Atrac 3 compatible decoder. More...

#include <math.h>
#include <stddef.h>
#include <stdio.h>
#include "avcodec.h"
#include "internal.h"
#include "get_bits.h"
#include "dsputil.h"
#include "bytestream.h"
#include "fft.h"
#include "fmtconvert.h"
#include "atrac.h"
#include "atrac3data.h"

Data Structures
struct	gain_info
struct	gain_block
struct	tonal_component
struct	channel_unit
struct	ATRAC3Context

Macros
#define	JOINT_STEREO 0x12
#define	STEREO 0x2
#define	SAMPLES_PER_FRAME 1024
#define	MDCT_SIZE 512
#define	INTERPOLATE(old, new, nsample) ((old) + (nsample)0.125((new)-(old)))

Functions
static void	IMLT (ATRAC3Context q, float pInput, float *pOutput, int odd_band)
	Regular 512 points IMDCT without overlapping, with the exception of the swapping of odd bands caused by the reverse spectra of the QMF.
static int	decode_bytes (const uint8_t inbuffer, uint8_t out, int bytes)
	Atrac 3 indata descrambling, only used for data coming from the rm container.
static av_cold int	init_atrac3_transforms (ATRAC3Context *q, int is_float)
static av_cold int	atrac3_decode_close (AVCodecContext *avctx)
	Atrac3 uninit, free all allocated memory.
static void	readQuantSpectralCoeffs (GetBitContext gb, int selector, int codingFlag, int mantissas, int numCodes)
	/ * Mantissa decoding
static int	decodeSpectrum (GetBitContext gb, float pOut)
	Restore the quantized band spectrum coefficients.
static int	decodeTonalComponents (GetBitContext gb, tonal_component pComponent, int numBands)
	Restore the quantized tonal components.
static int	decodeGainControl (GetBitContext gb, gain_block pGb, int numBands)
	Decode gain parameters for the coded bands.
static void	gainCompensateAndOverlap (float pIn, float pPrev, float pOut, gain_info pGain1, gain_info *pGain2)
	Apply gain parameters and perform the MDCT overlapping part.
static int	addTonalComponents (float pSpectrum, int numComponents, tonal_component pComponent)
	Combine the tonal band spectrum and regular band spectrum Return position of the last tonal coefficient.
static void	reverseMatrixing (float su1, float su2, int pPrevCode, int pCurrCode)
static void	getChannelWeights (int indx, int flag, float ch[2])
static void	channelWeighting (float su1, float su2, int *p3)
static int	decodeChannelSoundUnit (ATRAC3Context q, GetBitContext gb, channel_unit pSnd, float pOut, int channelNum, int codingMode)
	Decode a Sound Unit.
static int	decodeFrame (ATRAC3Context q, const uint8_t databuf, float **out_samples)
	Frame handling.
static int	atrac3_decode_frame (AVCodecContext avctx, void data, int got_frame_ptr, AVPacket avpkt)
	Atrac frame decoding.
static av_cold int	atrac3_decode_init (AVCodecContext *avctx)
	Atrac3 initialization.

Variables
static float	mdct_window [MDCT_SIZE]
static VLC	spectral_coeff_tab [7]
static float	gain_tab1 [16]
static float	gain_tab2 [31]
static DSPContext	dsp
AVCodec	ff_atrac3_decoder

Detailed Description

Atrac 3 compatible decoder.

This decoder handles Sony's ATRAC3 data.

Container formats used to store atrac 3 data: RealMedia (.rm), RIFF WAV (.wav, .at3), Sony OpenMG (.oma, .aa3).

To use this decoder, a calling application must supply the extradata bytes provided in the containers above.

Definition in file atrac3.c.

Macro Definition Documentation

#define INTERPOLATE	(	old,
		new,
		nsample
	)	((old) + (nsample)0.125((new)-(old)))

Definition at line 557 of file atrac3.c.

Referenced by channelWeighting(), and reverseMatrixing().

#define JOINT_STEREO 0x12

Definition at line 50 of file atrac3.c.

