Aegisub/vsfilter/subtitles/VobSubImage.cpp

/* 
 *	Copyright (C) 2003-2006 Gabest
 *	http://www.gabest.org
 *
 *  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, 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 GNU Make; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 
 *  http://www.gnu.org/copyleft/gpl.html
 *
 */

#include "stdafx.h"
#include "VobSubImage.h"

CVobSubImage::CVobSubImage()
{
	iLang = iIdx = -1;
	fForced = false;
	start = delay = 0;
	rect = CRect(0,0,0,0);
	lpPixels = lpTemp1 = lpTemp2 = NULL;
	org = CSize(0,0);
}

CVobSubImage::~CVobSubImage()
{
	Free();
}

bool CVobSubImage::Alloc(int w, int h)
{
	// if there is nothing to crop TrimSubImage might even add a 1 pixel
	// wide border around the text, that's why we need a bit more memory
	// to be allocated.

	if(lpTemp1 == NULL || w*h > org.cx*org.cy)
	{
		Free();

		lpTemp1 = new RGBQUAD[w*h];
		if(!lpTemp1) return(false);

		lpTemp2 = new RGBQUAD[(w+2)*(h+2)];
		if(!lpTemp2) {delete [] lpTemp1; lpTemp1 = NULL; return(false);}

		org.cx = w; 
		org.cy = h;
	}

	lpPixels = lpTemp1;

	return(true);
}

void CVobSubImage::Free()
{
	if(lpTemp1) delete [] lpTemp1;
	lpTemp1 = NULL;

	if(lpTemp2) delete [] lpTemp2;
	lpTemp2 = NULL;

	lpPixels = NULL;
}

bool CVobSubImage::Decode(BYTE* lpData, int packetsize, int datasize,
						  bool fCustomPal, 
						  int tridx, 
						  RGBQUAD* orgpal /*[16]*/, RGBQUAD* cuspal /*[4]*/,
						  bool fTrim)
{
	GetPacketInfo(lpData, packetsize, datasize);

	if(!Alloc(rect.Width(), rect.Height())) return(false);

	lpPixels = lpTemp1;

	nPlane = 0;
	fAligned = 1;

	this->fCustomPal = fCustomPal;
	this->orgpal = orgpal;
	this->tridx = tridx;
	this->cuspal = cuspal;

	CPoint p(rect.left, rect.top);

	int end0 = nOffset[1];
	int end1 = datasize;

	while((nPlane == 0 && nOffset[0] < end0) || (nPlane == 1 && nOffset[1] < end1))
	{
		DWORD code;

		if((code = GetNibble(lpData)) >= 0x4
		|| (code = (code << 4) | GetNibble(lpData)) >= 0x10
		|| (code = (code << 4) | GetNibble(lpData)) >= 0x40
		|| (code = (code << 4) | GetNibble(lpData)) >= 0x100)
		{
			DrawPixels(p, code >> 2, code & 3);
			if((p.x += code >> 2) < rect.right) continue;
		}

		DrawPixels(p, rect.right - p.x, code & 3);

		if(!fAligned) GetNibble(lpData); // align to byte

		p.x = rect.left;
		p.y++;
		nPlane = 1 - nPlane;
	}

	rect.bottom = min(p.y, rect.bottom);

	if(fTrim) TrimSubImage();

	return(true);
}

void CVobSubImage::GetPacketInfo(BYTE* lpData, int packetsize, int datasize)
{
//	delay = 0;

	int i, nextctrlblk = datasize;
	WORD pal = 0, tr = 0;

	do
	{
		i = nextctrlblk;

		int t = (lpData[i] << 8) | lpData[i+1]; i += 2;
		nextctrlblk = (lpData[i] << 8) | lpData[i+1]; i += 2;

		if(nextctrlblk > packetsize || nextctrlblk < datasize)
		{
			ASSERT(0);
			return;
		}

		bool fBreak = false;

