atrac.c File Reference

#include <math.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include "avcodec.h"
#include "atrac.h"

Go to the source code of this file.

Functions
av_cold void	ff_atrac_generate_tables (void)
	Generate common tables.
av_cold void	ff_atrac_init_gain_compensation (AtracGCContext *gctx, int id2exp_offset, int loc_scale)
	Initialize gain compensation context.
void	ff_atrac_gain_compensation (AtracGCContext *gctx, float *in, float *prev, AtracGainInfo *gc_now, AtracGainInfo *gc_next, int num_samples, float *out)
	Apply gain compensation and perform the MDCT overlapping part.
void	ff_atrac_iqmf (float *inlo, float *inhi, unsigned int nIn, float *pOut, float *delayBuf, float *temp)
	Quadrature mirror synthesis filter.

Variables
float	ff_atrac_sf_table [64]
static float	qmf_window [48]
static const float	qmf_48tap_half [24]

Function Documentation

av_cold void ff_atrac_generate_tables

(

void

)

Generate common tables.

Definition at line 48 of file atrac.c.

Referenced by atrac1_decode_init(), and atrac3_init_static_data().

av_cold void ff_atrac_init_gain_compensation	(	AtracGCContext *	gctx,
		int	id2exp_offset,
		int	loc_scale
	)

Initialize gain compensation context.

Parameters

gctx	pointer to gain compensation context to initialize
id2exp_offset	offset for converting level index into level exponent
loc_scale	location size factor

Definition at line 66 of file atrac.c.

Referenced by atrac3_decode_init(), and atrac3p_decode_init().

void ff_atrac_gain_compensation	(	AtracGCContext *	gctx,
		float *	in,
		float *	prev,
		AtracGainInfo *	gc_now,
		AtracGainInfo *	gc_next,
		int	num_samples,
		float *	out
	)

Apply gain compensation and perform the MDCT overlapping part.

Parameters

gctx	pointer to gain compensation context
in	input buffer
prev	previous buffer to perform overlap against
gc_now	gain control information for current frame
gc_next	gain control information for next frame
num_samples	number of samples to process
out	output data goes here

Definition at line 84 of file atrac.c.

Referenced by decode_channel_sound_unit(), and reconstruct_frame().

void ff_atrac_iqmf	(	float *	inlo,
		float *	inhi,
		unsigned int	nIn,
		float *	pOut,
		float *	delayBuf,
		float *	temp
	)

Quadrature mirror synthesis filter.

Parameters

inlo	lower part of spectrum
inhi	higher part of spectrum
nIn	size of spectrum buffer
pOut	out buffer
delayBuf	delayBuf buffer
temp	temp buffer

Definition at line 127 of file atrac.c.

Referenced by at1_subband_synthesis(), and decode_frame().

Variable Documentation

float ff_atrac_sf_table[64]

Definition at line 36 of file atrac.c.

Referenced by at1_unpack_dequant(), decode_spectrum(), decode_tonal_components(), and ff_atrac_generate_tables().

float qmf_window[48]

static

Definition at line 37 of file atrac.c.

Referenced by ff_atrac_generate_tables(), and ff_atrac_iqmf().

const float qmf_48tap_half[24]

static

Initial value:

= {
   -0.00001461907, -0.00009205479,-0.000056157569,0.00030117269,
    0.0002422519,  -0.00085293897,-0.0005205574,  0.0020340169,
    0.00078333891, -0.0042153862, -0.00075614988, 0.0078402944,
   -0.000061169922,-0.01344162,    0.0024626821,  0.021736089,
   -0.007801671,   -0.034090221,   0.01880949,    0.054326009,
   -0.043596379,   -0.099384367,   0.13207909,    0.46424159
}

Definition at line 39 of file atrac.c.

Referenced by ff_atrac_generate_tables().