PVRRipper.cpp

/***********************************************************************
* Copyright 2007-2010 Michael Drueing <michael@drueing.de>
*
* 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) version 3 or 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, see <http://www.gnu.org/licenses/>.
***********************************************************************/

#include <cstring>
#include <cstdio>
#include <cstdlib>

#include "PVRRipper.h"

/* Ripper for PVR files (PowerVR Textures, commonly used on the SEGA Dreamcast) */

const char *PVRRipper::s_name = "PVR/PVRT/GBIX Ripper v1.0";

const HeaderStruct PVRRipper::s_headers[] = {
	HS("PVRT", 4)
	HS_END
};

bool PVRRipper::checkLocation(unsigned char *pos, const HeaderStruct * /*header*/, FoundStruct *found)
{
	unsigned char *startpos = pos;
	unsigned long total_len = 0;
	unsigned long len;
	unsigned char type1, type2;
	unsigned short width, height;
  
	found->criterium = CRIT_STRONG;

	if (pos - m_start > 16)
	{
		// check for valid GBIX header before the PVRT header
		if ( (memcmp(pos - 16, "GBIX", 4) == 0) && (*((unsigned long *)(pos - 12)) == 0x00000008))
		{
			// if we have a GBIX header, then adjust the start position
			startpos -= 16;
			total_len += 16;
		}
	}

	// continue checking the PVRT fields
	len = *((unsigned long *)(pos+4));

	if (m_start + m_length < pos + len + 8) // file goes beyond EOF
		return false;

	total_len += len;
	total_len += 8; // 8 header bytes

	type1 = *(pos+8);
	type2 = *(pos+9);
	width = *((unsigned short *)(pos+12));
	height = *((unsigned short *)(pos+14));

	// Type 1: 0=ARGB1555 1=RGB565 2=ARGB444 3=UNKNOWN(Soul Calibur has them, for example)
	if ((type1 != 0) && (type1 != 1) && (type1 != 2))
		found->criterium = CRIT_WEAK;

	if ((type2 != 0) && (type2 != 1) && (type2 != 2) && (type2 != 3) && (type2 != 4)
		&& (type2 != 9) && (type2 != 16) && (type2 != 17))
		found->criterium = CRIT_WEAK;

	strcpy(found->extension, "pvr");
	found->startoffset = startpos;
	found->length = total_len;

	return true;
};