Referenced by atrac3_decode_init(), decodeChannelSoundUnit(), decodeFrame(), and MP3lame_encode_init().

#define MDCT_SIZE 512

Definition at line 54 of file atrac3.c.

Referenced by IMLT().

#define SAMPLES_PER_FRAME 1024

Definition at line 53 of file atrac3.c.

Referenced by atrac3_decode_frame(), atrac3_decode_init(), decodeSpectrum(), and decodeTonalComponents().

#define STEREO 0x2

Definition at line 51 of file atrac3.c.

Referenced by atrac3_decode_init().

Function Documentation

static int addTonalComponents	(	float *	pSpectrum,
		int	numComponents,
		tonal_component *	pComponent
	)

static

Combine the tonal band spectrum and regular band spectrum Return position of the last tonal coefficient.

Parameters

pSpectrum	output spectrum buffer
numComponents	amount of tonal components
pComponent	tonal components for this band

Definition at line 539 of file atrac3.c.

Referenced by decodeChannelSoundUnit().

static av_cold int atrac3_decode_close ( AVCodecContext * avctx )

static

Atrac3 uninit, free all allocated memory.

Definition at line 227 of file atrac3.c.

Referenced by atrac3_decode_init().

static int atrac3_decode_frame	(	AVCodecContext *	avctx,
		void *	data,
		int *	got_frame_ptr,
		AVPacket *	avpkt
	)

static

Atrac frame decoding.

Parameters

avctx pointer to the AVCodecContext

Definition at line 837 of file atrac3.c.

static av_cold int atrac3_decode_init ( AVCodecContext * avctx )

static

Atrac3 initialization.

Parameters

avctx pointer to the AVCodecContext

Definition at line 905 of file atrac3.c.

static void channelWeighting	(	float *	su1,
		float *	su2,
		int *	p3
	)

static

Definition at line 634 of file atrac3.c.

Referenced by decodeFrame().

static int decode_bytes	(	const uint8_t *	inbuffer,
		uint8_t *	out,
		int	bytes
	)

static

Atrac 3 indata descrambling, only used for data coming from the rm container.

Parameters

inbuffer	pointer to 8 bit array of indata
out	pointer to 8 bit array of outdata
bytes	amount of bytes

Definition at line 181 of file atrac3.c.

Referenced by atrac3_decode_frame().

static int decodeChannelSoundUnit	(	ATRAC3Context *	q,
		GetBitContext *	gb,
		channel_unit *	pSnd,
		float *	pOut,
		int	channelNum,
		int	codingMode
	)

static

Decode a Sound Unit.

Parameters

gb	the GetBit context
pSnd	the channel unit to be used
pOut	the decoded samples before IQMF in float representation
channelNum	channel number
codingMode	the coding mode (JOINT_STEREO or regular stereo/mono)

Definition at line 671 of file atrac3.c.

Referenced by decodeFrame().

static int decodeFrame	(	ATRAC3Context *	q,
		const uint8_t *	databuf,
		float **	out_samples
	)

static

Frame handling.

Parameters

q	Atrac3 private context
databuf	the input data

Definition at line 737 of file atrac3.c.

Referenced by atrac3_decode_frame().

static int decodeGainControl	(	GetBitContext *	gb,
		gain_block *	pGb,
		int	numBands
	)

static

Decode gain parameters for the coded bands.

Parameters

gb	the GetBit context
pGb	the gainblock for the current band
numBands	amount of coded bands

Definition at line 443 of file atrac3.c.

Referenced by decodeChannelSoundUnit().

static int decodeSpectrum	(	GetBitContext *	gb,
		float *	pOut
	)

static

Restore the quantized band spectrum coefficients.

Parameters

gb	the GetBit context
pOut	decoded band spectrum

Returns: outSubbands subband counter, fix for broken specification/files

Definition at line 308 of file atrac3.c.

Referenced by decodeChannelSoundUnit().

static int decodeTonalComponents	(	GetBitContext *	gb,
		tonal_component *	pComponent,
		int	numBands
	)

static

Restore the quantized tonal components.

