Atrac 3 compatible decoder. More...

#include <math.h>
#include <stddef.h>
#include <stdio.h>
#include "libavutil/float_dsp.h"
#include "libavutil/libm.h"
#include "avcodec.h"
#include "bytestream.h"
#include "fft.h"
#include "fmtconvert.h"
#include "get_bits.h"
#include "internal.h"
#include "atrac.h"
#include "atrac3data.h"

Data Structures
struct	GainInfo

struct	GainBlock

struct	TonalComponent

struct	ChannelUnit

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 input, float *output, 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 input, uint8_t out, int bytes)

static av_cold void	init_atrac3_window (void)

static av_cold int	atrac3_decode_close (AVCodecContext *avctx)

static void	read_quant_spectral_coeffs (GetBitContext gb, int selector, int coding_flag, int mantissas, int num_codes)
	Mantissa decoding.

static int	decode_spectrum (GetBitContext gb, float output)
	Restore the quantized band spectrum coefficients.

static int	decode_tonal_components (GetBitContext gb, TonalComponent components, int num_bands)
	Restore the quantized tonal components.

static int	decode_gain_control (GetBitContext gb, GainBlock block, int num_bands)
	Decode gain parameters for the coded bands.

static void	gain_compensate_and_overlap (float input, float prev, float output, GainInfo gain1, GainInfo *gain2)
	Apply gain parameters and perform the MDCT overlapping part.

static int	add_tonal_components (float spectrum, int num_components, TonalComponent components)
	Combine the tonal band spectrum and regular band spectrum.

static void	reverse_matrixing (float su1, float su2, int prev_code, int curr_code)

static void	get_channel_weights (int index, int flag, float ch[2])

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

static int	decode_channel_sound_unit (ATRAC3Context q, GetBitContext gb, ChannelUnit snd, float output, int channel_num, int coding_mode)
	Decode a Sound Unit.

static int	decode_frame (AVCodecContext avctx, const uint8_t databuf, float **out_samples)

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

static void	atrac3_init_static_data (void)

static av_cold int	atrac3_decode_init (AVCodecContext *avctx)

Variables
static float	mdct_window [MDCT_SIZE]

static VLC_TYPE	atrac3_vlc_table [4096][2]

static VLC	spectral_coeff_tab [7]

static float	gain_tab1 [16]

static float	gain_tab2 [31]

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 JOINT_STEREO 0x12

Definition at line 51 of file atrac3.c.

Referenced by atrac3_decode_init(), decode_channel_sound_unit(), decode_frame(), and mp3lame_encode_init().

#define STEREO 0x2

Definition at line 52 of file atrac3.c.

Referenced by atrac3_decode_init().

#define SAMPLES_PER_FRAME 1024

Definition at line 54 of file atrac3.c.

Referenced by atrac3_decode_frame(), atrac3_decode_init(), decode_spectrum(), and decode_tonal_components().

#define MDCT_SIZE 512

Definition at line 55 of file atrac3.c.

Referenced by imlt().

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

Definition at line 530 of file atrac3.c.

Referenced by channel_weighting(), and reverse_matrixing().

Function Documentation

static void imlt	(	ATRAC3Context *	q,
		float *	input,
		float *	output,
		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

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 133 of file atrac3.c.

Referenced by decode_channel_sound_unit().

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

static

Definition at line 159 of file atrac3.c.

Referenced by atrac3_decode_frame().

static av_cold void init_atrac3_window ( void )

static

Definition at line 182 of file atrac3.c.

Referenced by atrac3_init_static_data().

static av_cold int atrac3_decode_close ( AVCodecContext * avctx )

static

Definition at line 197 of file atrac3.c.

Referenced by atrac3_decode_init().

static void read_quant_spectral_coeffs	(	GetBitContext *	gb,
		int	selector,
		int	coding_flag,
		int *	mantissas,
		int	num_codes
	)

static

Mantissa decoding.

Parameters

selector	which table the output values are coded with
coding_flag	constant length coding or variable length coding
mantissas	mantissa output table
num_codes	number of values to get

Definition at line 217 of file atrac3.c.

Referenced by decode_spectrum(), and decode_tonal_components().

static int decode_spectrum	(	GetBitContext *	gb,
		float *	output
	)

static

Restore the quantized band spectrum coefficients.