		while(!fBreak)
		{
			int len = 0;

			switch(lpData[i])
			{
				case 0x00: len = 0; break;
				case 0x01: len = 0; break;
				case 0x02: len = 0; break;
				case 0x03: len = 2; break;
				case 0x04: len = 2; break;
				case 0x05: len = 6; break;
				case 0x06: len = 4; break;
				default: len = 0; break;
			}

			if(i+len >= packetsize)
			{
				TRACE(_T("Warning: Wrong subpicture parameter block ending\n"));
				break;
			}

			switch(lpData[i++])
			{
				case 0x00: // forced start displaying
					fForced = true;
					break;
				case 0x01: // start displaying
					fForced = false;
					break;
				case 0x02: // stop displaying
					delay = 1024 * t / 90;
					break;
				case 0x03:
					pal = (lpData[i] << 8) | lpData[i+1]; i += 2;
					break;
				case 0x04:
					tr = (lpData[i] << 8) | lpData[i+1]; i += 2;
//tr &= 0x00f0;
					break;
				case 0x05:
					rect = CRect((lpData[i] << 4) + (lpData[i+1] >> 4), 
						(lpData[i+3] << 4) + (lpData[i+4] >> 4), 
						((lpData[i+1] & 0x0f) << 8) + lpData[i+2] + 1, 
						((lpData[i+4] & 0x0f) << 8) + lpData[i+5] + 1);
					i += 6;
					break;
				case 0x06:
					nOffset[0] = (lpData[i] << 8) + lpData[i+1]; i += 2;
					nOffset[1] = (lpData[i] << 8) + lpData[i+1]; i += 2;
					break;
				case 0xff: // end of ctrlblk
					fBreak = true;
					continue;
				default: // skip this ctrlblk
					fBreak = true;
					break;
			}
		}
	}
	while(i <= nextctrlblk && i < packetsize);

	for(i = 0; i < 4; i++) 
	{
		this->pal[i].pal = (pal >> (i << 2)) & 0xf;
		this->pal[i].tr = (tr >> (i << 2)) & 0xf;
	}
}

BYTE CVobSubImage::GetNibble(BYTE* lpData)
{
	WORD& off = nOffset[nPlane];
	BYTE ret = (lpData[off] >> (fAligned << 2)) & 0x0f;
	fAligned = !fAligned;
	off += fAligned;
	return(ret);
}

void CVobSubImage::DrawPixels(CPoint p, int length, int colorid)
{
	if(length <= 0
	|| p.x + length < rect.left
	|| p.x >= rect.right
	|| p.y < rect.top
	|| p.y >= rect.bottom) 
	{
		return;
	}

	if(p.x < rect.left) p.x = rect.left;
	if(p.x + length >= rect.right) length = rect.right - p.x;

	RGBQUAD* ptr = &lpPixels[rect.Width() * (p.y - rect.top) + (p.x - rect.left)];

	RGBQUAD c;

	if(!fCustomPal) 
	{
		c = orgpal[pal[colorid].pal];
		c.rgbReserved = (pal[colorid].tr<<4)|pal[colorid].tr;
	}
	else
	{
		c = cuspal[colorid];
	}

	while(length-- > 0) *ptr++ = c;
}

void CVobSubImage::TrimSubImage()
{
	CRect r;
	r.left = rect.Width();
	r.top = rect.Height();
	r.right = 0;
	r.bottom = 0;

	RGBQUAD* ptr = lpTemp1;

	for(int j = 0, y = rect.Height(); j < y; j++)
	{
		for(int i = 0, x = rect.Width(); i < x; i++, ptr++)
		{
			if(ptr->rgbReserved)
			{
				if(r.top > j) r.top = j;
				if(r.bottom < j) r.bottom = j;
				if(r.left > i) r.left = i; 
				if(r.right < i) r.right = i; 
			}
		}
	}

	if(r.left > r.right || r.top > r.bottom) return;

	r += CRect(0, 0, 1, 1);

	r &= CRect(CPoint(0,0), rect.Size());

	int w = r.Width(), h = r.Height();

