AAC encoder utilities. More...

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

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 void	abs_pow34_v (float out, const float in, const int size)

static float	pos_pow34 (float a)

static int	quant (float coef, const float Q, const float rounding)
	Quantize one coefficient. More...

static void	quantize_bands (int out, const float in, const float *scaled, int size, int is_signed, int maxval, const float Q34, const float rounding)

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. More...

static uint8_t	coef2maxsf (float coef)
	Return the maximum scalefactor where the quantized coef is not zero. More...

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))) More...

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 More...

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.

◆ ROUND_TO_ZERO

#define ROUND_TO_ZERO 0.1054f

Definition at line 37 of file aacenc_utils.h.

◆ 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 268 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 274 of file aacenc_utils.h.

Referenced by aac_encode_init().

Function Documentation

◆ abs_pow34_v()

static void abs_pow34_v	(	float *	out,
		const float *	in,
		const int	size
	)

inlinestatic

Definition at line 40 of file aacenc_utils.h.

Referenced by aac_encode_init().

◆ pos_pow34()

static float pos_pow34 ( float a )

inlinestatic

Definition at line 49 of file aacenc_utils.h.

Referenced by ff_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 59 of file aacenc_utils.h.

◆ quantize_bands()

static void quantize_bands	(	int *	out,
		const float *	in,
		const float *	scaled,
		int	size,
		int	is_signed,
		int	maxval,
		const float	Q34,
		const float	rounding
	)

inlinestatic

Definition at line 65 of file aacenc_utils.h.

Referenced by aac_encode_init().

◆ find_max_val()

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

inlinestatic

Definition at line 80 of file aacenc_utils.h.

Referenced by ff_aac_is_encoding_err(), ff_aac_search_for_pred(), search_for_quantizers_anmr(), 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 92 of file aacenc_utils.h.

Referenced by ff_aac_is_encoding_err(), ff_aac_search_for_pred(), search_for_ms(), search_for_quantizers_anmr(), 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 104 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 157 of file aacenc_utils.h.

Referenced by search_for_quantizers_anmr(), 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 163 of file aacenc_utils.h.

Referenced by search_for_quantizers_anmr().

◆ quant_array_idx()

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

inlinestatic

Definition at line 171 of file aacenc_utils.h.

Referenced by get_lag(), and 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 188 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 199 of file aacenc_utils.h.

Referenced by ff_aac_search_for_is(), 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 221 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 232 of file aacenc_utils.h.

Referenced by ff_aac_search_for_is(), 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 246 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 262 of file aacenc_utils.h.

Macros

Functions

Detailed Description

Macro Definition Documentation

◆ ROUND_STANDARD

◆ ROUND_TO_ZERO

◆ C_QUANT

◆ ERROR_IF

◆ WARN_IF

Function Documentation

◆ abs_pow34_v()

◆ pos_pow34()

◆ quant()

◆ quantize_bands()

◆ find_max_val()

◆ find_min_book()

◆ find_form_factor()

◆ coef2minsf()

◆ coef2maxsf()

◆ quant_array_idx()

◆ bval2bmax()

◆ ff_init_nextband_map()

◆ ff_nextband_remove()

◆ ff_sfdelta_can_remove_band()

◆ ff_sfdelta_can_replace()

◆ lcg_random()