AAC decoder. More...

#include "libavutil/float_dsp.h"
#include "libavutil/opt.h"
#include "avcodec.h"
#include "internal.h"
#include "get_bits.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>

Data Structures
struct	elem_to_channel

struct	LATMContext

Macros
#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

#define	AACDEC_FLAGS AV_OPT_FLAG_DECODING_PARAM \| AV_OPT_FLAG_AUDIO_PARAM
	AVOptions for Japanese DTV specific extensions (ADTS only)

Functions
static int	output_configure (AACContext ac, uint8_t layout_map[MAX_ELEM_ID 4][3], int tags, enum OCStatus oc_type, int get_new_frame)
	Configure output channel order based on the current program configuration element.

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	frame_configure_elements (AVCodecContext *avctx)

static int	assign_pair (struct elem_to_channel e2c_vec[MAX_ELEM_ID], uint8_t(*layout_map)[3], int offset, 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 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 (unsigned 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 void	aacdec_init (AACContext *ac)

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 (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)
	Decode dynamic range information; reference: table 4.52.

static int	decode_fill (AACContext ac, GetBitContext gb, int len)

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, AVPacket *avpkt)

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 []

static const AVOption	options []

static const AVClass	aac_decoder_class

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.

Macro Definition Documentation

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

Definition at line 121 of file aacdec.c.

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

#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 876 of file aacdec.c.

Referenced by aac_decode_init().

#define LOAS_SYNC_WORD 0x2b7

11 bits LOAS sync word

Definition at line 2717 of file aacdec.c.

Referenced by latm_decode_frame().

#define AACDEC_FLAGS AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM

AVOptions for Japanese DTV specific extensions (ADTS only)

Definition at line 3003 of file aacdec.c.

Function Documentation

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

static

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

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

Definition at line 424 of file aacdec.c.

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

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

static

Definition at line 123 of file aacdec.c.

Referenced by decode_ga_specific_config().

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 147 of file aacdec.c.

Referenced by output_configure().

static int frame_configure_elements ( AVCodecContext * avctx )

static

Definition at line 176 of file aacdec.c.

Referenced by aac_decode_frame_int(), and output_configure().

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

static

Definition at line 215 of file aacdec.c.

Referenced by sniff_channel_order().

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

static

Definition at line 235 of file aacdec.c.

Referenced by sniff_channel_order().

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

static

Definition at line 265 of file aacdec.c.

Referenced by output_configure().

static void push_output_configuration ( AACContext * ac )

static

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

Definition at line 398 of file aacdec.c.

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

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 409 of file aacdec.c.

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

static void flush ( AVCodecContext * avctx )

static

Definition at line 473 of file aacdec.c.

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

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 496 of file aacdec.c.

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

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

static

Definition at line 511 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 602 of file aacdec.c.

Referenced by decode_pce().

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 636 of file aacdec.c.

Referenced by aac_decode_frame_int(), and decode_ga_specific_config().

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 703 of file aacdec.c.

Referenced by decode_audio_specific_config().

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 776 of file aacdec.c.

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

static av_always_inline int lcg_random ( unsigned 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 830 of file aacdec.c.

Referenced by decode_spectrum_and_dequant().

static av_always_inline void reset_predict_state ( PredictorState * ps )

static

Definition at line 836 of file aacdec.c.

Referenced by reset_all_predictors(), and reset_predictor_group().

static void reset_all_predictors ( PredictorState * ps )

static

Definition at line 846 of file aacdec.c.

Referenced by apply_prediction().

static int sample_rate_idx ( int rate )

static

Definition at line 853 of file aacdec.c.

Referenced by aac_decode_init().

static void reset_predictor_group	(	PredictorState *	ps,
		int	group_num
	)

static

Definition at line 869 of file aacdec.c.

Referenced by apply_prediction().

static void aacdec_init ( AACContext * ac )

static

Definition at line 2989 of file aacdec.c.

Referenced by aac_decode_init().

static av_cold int aac_decode_init ( AVCodecContext * avctx )

static

Definition at line 884 of file aacdec.c.

