image.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
 *  - Image management functions -
 *
 *  Copyright(C) 2001-2004 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: image.c,v 1.32 2005/09/09 12:18:10 suxen_drol Exp $
 *
 ****************************************************************************/

#include <stdlib.h>
#include <string.h>				/* memcpy, memset */
#include <math.h>
#include "../portab.h"
#include "../global.h"			/* XVID_CSP_XXX's */
#include "../xvid.h"			/* XVID_CSP_XXX's */
#include "image.h"
#include "colorspace.h"
#include "interpolate8x8.h"
#include "../utils/mem_align.h"
#include "../motion/sad.h"

#include "font.h"		/* XXX: remove later */

#define SAFETY	64
#define EDGE_SIZE2  (EDGE_SIZE/2)


int32_t
image_create(IMAGE * image,
			 uint32_t edged_width,
			 uint32_t edged_height)
{
	const uint32_t edged_width2 = edged_width / 2;
	const uint32_t edged_height2 = edged_height / 2;

	image->y =
		xvid_malloc(edged_width * (edged_height + 1) + SAFETY, CACHE_LINE);
	if (image->y == NULL) {
		return -1;
	}
	memset(image->y, 0, edged_width * (edged_height + 1) + SAFETY);

	image->u = xvid_malloc(edged_width2 * edged_height2 + SAFETY, CACHE_LINE);
	if (image->u == NULL) {
		xvid_free(image->y);
		image->y = NULL;
		return -1;
	}
	memset(image->u, 0, edged_width2 * edged_height2 + SAFETY);

	image->v = xvid_malloc(edged_width2 * edged_height2 + SAFETY, CACHE_LINE);
	if (image->v == NULL) {
		xvid_free(image->u);
		image->u = NULL;
		xvid_free(image->y);
		image->y = NULL;
		return -1;
	}
	memset(image->v, 0, edged_width2 * edged_height2 + SAFETY);

	image->y += EDGE_SIZE * edged_width + EDGE_SIZE;
	image->u += EDGE_SIZE2 * edged_width2 + EDGE_SIZE2;
	image->v += EDGE_SIZE2 * edged_width2 + EDGE_SIZE2;

	return 0;
}



void
image_destroy(IMAGE * image,
			  uint32_t edged_width,
			  uint32_t edged_height)
{
	const uint32_t edged_width2 = edged_width / 2;

	if (image->y) {
		xvid_free(image->y - (EDGE_SIZE * edged_width + EDGE_SIZE));
		image->y = NULL;
	}
	if (image->u) {
		xvid_free(image->u - (EDGE_SIZE2 * edged_width2 + EDGE_SIZE2));
		image->u = NULL;
	}
	if (image->v) {
		xvid_free(image->v - (EDGE_SIZE2 * edged_width2 + EDGE_SIZE2));
		image->v = NULL;
	}
}


void
image_swap(IMAGE * image1,
		   IMAGE * image2)
{
    SWAP(uint8_t*, image1->y, image2->y);
    SWAP(uint8_t*, image1->u, image2->u);
    SWAP(uint8_t*, image1->v, image2->v);
}


void
image_copy(IMAGE * image1,
		   IMAGE * image2,
		   uint32_t edged_width,
		   uint32_t height)
{
	memcpy(image1->y, image2->y, edged_width * height);
	memcpy(image1->u, image2->u, edged_width * height / 4);
	memcpy(image1->v, image2->v, edged_width * height / 4);
}

/* setedges bug was fixed in this BS version */
#define SETEDGES_BUG_BEFORE		18

void
image_setedges(IMAGE * image,
			   uint32_t edged_width,
			   uint32_t edged_height,
			   uint32_t width,
			   uint32_t height,
			   int bs_version)
{
	const uint32_t edged_width2 = edged_width / 2;
	uint32_t width2;
	uint32_t i;
	uint8_t *dst;
	uint8_t *src;

	dst = image->y - (EDGE_SIZE + EDGE_SIZE * edged_width);
	src = image->y;

	/* According to the Standard Clause 7.6.4, padding is done starting at 16
	 * pixel width and height multiples. This was not respected in old xvids */
	if (bs_version == 0 || bs_version >= SETEDGES_BUG_BEFORE) {
		width  = (width+15)&~15;
		height = (height+15)&~15;
	}

	width2 = width/2;

	for (i = 0; i < EDGE_SIZE; i++) {
		memset(dst, *src, EDGE_SIZE);
		memcpy(dst + EDGE_SIZE, src, width);
		memset(dst + edged_width - EDGE_SIZE, *(src + width - 1),
			   EDGE_SIZE);
		dst += edged_width;
	}

	for (i = 0; i < height; i++) {
		memset(dst, *src, EDGE_SIZE);
		memset(dst + edged_width - EDGE_SIZE, src[width - 1], EDGE_SIZE);
		dst += edged_width;
		src += edged_width;
	}

	src -= edged_width;
	for (i = 0; i < EDGE_SIZE; i++) {
		memset(dst, *src, EDGE_SIZE);
		memcpy(dst + EDGE_SIZE, src, width);
		memset(dst + edged_width - EDGE_SIZE, *(src + width - 1),
				   EDGE_SIZE);
		dst += edged_width;
	}


