aacenc_utils.h File Reference

AAC encoder utilities. More...

#include "libavutil/ffmath.h"
#include "aacenc.h"
#include "aacenctab.h"
#include "aactab.h"

Go to the source code of this file.

Macros
#define	ROUND_STANDARD   0.4054f
#define	ROUND_TO_ZERO   0.1054f
#define	C_QUANT   0.4054f
#define	ERROR_IF(cond, ...)
#define	WARN_IF(cond, ...)

Functions
static float	pos_pow34 (float a)
static int	quant (float coef, const float Q, const float rounding)
	Quantize one coefficient.
static float	find_max_val (int group_len, int swb_size, const float *scaled)
static int	find_min_book (float maxval, int sf)
static float	find_form_factor (int group_len, int swb_size, float thresh, const float *scaled, float nzslope)
static uint8_t	coef2minsf (float coef)
	Return the minimum scalefactor where the quantized coef does not clip.
static uint8_t	coef2maxsf (float coef)
	Return the maximum scalefactor where the quantized coef is not zero.
static int	quant_array_idx (const float val, const float *arr, const int num)
static av_always_inline float	bval2bmax (float b)
	approximates exp10f(-3.0f*(0.5f + 0.5f * cosf(FFMIN(b,15.5f) / 15.5f)))
static void	ff_init_nextband_map (const SingleChannelElement *sce, uint8_t *nextband)
static void	ff_nextband_remove (uint8_t *nextband, int prevband, int band)
static int	ff_sfdelta_can_remove_band (const SingleChannelElement *sce, const uint8_t *nextband, int prev_sf, int band)
static int	ff_sfdelta_can_replace (const SingleChannelElement *sce, const uint8_t *nextband, int prev_sf, int new_sf, int band)
static av_always_inline int	lcg_random (unsigned previous_val)
	linear congruential pseudorandom number generator

Detailed Description

AAC encoder utilities.

Author

Rostislav Pehlivanov ( atomnuker gmail com )

Definition in file aacenc_utils.h.

Macro Definition Documentation

ROUND_STANDARD

#define ROUND_STANDARD   0.4054f

Definition at line 36 of file aacenc_utils.h.

Referenced by test_quant_bands().

ROUND_TO_ZERO

#define ROUND_TO_ZERO   0.1054f

Definition at line 37 of file aacenc_utils.h.

Referenced by test_quant_bands().

C_QUANT

#define C_QUANT   0.4054f

Definition at line 38 of file aacenc_utils.h.

Referenced by find_min_book().

ERROR_IF

#define ERROR_IF	(		cond,
			... )

Value:

    if (cond) { \
        av_log(avctx, AV_LOG_ERROR, __VA_ARGS__); \
        return AVERROR(EINVAL); \
    }

Definition at line 244 of file aacenc_utils.h.

Referenced by aac_encode_init().

WARN_IF

#define WARN_IF	(		cond,
			... )

Value:

    if (cond) { \
        av_log(avctx, AV_LOG_WARNING, __VA_ARGS__); \
    }

Definition at line 250 of file aacenc_utils.h.

Referenced by aac_encode_init().

Function Documentation

pos_pow34()

static float pos_pow34 ( float a )

inlinestatic

Definition at line 40 of file aacenc_utils.h.

Referenced by aac_is_encoding_err().

quant()

static int quant ( float coef, const float Q, const float rounding )

inlinestatic

Quantize one coefficient.

Returns

absolute value of the quantized coefficient

See also

3GPP TS26.403 5.6.2 "Scalefactor determination"

Definition at line 50 of file aacenc_utils.h.

find_max_val()

static float find_max_val ( int group_len, int swb_size, const float * scaled )

inlinestatic

Definition at line 56 of file aacenc_utils.h.

Referenced by aac_is_encoding_err(), nmr_setup_channel(), search_for_quantizers_fast(), and search_for_quantizers_twoloop().

find_min_book()

static int find_min_book ( float maxval, int sf )

inlinestatic

Definition at line 68 of file aacenc_utils.h.

Referenced by aac_is_encoding_err(), nmr_band_curve(), nmr_commit_channel(), search_for_ms(), search_for_quantizers_fast(), and search_for_quantizers_twoloop().

find_form_factor()

static float find_form_factor ( int group_len, int swb_size, float thresh, const float * scaled, float nzslope )

inlinestatic

compute variance

Definition at line 80 of file aacenc_utils.h.

Referenced by search_for_quantizers_twoloop().

coef2minsf()

static uint8_t coef2minsf ( float coef )

inlinestatic

Return the minimum scalefactor where the quantized coef does not clip.

Definition at line 133 of file aacenc_utils.h.

Referenced by nmr_setup_channel(), and search_for_quantizers_twoloop().

coef2maxsf()

static uint8_t coef2maxsf ( float coef )

inlinestatic

Return the maximum scalefactor where the quantized coef is not zero.

Definition at line 139 of file aacenc_utils.h.

quant_array_idx()

static int quant_array_idx ( const float val, const float * arr, const int num )

inlinestatic

Definition at line 147 of file aacenc_utils.h.

Referenced by quantize_coefs().

bval2bmax()

static av_always_inline float bval2bmax ( float b )

static

approximates exp10f(-3.0f*(0.5f + 0.5f * cosf(FFMIN(b,15.5f) / 15.5f)))

Definition at line 164 of file aacenc_utils.h.

Referenced by search_for_ms().

ff_init_nextband_map()

static void ff_init_nextband_map ( const SingleChannelElement * sce, uint8_t * nextband )

inlinestatic

Just a safe default

Now really navigate the nonzero band chain

Definition at line 175 of file aacenc_utils.h.

Referenced by ff_aac_search_for_is(), nmr_commit_channel(), search_for_ms(), search_for_pns(), and search_for_quantizers_twoloop().

ff_nextband_remove()

static void ff_nextband_remove ( uint8_t * nextband, int prevband, int band )

inlinestatic

Definition at line 197 of file aacenc_utils.h.

ff_sfdelta_can_remove_band()

static int ff_sfdelta_can_remove_band ( const SingleChannelElement * sce, const uint8_t * nextband, int prev_sf, int band )

inlinestatic

Definition at line 208 of file aacenc_utils.h.

Referenced by ff_aac_search_for_is(), nmr_commit_channel(), search_for_pns(), and search_for_quantizers_twoloop().

ff_sfdelta_can_replace()

static int ff_sfdelta_can_replace ( const SingleChannelElement * sce, const uint8_t * nextband, int prev_sf, int new_sf, int band )

inlinestatic

Definition at line 222 of file aacenc_utils.h.

Referenced by search_for_ms().

lcg_random()

static av_always_inline int lcg_random ( unsigned previous_val )

static

linear congruential pseudorandom number generator

Parameters

previous_val

pointer to the current state of the generator

Returns

Returns a 32-bit pseudorandom integer

Definition at line 238 of file aacenc_utils.h.