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_props(), cook_decode_init(), dct_error(), decode_init(), encode_init(), ff_dither_alloc(), fill_random(), generate_dither_noise(), idct248_error(), init(), init_noise(), main(), mkv_write_attachments(), mkv_write_header(), 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.

Return value: 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(), audiogen(), av_bmg_get(), cng_decode_frame(), dbl_rand(), drand(), ff_dither_alloc(), ff_eac3_apply_spectral_extension(), ff_eac3_decode_transform_coeffs_aht_ch(), fill_random(), filter_frame(), frandom(), generate_dither_noise(), get_high_utility_cell(), idct248_error(), idx_to_quant(), init(), init_block(), init_noise(), main(), mkv_write_attachments(), mkv_write_header(), mpc8_decode_frame(), nelly_decode_block(), request_frame(), 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

out	array where the two generated numbers are placed

Definition at line 49 of file lfg.c.

Referenced by fill_with_noise(), and main().