	DWORD offset = r.top*rect.Width() + r.left;

	r += CRect(1, 1, 1, 1);

	DWORD* src = (DWORD*)&lpTemp1[offset];
	DWORD* dst = (DWORD*)&lpTemp2[1 + w + 1];

	memset(lpTemp2, 0, (1 + w + 1)*sizeof(RGBQUAD));

	for(int height = h; height; height--, src += rect.Width())
	{
		*dst++ = 0;
		memcpy(dst, src, w*sizeof(RGBQUAD)); dst += w; 
		*dst++ = 0;
	}

	memset(dst, 0, (1 + w + 1)*sizeof(RGBQUAD));

	lpPixels = lpTemp2;

	rect = r + rect.TopLeft();
}

////////////////////////////////

#include "RTS.h"
#include <math.h>

#define GP(xx, yy) (((xx) < 0 || (yy) < 0 || (xx) >= w || (yy) >= h) ? 0 : p[(yy)*w+(xx)])

CAutoPtrList<COutline>* CVobSubImage::GetOutlineList(CPoint& topleft)
{
	int w = rect.Width(), h = rect.Height(), len = w*h;
	if(len <= 0) return NULL;

	CAutoVectorPtr<BYTE> p;
	if(!p.Allocate(len)) return NULL;

	CAutoPtrList<COutline>* ol = new CAutoPtrList<COutline>();
	if(!ol) return NULL;

	BYTE* cp = p;
	RGBQUAD* rgbp = (RGBQUAD*)lpPixels;

	for(int i = 0; i < len; i++, cp++, rgbp++)
		*cp = !!rgbp->rgbReserved;

	enum {UP, RIGHT, DOWN, LEFT};

	topleft.x = topleft.y = INT_MAX;

	while(1)
	{
		cp = p;

		int x, y; 

		for(y = 0; y < h; y++)
		{
			for(x = 0; x < w-1; x++, cp++)
			{
				if(cp[0] == 0 && cp[1] == 1) break;
			}

			if(x < w-1) break;

			cp++;
		}

		if(y == h) break;

		int prevdir, dir = UP;

		int ox = x, oy = y, odir = dir;

		CAutoPtr<COutline> o(new COutline);
		if(!o) break;

		do
		{
			CPoint pp;
			BYTE fl, fr, br;

			prevdir = dir;

			switch(prevdir)
			{
			case UP:
				pp = CPoint(x+1, y);
				fl = GP(x, y-1);
				fr = GP(x+1, y-1);
				br = GP(x+1, y);
				break;
			case RIGHT:
				pp = CPoint(x+1, y+1);
				fl = GP(x+1, y);
				fr = GP(x+1, y+1);
				br = GP(x, y+1);
				break;
			case DOWN:
				pp = CPoint(x, y+1);
				fl = GP(x, y+1);
				fr = GP(x-1, y+1);
				br = GP(x-1, y);
				break;
			case LEFT:
				pp = CPoint(x, y);
				fl = GP(x-1, y);
				fr = GP(x-1, y-1);
				br = GP(x, y-1);
				break;
			}

			// turning left if:
			// o . | o .
			// ^ o | < o
			// turning right if:
			// x x | x >
			// ^ o | x o
			//
			// o set, x empty, . can be anything

			if(fl==1) dir = (dir-1+4)&3;
			else if(fl!=1 && fr!=1 && br==1) dir = (dir+1)&3;
			else if(p[y*w+x]&16) {ASSERT(0); break;} // we are going around in one place (this must not happen if the starting conditions were correct)

			p[y*w+x] = (p[y*w+x]<<1) | 2; // increase turn count (== log2(highordbit(*p)))