Returns: subband count, fix for broken specification/files

Definition at line 276 of file atrac3.c.

Referenced by decode_channel_sound_unit().

static int decode_tonal_components	(	GetBitContext *	gb,
		TonalComponent *	components,
		int	num_bands
	)

static

Restore the quantized tonal components.

Parameters

components	tonal components
num_bands	number of coded bands

Definition at line 334 of file atrac3.c.

Referenced by decode_channel_sound_unit().

static int decode_gain_control	(	GetBitContext *	gb,
		GainBlock *	block,
		int	num_bands
	)

static

Decode gain parameters for the coded bands.

Parameters

block	the gainblock for the current band
num_bands	amount of coded bands

Definition at line 418 of file atrac3.c.

Referenced by decode_channel_sound_unit().

static void gain_compensate_and_overlap	(	float *	input,
		float *	prev,
		float *	output,
		GainInfo *	gain1,
		GainInfo *	gain2
	)

static

Apply gain parameters and perform the MDCT overlapping part.

Parameters

input	input buffer
prev	previous buffer to perform overlap against
output	output buffer
gain1	current band gain info
gain2	next band gain info

Definition at line 456 of file atrac3.c.

Referenced by decode_channel_sound_unit().

static int add_tonal_components	(	float *	spectrum,
		int	num_components,
		TonalComponent *	components
	)

static

Combine the tonal band spectrum and regular band spectrum.

Parameters

spectrum	output spectrum buffer
num_components	number of tonal components
components	tonal components for this band

Returns: position of the last tonal coefficient

Definition at line 512 of file atrac3.c.

Referenced by decode_channel_sound_unit().

static void reverse_matrixing	(	float *	su1,
		float *	su2,
		int *	prev_code,
		int *	curr_code
	)

static

Definition at line 533 of file atrac3.c.

Referenced by decode_frame().

static void get_channel_weights	(	int	index,
		int	flag,
		float	ch[2]
	)

static

Definition at line 595 of file atrac3.c.

Referenced by channel_weighting().

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

static

Definition at line 608 of file atrac3.c.

Referenced by decode_frame().

static int decode_channel_sound_unit	(	ATRAC3Context *	q,
		GetBitContext *	gb,
		ChannelUnit *	snd,
		float *	output,
		int	channel_num,
		int	coding_mode
	)

static

Decode a Sound Unit.

Parameters

snd	the channel unit to be used
output	the decoded samples before IQMF in float representation
channel_num	channel number
coding_mode	the coding mode (JOINT_STEREO or regular stereo/mono)

Definition at line 639 of file atrac3.c.

Referenced by decode_frame().

static int decode_frame	(	AVCodecContext *	avctx,
		const uint8_t *	databuf,
		float **	out_samples
	)

static

Definition at line 707 of file atrac3.c.

Referenced by atrac3_decode_frame().

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

static

Definition at line 802 of file atrac3.c.

static void atrac3_init_static_data ( void )

static

Definition at line 844 of file atrac3.c.

Referenced by atrac3_decode_init().

static av_cold int atrac3_decode_init ( AVCodecContext * avctx )

static

Definition at line 869 of file atrac3.c.

Variable Documentation

float mdct_window[MDCT_SIZE]

static

Definition at line 120 of file atrac3.c.

Referenced by imlt(), and init_atrac3_window().

VLC_TYPE atrac3_vlc_table[4096][2]

static

Definition at line 121 of file atrac3.c.

Referenced by atrac3_init_static_data().

VLC spectral_coeff_tab[7]

static

Definition at line 122 of file atrac3.c.

float gain_tab1[16]

static

Definition at line 123 of file atrac3.c.

Referenced by atrac3_init_static_data(), and gain_compensate_and_overlap().

float gain_tab2[31]

static

Definition at line 124 of file atrac3.c.

Referenced by atrac3_init_static_data(), and gain_compensate_and_overlap().

AVCodec ff_atrac3_decoder

Initial value:

= {
    .name             = "atrac3",
    .type             = AVMEDIA_TYPE_AUDIO,
    .id               = AV_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)"),
    .sample_fmts      = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
                                                        AV_SAMPLE_FMT_NONE },
}

Definition at line 1009 of file atrac3.c.

Data Structures

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

Function Documentation

Variable Documentation