libavcodec/atrac3.c File Reference

Atrac 3 compatible decoder. More...

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

Go to the source code of this file.

Data Structures

struct gain_info

struct gain_block

struct tonal_component

struct channel_unit

struct ATRAC3Context

Defines

#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.

Define Documentation

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

Definition at line 553 of file atrac3.c.

Referenced by channelWeighting(), reverseMatrixing(), and Super2xSaI_ex().

#define JOINT_STEREO 0x12

Definition at line 49 of file atrac3.c.

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

#define MDCT_SIZE 512

Definition at line 53 of file atrac3.c.

Referenced by IMLT().

#define SAMPLES_PER_FRAME 1024

Definition at line 52 of file atrac3.c.

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

#define STEREO 0x2

Definition at line 50 of file atrac3.c.

Referenced by atrac3_decode_init(), and cook_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 535 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 223 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 832 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 900 of file atrac3.c.

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

Definition at line 630 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 180 of file atrac3.c.

Referenced by atrac3_decode_frame(), and decode_bytes_and_gain().

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 667 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 732 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 439 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 304 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 362 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 478 of file atrac3.c.

Referenced by decodeChannelSoundUnit().

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

Definition at line 617 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 146 of file atrac3.c.

Referenced by decodeChannelSoundUnit().

static av_cold int init_atrac3_transforms	(	ATRAC3Context *	q,
		int	is_float
	)			`[static]`

Definition at line 200 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 246 of file atrac3.c.

Referenced by decodeSpectrum(), and decodeTonalComponents().

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

Definition at line 555 of file atrac3.c.

Referenced by decodeFrame().

Variable Documentation

DSPContext dsp [static]

Definition at line 134 of file atrac3.c.

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

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 1067 of file atrac3.c.

float gain_tab1[16] [static]

Definition at line 132 of file atrac3.c.

Referenced by atrac3_decode_init(), and gainCompensateAndOverlap().

float gain_tab2[31] [static]

Definition at line 133 of file atrac3.c.

Referenced by atrac3_decode_init(), and gainCompensateAndOverlap().

float mdct_window[MDCT_SIZE] [static]

Definition at line 130 of file atrac3.c.

Referenced by IMLT(), and init_atrac3_transforms().

VLC spectral_coeff_tab[7] [static]

Definition at line 131 of file atrac3.c.


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