			switch(dir)
			{
			case UP:
				if(prevdir == LEFT) {x--; y--;}
				if(prevdir == UP) y--;
				break;
			case RIGHT:
				if(prevdir == UP) {x++; y--;}
				if(prevdir == RIGHT) x++;
				break;
			case DOWN:
				if(prevdir == RIGHT) {x++; y++;}
				if(prevdir == DOWN) y++;
				break;
			case LEFT:
				if(prevdir == DOWN) {x--; y++;}
				if(prevdir == LEFT) x--;
				break;
			}

			int d = dir - prevdir;
			o->Add(pp, d == 3 ? -1 : d == -3 ? 1 : d);

			if(topleft.x > pp.x) topleft.x = pp.x;
			if(topleft.y > pp.y) topleft.y = pp.y;
		}
		while(!(x == ox && y == oy && dir == odir));

		if(o->pa.GetCount() > 0 && (x == ox && y == oy && dir == odir)) 
		{
			ol->AddTail(o);
		}
		else
		{
			ASSERT(0);
		}
	}

	return(ol);
}

static bool FitLine(COutline& o, int& start, int& end)
{
	int len = o.pa.GetCount();
	if(len < 7) return(false); // small segments should be handled with beziers...

	for(start = 0; start < len && !o.da[start]; start++);
	for(end = len-1; end > start && !o.da[end]; end--);

	if(end-start < 8 || end-start < (len-end)+(start-0)) return(false);

	CUIntArray la, ra;

	int i, j, k;

	for(i = start+1, j = end, k = start; i <= j; i++)
	{
		if(!o.da[i]) continue;
		if(o.da[i] == o.da[k]) return(false);
		if(o.da[i] == -1) la.Add(i-k);
		else ra.Add(i-k);
		k = i;
	}

	bool fl = true, fr = true;

	// these tests are completly heuristic and might be redundant a bit...

	for(i = 0, j = la.GetSize(); i < j && fl; i++) {if(la[i] != 1) fl = false;} 
	for(i = 0, j = ra.GetSize(); i < j && fr; i++) {if(ra[i] != 1) fr = false;}

	if(!fl && !fr) return(false); // can't be a line if there are bigger steps than one in both directions (lines are usually drawn by stepping one either horizontally or vertically)
	if(fl && fr && 1.0*(end-start)/((len-end)*2+(start-0)*2) > 0.4) return(false); // if this section is relatively too small it may only be a rounded corner
	if(!fl && la.GetSize() > 0 && la.GetSize() <= 4 && (la[0] == 1 && la[la.GetSize()-1] == 1)) return(false); // one step at both ends, doesn't sound good for a line (may be it was skewed, so only eliminate smaller sections where beziers going to look just as good)
	if(!fr && ra.GetSize() > 0 && ra.GetSize() <= 4 && (ra[0] == 1 && ra[ra.GetSize()-1] == 1)) return(false); // -''-

	CUIntArray& a = !fl ? la : ra;

	len = a.GetSize();

	int sum = 0;

	for(i = 0, j = INT_MAX, k = 0; i < len; i++)
	{
		if(j > a[i]) j = a[i];
		if(k < a[i]) k = a[i];
		sum += a[i];
	}

	if(k - j > 2 && 1.0*sum/len < 2) return(false);
	if(k - j > 2 && 1.0*sum/len >= 2 && len < 4) return(false);

	if((la.GetSize()/2+ra.GetSize()/2)/2 <= 2)
	{
		if((k+j)/2 < 2 && k*j!=1) return(false);
	}

	double err = 0;

