libavcodec/aacdec.c File Reference

AAC decoder. More...

#include "avcodec.h"
#include "internal.h"
#include "get_bits.h"
#include "dsputil.h"
#include "fft.h"
#include "fmtconvert.h"
#include "lpc.h"
#include "kbdwin.h"
#include "sinewin.h"
#include "aac.h"
#include "aactab.h"
#include "aacdectab.h"
#include "cbrt_tablegen.h"
#include "sbr.h"
#include "aacsbr.h"
#include "mpeg4audio.h"
#include "aacadtsdec.h"
#include "libavutil/intfloat.h"
#include <assert.h>
#include <errno.h>
#include <math.h>
#include <string.h>

Go to the source code of this file.

Data Structures

struct  elem_to_channel
struct  LATMContext

Defines

#define overread_err   "Input buffer exhausted before END element found\n"
#define AAC_INIT_VLC_STATIC(num, size)
#define LOAS_SYNC_WORD   0x2b7
 11 bits LOAS sync word

Functions

static int count_channels (uint8_t(*layout)[3], int tags)
static av_cold int che_configure (AACContext *ac, enum ChannelPosition che_pos, int type, int id, int *channels)
 Check for the channel element in the current channel position configuration.
static int assign_pair (struct elem_to_channel e2c_vec[MAX_ELEM_ID], uint8_t(*layout_map)[3], int offset, int tags, uint64_t left, uint64_t right, int pos)
static int count_paired_channels (uint8_t(*layout_map)[3], int tags, int pos, int *current)
static uint64_t sniff_channel_order (uint8_t(*layout_map)[3], int tags)
static void push_output_configuration (AACContext *ac)
 Save current output configuration if and only if it has been locked.
static void pop_output_configuration (AACContext *ac)
 Restore the previous output configuration if and only if the current configuration is unlocked.
static int output_configure (AACContext *ac, uint8_t layout_map[MAX_ELEM_ID *4][3], int tags, int channel_config, enum OCStatus oc_type)
 Configure output channel order based on the current program configuration element.
static void flush (AVCodecContext *avctx)
static int set_default_channel_config (AVCodecContext *avctx, uint8_t(*layout_map)[3], int *tags, int channel_config)
 Set up channel positions based on a default channel configuration as specified in table 1.17.
static ChannelElement * get_che (AACContext *ac, int type, int elem_id)
static void decode_channel_map (uint8_t layout_map[][3], enum ChannelPosition type, GetBitContext *gb, int n)
 Decode an array of 4 bit element IDs, optionally interleaved with a stereo/mono switching bit.
static int decode_pce (AVCodecContext *avctx, MPEG4AudioConfig *m4ac, uint8_t(*layout_map)[3], GetBitContext *gb)
 Decode program configuration element; reference: table 4.2.
static int decode_ga_specific_config (AACContext *ac, AVCodecContext *avctx, GetBitContext *gb, MPEG4AudioConfig *m4ac, int channel_config)
 Decode GA "General Audio" specific configuration; reference: table 4.1.
static int decode_audio_specific_config (AACContext *ac, AVCodecContext *avctx, MPEG4AudioConfig *m4ac, const uint8_t *data, int bit_size, int sync_extension)
 Decode audio specific configuration; reference: table 1.13.
static av_always_inline int lcg_random (int previous_val)
 linear congruential pseudorandom number generator
static av_always_inline void reset_predict_state (PredictorState *ps)
static void reset_all_predictors (PredictorState *ps)
static int sample_rate_idx (int rate)
static void reset_predictor_group (PredictorState *ps, int group_num)
static av_cold int aac_decode_init (AVCodecContext *avctx)
static int skip_data_stream_element (AACContext *ac, GetBitContext *gb)
 Skip data_stream_element; reference: table 4.10.
static int decode_prediction (AACContext *ac, IndividualChannelStream *ics, GetBitContext *gb)
static void decode_ltp (AACContext *ac, LongTermPrediction *ltp, GetBitContext *gb, uint8_t max_sfb)
 Decode Long Term Prediction data; reference: table 4.xx.
static int decode_ics_info (AACContext *ac, IndividualChannelStream *ics, GetBitContext *gb)
 Decode Individual Channel Stream info; reference: table 4.6.
static int decode_band_types (AACContext *ac, enum BandType band_type[120], int band_type_run_end[120], GetBitContext *gb, IndividualChannelStream *ics)
 Decode band types (section_data payload); reference: table 4.46.
static int decode_scalefactors (AACContext *ac, float sf[120], GetBitContext *gb, unsigned int global_gain, IndividualChannelStream *ics, enum BandType band_type[120], int band_type_run_end[120])
 Decode scalefactors; reference: table 4.47.
static int decode_pulses (Pulse *pulse, GetBitContext *gb, const uint16_t *swb_offset, int num_swb)
 Decode pulse data; reference: table 4.7.
static int decode_tns (AACContext *ac, TemporalNoiseShaping *tns, GetBitContext *gb, const IndividualChannelStream *ics)
 Decode Temporal Noise Shaping data; reference: table 4.48.
