colorspace.c

这是一个压缩解压包,用C语言进行编程的,里面有详细的源代码.

/*****************************************************************************
 *
 *  XVID MPEG-4 VIDEO CODEC
 *  - Colorspace conversion functions -
 *
 *  Copyright(C) 2001-2003 Peter Ross <[e-mail]>
 *
 *  This program is free software ; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation ; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY ; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program ; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 * $Id: colorspace.c,v 1.11 2005/11/22 10:23:01 suxen_drol Exp $
 *
 ****************************************************************************/

#include <string.h>				/* memcpy */

#include "../global.h"
#include "colorspace.h"

/* function pointers */

/* input */
packedFuncPtr rgb555_to_yv12;
packedFuncPtr rgb565_to_yv12;
packedFuncPtr bgr_to_yv12;
packedFuncPtr bgra_to_yv12;
packedFuncPtr abgr_to_yv12;
packedFuncPtr rgba_to_yv12;
packedFuncPtr argb_to_yv12;
packedFuncPtr yuyv_to_yv12;
packedFuncPtr uyvy_to_yv12;

packedFuncPtr rgb555i_to_yv12;
packedFuncPtr rgb565i_to_yv12;
packedFuncPtr bgri_to_yv12;
packedFuncPtr bgrai_to_yv12;
packedFuncPtr abgri_to_yv12;
packedFuncPtr rgbai_to_yv12;
packedFuncPtr argbi_to_yv12;
packedFuncPtr yuyvi_to_yv12;
packedFuncPtr uyvyi_to_yv12;

/* output */
packedFuncPtr yv12_to_rgb555;
packedFuncPtr yv12_to_rgb565;
packedFuncPtr yv12_to_bgr;
packedFuncPtr yv12_to_bgra;
packedFuncPtr yv12_to_abgr;
packedFuncPtr yv12_to_rgba;
packedFuncPtr yv12_to_argb;
packedFuncPtr yv12_to_yuyv;
packedFuncPtr yv12_to_uyvy;

packedFuncPtr yv12_to_rgb555i;
packedFuncPtr yv12_to_rgb565i;
packedFuncPtr yv12_to_bgri;
packedFuncPtr yv12_to_bgrai;
packedFuncPtr yv12_to_abgri;
packedFuncPtr yv12_to_rgbai;
packedFuncPtr yv12_to_argbi;
packedFuncPtr yv12_to_yuyvi;
packedFuncPtr yv12_to_uyvyi;

planarFuncPtr yv12_to_yv12;


static int32_t RGB_Y_tab[256];
static int32_t B_U_tab[256];
static int32_t G_U_tab[256];
static int32_t G_V_tab[256];
static int32_t R_V_tab[256];



/********** generic colorspace macro **********/


#define MAKE_COLORSPACE(NAME,SIZE,PIXELS,VPIXELS,FUNC,C1,C2,C3,C4) \
void	\
NAME(uint8_t * x_ptr, int x_stride,	\
				 uint8_t * y_ptr, uint8_t * u_ptr, uint8_t * v_ptr,	\
				 int y_stride, int uv_stride,	\
				 int width, int height, int vflip)	\
{	\
	int fixed_width = (width + 1) & ~1;				\
	int x_dif = x_stride - (SIZE)*fixed_width;		\
	int y_dif = y_stride - fixed_width;				\
	int uv_dif = uv_stride - (fixed_width / 2);		\
	int x, y;										\
	if (vflip) {								\
		x_ptr += (height - 1) * x_stride;			\
		x_dif = -(SIZE)*fixed_width - x_stride;		\
		x_stride = -x_stride;						\
	}												\
	for (y = 0; y < height; y+=(VPIXELS)) {			\
		FUNC##_ROW(SIZE,C1,C2,C3,C4);				\
		for (x = 0; x < fixed_width; x+=(PIXELS)) {	\
			FUNC(SIZE,C1,C2,C3,C4);				\
			x_ptr += (PIXELS)*(SIZE);				\
			y_ptr += (PIXELS);						\
			u_ptr += (PIXELS)/2;					\
			v_ptr += (PIXELS)/2;					\
		}											\
		x_ptr += x_dif + (VPIXELS-1)*x_stride;		\
		y_ptr += y_dif + (VPIXELS-1)*y_stride;		\
		u_ptr += uv_dif + ((VPIXELS/2)-1)*uv_stride;	\
		v_ptr += uv_dif + ((VPIXELS/2)-1)*uv_stride;	\
	}												\
}