Referenced by latm_decode_init().

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

static

Skip data_stream_element; reference: table 4.10.

Definition at line 978 of file aacdec.c.

Referenced by aac_decode_frame_int().

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

static

Definition at line 995 of file aacdec.c.

Referenced by decode_ics_info().

static void decode_ltp	(	LongTermPrediction *	ltp,
		GetBitContext *	gb,
		uint8_t	max_sfb
	)

static

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

Definition at line 1015 of file aacdec.c.

Referenced by decode_cpe(), and decode_ics_info().

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

static

Decode Individual Channel Stream info; reference: table 4.6.

Definition at line 1029 of file aacdec.c.

Referenced by decode_cpe(), and decode_ics().

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 1102 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 1151 of file aacdec.c.

Referenced by decode_ics().

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 1213 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 1240 of file aacdec.c.

Referenced by decode_ics().

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 1282 of file aacdec.c.

Referenced by decode_cpe().

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

inlinestatic

Definition at line 1295 of file aacdec.c.

Referenced by decode_spectrum_and_dequant().

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

inlinestatic

Definition at line 1306 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
	)

inlinestatic

Definition at line 1319 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
	)

inlinestatic

Definition at line 1336 of file aacdec.c.

Referenced by decode_spectrum_and_dequant().

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 1374 of file aacdec.c.

Referenced by decode_ics().

static av_always_inline float flt16_round ( float pf )

static

Definition at line 1588 of file aacdec.c.

Referenced by predict().

static av_always_inline float flt16_even ( float pf )

static

Definition at line 1596 of file aacdec.c.

Referenced by predict().

static av_always_inline float flt16_trunc ( float pf )

static

Definition at line 1604 of file aacdec.c.

Referenced by predict().

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

static

Definition at line 1612 of file aacdec.c.

Referenced by apply_prediction(), decode_line(), and encode_line().

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

static

Apply AAC-Main style frequency domain prediction.

Definition at line 1646 of file aacdec.c.

Referenced by decode_cpe(), and decode_ics().

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 1676 of file aacdec.c.

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

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

static

Mid/Side stereo decoding; reference: 4.6.8.1.3.

Definition at line 1734 of file aacdec.c.

Referenced by decode_cpe().

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 1764 of file aacdec.c.

Referenced by decode_cpe().

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 1804 of file aacdec.c.

Referenced by aac_decode_frame_int().

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 1855 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 1927 of file aacdec.c.

Referenced by decode_dynamic_range().

static int decode_dynamic_range	(	DynamicRangeControl *	che_drc,
		GetBitContext *	gb
	)

static

Decode dynamic range information; reference: table 4.52.

Returns: Returns number of bytes consumed.

Definition at line 1946 of file aacdec.c.

Referenced by decode_extension_payload().

static int decode_fill	(	AACContext *	ac,
		GetBitContext *	gb,
		int	len
	)

static

Definition at line 1993 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 2026 of file aacdec.c.

Referenced by aac_decode_frame_int().

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 2077 of file aacdec.c.

Referenced by aacdec_init().

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 2133 of file aacdec.c.

Referenced by aacdec_init().

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

static

Apply the long term prediction.

Definition at line 2159 of file aacdec.c.

Referenced by aacdec_init().

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

static

Update the LTP buffer for next frame.

Definition at line 2191 of file aacdec.c.

Referenced by aacdec_init().

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

static

Conduct IMDCT and windowing.

Definition at line 2226 of file aacdec.c.

Referenced by aacdec_init().

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 2291 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 2327 of file aacdec.c.

Referenced by spectral_to_sample().

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 2346 of file aacdec.c.

Referenced by spectral_to_sample().

static void spectral_to_sample ( AACContext * ac )

static

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

Definition at line 2379 of file aacdec.c.

Referenced by aac_decode_frame_int().

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

static

dual mono frames in Japanese DTV can have chan_config 0 WITHOUT specifying PCE. thus, set dual mono as default.

Definition at line 2422 of file aacdec.c.