static void decode_mid_side_stereo (ChannelElement *cpe, GetBitContext *gb, int ms_present)
 Decode Mid/Side data; reference: table 4.54.
static float * VMUL2 (float *dst, const float *v, unsigned idx, const float *scale)
static float * VMUL4 (float *dst, const float *v, unsigned idx, const float *scale)
static float * VMUL2S (float *dst, const float *v, unsigned idx, unsigned sign, const float *scale)
static float * VMUL4S (float *dst, const float *v, unsigned idx, unsigned sign, const float *scale)
static int decode_spectrum_and_dequant (AACContext *ac, float coef[1024], GetBitContext *gb, const float sf[120], int pulse_present, const Pulse *pulse, const IndividualChannelStream *ics, enum BandType band_type[120])
 Decode spectral data; reference: table 4.50.
static av_always_inline float flt16_round (float pf)
static av_always_inline float flt16_even (float pf)
static av_always_inline float flt16_trunc (float pf)
static av_always_inline void predict (PredictorState *ps, float *coef, int output_enable)
static void apply_prediction (AACContext *ac, SingleChannelElement *sce)
 Apply AAC-Main style frequency domain prediction.
static int decode_ics (AACContext *ac, SingleChannelElement *sce, GetBitContext *gb, int common_window, int scale_flag)
 Decode an individual_channel_stream payload; reference: table 4.44.
static void apply_mid_side_stereo (AACContext *ac, ChannelElement *cpe)
 Mid/Side stereo decoding; reference: 4.6.8.1.3.
static void apply_intensity_stereo (AACContext *ac, ChannelElement *cpe, int ms_present)
 intensity stereo decoding; reference: 4.6.8.2.3
static int decode_cpe (AACContext *ac, GetBitContext *gb, ChannelElement *cpe)
 Decode a channel_pair_element; reference: table 4.4.
static int decode_cce (AACContext *ac, GetBitContext *gb, ChannelElement *che)
 Decode coupling_channel_element; reference: table 4.8.
static int decode_drc_channel_exclusions (DynamicRangeControl *che_drc, GetBitContext *gb)
 Parse whether channels are to be excluded from Dynamic Range Compression; reference: table 4.53.
static int decode_dynamic_range (DynamicRangeControl *che_drc, GetBitContext *gb, int cnt)
 Decode dynamic range information; reference: table 4.52.
static int decode_extension_payload (AACContext *ac, GetBitContext *gb, int cnt, ChannelElement *che, enum RawDataBlockType elem_type)
 Decode extension data (incomplete); reference: table 4.51.
static void apply_tns (float coef[1024], TemporalNoiseShaping *tns, IndividualChannelStream *ics, int decode)
 Decode Temporal Noise Shaping filter coefficients and apply all-pole filters; reference: 4.6.9.3.
static void windowing_and_mdct_ltp (AACContext *ac, float *out, float *in, IndividualChannelStream *ics)
 Apply windowing and MDCT to obtain the spectral coefficient from the predicted sample by LTP.
static void apply_ltp (AACContext *ac, SingleChannelElement *sce)
 Apply the long term prediction.
static void update_ltp (AACContext *ac, SingleChannelElement *sce)
 Update the LTP buffer for next frame.
static void imdct_and_windowing (AACContext *ac, SingleChannelElement *sce)
 Conduct IMDCT and windowing.
static void apply_dependent_coupling (AACContext *ac, SingleChannelElement *target, ChannelElement *cce, int index)
 Apply dependent channel coupling (applied before IMDCT).
static void apply_independent_coupling (AACContext *ac, SingleChannelElement *target, ChannelElement *cce, int index)
 Apply independent channel coupling (applied after IMDCT).
static void apply_channel_coupling (AACContext *ac, ChannelElement *cc, enum RawDataBlockType type, int elem_id, enum CouplingPoint coupling_point, void(*apply_coupling_method)(AACContext *ac, SingleChannelElement *target, ChannelElement *cce, int index))
 channel coupling transformation interface
static void spectral_to_sample (AACContext *ac)
 Convert spectral data to float samples, applying all supported tools as appropriate.
static int parse_adts_frame_header (AACContext *ac, GetBitContext *gb)
static int aac_decode_frame_int (AVCodecContext *avctx, void *data, int *got_frame_ptr, GetBitContext *gb)
static int aac_decode_frame (AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
static av_cold int aac_decode_close (AVCodecContext *avctx)
static uint32_t latm_get_value (GetBitContext *b)
static int latm_decode_audio_specific_config (struct LATMContext *latmctx, GetBitContext *gb, int asclen)
static int read_stream_mux_config (struct LATMContext *latmctx, GetBitContext *gb)
static int read_payload_length_info (struct LATMContext *ctx, GetBitContext *gb)
static int read_audio_mux_element (struct LATMContext *latmctx, GetBitContext *gb)
static int latm_decode_frame (AVCodecContext *avctx, void *out, int *got_frame_ptr, AVPacket *avpkt)
static av_cold int latm_decode_init (AVCodecContext *avctx)