/********** colorspace input (xxx_to_yv12) functions **********/

/*	rgb -> yuv def's

	this following constants are "official spec"
	Video Demystified" (ISBN 1-878707-09-4)

	rgb<->yuv _is_ lossy, since most programs do the conversion differently

	SCALEBITS/FIX taken from  ffmpeg
*/

#define Y_R_IN			0.257
#define Y_G_IN			0.504
#define Y_B_IN			0.098
#define Y_ADD_IN		16

#define U_R_IN			0.148
#define U_G_IN			0.291
#define U_B_IN			0.439
#define U_ADD_IN		128

#define V_R_IN			0.439
#define V_G_IN			0.368
#define V_B_IN			0.071
#define V_ADD_IN		128

#define SCALEBITS_IN	8
#define FIX_IN(x)		((uint16_t) ((x) * (1L<<SCALEBITS_IN) + 0.5))


/* rgb16/rgb16i input */

#define MK_RGB555_B(RGB)  ((RGB) << 3) & 0xf8
#define MK_RGB555_G(RGB)  ((RGB) >> 2) & 0xf8
#define MK_RGB555_R(RGB)  ((RGB) >> 7) & 0xf8

#define MK_RGB565_B(RGB)  ((RGB) << 3) & 0xf8
#define MK_RGB565_G(RGB)  ((RGB) >> 3) & 0xfc
#define MK_RGB565_R(RGB)  ((RGB) >> 8) & 0xf8


#define READ_RGB16_Y(ROW, UVID, C1,C2,C3,C4)	\
	rgb = *(uint16_t *) (x_ptr + ((ROW)*x_stride) + 0);	\
	b##UVID += b = C1##_B(rgb);				\
	g##UVID += g = C1##_G(rgb);				\
	r##UVID += r = C1##_R(rgb);				\
	y_ptr[(ROW)*y_stride+0] =				\
		(uint8_t) ((FIX_IN(Y_R_IN) * r + FIX_IN(Y_G_IN) * g +	\
					FIX_IN(Y_B_IN) * b) >> SCALEBITS_IN) + Y_ADD_IN;	\
	rgb = *(uint16_t *) (x_ptr + ((ROW)*x_stride) + 2);	\
	b##UVID += b = C1##_B(rgb);				\
	g##UVID += g = C1##_G(rgb);				\
	r##UVID += r = C1##_R(rgb);				\
	y_ptr[(ROW)*y_stride+1] =				\
		(uint8_t) ((FIX_IN(Y_R_IN) * r + FIX_IN(Y_G_IN) * g +			\
					FIX_IN(Y_B_IN) * b) >> SCALEBITS_IN) + Y_ADD_IN;

#define READ_RGB16_UV(UV_ROW,UVID)	\
	u_ptr[(UV_ROW)*uv_stride] =														\
		(uint8_t) ((-FIX_IN(U_R_IN) * r##UVID - FIX_IN(U_G_IN) * g##UVID +			\
					FIX_IN(U_B_IN) * b##UVID) >> (SCALEBITS_IN + 2)) + U_ADD_IN;	\
	v_ptr[(UV_ROW)*uv_stride] =														\
		(uint8_t) ((FIX_IN(V_R_IN) * r##UVID - FIX_IN(V_G_IN) * g##UVID -			\
					FIX_IN(V_B_IN) * b##UVID) >> (SCALEBITS_IN + 2)) + V_ADD_IN;

#define RGB16_TO_YV12_ROW(SIZE,C1,C2,C3,C4) \
	/* nothing */
#define RGB16_TO_YV12(SIZE,C1,C2,C3,C4)	\
	uint32_t rgb, r, g, b, r0, g0, b0;	\
	r0 = g0 = b0 = 0;					\
	READ_RGB16_Y (0, 0, C1,C2,C3,C4)	\
	READ_RGB16_Y (1, 0, C1,C2,C3,C4)	\
	READ_RGB16_UV(0, 0)


