global.h

用MPEG-4对YUV视频文件编码压缩成divx视频文件

#ifndef _GLOBAL_H_
#define _GLOBAL_H_

#include "user_macro.h"
#include "xvid.h"
#include "portab.h"

/* --- macroblock modes --- */

#define MODE_INTER		0
#define MODE_INTER_Q	1
#define MODE_INTER4V	2
#define	MODE_INTRA		3
#define MODE_INTRA_Q	4
#define MODE_STUFFING	7
#define MODE_NOT_CODED	16

/* --- bframe specific --- */

#define MODE_DIRECT			0
#define MODE_INTERPOLATE	1
#define MODE_BACKWARD		2
#define MODE_FORWARD		3
#define MODE_DIRECT_NONE_MV	4


typedef struct
{
	uint32_t bufa;
	uint32_t bufb;
	uint32_t buf;
	uint32_t pos;
	uint32_t *tail;
	uint32_t *start;
	uint32_t length;
}
Bitstream;


#define MBPRED_SIZE  15


typedef struct
{
	/* decoder/encoder */ 
	VECTOR mvs[4];

	short int pred_values[6][MBPRED_SIZE];
	int acpred_directions[6];

	int mode;
	int quant;					/* absolute quant*/

/*	int field_dct;
	int field_pred;
	int field_for_top;
	int field_for_bot;*/

	/* encoder specific */

	VECTOR mv16;
	VECTOR pmvs[4];

	int32_t sad8[4];			/* SAD values for inter4v-VECTORs*/
	int32_t sad16;				/* SAD value for inter-VECTOR   */

	int dquant;
	int cbp;

	/* bframe stuff   */
/*
	VECTOR b_mvs[4];
	VECTOR b_pmvs[4];
*/
/*	int mb_type;*/
/*	int dbquant;*/

}
MACROBLOCK;

static __inline int8_t
get_dc_scaler(uint32_t quant,
			  uint32_t lum)
{
	if (quant < 5)
		return 8;

	if (quant < 25 && !lum)
		return (quant + 13) / 2;

	if (quant < 9)
		return 2 * quant;

	if (quant < 25)
		return quant + 8;

	if (lum)
		return 2 * quant - 16;
	else
		return quant - 6;
}

/* useful macros */

/*#define SIGN(X)   (((X)>0)?1:-1)*/


#endif							/* _GLOBAL_H_ */