during decoding at which channel coupling is applied.
Definition: aac.h:108
SingleChannelElement::band_alt
enum BandType band_alt[128]
alternative band type (used by encoder)
Definition: aac.h:254
SingleChannelElement::can_pns
uint8_t can_pns[128]
band is allowed to PNS (informative)
Definition: aac.h:259
TemporalNoiseShaping::order
int order[8][4]
Definition: aac.h:204
SingleChannelElement::pulse
Pulse pulse
Definition: aac.h:252
mem_internal.h
TYPE_FIL
@ TYPE_FIL
Definition: aac.h:64
out
FILE * out
Definition: movenc.c:54
EXT_FILL
@ EXT_FILL
Definition: aac.h:69
TemporalNoiseShaping::direction
int direction[8][4]
Definition: aac.h:203
Pulse::num_pulse
int num_pulse
Definition: aac.h:226
SingleChannelElement::zeroes
uint8_t zeroes[128]
band is not coded (used by encoder)
Definition: aac.h:258
AACContext::subband_scale
void(* subband_scale)(int *dst, int *src, int scale, int offset, int len, void *log_context)
Definition: aac.h:380
PredictorState::var1
AAC_FLOAT var1
Definition: aac.h:140
TemporalNoiseShaping::coef_idx
int coef_idx[8][4][TNS_MAX_ORDER]
Definition: aac.h:205
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
PredictorState::var0
AAC_FLOAT var0
Definition: aac.h:139
TYPE_PCE
@ TYPE_PCE
Definition: aac.h:63
AACContext::tag_che_map
ChannelElement * tag_che_map[4][MAX_ELEM_ID]
Definition: aac.h:312
MAX_PREDICTORS
#define MAX_PREDICTORS
Definition: aac.h:147
mdct15.h
TemporalNoiseShaping::present
int present
Definition: aac.h:200
AVFixedDSPContext
Definition: fixed_dsp.h:56
LongTermPrediction::used
int8_t used[MAX_LTP_LONG_SFB]
Definition: aac.h:169
AACContext::random_state
int random_state
Definition: aac.h:341
SingleChannelElement::pcoeffs
INTFLOAT pcoeffs[1024]
coefficients for IMDCT, pristine
Definition: aac.h:262
SingleChannelElement::ret
INTFLOAT * ret
PCM output.
Definition: aac.h:270
AACContext::warned_he_aac_mono
int warned_he_aac_mono
Definition: aac.h:369
EXT_DYNAMIC_RANGE
@ EXT_DYNAMIC_RANGE
Definition: aac.h:72
ChannelElement::present
int present
Definition: aac.h:277
sbr.h
MPEG4AudioConfig
Definition: mpeg4audio.h:32
DynamicRangeControl
Dynamic Range Control - decoded from the bitstream but not processed further.
Definition: aac.h:212
IndividualChannelStream::num_swb
int num_swb
number of scalefactor window bands
Definition: aac.h:184
AACContext::temp
INTFLOAT temp[128]
Definition: aac.h:362
ChannelCoupling::coupling_point
enum CouplingPoint coupling_point
The point during decoding at which coupling is applied.
Definition: aac.h:236
OC_LOCKED
@ OC_LOCKED
Output configuration locked in place.
Definition: aac.h:122
mpeg4audio.h
AACContext::apply_ltp
void(* apply_ltp)(AACContext *ac, SingleChannelElement *sce)
Definition: aac.h:373
SingleChannelElement::saved
INTFLOAT saved[1536]
overlap
Definition: aac.h:264
LongTermPrediction::coef
INTFLOAT coef
Definition: aac.h:168
SingleChannelElement::ret_buf
INTFLOAT ret_buf[2048]
PCM output buffer.