	/* U */
	dst = image->u - (EDGE_SIZE2 + EDGE_SIZE2 * edged_width2);
	src = image->u;

	for (i = 0; i < EDGE_SIZE2; i++) {
		memset(dst, *src, EDGE_SIZE2);
		memcpy(dst + EDGE_SIZE2, src, width2);
		memset(dst + edged_width2 - EDGE_SIZE2, *(src + width2 - 1),
			   EDGE_SIZE2);
		dst += edged_width2;
	}

	for (i = 0; i < height / 2; i++) {
		memset(dst, *src, EDGE_SIZE2);
		memset(dst + edged_width2 - EDGE_SIZE2, src[width2 - 1], EDGE_SIZE2);
		dst += edged_width2;
		src += edged_width2;
	}
	src -= edged_width2;
	for (i = 0; i < EDGE_SIZE2; i++) {
		memset(dst, *src, EDGE_SIZE2);
		memcpy(dst + EDGE_SIZE2, src, width2);
		memset(dst + edged_width2 - EDGE_SIZE2, *(src + width2 - 1),
			   EDGE_SIZE2);
		dst += edged_width2;
	}


	/* V */
	dst = image->v - (EDGE_SIZE2 + EDGE_SIZE2 * edged_width2);
	src = image->v;

	for (i = 0; i < EDGE_SIZE2; i++) {
		memset(dst, *src, EDGE_SIZE2);
		memcpy(dst + EDGE_SIZE2, src, width2);
		memset(dst + edged_width2 - EDGE_SIZE2, *(src + width2 - 1),
			   EDGE_SIZE2);
		dst += edged_width2;
	}

	for (i = 0; i < height / 2; i++) {
		memset(dst, *src, EDGE_SIZE2);
		memset(dst + edged_width2 - EDGE_SIZE2, src[width2 - 1], EDGE_SIZE2);
		dst += edged_width2;
		src += edged_width2;
	}
	src -= edged_width2;
	for (i = 0; i < EDGE_SIZE2; i++) {
		memset(dst, *src, EDGE_SIZE2);
		memcpy(dst + EDGE_SIZE2, src, width2);
		memset(dst + edged_width2 - EDGE_SIZE2, *(src + width2 - 1),
			   EDGE_SIZE2);
		dst += edged_width2;
	}
}

/* bframe encoding requires image-based u,v interpolation */
void
image_interpolate(const IMAGE * refn,
				  IMAGE * refh,
				  IMAGE * refv,
				  IMAGE * refhv,
				  uint32_t edged_width,
				  uint32_t edged_height,
				  uint32_t quarterpel,
				  uint32_t rounding)
{
	const uint32_t offset = EDGE_SIZE2 * (edged_width + 1); /* we only interpolate half of the edge area */
	const uint32_t stride_add = 7 * edged_width;
#if 0
	const uint32_t edged_width2 = edged_width / 2;
	const uint32_t edged_height2 = edged_height / 2;
	const uint32_t offset2 = EDGE_SIZE2 * (edged_width2 + 1);
	const uint32_t stride_add2 = 7 * edged_width2;
#endif
	uint8_t *n_ptr, *h_ptr, *v_ptr, *hv_ptr;
	uint32_t x, y;


	n_ptr = refn->y;
	h_ptr = refh->y;
	v_ptr = refv->y;

	n_ptr -= offset;
	h_ptr -= offset;
	v_ptr -= offset;

	/* Note we initialize the hv pointer later, as we can optimize code a bit
	 * doing it down to up in quarterpel and up to down in halfpel */
	if(quarterpel) {

		for (y = 0; y < (edged_height - EDGE_SIZE); y += 8) {
			for (x = 0; x < (edged_width - EDGE_SIZE); x += 8) {
				interpolate8x8_6tap_lowpass_h(h_ptr, n_ptr, edged_width, rounding);
				interpolate8x8_6tap_lowpass_v(v_ptr, n_ptr, edged_width, rounding);

				n_ptr += 8;
				h_ptr += 8;
				v_ptr += 8;
			}

			n_ptr += EDGE_SIZE;
			h_ptr += EDGE_SIZE;
			v_ptr += EDGE_SIZE;