Parameters

gb	the GetBit context
pComponent	tone component
numBands	amount of coded bands

Definition at line 366 of file atrac3.c.

Referenced by decodeChannelSoundUnit().

static void gainCompensateAndOverlap	(	float *	pIn,
		float *	pPrev,
		float *	pOut,
		gain_info *	pGain1,
		gain_info *	pGain2
	)

static

Apply gain parameters and perform the MDCT overlapping part.

Parameters

pIn	input float buffer
pPrev	previous float buffer to perform overlap against
pOut	output float buffer
pGain1	current band gain info
pGain2	next band gain info

Definition at line 482 of file atrac3.c.

Referenced by decodeChannelSoundUnit().

static void getChannelWeights	(	int	indx,
		int	flag,
		float	ch[2]
	)

static

Definition at line 621 of file atrac3.c.

Referenced by channelWeighting().

static void IMLT	(	ATRAC3Context *	q,
		float *	pInput,
		float *	pOutput,
		int	odd_band
	)

static

Regular 512 points IMDCT without overlapping, with the exception of the swapping of odd bands caused by the reverse spectra of the QMF.

Parameters

pInput	float input
pOutput	float output
odd_band	1 if the band is an odd band

Reverse the odd bands before IMDCT, this is an effect of the QMF transform or it gives better compression to do it this way. FIXME: It should be possible to handle this in imdct_calc for that to happen a modification of the prerotation step of all SIMD code and C code is needed. Or fix the functions before so they generate a pre reversed spectrum.

Definition at line 147 of file atrac3.c.

Referenced by decodeChannelSoundUnit().

static av_cold int init_atrac3_transforms	(	ATRAC3Context *	q,
		int	is_float
	)

static

Definition at line 204 of file atrac3.c.

Referenced by atrac3_decode_init().

static void readQuantSpectralCoeffs	(	GetBitContext *	gb,
		int	selector,
		int	codingFlag,
		int *	mantissas,
		int	numCodes
	)

static

/ * Mantissa decoding

Parameters

gb	the GetBit context
selector	what table is the output values coded with
codingFlag	constant length coding or variable length coding
mantissas	mantissa output table
numCodes	amount of values to get

Definition at line 250 of file atrac3.c.

Referenced by decodeSpectrum(), and decodeTonalComponents().

static void reverseMatrixing	(	float *	su1,
		float *	su2,
		int *	pPrevCode,
		int *	pCurrCode
	)

static

Definition at line 559 of file atrac3.c.

Referenced by decodeFrame().

Variable Documentation

DSPContext dsp

static

Definition at line 135 of file atrac3.c.

Referenced by dnxhd_get_blocks(), dvvideo_init(), rtjpeg_decode_init(), vc1_interp_mc(), vc1_mc_1mv(), vc1_mc_4mv_chroma(), vc1_mc_4mv_chroma4(), vc1_mc_4mv_luma(), and vp3_update_thread_context().

AVCodec ff_atrac3_decoder

Initial value:

{
    .name = "atrac3",
    .type = AVMEDIA_TYPE_AUDIO,
    .id = CODEC_ID_ATRAC3,
    .priv_data_size = sizeof(ATRAC3Context),
    .init = atrac3_decode_init,
    .close = atrac3_decode_close,
    .decode = atrac3_decode_frame,
    .capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_DR1,
    .long_name = NULL_IF_CONFIG_SMALL("Atrac 3 (Adaptive TRansform Acoustic Coding 3)"),
}

Definition at line 1074 of file atrac3.c.

float gain_tab1[16]

static

Definition at line 133 of file atrac3.c.

Referenced by atrac3_decode_init(), and gainCompensateAndOverlap().

float gain_tab2[31]

static

Definition at line 134 of file atrac3.c.

Referenced by atrac3_decode_init(), and gainCompensateAndOverlap().

float mdct_window[MDCT_SIZE]

static

Definition at line 131 of file atrac3.c.

Referenced by IMLT(), and init_atrac3_transforms().

VLC spectral_coeff_tab[7]

static

Definition at line 132 of file atrac3.c.

Data Structures

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

Function Documentation

Variable Documentation