Definition: aac.h:265
ChannelElement::coup
ChannelCoupling coup
Definition: aac.h:287
ChannelCoupling::id_select
int id_select[8]
element id
Definition: aac.h:239
BEFORE_TNS
@ BEFORE_TNS
Definition: aac.h:109
TYPE_CPE
@ TYPE_CPE
Definition: aac.h:59
ChannelElement::ms_mode
int ms_mode
Signals mid/side stereo flags coding mode (used by encoder)
Definition: aac.h:280
Pulse::amp
int amp[4]
Definition: aac.h:229
Pulse::pos
int pos[4]
Definition: aac.h:228
OutputConfiguration::status
enum OCStatus status
Definition: aac.h:130
TemporalNoiseShaping::length
int length[8][4]
Definition: aac.h:202
Pulse::start
int start
Definition: aac.h:227
scale
static av_always_inline float scale(float x, float s)
Definition: vf_v360.c:1389
PredictorState::r0
AAC_FLOAT r0
Definition: aac.h:141
IndividualChannelStream::prediction_used
uint8_t prediction_used[41]
Definition: aac.h:191
MAX_LTP_LONG_SFB
#define MAX_LTP_LONG_SFB
Definition: aac.h:53
SingleChannelElement::ics
IndividualChannelStream ics
Definition: aac.h:250
AACContext::mdct
FFTContext mdct
Definition: aac.h:329
IndividualChannelStream::predictor_reset_count
int predictor_reset_count[31]
used by encoder to count prediction resets
Definition: aac.h:190
AACContext::warned_960_sbr
int warned_960_sbr
Definition: aac.h:366
AFTER_IMDCT
@ AFTER_IMDCT
Definition: aac.h:111
AACContext::is_saved
int is_saved
Set if elements have stored overlap from previous frame.
Definition: aac.h:304
AACOutputChannelOrder
AACOutputChannelOrder
Definition: aac.h:291
ZERO_BT
@ ZERO_BT
Scalefactors and spectral data are all zero.
Definition: aac.h:85
DynamicRangeControl::exclude_mask
int exclude_mask[MAX_CHANNELS]
Channels to be excluded from DRC processing.
Definition: aac.h:216
IndividualChannelStream::clip_avoidance_factor
float clip_avoidance_factor
set if any window is near clipping to the necessary atennuation factor to avoid it
Definition: aac.h:193
AACContext::vector_pow43
void(* vector_pow43)(int *coefs, int len)
Definition: aac.h:379
AACContext::mdct_ld
FFTContext mdct_ld
Definition: aac.h:331
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
NOISE_BT
@ NOISE_BT
Spectral data are scaled white noise not coded in the bitstream.
Definition: aac.h:89
OC_TRIAL_FRAME
@ OC_TRIAL_FRAME
Output configuration under trial specified by a frame header.
Definition: aac.h:120
SingleChannelElement::coeffs
INTFLOAT coeffs[1024]
coefficients for IMDCT, maybe processed
Definition: aac.h:263
ChannelCoupling::num_coupled
int num_coupled
number of target elements
Definition: aac.h:237
IndividualChannelStream::swb_sizes
const uint8_t * swb_sizes
table of scalefactor band sizes for a particular window
Definition: aac.h:183
EIGHT_SHORT_SEQUENCE
@ EIGHT_SHORT_SEQUENCE
Definition: aac.h:80
OC_NONE
@ OC_NONE
Output unconfigured.
Definition: aac.h:118
INTENSITY_BT2
@ INTENSITY_BT2
Scalefactor data are intensity stereo positions (out of phase).
Definition: aac.h:90
TYPE_DSE
@ TYPE_DSE
Definition: aac.h:62
IndividualChannelStream::group_len
uint8_t group_len[8]
Definition: aac.h:180
PredictorState
Predictor State.
Definition: aac.h:136
ChannelPosition
ChannelPosition
Definition: aac.h:96
AACContext::fdsp
AVFloatDSPContext * fdsp
Definition: aac.h:339
LongTermPrediction::present
int8_t present
Definition: aac.h:165
AACContext::force_dmono_mode
int force_dmono_mode
0->not dmono, 1->use first channel, 2->use second channel
Definition: aac.h:356
fixed_dsp.h
IndividualChannelStream
Individual Channel Stream.
Definition: aac.h:175
MDCT15Context
Definition: mdct15.h:30
TemporalNoiseShaping::coef
INTFLOAT coef[8][4][TNS_MAX_ORDER]
Definition: aac.h:206
IndividualChannelStream::swb_offset
const uint16_t * swb_offset
table of offsets to the lowest spectral coefficient of a scalefactor band, sfb, for a particular wind...
Definition: aac.h:182
AACContext::warned_num_aac_frames
int warned_num_aac_frames
Definition: aac.h:365
INTENSITY_BT
@ INTENSITY_BT
Scalefactor data are intensity stereo positions (in phase).
