global.h

基于Linux的ffmepg decoder

#ifndef _GLOBAL_H_
#define _GLOBAL_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;
	int32_t pos;
	int32_t start_pos;
	uint32_t *tail;
	uint32_t *start;
	uint32_t length;
	uint32_t * start_phy;
	uint32_t * tail_phy;
}
Bitstream;

union VECTOR1
{
	uint32_t u32num;
	struct
	{
		int16_t s16y;
		int16_t s16x;
	} vec;			// current mb Motion Vector for UV
};



#define MBPRED_SIZE  15

typedef struct
{
//	int32_t x;				// current mb x
//	int32_t y;				// current mb y
//	int32_t mbpos;			// current mb position
//	uint32_t toggle;		// indicate which table will be used;
	int32_t mb_jump;		// mb jump offset from the prevous
//	VECTOR MVuv;			// current mb Motion Vector for UV
	union VECTOR1 MVuv;

//	int quant;					// absolute quant
//	int cbp;
	int mode;

//	VECTOR mvs[4];
	union VECTOR1 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

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

	int dquant;
	// bframe stuff

	VECTOR b_mvs[4];
	VECTOR b_pmvs[4];

	// bframe direct mode

	VECTOR directmv[4];
	VECTOR deltamv;

	int mb_type;
	int dbquant;

	// stuff for block based ME (needed for Qpel ME)
	// backup of last integer ME vectors/sad
	
	VECTOR i_mv16;
	VECTOR i_mvs[4];

	int32_t i_sad8[4];	// SAD values for inter4v-VECTORs
	int32_t i_sad16;	// SAD value for inter-VECTOR
*/
}
MACROBLOCK;

typedef struct
{
	int32_t x;				// current mb x
	uint32_t y;			// current mb y
	int32_t mbpos;			// current mb position
	uint32_t toggle;		// indicate which table will be used;

	int quant;					// absolute quant
	int cbp;
}
MACROBLOCK_b;
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 MIN(X, Y) ((X)<(Y)?(X):(Y))
#define MAX(X, Y) ((X)>(Y)?(X):(Y))
#define ABS(X)    (((X)>0)?(X):-(X))
#define SIGN(X)   (((X)>0)?1:-1)


#endif /* _GLOBAL_H_ */