bgmc.c File Reference

Block Gilbert-Moore decoder as used by MPEG-4 ALS. More...

#include "libavutil/attributes.h"
#include "bgmc.h"

Macros
#define	FREQ_BITS   14
#define	VALUE_BITS   18
#define	TOP_VALUE   ((1 << VALUE_BITS) - 1)
#define	FIRST_QTR   (TOP_VALUE / 4 + 1)
#define	HALF   (2 * FIRST_QTR)
#define	THIRD_QTR   (3 * FIRST_QTR)
#define	LUT_BITS   (FREQ_BITS - 8)
#define	LUT_SIZE   (1 << LUT_BITS)
#define	LUT_BUFF   4

Functions
av_cold int	ff_bgmc_init (AVCodecContext *avctx, uint8_t **cf_lut, int **cf_lut_status)
	Initialize the lookup table arrays.
av_cold void	ff_bgmc_end (uint8_t **cf_lut, int **cf_lut_status)
	Release the lookup table arrays.
void	ff_bgmc_decode_init (GetBitContext *gb, unsigned int *h, unsigned int *l, unsigned int *v)
	Initialize decoding and reads the first value.
void	ff_bgmc_decode_end (GetBitContext *gb)
	Finish decoding.
void	ff_bgmc_decode (GetBitContext *gb, unsigned int num, int32_t *dst, int delta, unsigned int sx, unsigned int *h, unsigned int *l, unsigned int *v, uint8_t *cf_lut, int *cf_lut_status)
	Read and decode a block Gilbert-Moore coded symbol.

Detailed Description

Block Gilbert-Moore decoder as used by MPEG-4 ALS.

Author

Thilo Borgmann <thilo.borgmann at mail.de>