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

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

Data Structures
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(VERSION)

#define	ARITH_GET_MODEL_SYM(VERSION)

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.

Definition in file mss12.h.

Macro Definition Documentation

#define MODEL_MIN_SYMS 2

Definition at line 34 of file mss12.h.

#define MODEL_MAX_SYMS 256

Definition at line 35 of file mss12.h.

#define THRESH_ADAPTIVE -1

Definition at line 36 of file mss12.h.

Referenced by model_rescale_weights(), pixctx_init(), and slicecontext_init().

#define THRESH_LOW 15

Definition at line 37 of file mss12.h.

Referenced by pixctx_init(), and slicecontext_init().

#define THRESH_HIGH 50

Definition at line 38 of file mss12.h.

Referenced by pixctx_init(), and slicecontext_init().

#define ARITH_GET_BIT ( VERSION )

Value:

static int arith ## VERSION ## _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;                            \
                                                                        \
    arith ## VERSION ## _normalise(c);                                  \
                                                                        \
    return bit;                                                         \
}

Definition at line 102 of file mss12.h.

#define ARITH_GET_MODEL_SYM ( VERSION )

Value:

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