	CPoint sp = o.pa[start], ep = o.pa[end];

	double minerr = 0, maxerr = 0;
	
	double vx = ep.x - sp.x, vy = ep.y - sp.y, l = sqrt(vx*vx+vy*vy);
	vx /= l; vy /= l;

	for(i = start+1, j = end-1; i <= j; i++)
	{
		CPoint p = o.pa[i], dp = p - sp;
		double t = vx*dp.x+vy*dp.y, dx = vx*t + sp.x - p.x, dy = vy*t + sp.y - p.y;
		t = dx*dx+dy*dy;
		err += t;
		t = sqrt(t);
		if(vy*dx-dy*vx < 0) {if(minerr > -t) minerr = -t;}
		else {if(maxerr < t) maxerr = t;}
	}

	return((maxerr-minerr)/l < 0.1  || err/l < 1.5 || (fabs(maxerr) < 8 && fabs(minerr) < 8));
}

static int CalcPossibleCurveDegree(COutline& o)
{
	int len2 = o.da.GetCount();

	CUIntArray la;

	for(int i = 0, j = 0; j < len2; j++)
	{
		if(j == len2-1 || o.da[j])
		{
			la.Add(j-i);
			i = j;
		}
	}

	int len = la.GetCount();

	int ret = 0;

	// check if we can find a reason to add a penalty degree, or two :P
	// it is mainly about looking for distant corners
	{
		int penalty = 0;

		int ma[2] = {0, 0};
		for(int i = 0; i < len; i++) ma[i&1] += la[i];

		int ca[2] = {ma[0], ma[1]};
		for(int i = 0; i < len; i++) 
		{
			ca[i&1] -= la[i];

			double c1 = 1.0*ca[0]/ma[0], c2 = 1.0*ca[1]/ma[1], c3 = 1.0*la[i]/ma[i&1];

			if(len2 > 16 && (fabs(c1-c2) > 0.7 || (c3 > 0.6 && la[i] > 5)))
				{penalty = 2; break;}

			if(fabs(c1-c2) > 0.6 || (c3 > 0.4 && la[i] > 5))
				{penalty = 1;}
		}

		ret += penalty;
	}

	la[0] <<= 1;
	la[len-1] <<= 1;

	for(int i = 0; i < len; i+=2)
	{
		if(la[i] > 1) {ret++; i--;} // prependicular to the last chosen section and bigger then 1 -> add a degree and continue with the other dir
	}

	return(ret);
}

inline double vectlen(CPoint p)
{
	return(sqrt((double)(p.x*p.x+p.y*p.y)));
}

inline double vectlen(CPoint p1, CPoint p2)
{
	return(vectlen(p2 - p1));
}

static bool MinMaxCosfi(COutline& o, double& mincf, double& maxcf) // not really cosfi, it is weighted by the distance from the segment endpoints, and since it would be always between -1 and 0, the applied sign marks side 
{
	CAtlArray<CPoint>& pa = o.pa;

	int len = (int)pa.GetCount();
	if(len < 6) return(false);

	mincf = 1;
	maxcf = -1;

	CPoint p = pa[len-1] - pa[0];
	double l = vectlen(p);

	for(int i = 2; i < len-2; i++) // skip the endpoints, they aren't accurate
	{
		CPoint p1 = pa[0] - pa[i], p2 = pa[len-1] - pa[i];
		double l1 = vectlen(p1), l2 = vectlen(p2);
		int sign = p1.x*p.y-p1.y*p.x >= 0 ? 1 : -1;

		double c = (1.0*len/2 - fabs(i - 1.0*len/2)) / len * 2; // c: 0 -> 1 -> 0

		double cosfi = (1+(p1.x*p2.x+p1.y*p2.y)/(l1*l2)) * sign * c;
		if(mincf > cosfi) mincf = cosfi;
		if(maxcf < cosfi) maxcf = cosfi;
	}

	return(true);
}

static bool FitBezierVH(COutline& o, CPoint& p1, CPoint& p2)
{
	int i;

	CAtlArray<CPoint>& pa = o.pa;

	int len = (int)pa.GetCount();

	if(len <= 1)
	{
		return(false);
	}
	else if(len == 2)
	{
		CPoint mid = pa[0]+pa[1];
		mid.x >>= 1;
		mid.y >>= 1;
		p1 = p2 = mid;
		return(true);
	}