Variables

static VLC vlc_scalefactors
static VLC vlc_spectral [11]
static const float cce_scale []
AVCodec ff_aac_decoder
AVCodec ff_aac_latm_decoder

Detailed Description

AAC decoder.

Author:
Oded Shimon ( ods15 ods15 dyndns org )

Maxim Gavrilov ( maxim.gavrilov gmail com )

Definition in file aacdec.c.

Define Documentation

#define AAC_INIT_VLC_STATIC ( num,
size   ) 

Value:

INIT_VLC_STATIC(&vlc_spectral[num], 8, ff_aac_spectral_sizes[num], \
         ff_aac_spectral_bits[num], sizeof( ff_aac_spectral_bits[num][0]), sizeof( ff_aac_spectral_bits[num][0]), \
        ff_aac_spectral_codes[num], sizeof(ff_aac_spectral_codes[num][0]), sizeof(ff_aac_spectral_codes[num][0]), \
        size);

Definition at line 829 of file aacdec.c.

Referenced by aac_decode_init().

#define LOAS_SYNC_WORD   0x2b7

11 bits LOAS sync word

Definition at line 2612 of file aacdec.c.

Referenced by latm_decode_frame().

#define overread_err   "Input buffer exhausted before END element found\n"

Definition at line 115 of file aacdec.c.

Referenced by aac_decode_frame_int(), decode_band_types(), decode_pce(), and skip_data_stream_element().

Function Documentation

static av_cold int aac_decode_close ( AVCodecContext *  avctx  )  [static]

Definition at line 2592 of file aacdec.c.

static int aac_decode_frame ( AVCodecContext *  avctx,
void *  data,
int *  got_frame_ptr,
AVPacket *  avpkt 
) [static]

Definition at line 2547 of file aacdec.c.

static int aac_decode_frame_int ( AVCodecContext *  avctx,
void *  data,
int *  got_frame_ptr,
GetBitContext *  gb 
) [static]

Definition at line 2393 of file aacdec.c.

Referenced by aac_decode_frame(), and latm_decode_frame().

static av_cold int aac_decode_init ( AVCodecContext *  avctx  )  [static]

Definition at line 835 of file aacdec.c.

Referenced by latm_decode_init().

static void apply_channel_coupling ( AACContext *  ac,
ChannelElement *  cc,
enum RawDataBlockType  type,
int  elem_id,
enum CouplingPoint  coupling_point,
void(*)(AACContext *ac, SingleChannelElement *target, ChannelElement *cce, int index)  apply_coupling_method 
) [static]

channel coupling transformation interface

Parameters:
apply_coupling_method pointer to (in)dependent coupling function

Definition at line 2274 of file aacdec.c.

