Global structures, constants and data for ATRAC3+ decoder. More...

#include <stdint.h>
#include "libavutil/float_dsp.h"
#include "atrac.h"
#include "avcodec.h"
#include "fft.h"
#include "get_bits.h"

Go to the source code of this file.

Data Structures
struct	Atrac3pIPQFChannelCtx
	Per-channel IPQF history. More...

struct	Atrac3pWaveEnvelope
	Amplitude envelope of a group of sine waves. More...

struct	Atrac3pWavesData
	Parameters of a group of sine waves. More...

struct	Atrac3pWaveParam
	Parameters of a single sine wave. More...

struct	Atrac3pChanParams
	Sound channel parameters. More...

struct	Atrac3pWaveSynthParams

struct	Atrac3pChanUnitCtx
	Channel unit parameters. More...

Macros
#define	ATRAC3P_SUBBANDS 16
	Global unit sizes.

#define	ATRAC3P_SUBBAND_SAMPLES 128
	number of samples per subband

#define	ATRAC3P_FRAME_SAMPLES (ATRAC3P_SUBBAND_SAMPLES * ATRAC3P_SUBBANDS)

#define	ATRAC3P_PQF_FIR_LEN 12
	length of the prototype FIR of the PQF

#define	ATRAC3P_POWER_COMP_OFF 15
	Global constants.

Enumerations
enum	Atrac3pChannelUnitTypes { CH_UNIT_MONO = 0, CH_UNIT_STEREO = 1, CH_UNIT_EXTENSION = 2, CH_UNIT_TERMINATOR = 3 }
	ATRAC3+ channel unit types. More...

Functions
void	ff_atrac3p_init_vlcs (void)
	Initialize VLC tables for bitstream parsing.

int	ff_atrac3p_decode_channel_unit (GetBitContext gb, Atrac3pChanUnitCtx ctx, int num_channels, AVCodecContext *avctx)
	Decode bitstream data of a channel unit.

void	ff_atrac3p_init_imdct (AVCodecContext avctx, FFTContext mdct_ctx)
	Initialize IMDCT transform.

void	ff_atrac3p_init_wave_synth (void)
	Initialize sine waves synthesizer.

void	ff_atrac3p_generate_tones (Atrac3pChanUnitCtx ch_unit, AVFloatDSPContext fdsp, int ch_num, int sb, float *out)
	Synthesize sine waves for a particular subband.

void	ff_atrac3p_power_compensation (Atrac3pChanUnitCtx ctx, int ch_index, float sp, int rng_index, int sb_num)
	Perform power compensation aka noise dithering.

void	ff_atrac3p_imdct (AVFloatDSPContext fdsp, FFTContext mdct_ctx, float pIn, float pOut, int wind_id, int sb)
	Regular IMDCT and windowing without overlapping, with spectrum reversal in the odd subbands.

void	ff_atrac3p_ipqf (FFTContext dct_ctx, Atrac3pIPQFChannelCtx hist, const float in, float out)
	Subband synthesis filter based on the polyphase quadrature (pseudo-QMF) filter bank.

Variables
const uint16_t	ff_atrac3p_qu_to_spec_pos [33]
	Map quant unit number to its position in the spectrum.

const float	ff_atrac3p_sf_tab [64]

const float	ff_atrac3p_mant_tab [8]

Detailed Description

Global structures, constants and data for ATRAC3+ decoder.

Definition in file atrac3plus.h.

Macro Definition Documentation

#define ATRAC3P_SUBBANDS 16

Global unit sizes.

number of PQF subbands

Definition at line 40 of file atrac3plus.h.

Referenced by decode_gainc_data(), decode_residual_spectrum(), decode_tones_info(), ff_atrac3p_ipqf(), and reconstruct_frame().

#define ATRAC3P_SUBBAND_SAMPLES 128

number of samples per subband

Definition at line 41 of file atrac3plus.h.

Referenced by decode_residual_spectrum(), ff_atrac3p_imdct(), ff_atrac3p_ipqf(), ff_atrac3p_power_compensation(), and reconstruct_frame().