	CPoint dir1 = pa[1] - pa[0], dir2 = pa[len-2] - pa[len-1];
	if((dir1.x&&dir1.y)||(dir2.x&&dir2.y)) 
		return(false); // we are only fitting beziers with hor./ver. endings

	if(CalcPossibleCurveDegree(o) > 3) 
		return(false);
	
	double mincf, maxcf;
	if(MinMaxCosfi(o, mincf, maxcf))
	{
		if(maxcf-mincf > 0.8 
		|| maxcf-mincf > 0.6 && (maxcf >= 0.4 || mincf <= -0.4)) 
			return(false);
	}

	CPoint p0 = p1 = pa[0];
	CPoint p3 = p2 = pa[len-1];

	CAtlArray<double> pl;
	pl.SetCount(len);

	double c10 = 0, c11 = 0, c12 = 0, c13 = 0, c1x = 0, c1y = 0;
	double c20 = 0, c21 = 0, c22 = 0, c23 = 0, c2x = 0, c2y = 0;
	double length = 0;

	for(pl[0] = 0, i = 1; i < len; i++)
	{
		CPoint diff = (pa[i] - pa[i-1]);
		pl[i] = (length += sqrt((double)(diff.x*diff.x+diff.y*diff.y)));
	}

	for(i = 0; i < len; i++) 
	{
		double t1 = pl[i] / length;
		double t2 = t1*t1;
		double t3 = t2*t1;
		double it1 = 1 - t1;
		double it2 = it1*it1;
		double it3 = it2*it1;

		double dc1 = 3.0*it2*t1;
		double dc2 = 3.0*it1*t2;

		c10 += it3*dc1;
		c11 += dc1*dc1;
		c12 += dc2*dc1;
		c13 += t3*dc1;
		c1x += pa[i].x*dc1;
		c1y += pa[i].y*dc1;

		c20 += it3*dc2;
		c21 += dc1*dc2;
		c22 += dc2*dc2;
		c23 += t3*dc2;
		c2x += pa[i].x*dc2;
		c2y += pa[i].y*dc2;
	}

	if(dir1.y == 0 && dir2.x == 0)
	{
		p1.x = (int)((c1x - c10*p0.x - c12*p3.x - c13*p3.x) / c11 + 0.5);
		p2.y = (int)((c2y - c20*p0.y - c21*p0.y - c23*p3.y) / c22 + 0.5);
	}
	else if(dir1.x == 0 && dir2.y == 0)
	{
		p2.x = (int)((c2x - c20*p0.x - c21*p0.x - c23*p3.x) / c22 + 0.5);
		p1.y = (int)((c1y - c10*p0.y - c12*p3.y - c13*p3.y) / c11 + 0.5);
	}
	else if(dir1.y == 0 && dir2.y == 0)
	{
		// cramer's rule
		double D = c11*c22 - c12*c21;
		p1.x = (int)(((c1x-c10*p0.x-c13*p3.x)*c22 - c12*(c2x-c20*p0.x-c23*p3.x)) / D + 0.5);
		p2.x = (int)((c11*(c2x-c20*p0.x-c23*p3.x) - (c1x-c10*p0.x-c13*p3.x)*c21) / D + 0.5);
	}
	else if(dir1.x == 0 && dir2.x == 0)
	{
		// cramer's rule
		double D = c11*c22 - c12*c21;
		p1.y = (int)(((c1y-c10*p0.y-c13*p3.y)*c22 - c12*(c2y-c20*p0.y-c23*p3.y)) / D + 0.5);
		p2.y = (int)((c11*(c2y-c20*p0.y-c23*p3.y) - (c1y-c10*p0.y-c13*p3.y)*c21) / D + 0.5);
	}
	else // must not happen
	{
		ASSERT(0); 
		return(false);
	}

