mss12.h File Reference

Common header for Microsoft Screen 1 and 2. More...

#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "get_bits.h"
#include "bytestream.h"

Go to the source code of this file.

Classes
struct	Model
struct	ArithCoder
struct	PixContext
struct	SliceContext
struct	MSS12Context

Macros
#define	MODEL_MIN_SYMS   2
#define	MODEL_MAX_SYMS   256
#define	THRESH_ADAPTIVE   -1
#define	THRESH_LOW   15
#define	THRESH_HIGH   50
#define	ARITH_GET_BIT(prefix)
#define	ARITH_GET_MODEL_SYM(prefix)

Typedefs
typedef struct Model	Model
typedef struct ArithCoder	ArithCoder
typedef struct PixContext	PixContext
typedef struct SliceContext	SliceContext
typedef struct MSS12Context	MSS12Context

Functions
int	ff_mss12_decode_rect (SliceContext *ctx, ArithCoder *acoder, int x, int y, int width, int height)
void	ff_mss12_model_update (Model *m, int val)
void	ff_mss12_slicecontext_reset (SliceContext *sc)
int	ff_mss12_decode_init (MSS12Context *c, int version, SliceContext *sc1, SliceContext *sc2)
int	ff_mss12_decode_end (MSS12Context *ctx)

Detailed Description

Common header for Microsoft Screen 1 and 2.

Macro Definition Documentation

ARITH_GET_BIT

#define ARITH_GET_BIT

(

prefix

)

Value:

static int prefix ## _get_bit(ArithCoder *c)                            \
{                                                                       \
    int range = c->high - c->low + 1;                                   \
    int bit   = 2 * c->value - c->low >= c->high;                       \
                                                                        \
    if (bit)                                                            \
        c->low += range >> 1;                                           \
    else                                                                \
        c->high = c->low + (range >> 1) - 1;                            \
                                                                        \
    prefix ## _normalise(c);                                            \
                                                                        \
    return bit;                                                         \
}

ARITH_GET_MODEL_SYM

#define ARITH_GET_MODEL_SYM

(

prefix

)

Value:

static int prefix ## _get_model_sym(ArithCoder *c, Model *m)            \
{                                                                       \
    int idx, val;                                                       \
                                                                        \
    idx = prefix ## _get_prob(c, m->cum_prob);                          \
                                                                        \
    val = m->idx2sym[idx];                                              \
    ff_mss12_model_update(m, idx);                                      \
                                                                        \
    prefix ## _normalise(c);                                            \
                                                                        \
    return val;                                                         \
}