Referenced by encode_frame(), and spectral_to_sample().

static void apply_dependent_coupling ( AACContext *  ac,
SingleChannelElement *  target,
ChannelElement *  cce,
int  index 
) [static]

Apply dependent channel coupling (applied before IMDCT).

Parameters:
index index into coupling gain array

Definition at line 2219 of file aacdec.c.

Referenced by spectral_to_sample().

static void apply_independent_coupling ( AACContext *  ac,
SingleChannelElement *  target,
ChannelElement *  cce,
int  index 
) [static]

Apply independent channel coupling (applied after IMDCT).

Parameters:
index index into coupling gain array

Definition at line 2255 of file aacdec.c.

Referenced by spectral_to_sample().

static void apply_intensity_stereo ( AACContext *  ac,
ChannelElement *  cpe,
int  ms_present 
) [static]

intensity stereo decoding; reference: 4.6.8.2.3

Parameters:
ms_present Indicates mid/side stereo presence. [0] mask is all 0s; [1] mask is decoded from bitstream; [2] mask is all 1s; [3] reserved for scalable AAC

Definition at line 1718 of file aacdec.c.

Referenced by decode_cpe().

static void apply_ltp ( AACContext *  ac,
SingleChannelElement *  sce 
) [static]

Apply the long term prediction.

Definition at line 2087 of file aacdec.c.

Referenced by spectral_to_sample().

static void apply_mid_side_stereo ( AACContext *  ac,
ChannelElement *  cpe 
) [static]

Mid/Side stereo decoding; reference: 4.6.8.1.3.

Definition at line 1688 of file aacdec.c.

Referenced by decode_cpe().

static void apply_prediction ( AACContext *  ac,
SingleChannelElement *  sce 
) [static]

Apply AAC-Main style frequency domain prediction.

Definition at line 1600 of file aacdec.c.

Referenced by decode_cpe(), and decode_ics().

static void apply_tns ( float  coef[1024],
TemporalNoiseShaping *  tns,
IndividualChannelStream *  ics,
int  decode 
) [static]

Decode Temporal Noise Shaping filter coefficients and apply all-pole filters; reference: 4.6.9.3.

Parameters:
decode 1 if tool is used normally, 0 if tool is used in LTP.
coef spectral coefficients

Definition at line 2005 of file aacdec.c.

Referenced by apply_ltp(), and spectral_to_sample().

static int assign_pair ( struct elem_to_channel  e2c_vec[MAX_ELEM_ID],
uint8_t(*)  layout_map[3],
int  offset,
int  tags,
uint64_t  left,
uint64_t  right,
int  pos 
) [static]

Definition at line 177 of file aacdec.c.

Referenced by sniff_channel_order().

static av_cold int che_configure ( AACContext *  ac,
enum ChannelPosition  che_pos,
int  type,
int  id,
int *  channels 
) [static]

Check for the channel element in the current channel position configuration.

If it exists, make sure the appropriate element is allocated and map the channel order to match the internal FFmpeg channel layout.

Parameters:
che_pos current channel position configuration
type channel element type
id channel element id
channels count of the number of channels in the configuration
Returns:
Returns error status. 0 - OK, !0 - error

Definition at line 141 of file aacdec.c.

Referenced by output_configure().

static int count_channels ( uint8_t(*)  layout[3],
int  tags 
) [static]

Definition at line 117 of file aacdec.c.

Referenced by decode_ga_specific_config().

static int count_paired_channels ( uint8_t(*)  layout_map[3],
int  tags,
int  pos,
int *  current 
) [static]

Definition at line 197 of file aacdec.c.

Referenced by sniff_channel_order().

static int decode_audio_specific_config ( AACContext *  ac,
AVCodecContext *  avctx,
MPEG4AudioConfig *  m4ac,
const uint8_t *  data,
int  bit_size,
int  sync_extension 
) [static]

Decode audio specific configuration; reference: table 1.13.

Parameters:
ac pointer to AACContext, may be null
avctx pointer to AVCCodecContext, used for logging
m4ac pointer to MPEG4AudioConfig, used for parsing
data pointer to buffer holding an audio specific config
bit_size size of audio specific config or data in bits
sync_extension look for an appended sync extension
Returns:
Returns error status or number of consumed bits. <0 - error

Definition at line 732 of file aacdec.c.