	// check for "inside-out" beziers
	CPoint dir3 = p1 - p0, dir4 = p2 - p3;
	if((dir1.x*dir3.x+dir1.y*dir3.y) <= 0 || (dir2.x*dir4.x+dir2.y*dir4.y) <= 0)
		return(false);

	return(true);
}

int CVobSubImage::GrabSegment(int start, COutline& o, COutline& ret)
{
	ret.RemoveAll();

	int len = o.pa.GetCount();
	
	int cur = (start)%len, first = -1, last = -1;
	int curDir = 0, lastDir = 0;

	for(int i = 0; i < len; i++)
	{
		cur = (cur+1)%len;

		if(o.da[cur] == 0) continue;

		if(first == -1) first = cur;

		if(lastDir == o.da[cur])
		{
			CPoint startp = o.pa[first]+o.pa[start]; startp.x >>= 1; startp.y >>= 1;
			CPoint endp = o.pa[last]+o.pa[cur]; endp.x >>= 1; endp.y >>= 1;

			if(first < start) first += len;
			start = ((start+first)>>1)+1;
			if(start >= len) start -= len;
			if(cur < last) cur += len;
			cur = ((last+cur+1)>>1);
			if(cur >= len) cur -= len;

			ret.Add(startp, 0);

			while(start != cur)
			{
				ret.Add(o.pa[start], o.da[start]);

				start++;
				if(start >= len) start -= len;
			}

			ret.Add(endp, 0);

			return(last);
		}

		lastDir = o.da[cur];
		last = cur;
	}

	ASSERT(0);

	return(start);
}

void CVobSubImage::SplitOutline(COutline& o, COutline& o1, COutline& o2)
{
	int len = o.pa.GetCount();
	if(len < 4) return;

	CAtlArray<UINT> la, sa, ea;

	int i, j, k;

	for(i = 0, j = 0; j < len; j++)
	{
		if(j == len-1 || o.da[j])
		{
			la.Add(j-i);
			sa.Add(i);
			ea.Add(j);
			i = j;
		}
	}

	int maxlen = 0, maxidx = -1;
	int maxlen2 = 0, maxidx2 = -1;

	for(i = 0; i < la.GetCount(); i++)
	{
		if(maxlen < la[i])
		{
			maxlen = la[i];
			maxidx = i;
		}

		if(maxlen2 < la[i] && i > 0 && i < la.GetCount()-1)
		{
			maxlen2 = la[i];
			maxidx2 = i;
		}
	}

	if(maxlen == maxlen2) maxidx = maxidx2; // if equal choose the inner section

	j = (sa[maxidx] + ea[maxidx]) >> 1, k = (sa[maxidx] + ea[maxidx] + 1) >> 1;

	o1.RemoveAll();
	o2.RemoveAll();

	for(i = 0; i <= j; i++)
		o1.Add(o.pa[i], o.da[i]);

	if(j != k)
	{
		CPoint mid = o.pa[j]+o.pa[k]; mid.x >>= 1; mid.y >>= 1;
		o1.Add(mid, 0);
		o2.Add(mid, 0);
	}

	for(i = k; i < len; i++)
		o2.Add(o.pa[i], o.da[i]);
}

void CVobSubImage::AddSegment(COutline& o, CAtlArray<BYTE>& pathTypes, CAtlArray<CPoint>& pathPoints)
{
	int i, len = o.pa.GetCount();
	if(len < 3) return;

	int nLeftTurns = 0, nRightTurns = 0;

	for(i = 0; i < len; i++)
	{
		if(o.da[i] == -1) nLeftTurns++;
		else if(o.da[i] == 1) nRightTurns++;
	}

	if(nLeftTurns == 0 && nRightTurns == 0) // line
	{
		pathTypes.Add(PT_LINETO);
		pathPoints.Add(o.pa[len-1]);

		return;
	}

	if(nLeftTurns == 0 || nRightTurns == 0) // b-spline
	{
		pathTypes.Add(PT_MOVETONC);
		pathPoints.Add(o.pa[0]+(o.pa[0]-o.pa[1]));