Referenced by aac_decode_frame_int().

static int aac_decode_frame_int	(	AVCodecContext *	avctx,
		void *	data,
		int *	got_frame_ptr,
		GetBitContext *	gb,
		AVPacket *	avpkt
	)

static

Definition at line 2479 of file aacdec.c.

Referenced by aac_decode_frame(), and latm_decode_frame().

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

static

Definition at line 2639 of file aacdec.c.

static av_cold int aac_decode_close ( AVCodecContext * avctx )

static

Definition at line 2697 of file aacdec.c.

static uint32_t latm_get_value ( GetBitContext * b )

inlinestatic

Definition at line 2729 of file aacdec.c.

Referenced by read_stream_mux_config().

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

static

Definition at line 2736 of file aacdec.c.

Referenced by read_stream_mux_config().

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

static

Definition at line 2795 of file aacdec.c.

Referenced by read_audio_mux_element().

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

static

Definition at line 2877 of file aacdec.c.

Referenced by read_audio_mux_element().

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

static

Definition at line 2898 of file aacdec.c.

Referenced by latm_decode_frame().

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

static

Definition at line 2927 of file aacdec.c.

static av_cold int latm_decode_init ( AVCodecContext * avctx )

static

Definition at line 2978 of file aacdec.c.

Variable Documentation

VLC vlc_scalefactors

static

Definition at line 114 of file aacdec.c.

VLC vlc_spectral[11]

static

Definition at line 115 of file aacdec.c.

const float cce_scale[]

static

Initial value:

= {
    1.09050773266525765921, 
    1.18920711500272106672, 
    M_SQRT2,
    2,
}

Definition at line 1843 of file aacdec.c.

const AVOption options[]

static

Initial value:

= {
    {"dual_mono_mode", "Select the channel to decode for dual mono",
     0x42, AV_OPT_TYPE_INT, {.i64=-1}, -1, 2,
     AACDEC_FLAGS, "dual_mono_mode"},
    {"auto", "autoselection",            0, AV_OPT_TYPE_CONST, {.i64=-1}, INT_MIN, INT_MAX, AACDEC_FLAGS, "dual_mono_mode"},
    {"main", "Select Main/Left channel", 0, AV_OPT_TYPE_CONST, {.i64= 1}, INT_MIN, INT_MAX, AACDEC_FLAGS, "dual_mono_mode"},
    {"sub" , "Select Sub/Right channel", 0, AV_OPT_TYPE_CONST, {.i64= 2}, INT_MIN, INT_MAX, AACDEC_FLAGS, "dual_mono_mode"},
    {"both", "Select both channels",     0, AV_OPT_TYPE_CONST, {.i64= 0}, INT_MIN, INT_MAX, AACDEC_FLAGS, "dual_mono_mode"},
    {NULL},
}

Definition at line 3004 of file aacdec.c.

const AVClass aac_decoder_class

static

Initial value:

= {
    .class_name = "AAC decoder",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
}

Definition at line 3017 of file aacdec.c.

AVCodec ff_aac_decoder

Initial value:

= {
    .name            = "aac",
    .type            = AVMEDIA_TYPE_AUDIO,
    .id              = AV_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("AAC (Advanced Audio Coding)"),
    .sample_fmts     = (const enum AVSampleFormat[]) {
        AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE
    },
    .capabilities    = CODEC_CAP_CHANNEL_CONF | CODEC_CAP_DR1,
    .channel_layouts = aac_channel_layout,
    .flush = flush,
    .priv_class      = &aac_decoder_class,
}

Definition at line 3024 of file aacdec.c.

AVCodec ff_aac_latm_decoder

Initial value:

= {
    .name            = "aac_latm",
    .type            = AVMEDIA_TYPE_AUDIO,
    .id              = AV_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 Coding LATM syntax)"),
    .sample_fmts     = (const enum AVSampleFormat[]) {
        AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE
    },
    .capabilities    = CODEC_CAP_CHANNEL_CONF | CODEC_CAP_DR1,
    .channel_layouts = aac_channel_layout,
    .flush = flush,
}

Definition at line 3047 of file aacdec.c.

Data Structures

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

Function Documentation

Variable Documentation