Referenced by aac_decode_frame(), aac_decode_init(), latm_decode_audio_specific_config(), and latm_decode_frame().

static int decode_band_types ( AACContext *  ac,
enum BandType  band_type[120],
int  band_type_run_end[120],
GetBitContext *  gb,
IndividualChannelStream *  ics 
) [static]

Decode band types (section_data payload); reference: table 4.46.

Parameters:
band_type array of the used band type
band_type_run_end array of the last scalefactor band of a band type run
Returns:
Returns error status. 0 - OK, !0 - error

Definition at line 1056 of file aacdec.c.

Referenced by decode_ics().

static int decode_cce ( AACContext *  ac,
GetBitContext *  gb,
ChannelElement *  che 
) [static]

Decode coupling_channel_element; reference: table 4.8.

Returns:
Returns error status. 0 - OK, !0 - error

Definition at line 1809 of file aacdec.c.

Referenced by aac_decode_frame_int().

static void decode_channel_map ( uint8_t  layout_map[][3],
enum ChannelPosition  type,
GetBitContext *  gb,
int  n 
) [static]

Decode an array of 4 bit element IDs, optionally interleaved with a stereo/mono switching bit.

Parameters:
type speaker type/position for these channels

Definition at line 559 of file aacdec.c.

Referenced by decode_pce().

static int decode_cpe ( AACContext *  ac,
GetBitContext *  gb,
ChannelElement *  cpe 
) [static]

Decode a channel_pair_element; reference: table 4.4.

Returns:
Returns error status. 0 - OK, !0 - error

Definition at line 1758 of file aacdec.c.

Referenced by aac_decode_frame_int().

static int decode_drc_channel_exclusions ( DynamicRangeControl *  che_drc,
GetBitContext *  gb 
) [static]

Parse whether channels are to be excluded from Dynamic Range Compression; reference: table 4.53.

Returns:
Returns number of bytes consumed.

Definition at line 1881 of file aacdec.c.

Referenced by decode_dynamic_range().

static int decode_dynamic_range ( DynamicRangeControl *  che_drc,
GetBitContext *  gb,
int  cnt 
) [static]

Decode dynamic range information; reference: table 4.52.

Parameters:
cnt length of TYPE_FIL syntactic element in bytes
Returns:
Returns number of bytes consumed.

Definition at line 1902 of file aacdec.c.

Referenced by decode_extension_payload().

static int decode_extension_payload ( AACContext *  ac,
GetBitContext *  gb,
int  cnt,
ChannelElement *  che,
enum RawDataBlockType  elem_type 
) [static]

Decode extension data (incomplete); reference: table 4.51.

Parameters:
cnt length of TYPE_FIL syntactic element in bytes
Returns:
Returns number of bytes consumed

Definition at line 1956 of file aacdec.c.

Referenced by aac_decode_frame_int().

static int decode_ga_specific_config ( AACContext *  ac,
AVCodecContext *  avctx,
GetBitContext *  gb,
MPEG4AudioConfig *  m4ac,
int  channel_config 
) [static]

Decode GA "General Audio" specific configuration; reference: table 4.1.

Parameters:
ac pointer to AACContext, may be null
avctx pointer to AVCCodecContext, used for logging
Returns:
Returns error status. 0 - OK, !0 - error

Definition at line 658 of file aacdec.c.

Referenced by decode_audio_specific_config().

static int decode_ics ( AACContext *  ac,
SingleChannelElement *  sce,
GetBitContext *  gb,
int  common_window,
int  scale_flag 
) [static]

Decode an individual_channel_stream payload; reference: table 4.44.

Parameters:
common_window Channels have independent [0], or shared [1], Individual Channel Stream information.
scale_flag scalable [1] or non-scalable [0] AAC (Unused until scalable AAC is implemented.)
Returns:
Returns error status. 0 - OK, !0 - error

Definition at line 1630 of file aacdec.c.

Referenced by aac_decode_frame_int(), decode_cce(), and decode_cpe().

static int decode_ics_info ( AACContext *  ac,
IndividualChannelStream *  ics,
GetBitContext *  gb 
) [static]

Decode Individual Channel Stream info; reference: table 4.6.

Definition at line 983 of file aacdec.c.

