colorspace.c

基于Linux的ffmepg decoder

#include <string.h>				// memcpy

#include "colorspace.h"
#include "../divx4.h"			// DEC_PICTURE

// function pointers

color_outputFuncPtr yv12_to_yuv;

#define MIN(A,B)	((A)<(B)?(A):(B))
#define MAX(A,B)	((A)>(B)?(A):(B))


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


/*	yuv 4:2:0 planar -> yuv planar */

void
yv12_to_yuv_c(uint8_t * dst,
			  int dst_stride,
			  uint8_t * y_src,
			  uint8_t * u_src,
			  uint8_t * v_src,
			  int y_stride,
			  int uv_stride,
			  int width,
			  int height)
{
	uint32_t dst_stride2 = dst_stride >> 1;
	uint32_t width2 = width >> 1;
	uint32_t y;

	if (height < 0) {
		height = -height;
		y_src += (height - 1) * y_stride;
		u_src += (height / 2 - 1) * uv_stride;
		v_src += (height / 2 - 1) * uv_stride;
		y_stride = -y_stride;
		uv_stride = -uv_stride;
	}

	for (y = height; y; y--) {
		memcpy(dst, y_src, width);
		dst += dst_stride;
		y_src += y_stride;
	}

	for (y = height >> 1; y; y--) {
		memcpy(dst, u_src, width2);
		dst += dst_stride2;
		u_src += uv_stride;
	}

	for (y = height >> 1; y; y--) {
		memcpy(dst, v_src, width2);
		dst += dst_stride2;
		v_src += uv_stride;
	}
}