Definition: aac.h:91
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
ChannelElement::is_mask
uint8_t is_mask[128]
Set if intensity stereo is used (used by encoder)
Definition: aac.h:283
SingleChannelElement::is_ener
float is_ener[128]
Intensity stereo pos (used by encoder)
Definition: aac.h:260
AACContext::output_channel_order
enum AACOutputChannelOrder output_channel_order
Definition: aac.h:360
IndividualChannelStream::num_window_groups
int num_window_groups
Definition: aac.h:179
AACContext::mdct480
MDCT15Context * mdct480
Definition: aac.h:337
AAC_CHANNEL_SIDE
@ AAC_CHANNEL_SIDE
Definition: aac.h:99
AACContext::frame
AVFrame * frame
Definition: aac.h:302
LongTermPrediction::coef_idx
int coef_idx
Definition: aac.h:167
IndividualChannelStream::predictor_present
int predictor_present
Definition: aac.h:187
DynamicRangeControl::band_top
int band_top[17]
Indicates the top of the i-th DRC band in units of 4 spectral lines.
Definition: aac.h:219
AACContext::che
ChannelElement * che[4][MAX_ELEM_ID]
Definition: aac.h:311
AAC_CHANNEL_FRONT
@ AAC_CHANNEL_FRONT
Definition: aac.h:98
SingleChannelElement::predictor_state
PredictorState predictor_state[MAX_PREDICTORS]
Definition: aac.h:269
PredictorState::k1
AAC_FLOAT k1
Definition: aac.h:143
TNS_MAX_ORDER
#define TNS_MAX_ORDER
Definition: aac.h:52
AAC_CHANNEL_OFF
@ AAC_CHANNEL_OFF
Definition: aac.h:97
PredictorState::r1
AAC_FLOAT r1
Definition: aac.h:142
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
SingleChannelElement::band_type_run_end
int band_type_run_end[120]
band type run end points
Definition: aac.h:255
SingleChannelElement::sf_idx
int sf_idx[128]
scalefactor indices (used by encoder)
Definition: aac.h:257
float_dsp.h
OutputConfiguration::layout_map_tags
int layout_map_tags
Definition: aac.h:128
OutputConfiguration::layout_map
uint8_t layout_map[MAX_ELEM_ID *4][3]
Definition: aac.h:127
CHANNEL_ORDER_CODED
@ CHANNEL_ORDER_CODED
Definition: aac.h:293
AACContext::apply_tns
void(* apply_tns)(INTFLOAT coef[1024], TemporalNoiseShaping *tns, IndividualChannelStream *ics, int decode)
Definition: aac.h:374
SingleChannelElement::lcoeffs
AAC_FLOAT lcoeffs[1024]
MDCT of LTP coefficients (used by encoder)
Definition: aac.h:267
CHANNEL_ORDER_DEFAULT
@ CHANNEL_ORDER_DEFAULT
Definition: aac.h:292
AACContext::tags_mapped
int tags_mapped
Definition: aac.h:313
AACContext::avctx
AVCodecContext * avctx
Definition: aac.h:301
ChannelElement::ch
SingleChannelElement ch[2]
Definition: aac.h:285
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:290
ONLY_LONG_SEQUENCE
@ ONLY_LONG_SEQUENCE
Definition: aac.h:78
TYPE_END
@ TYPE_END
Definition: aac.h:65
AACContext::warned_remapping_once
int warned_remapping_once
Definition: aac.h:314
TemporalNoiseShaping::n_filt
int n_filt[8]
Definition: aac.h:201
BandType
BandType
Definition: aac.h:84
AACContext::mdct120
MDCT15Context * mdct120
Definition: aac.h:336
ESC_BT
@ ESC_BT
Spectral data are coded with an escape sequence.
Definition: aac.h:87
DynamicRangeControl::prog_ref_level
int prog_ref_level
A reference level for the long-term program audio level for all channels combined.
Definition: aac.h:220
SpectralBandReplication
Spectral Band Replication.
Definition: sbr.h:142
OCStatus
OCStatus
Output configuration status.
Definition: aac.h:117
AVFloatDSPContext
Definition: float_dsp.h:24
OutputConfiguration
Definition: aac.h:125
ChannelElement::common_window
int common_window
Set if channels share a common 'IndividualChannelStream' in bitstream.