#define ATRAC3P_FRAME_SAMPLES (ATRAC3P_SUBBAND_SAMPLES * ATRAC3P_SUBBANDS)

Definition at line 42 of file atrac3plus.h.

Referenced by atrac3p_decode_frame(), and ff_atrac3p_ipqf().

#define ATRAC3P_PQF_FIR_LEN 12

length of the prototype FIR of the PQF

Definition at line 44 of file atrac3plus.h.

Referenced by ff_atrac3p_ipqf().

#define ATRAC3P_POWER_COMP_OFF 15

Global constants.

disable power compensation

Definition at line 47 of file atrac3plus.h.

Referenced by decode_spectrum(), and ff_atrac3p_power_compensation().

Enumeration Type Documentation

enum Atrac3pChannelUnitTypes

ATRAC3+ channel unit types.

Enumerator:

CH_UNIT_MONO	unit containing one coded channel
CH_UNIT_STEREO	unit containing two jointly-coded channels
CH_UNIT_EXTENSION	unit containing extension information
CH_UNIT_TERMINATOR	unit sequence terminator

Definition at line 50 of file atrac3plus.h.

Function Documentation

void ff_atrac3p_init_vlcs ( void )

Initialize VLC tables for bitstream parsing.

Definition at line 83 of file atrac3plus.c.

Referenced by atrac3p_decode_init().

int ff_atrac3p_decode_channel_unit	(	GetBitContext *	gb,
		Atrac3pChanUnitCtx *	ctx,
		int	num_channels,
		AVCodecContext *	avctx
	)

Decode bitstream data of a channel unit.

Parameters

[in]	gb	the GetBit context
[in,out]	ctx	ptr to the channel unit context
[in]	num_channels	number of channels to process
[in]	avctx	ptr to the AVCodecContext

Returns: result code: 0 = OK, otherwise - error code

Definition at line 1764 of file atrac3plus.c.

Referenced by atrac3p_decode_frame().

void ff_atrac3p_init_imdct	(	AVCodecContext *	avctx,
		FFTContext *	mdct_ctx
	)

Initialize IMDCT transform.

Parameters

[in]	avctx	ptr to the AVCodecContext
[in]	mdct_ctx	pointer to MDCT transform context

Definition at line 79 of file atrac3plusdsp.c.

Referenced by atrac3p_decode_init().

void ff_atrac3p_init_wave_synth ( void )

Initialize sine waves synthesizer.

Definition at line 96 of file atrac3plusdsp.c.

Referenced by atrac3p_decode_init().

void ff_atrac3p_generate_tones	(	Atrac3pChanUnitCtx *	ch_unit,
		AVFloatDSPContext *	fdsp,
		int	ch_num,
		int	sb,
		float *	out
	)

Synthesize sine waves for a particular subband.

Parameters

[in]	ch_unit	pointer to the channel unit context
[in]	fdsp	pointer to float DSP context
[in]	ch_num	which channel to process
[in]	sb	which subband to process
[out]	out	receives processed data

Definition at line 177 of file atrac3plusdsp.c.

Referenced by reconstruct_frame().

void ff_atrac3p_power_compensation	(	Atrac3pChanUnitCtx *	ctx,
		int	ch_index,
		float *	sp,
		int	rng_index,
		int	sb_num
	)

Perform power compensation aka noise dithering.

Parameters

[in]	ctx	ptr to the channel context
[in]	ch_index	which channel to process
[in,out]	sp	ptr to channel spectrum to process
[in]	rng_index	indicates which RNG table to use
[in]	sb_num	which subband to process

Definition at line 411 of file atrac3plusdsp.c.

Referenced by decode_residual_spectrum().

void ff_atrac3p_imdct	(	AVFloatDSPContext *	fdsp,
		FFTContext *	mdct_ctx,
		float *	pIn,
		float *	pOut,
		int	wind_id,
		int	sb
	)

Regular IMDCT and windowing without overlapping, with spectrum reversal in the odd subbands.

Parameters

[in]	fdsp	pointer to float DSP context
[in]	mdct_ctx	pointer to MDCT transform context
[in]	pIn	float input
[out]	pOut	float output
[in]	wind_id	which MDCT window to apply
[in]	sb	subband number