			h_ptr += stride_add;
			v_ptr += stride_add;
			n_ptr += stride_add;
		}

		h_ptr = refh->y + (edged_height - EDGE_SIZE - EDGE_SIZE2)*edged_width - EDGE_SIZE2;
		hv_ptr = refhv->y + (edged_height - EDGE_SIZE - EDGE_SIZE2)*edged_width - EDGE_SIZE2;

		for (y = 0; y < (edged_height - EDGE_SIZE); y = y + 8) {
			hv_ptr -= stride_add;
			h_ptr -= stride_add;
			hv_ptr -= EDGE_SIZE;
			h_ptr -= EDGE_SIZE;

			for (x = 0; x < (edged_width - EDGE_SIZE); x = x + 8) {
				hv_ptr -= 8;
				h_ptr -= 8;
				interpolate8x8_6tap_lowpass_v(hv_ptr, h_ptr, edged_width, rounding);
			}
		}
	} else {

		hv_ptr = refhv->y;
		hv_ptr -= offset;

		for (y = 0; y < (edged_height - EDGE_SIZE); y += 8) {
			for (x = 0; x < (edged_width - EDGE_SIZE); x += 8) {
				interpolate8x8_halfpel_h(h_ptr, n_ptr, edged_width, rounding);
				interpolate8x8_halfpel_v(v_ptr, n_ptr, edged_width, rounding);
				interpolate8x8_halfpel_hv(hv_ptr, n_ptr, edged_width, rounding);

				n_ptr += 8;
				h_ptr += 8;
				v_ptr += 8;
				hv_ptr += 8;
			}

			h_ptr += EDGE_SIZE;
			v_ptr += EDGE_SIZE;
			hv_ptr += EDGE_SIZE;
			n_ptr += EDGE_SIZE;

			h_ptr += stride_add;
			v_ptr += stride_add;
			hv_ptr += stride_add;
			n_ptr += stride_add;
		}
	}
/*
#ifdef BFRAMES
	n_ptr = refn->u;
	h_ptr = refh->u;
	v_ptr = refv->u;
	hv_ptr = refhv->u;

	n_ptr -= offset2;
	h_ptr -= offset2;
	v_ptr -= offset2;
	hv_ptr -= offset2;

	for (y = 0; y < edged_height2; y += 8) {
		for (x = 0; x < edged_width2; x += 8) {
			interpolate8x8_halfpel_h(h_ptr, n_ptr, edged_width2, rounding);
			interpolate8x8_halfpel_v(v_ptr, n_ptr, edged_width2, rounding);
			interpolate8x8_halfpel_hv(hv_ptr, n_ptr, edged_width2, rounding);

			n_ptr += 8;
			h_ptr += 8;
			v_ptr += 8;
			hv_ptr += 8;
		}
		h_ptr += stride_add2;
		v_ptr += stride_add2;
		hv_ptr += stride_add2;
		n_ptr += stride_add2;
	}

	n_ptr = refn->v;
	h_ptr = refh->v;
	v_ptr = refv->v;
	hv_ptr = refhv->v;

	n_ptr -= offset2;
	h_ptr -= offset2;
	v_ptr -= offset2;
	hv_ptr -= offset2;

	for (y = 0; y < edged_height2; y = y + 8) {
		for (x = 0; x < edged_width2; x = x + 8) {
			interpolate8x8_halfpel_h(h_ptr, n_ptr, edged_width2, rounding);
			interpolate8x8_halfpel_v(v_ptr, n_ptr, edged_width2, rounding);
			interpolate8x8_halfpel_hv(hv_ptr, n_ptr, edged_width2, rounding);

			n_ptr += 8;
			h_ptr += 8;
			v_ptr += 8;
			hv_ptr += 8;
		}
		h_ptr += stride_add2;
		v_ptr += stride_add2;
		hv_ptr += stride_add2;
		n_ptr += stride_add2;
	}
#endif
*/
	/*
	   interpolate_halfpel_h(
	   refh->y - offset,
	   refn->y - offset,
	   edged_width, edged_height,
	   rounding);

	   interpolate_halfpel_v(
	   refv->y - offset,
	   refn->y - offset,
	   edged_width, edged_height,
	   rounding);

	   interpolate_halfpel_hv(
	   refhv->y - offset,
	   refn->y - offset,
	   edged_width, edged_height,
	   rounding);
	 */