Definition: aac.h:279
SingleChannelElement::prcoeffs
AAC_FLOAT prcoeffs[1024]
Main prediction coefs (used by encoder)
Definition: aac.h:268
offset
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
Definition: writing_filters.txt:86
MAX_CHANNELS
#define MAX_CHANNELS
Definition: aac.h:49
ChannelElement::ms_mask
uint8_t ms_mask[128]
Set if mid/side stereo is used for each scalefactor window band.
Definition: aac.h:282
DynamicRangeControl::dyn_rng_ctl
int dyn_rng_ctl[17]
DRC magnitude information.
Definition: aac.h:215
EXT_FILL_DATA
@ EXT_FILL_DATA
Definition: aac.h:70
SingleChannelElement::pns_ener
float pns_ener[128]
Noise energy values (used by encoder)
Definition: aac.h:261
OC_GLOBAL_HDR
@ OC_GLOBAL_HDR
Output configuration set in a global header but not yet locked.
Definition: aac.h:121
DECLARE_ALIGNED
#define DECLARE_ALIGNED(n, t, v)
Definition: mem.h:116
AACContext::mdct960
MDCT15Context * mdct960
Definition: aac.h:338
FFTContext
Definition: fft.h:75
AACContext::mdct_ltp
FFTContext mdct_ltp
Definition: aac.h:332
BETWEEN_TNS_AND_IMDCT
@ BETWEEN_TNS_AND_IMDCT
Definition: aac.h:110
RawDataBlockType
RawDataBlockType
Definition: aac.h:57
SingleChannelElement
Single Channel Element - used for both SCE and LFE elements.
Definition: aac.h:249
IndividualChannelStream::num_windows
int num_windows
Definition: aac.h:185
ChannelElement::sbr
SpectralBandReplication sbr
Definition: aac.h:288
LONG_STOP_SEQUENCE
@ LONG_STOP_SEQUENCE
Definition: aac.h:81
ChannelElement
channel element - generic struct for SCE/CPE/CCE/LFE
Definition: aac.h:276
PredictorState::x_est
AAC_FLOAT x_est
Definition: aac.h:144
TYPE_LFE
@ TYPE_LFE
Definition: aac.h:61
LongTermPrediction::lag
int16_t lag
Definition: aac.h:166
TYPE_SCE
@ TYPE_SCE
Definition: aac.h:58
AACContext::oc
OutputConfiguration oc[2]
Definition: aac.h:364
len
int len
Definition: vorbis_enc_data.h:426
IndividualChannelStream::tns_max_bands
int tns_max_bands
Definition: aac.h:186
OC_TRIAL_PCE
@ OC_TRIAL_PCE
Output configuration under trial specified by an inband PCE.
Definition: aac.h:119
AACContext::che_drc
DynamicRangeControl che_drc
Definition: aac.h:305
avcodec.h
AAC_CHANNEL_LFE
@ AAC_CHANNEL_LFE
Definition: aac.h:101
DynamicRangeControl::pce_instance_tag
int pce_instance_tag
Indicates with which program the DRC info is associated.
Definition: aac.h:213
SingleChannelElement::sf
INTFLOAT sf[120]
scalefactors
Definition: aac.h:256
AACContext::output_element
SingleChannelElement * output_element[MAX_CHANNELS]
Points to each SingleChannelElement.
Definition: aac.h:348
RESERVED_BT
@ RESERVED_BT
Band types following are encoded differently from others.
Definition: aac.h:88
LONG_START_SEQUENCE
@ LONG_START_SEQUENCE
Definition: aac.h:79
AACContext::update_ltp
void(* update_ltp)(AACContext *ac, SingleChannelElement *sce)
Definition: aac.h:378
ChannelCoupling::ch_select
int ch_select[8]
[0] shared list of gains; [1] list of gains for right channel; [2] list of gains for left channel; [3...
Definition: aac.h:240
SingleChannelElement::tns
TemporalNoiseShaping tns
Definition: aac.h:251
AACContext::warned_71_wide
unsigned warned_71_wide
Definition: aac.h:367
EXT_SBR_DATA_CRC
@ EXT_SBR_DATA_CRC
Definition: aac.h:74
fft.h
AVCodecContext
main external API structure.