#define RGB16I_TO_YV12_ROW(SIZE,C1,C2,C3,C4) \
	/* nothing */
#define RGB16I_TO_YV12(SIZE,C1,C2,C3,C4)	\
	uint32_t rgb, r, g, b, r0, g0, b0, r1, g1, b1;	\
	r0 = g0 = b0 = r1 = g1 = b1 = 0;	\
	READ_RGB16_Y (0, 0, C1,C2,C3,C4)	\
	READ_RGB16_Y (1, 1, C1,C2,C3,C4)	\
	READ_RGB16_Y (2, 0, C1,C2,C3,C4)	\
	READ_RGB16_Y (3, 1, C1,C2,C3,C4)	\
	READ_RGB16_UV(0, 0)					\
	READ_RGB16_UV(1, 1)


/* rgb/rgbi input */

#define READ_RGB_Y(SIZE, ROW, UVID, C1,C2,C3,C4)	\
	r##UVID += r = x_ptr[(ROW)*x_stride+(C1)];						\
	g##UVID += g = x_ptr[(ROW)*x_stride+(C2)];						\
	b##UVID += b = x_ptr[(ROW)*x_stride+(C3)];						\
	y_ptr[(ROW)*y_stride+0] =									\
		(uint8_t) ((FIX_IN(Y_R_IN) * r + FIX_IN(Y_G_IN) * g +	\
					FIX_IN(Y_B_IN) * b) >> SCALEBITS_IN) + Y_ADD_IN;	\
	r##UVID += r = x_ptr[(ROW)*x_stride+(SIZE)+(C1)];				\
	g##UVID += g = x_ptr[(ROW)*x_stride+(SIZE)+(C2)];				\
	b##UVID += b = x_ptr[(ROW)*x_stride+(SIZE)+(C3)];				\
	y_ptr[(ROW)*y_stride+1] =									\
		(uint8_t) ((FIX_IN(Y_R_IN) * r + FIX_IN(Y_G_IN) * g +	\
					FIX_IN(Y_B_IN) * b) >> SCALEBITS_IN) + Y_ADD_IN;

#define READ_RGB_UV(UV_ROW,UVID)	\
	u_ptr[(UV_ROW)*uv_stride] =														\
		(uint8_t) ((-FIX_IN(U_R_IN) * r##UVID - FIX_IN(U_G_IN) * g##UVID +			\
					FIX_IN(U_B_IN) * b##UVID) >> (SCALEBITS_IN + 2)) + U_ADD_IN;	\
	v_ptr[(UV_ROW)*uv_stride] =														\
		(uint8_t) ((FIX_IN(V_R_IN) * r##UVID - FIX_IN(V_G_IN) * g##UVID -			\
					FIX_IN(V_B_IN) * b##UVID) >> (SCALEBITS_IN + 2)) + V_ADD_IN;


#define RGB_TO_YV12_ROW(SIZE,C1,C2,C3,C4) \
	/* nothing */
#define RGB_TO_YV12(SIZE,C1,C2,C3,C4)	\
	uint32_t r, g, b, r0, g0, b0;		\
	r0 = g0 = b0 = 0;					\
	READ_RGB_Y(SIZE, 0, 0, C1,C2,C3,C4)	\
	READ_RGB_Y(SIZE, 1, 0, C1,C2,C3,C4)	\
	READ_RGB_UV(     0, 0)

#define RGBI_TO_YV12_ROW(SIZE,C1,C2,C3,C4) \
	/* nothing */
#define RGBI_TO_YV12(SIZE,C1,C2,C3,C4)	\
	uint32_t r, g, b, r0, g0, b0, r1, g1, b1;	\
	r0 = g0 = b0 = r1 = g1 = b1 = 0;	\
	READ_RGB_Y(SIZE, 0, 0, C1,C2,C3,C4)	\
	READ_RGB_Y(SIZE, 1, 1, C1,C2,C3,C4)	\
	READ_RGB_Y(SIZE, 2, 0, C1,C2,C3,C4)	\
	READ_RGB_Y(SIZE, 3, 1, C1,C2,C3,C4)	\
	READ_RGB_UV(     0, 0)				\
	READ_RGB_UV(     1, 1)


/* yuyv/yuyvi input */