lfg.h File Reference

#include <stdint.h>

Go to the source code of this file.

Data Structures
struct	AVLFG
	Context structure for the Lagged Fibonacci PRNG. More...

Functions
void	av_lfg_init (AVLFG *c, unsigned int seed)
int	av_lfg_init_from_data (AVLFG *c, const uint8_t *data, unsigned int length)
	Seed the state of the ALFG using binary data. More...
static unsigned int	av_lfg_get (AVLFG *c)
	Get the next random unsigned 32-bit number using an ALFG. More...
static unsigned int	av_mlfg_get (AVLFG *c)
	Get the next random unsigned 32-bit number using a MLFG. More...
void	av_bmg_get (AVLFG *lfg, double out[2])
	Get the next two numbers generated by a Box-Muller Gaussian generator using the random numbers issued by lfg. More...

Function Documentation

av_lfg_init()

void av_lfg_init	(	AVLFG *	c,
		unsigned int	seed
	)

Definition at line 32 of file lfg.c.

Referenced by a64multi_encode_init(), ac3_decode_init(), amrwb_decode_init(), atrac9_decode_init(), cinepak_encode_init(), cng_decode_init(), config_input(), config_output(), config_props(), cook_decode_init(), dct_error(), decode_init(), deshake_opencl_init(), encode_init(), ff_perlin_init(), fill_random(), idct248_error(), init(), init_noise(), main(), mkv_init(), mpc7_decode_init(), mpc8_decode_init(), roq_encode_init(), and rtmp_handshake().

av_lfg_init_from_data()

int av_lfg_init_from_data	(	AVLFG *	c,
		const uint8_t *	data,
		unsigned int	length
	)

Seed the state of the ALFG using binary data.

Returns

0 on success, negative value (AVERROR) on failure.

Definition at line 64 of file lfg.c.

Referenced by ac3_decode_frame().

av_lfg_get()

static unsigned int av_lfg_get ( AVLFG *  c )

inlinestatic

Get the next random unsigned 32-bit number using an ALFG.

Please also consider a simple LCG like state= state*1664525+1013904223, it may be good enough and faster for your specific use case.

Definition at line 53 of file lfg.h.

Referenced by ac3_decode_transform_coeffs_ch(), activate(), av_bmg_get(), cng_decode_frame(), config_input(), config_output(), drand(), draw_sierpinski(), ff_eac3_apply_spectral_extension(), ff_eac3_decode_transform_coeffs_aht_ch(), ff_perlin_init(), fill_random(), filter_frame(), get_high_utility_cell(), idct248_error(), idx_to_quant(), init(), init_block(), init_noise(), main(), make_block_map(), make_horizontal_map(), make_vertical_map(), mkv_get_uid(), mkv_init(), mpc8_decode_frame(), nelly_decode_block(), process_frame(), rand_in(), rtmp_handshake(), scalar_dequant_float(), and scaled_hb_excitation().

av_mlfg_get()

static unsigned int av_mlfg_get ( AVLFG *  c )

inlinestatic

Get the next random unsigned 32-bit number using a MLFG.

Please also consider av_lfg_get() above, it is faster.

Definition at line 64 of file lfg.h.

av_bmg_get()

void av_bmg_get	(	AVLFG *	lfg,
		double	out[2]
	)

Get the next two numbers generated by a Box-Muller Gaussian generator using the random numbers issued by lfg.

Parameters

lfg	pointer to the contex structure
out	array where the two generated numbers are placed

Definition at line 49 of file lfg.c.

Referenced by fill_with_noise(), and main().