Definition: avcodec.h:398
LongTermPrediction
Long Term Prediction.
Definition: aac.h:164
EXT_SBR_DATA
@ EXT_SBR_DATA
Definition: aac.h:73
channel_layout.h
ff_aacdec_init_mips
void ff_aacdec_init_mips(AACContext *c)
Definition: aacdec_mips.c:434
IndividualChannelStream::window_sequence
enum WindowSequence window_sequence[2]
Definition: aac.h:177
FIRST_PAIR_BT
@ FIRST_PAIR_BT
This and later band types encode two values (rather than four) with one code word.
Definition: aac.h:86
TemporalNoiseShaping
Temporal Noise Shaping.
Definition: aac.h:199
ChannelCoupling::gain
INTFLOAT gain[16][120]
Definition: aac.h:243
ChannelElement::is_mode
uint8_t is_mode
Set if any bands have been encoded using intensity stereo (used by encoder)
Definition: aac.h:281
DynamicRangeControl::band_incr
int band_incr
Number of DRC bands greater than 1 having DRC info.
Definition: aac.h:217
AACContext::buf_mdct
INTFLOAT buf_mdct[1024]
Definition: aac.h:322
OutputConfiguration::m4ac
MPEG4AudioConfig m4ac
Definition: aac.h:126
TYPE_CCE
@ TYPE_CCE
Definition: aac.h:60
OutputConfiguration::ch_layout
AVChannelLayout ch_layout
Definition: aac.h:129
PredictorState::cor1
AAC_FLOAT cor1
Definition: aac.h:138
AACContext::windowing_and_mdct_ltp
void(* windowing_and_mdct_ltp)(AACContext *ac, INTFLOAT *out, INTFLOAT *in, IndividualChannelStream *ics)
Definition: aac.h:376
AAC_FLOAT
float AAC_FLOAT
Definition: aac_defines.h:90
DynamicRangeControl::dyn_rng_sgn
int dyn_rng_sgn[17]
DRC sign information; 0 - positive, 1 - negative.
Definition: aac.h:214
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
ExtensionPayloadID
ExtensionPayloadID
Definition: aac.h:68
IndividualChannelStream::window_clipping
uint8_t window_clipping[8]
set if a certain window is near clipping
Definition: aac.h:192
AACContext::mdct_small
FFTContext mdct_small
Definition: aac.h:330
ChannelCoupling
coupling parameters
Definition: aac.h:235
EXT_DATA_ELEMENT
@ EXT_DATA_ELEMENT
Definition: aac.h:71
AACContext
main AAC context
Definition: aac.h:299
aac_defines.h
IndividualChannelStream::max_sfb
uint8_t max_sfb
number of scalefactor bands per group
Definition: aac.h:176
Pulse
Definition: aac.h:225
AAC_CHANNEL_CC
@ AAC_CHANNEL_CC
Definition: aac.h:102
SingleChannelElement::ltp_state
INTFLOAT ltp_state[3072]
time signal for LTP
Definition: aac.h:266
DynamicRangeControl::interpolation_scheme
int interpolation_scheme
Indicates the interpolation scheme used in the SBR QMF domain.
Definition: aac.h:218
AACContext::warned_gain_control
int warned_gain_control
Definition: aac.h:368
WindowSequence
WindowSequence
Definition: aac.h:77
IndividualChannelStream::ltp
LongTermPrediction ltp
Definition: aac.h:181
AACContext::imdct_and_windowing
void(* imdct_and_windowing)(AACContext *ac, SingleChannelElement *sce)
Definition: aac.h:372
SingleChannelElement::band_type
enum BandType band_type[128]
band types
Definition: aac.h:253
IndividualChannelStream::use_kb_window
uint8_t use_kb_window[2]
If set, use Kaiser-Bessel window, otherwise use a sine window.
Definition: aac.h:178
INTFLOAT
float INTFLOAT
Definition: aac_defines.h:86
AACContext::dmono_mode
int dmono_mode
0->not dmono, 1->use first channel, 2->use second channel
Definition: aac.h:357
IndividualChannelStream::predictor_reset_group
int predictor_reset_group
Definition: aac.h:189
IndividualChannelStream::predictor_initialized
int predictor_initialized
Definition: aac.h:188
PredictorState::cor0
AAC_FLOAT cor0
Definition: aac.h:137