FreeRDP/libfreerdp/primitives/prim_YCoCg.c

/* FreeRDP: A Remote Desktop Protocol Client
 * YCoCg<->RGB Color conversion operations.
 * vi:ts=4 sw=4:
 *
 * (c) Copyright 2014 Hewlett-Packard Development Company, L.P.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <freerdp/types.h>
#include <freerdp/primitives.h>

#include "prim_internal.h"

#ifndef MINMAX
#define MINMAX(_v_, _l_, _h_) \
	((_v_) < (_l_) ? (_l_) : ((_v_) > (_h_) ? (_h_) : (_v_)))
#endif /* !MINMAX */

/* ------------------------------------------------------------------------- */
static pstatus_t general_YCoCgToRGB_8u_AC4R(
		const BYTE* pSrc, INT32 srcStep,
		BYTE* pDst, UINT32 DstFormat, INT32 dstStep,
		UINT32 width, UINT32 height,
		UINT8 shift,
		BOOL withAlpha)
{
	BYTE A;
	UINT32 x, y;
	BYTE* dptr = pDst;
	const BYTE* sptr = pSrc;
	INT16 Cg, Co, Y, T, R, G, B;
	int cll = shift - 1;  /* -1 builds in the /2's */
	UINT32 srcPad = srcStep - (width * 4);
	UINT32 dstPad = dstStep - (width * GetBytesPerPixel(DstFormat));

	for (y = 0; y < height; y++)
	{
		for (x = 0; x < width; x++)
		{
			UINT32 color;
			/* Note: shifts must be done before sign-conversion. */
			Cg = (INT16)((INT8)((*sptr++) << cll));
			Co = (INT16)((INT8)((*sptr++) << cll));
			Y = (INT16)(*sptr++);	/* UINT8->INT16 */
			A = *sptr++;

			if (!withAlpha)
				A = 0xFFU;

			T  = Y - Cg;
			R  = T + Co;
			G  = Y + Cg;
			B  = T - Co;

			color = GetColor(DstFormat,
					 MINMAX(R, 0, 255), MINMAX(G, 0, 255),
					 MINMAX(B, 0, 255), A);
			WriteColor(dptr, DstFormat, color);
			dptr += GetBytesPerPixel(DstFormat);
		}

		sptr += srcPad;
		dptr += dstPad;
	}

	return PRIMITIVES_SUCCESS;
}

/* ------------------------------------------------------------------------- */
void primitives_init_YCoCg(primitives_t* prims)
{
	prims->YCoCgToRGB_8u_AC4R = general_YCoCgToRGB_8u_AC4R;
}