	/* uv-image-based compensation
	   offset = EDGE_SIZE2 * (edged_width / 2 + 1);

	   interpolate_halfpel_h(
	   refh->u - offset,
	   refn->u - offset,
	   edged_width / 2, edged_height / 2,
	   rounding);

	   interpolate_halfpel_v(
	   refv->u - offset,
	   refn->u - offset,
	   edged_width / 2, edged_height / 2,
	   rounding);

	   interpolate_halfpel_hv(
	   refhv->u - offset,
	   refn->u - offset,
	   edged_width / 2, edged_height / 2,
	   rounding);


	   interpolate_halfpel_h(
	   refh->v - offset,
	   refn->v - offset,
	   edged_width / 2, edged_height / 2,
	   rounding);

	   interpolate_halfpel_v(
	   refv->v - offset,
	   refn->v - offset,
	   edged_width / 2, edged_height / 2,
	   rounding);

	   interpolate_halfpel_hv(
	   refhv->v - offset,
	   refn->v - offset,
	   edged_width / 2, edged_height / 2,
	   rounding);
	 */
}


/*
chroma optimize filter, invented by mf
a chroma pixel is average from the surrounding pixels, when the
correpsonding luma pixels are pure black or white.
*/

void
image_chroma_optimize(IMAGE * img, int width, int height, int edged_width)
{
	int x,y;
	int pixels = 0;

	for (y = 1; y < height/2 - 1; y++)
	for (x = 1; x < width/2 - 1; x++)
	{
#define IS_PURE(a)  ((a)<=16||(a)>=235)
#define IMG_Y(Y,X)	img->y[(Y)*edged_width + (X)]
#define IMG_U(Y,X)	img->u[(Y)*edged_width/2 + (X)]
#define IMG_V(Y,X)	img->v[(Y)*edged_width/2 + (X)]

		if (IS_PURE(IMG_Y(y*2  ,x*2  )) &&
			IS_PURE(IMG_Y(y*2  ,x*2+1)) &&
			IS_PURE(IMG_Y(y*2+1,x*2  )) &&
			IS_PURE(IMG_Y(y*2+1,x*2+1)))
		{
			IMG_U(y,x) = (IMG_U(y,x-1) + IMG_U(y-1, x) + IMG_U(y, x+1) + IMG_U(y+1, x)) / 4;
			IMG_V(y,x) = (IMG_V(y,x-1) + IMG_V(y-1, x) + IMG_V(y, x+1) + IMG_V(y+1, x)) / 4;
			pixels++;
		}

#undef IS_PURE
#undef IMG_Y
#undef IMG_U
#undef IMG_V
	}

	DPRINTF(XVID_DEBUG_DEBUG,"chroma_optimized_pixels = %i/%i\n", pixels, width*height/4);
}





/*
  perform safe packed colorspace conversion, by splitting
  the image up into an optimized area (pixel width divisible by 16),
  and two unoptimized/plain-c areas (pixel width divisible by 2)
*/

static void
safe_packed_conv(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,
				 packedFunc * func_opt, packedFunc func_c, int size)
{
	int width_opt, width_c;

	if (func_opt != func_c && x_stride < size*((width+15)/16)*16)
	{
		width_opt = width & (~15);
		width_c = width - width_opt;
	}
	else
	{
		width_opt = width;
		width_c = 0;
	}

	func_opt(x_ptr, x_stride,
			y_ptr, u_ptr, v_ptr, y_stride, uv_stride,
			width_opt, height, vflip);

	if (width_c)
	{
		func_c(x_ptr + size*width_opt, x_stride,
			y_ptr + width_opt, u_ptr + width_opt/2, v_ptr + width_opt/2,
			y_stride, uv_stride, width_c, height, vflip);
	}
}



int
image_input(IMAGE * image,
			uint32_t width,
			int height,
			uint32_t edged_width,
			uint8_t * src[4],
			int src_stride[4],
			int csp,
			int interlacing)
{
	const int edged_width2 = edged_width/2;
	const int width2 = width/2;
	const int height2 = height/2;
#if 0
	const int height_signed = (csp & XVID_CSP_VFLIP) ? -height : height;
#endif

	switch (csp & ~XVID_CSP_VFLIP) {
	case XVID_CSP_RGB555:
		safe_packed_conv(
			src[0], src_stride[0], image->y, image->u, image->v,
			edged_width, edged_width2, width, height, (csp & XVID_CSP_VFLIP),
			interlacing?rgb555i_to_yv12  :rgb555_to_yv12,
			interlacing?rgb555i_to_yv12_c:rgb555_to_yv12_c, 2);
		break;

	case XVID_CSP_RGB565:
		safe_packed_conv(
			src[0], src_stride[0], image->y, image->u, image->v,
			edged_width, edged_width2, width, height, (csp & XVID_CSP_VFLIP),
			interlacing?rgb565i_to_yv12  :rgb565_to_yv12,
			interlacing?rgb565i_to_yv12_c:rgb565_to_yv12_c, 2);