Referenced by decode_cpe(), and decode_ics().

static void decode_ltp ( AACContext *  ac,
LongTermPrediction *  ltp,
GetBitContext *  gb,
uint8_t  max_sfb 
) [static]

Decode Long Term Prediction data; reference: table 4.xx.

Definition at line 969 of file aacdec.c.

Referenced by decode_cpe(), and decode_ics_info().

static void decode_mid_side_stereo ( ChannelElement *  cpe,
GetBitContext *  gb,
int  ms_present 
) [static]

Decode Mid/Side data; reference: table 4.54.

Parameters:
ms_present Indicates mid/side stereo presence. [0] mask is all 0s; [1] mask is decoded from bitstream; [2] mask is all 1s; [3] reserved for scalable AAC

Definition at line 1236 of file aacdec.c.

Referenced by decode_cpe().

static int decode_pce ( AVCodecContext *  avctx,
MPEG4AudioConfig *  m4ac,
uint8_t(*)  layout_map[3],
GetBitContext *  gb 
) [static]

Decode program configuration element; reference: table 4.2.

Returns:
Returns error status. 0 - OK, !0 - error

Definition at line 591 of file aacdec.c.

Referenced by aac_decode_frame_int(), and decode_ga_specific_config().

static int decode_prediction ( AACContext *  ac,
IndividualChannelStream *  ics,
GetBitContext *  gb 
) [static]

Definition at line 949 of file aacdec.c.

Referenced by decode_ics_info().

static int decode_pulses ( Pulse *  pulse,
GetBitContext *  gb,
const uint16_t *  swb_offset,
int  num_swb 
) [static]

Decode pulse data; reference: table 4.7.

Definition at line 1167 of file aacdec.c.

Referenced by decode_ics().

static int decode_scalefactors ( AACContext *  ac,
float  sf[120],
GetBitContext *  gb,
unsigned int  global_gain,
IndividualChannelStream *  ics,
enum BandType  band_type[120],
int  band_type_run_end[120] 
) [static]

Decode scalefactors; reference: table 4.47.

Parameters:
global_gain first scalefactor value as scalefactors are differentially coded
band_type array of the used band type
band_type_run_end array of the last scalefactor band of a band type run
sf array of scalefactors or intensity stereo positions
Returns:
Returns error status. 0 - OK, !0 - error

Definition at line 1105 of file aacdec.c.

Referenced by decode_ics().

static int decode_spectrum_and_dequant ( AACContext *  ac,
float  coef[1024],
GetBitContext *  gb,
const float  sf[120],
int  pulse_present,
const Pulse *  pulse,
const IndividualChannelStream *  ics,
enum BandType  band_type[120] 
) [static]

Decode spectral data; reference: table 4.50.

Dequantize and scale spectral data; reference: 4.6.3.3.

Parameters:
coef array of dequantized, scaled spectral data
sf array of scalefactors or intensity stereo positions
pulse_present set if pulses are present
pulse pointer to pulse data struct
band_type array of the used band type
Returns:
Returns error status. 0 - OK, !0 - error

Definition at line 1328 of file aacdec.c.

Referenced by decode_ics().

static int decode_tns ( AACContext *  ac,
TemporalNoiseShaping *  tns,
GetBitContext *  gb,
const IndividualChannelStream *  ics 
) [static]

Decode Temporal Noise Shaping data; reference: table 4.48.

Returns:
Returns error status. 0 - OK, !0 - error

Definition at line 1194 of file aacdec.c.

Referenced by decode_ics().

static av_always_inline float flt16_even ( float  pf  )  [static]

Definition at line 1550 of file aacdec.c.

Referenced by predict().

static av_always_inline float flt16_round ( float  pf  )  [static]

Definition at line 1542 of file aacdec.c.

Referenced by predict().

static av_always_inline float flt16_trunc ( float  pf  )  [static]

Definition at line 1558 of file aacdec.c.

Referenced by predict().

static void flush ( AVCodecContext *  avctx  )  [static]

Definition at line 430 of file aacdec.c.

Referenced by av_interleaved_write_frame(), ogg_buffer_data(), and png_parse().

static ChannelElement* get_che ( AACContext *  ac,
int  type,
int  elem_id 
) [static]

Definition at line 468 of file aacdec.c.

Referenced by aac_decode_frame_int().

static void imdct_and_windowing ( AACContext *  ac,
SingleChannelElement *  sce 
) [static]

Conduct IMDCT and windowing.

Definition at line 2154 of file aacdec.c.

Referenced by spectral_to_sample().

static int latm_decode_audio_specific_config ( struct LATMContext *  latmctx,
GetBitContext *  gb,
int  asclen 
) [static]

Definition at line 2631 of file aacdec.c.

Referenced by read_stream_mux_config().

static int latm_decode_frame ( AVCodecContext *  avctx,
void *  out,
int *  got_frame_ptr,
AVPacket *  avpkt 
) [static]

Definition at line 2817 of file aacdec.c.

static av_cold int latm_decode_init ( AVCodecContext *  avctx  )  [static]

Definition at line 2867 of file aacdec.c.

static uint32_t latm_get_value ( GetBitContext *  b  )  [inline, static]

Definition at line 2624 of file aacdec.c.

Referenced by read_stream_mux_config().

static av_always_inline int lcg_random ( int  previous_val  )  [static]

linear congruential pseudorandom number generator

Parameters:
previous_val pointer to the current state of the generator
Returns:
Returns a 32-bit pseudorandom integer

Definition at line 784 of file aacdec.c.

Referenced by decode_spectrum_and_dequant().

static int output_configure ( AACContext *  ac,
uint8_t  layout_map[MAX_ELEM_ID *4][3],
int  tags,
int  channel_config,
enum OCStatus  oc_type 
) [static]

Configure output channel order based on the current program configuration element.

Returns:
Returns error status. 0 - OK, !0 - error

Definition at line 386 of file aacdec.c.

Referenced by aac_decode_frame_int(), aac_decode_init(), decode_extension_payload(), decode_ga_specific_config(), get_che(), and parse_adts_frame_header().

static int parse_adts_frame_header ( AACContext *  ac,
GetBitContext *  gb 
) [static]

Definition at line 2350 of file aacdec.c.

Referenced by aac_decode_frame_int().

static void pop_output_configuration ( AACContext *  ac  )  [static]

Restore the previous output configuration if and only if the current configuration is unlocked.

Definition at line 371 of file aacdec.c.

Referenced by aac_decode_frame(), aac_decode_frame_int(), and latm_decode_frame().

static av_always_inline void predict ( PredictorState *  ps,
float *  coef,
int  output_enable 
) [static]

Definition at line 1566 of file aacdec.c.

Referenced by apply_prediction(), and decode_line().

static void push_output_configuration ( AACContext *  ac  )  [static]

Save current output configuration if and only if it has been locked.

Definition at line 360 of file aacdec.c.

Referenced by aac_decode_frame(), aac_decode_frame_int(), get_che(), latm_decode_frame(), and parse_adts_frame_header().

static int read_audio_mux_element ( struct LATMContext *  latmctx,
GetBitContext *  gb 
) [static]

Definition at line 2788 of file aacdec.c.

Referenced by latm_decode_frame().

static int read_payload_length_info ( struct LATMContext *  ctx,
GetBitContext *  gb 
) [static]

Definition at line 2767 of file aacdec.c.

Referenced by read_audio_mux_element().

static int read_stream_mux_config ( struct LATMContext *  latmctx,
GetBitContext *  gb 
) [static]

Definition at line 2685 of file aacdec.c.

Referenced by read_audio_mux_element().

static void reset_all_predictors ( PredictorState *  ps  )  [static]

Definition at line 799 of file aacdec.c.

Referenced by apply_prediction().

static av_always_inline void reset_predict_state ( PredictorState *  ps  )  [static]

Definition at line 789 of file aacdec.c.

Referenced by reset_all_predictors(), and reset_predictor_group().

static void reset_predictor_group ( PredictorState *  ps,
int  group_num 
) [static]

Definition at line 822 of file aacdec.c.

Referenced by apply_prediction().

static int sample_rate_idx ( int  rate  )  [static]

Definition at line 806 of file aacdec.c.

Referenced by aac_decode_init().

static int set_default_channel_config ( AVCodecContext *  avctx,
uint8_t(*)  layout_map[3],
int *  tags,
int  channel_config 
) [static]

Set up channel positions based on a default channel configuration as specified in table 1.17.

Returns:
Returns error status. 0 - OK, !0 - error

Definition at line 453 of file aacdec.c.

Referenced by aac_decode_init(), decode_ga_specific_config(), get_che(), and parse_adts_frame_header().

static int skip_data_stream_element ( AACContext *  ac,
GetBitContext *  gb 
) [static]

Skip data_stream_element; reference: table 4.10.

Definition at line 932 of file aacdec.c.

Referenced by aac_decode_frame_int().

static uint64_t sniff_channel_order ( uint8_t(*)  layout_map[3],
int  tags 
) [static]

Definition at line 227 of file aacdec.c.

Referenced by output_configure().

static void spectral_to_sample ( AACContext *  ac  )  [static]

Convert spectral data to float samples, applying all supported tools as appropriate.

Definition at line 2307 of file aacdec.c.

Referenced by aac_decode_frame_int().

static void update_ltp ( AACContext *  ac,
SingleChannelElement *  sce 
) [static]

Update the LTP buffer for next frame.

Definition at line 2119 of file aacdec.c.

Referenced by spectral_to_sample().

static float* VMUL2 ( float *  dst,
const float *  v,
unsigned  idx,
const float *  scale 
) [inline, static]

Definition at line 1249 of file aacdec.c.

Referenced by decode_spectrum_and_dequant().

static float* VMUL2S ( float *  dst,
const float *  v,
unsigned  idx,
unsigned  sign,
const float *  scale 
) [inline, static]

Definition at line 1273 of file aacdec.c.

Referenced by decode_spectrum_and_dequant().

static float* VMUL4 ( float *  dst,
const float *  v,
unsigned  idx,
const float *  scale 
) [inline, static]

Definition at line 1260 of file aacdec.c.

Referenced by decode_spectrum_and_dequant().

static float* VMUL4S ( float *  dst,
const float *  v,
unsigned  idx,
unsigned  sign,
const float *  scale 
) [inline, static]

Definition at line 1290 of file aacdec.c.

Referenced by decode_spectrum_and_dequant().

static void windowing_and_mdct_ltp ( AACContext *  ac,
float *  out,
float *  in,
IndividualChannelStream *  ics 
) [static]

Apply windowing and MDCT to obtain the spectral coefficient from the predicted sample by LTP.

Definition at line 2061 of file aacdec.c.

Referenced by apply_ltp().

Variable Documentation

const float cce_scale[] [static]

Initial value:

 {
    1.09050773266525765921, 
    1.18920711500272106672, 
    M_SQRT2,
    2,
}

Definition at line 1797 of file aacdec.c.

AVCodec ff_aac_decoder

Initial value:

 {
    .name            = "aac",
    .type            = AVMEDIA_TYPE_AUDIO,
    .id              = CODEC_ID_AAC,
    .priv_data_size  = sizeof(AACContext),
    .init            = aac_decode_init,
    .close           = aac_decode_close,
    .decode          = aac_decode_frame,
    .long_name       = NULL_IF_CONFIG_SMALL("Advanced Audio Coding"),
    .sample_fmts     = (const enum AVSampleFormat[]) {
        AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE
    },
    .capabilities    = CODEC_CAP_CHANNEL_CONF | CODEC_CAP_DR1,
    .channel_layouts = aac_channel_layout,
    .flush = flush,
}

Definition at line 2879 of file aacdec.c.

AVCodec ff_aac_latm_decoder

Initial value:

 {
    .name            = "aac_latm",
    .type            = AVMEDIA_TYPE_AUDIO,
    .id              = CODEC_ID_AAC_LATM,
    .priv_data_size  = sizeof(struct LATMContext),
    .init            = latm_decode_init,
    .close           = aac_decode_close,
    .decode          = latm_decode_frame,
    .long_name       = NULL_IF_CONFIG_SMALL("AAC LATM (Advanced Audio Codec LATM syntax)"),
    .sample_fmts     = (const enum AVSampleFormat[]) {
        AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE
    },
    .capabilities    = CODEC_CAP_CHANNEL_CONF | CODEC_CAP_DR1,
    .channel_layouts = aac_channel_layout,
    .flush = flush,
}

Definition at line 2901 of file aacdec.c.

VLC vlc_scalefactors [static]

Definition at line 112 of file aacdec.c.

VLC vlc_spectral[11] [static]

Definition at line 113 of file aacdec.c.

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