		for(i = 0; i < 3; i++)
		{
			pathTypes.Add(PT_BSPLINETO);
			pathPoints.Add(o.pa[i]);
		}

		for(; i < len; i++)
		{
			pathTypes.Add(PT_BSPLINEPATCHTO);
			pathPoints.Add(o.pa[i]);
		}

		pathTypes.Add(PT_BSPLINEPATCHTO);
		pathPoints.Add(o.pa[len-1]+(o.pa[len-1]-o.pa[len-2]));

		pathTypes.Add(PT_MOVETONC);
		pathPoints.Add(o.pa[len-1]);

		return;
	}

	int start, end;
	if(FitLine(o, start, end)) // b-spline, line, b-spline
	{
		pathTypes.Add(PT_MOVETONC);
		pathPoints.Add(o.pa[0]+(o.pa[0]-o.pa[1]));

		pathTypes.Add(PT_BSPLINETO);
		pathPoints.Add(o.pa[0]);

		pathTypes.Add(PT_BSPLINETO);
		pathPoints.Add(o.pa[1]);

		CPoint p[4], pp, d = o.pa[end] - o.pa[start];
		double l = sqrt((double)(d.x*d.x+d.y*d.y)), dx = 1.0 * d.x / l, dy = 1.0 * d.y / l;

		pp = o.pa[start]-o.pa[start-1];
		double l1 = abs(pp.x)+abs(pp.y);
		pp = o.pa[end]-o.pa[end+1];
		double l2 = abs(pp.x)+abs(pp.y);
		p[0] = CPoint((int)(1.0 * o.pa[start].x + dx*l1 + 0.5), (int)(1.0 * o.pa[start].y + dy*l1 + 0.5));
		p[1] = CPoint((int)(1.0 * o.pa[start].x + dx*l1*2 + 0.5), (int)(1.0 * o.pa[start].y + dy*l1*2 + 0.5));
		p[2] = CPoint((int)(1.0 * o.pa[end].x - dx*l2*2 + 0.5), (int)(1.0 * o.pa[end].y - dy*l2*2 + 0.5));
		p[3] = CPoint((int)(1.0 * o.pa[end].x - dx*l2 + 0.5), (int)(1.0 * o.pa[end].y - dy*l2 + 0.5));

		if(start == 1)
		{
			pathTypes.Add(PT_BSPLINETO);
			pathPoints.Add(p[0]);
		}
		else
		{
			pathTypes.Add(PT_BSPLINETO);
			pathPoints.Add(o.pa[2]);

			for(int i = 3; i <= start; i++)
			{
				pathTypes.Add(PT_BSPLINEPATCHTO);
				pathPoints.Add(o.pa[i]);
			}

			pathTypes.Add(PT_BSPLINEPATCHTO);
			pathPoints.Add(p[0]);
		}

		pathTypes.Add(PT_BSPLINEPATCHTO);
		pathPoints.Add(p[1]);

		pathTypes.Add(PT_MOVETONC);
		pathPoints.Add(p[0]);

		pathTypes.Add(PT_LINETO);
		pathPoints.Add(p[3]);

		pathTypes.Add(PT_MOVETONC);
		pathPoints.Add(p[2]);

		pathTypes.Add(PT_BSPLINEPATCHTO);
		pathPoints.Add(p[3]);

		for(i = end; i < len; i++)
		{
			pathTypes.Add(PT_BSPLINEPATCHTO);
			pathPoints.Add(o.pa[i]);
		}

		pathTypes.Add(PT_BSPLINEPATCHTO);
		pathPoints.Add(o.pa[len-1]+(o.pa[len-1]-o.pa[len-2]));

		pathTypes.Add(PT_MOVETONC);
		pathPoints.Add(o.pa[len-1]);

		return;
	}

	CPoint p1, p2;
	if(FitBezierVH(o, p1, p2)) // bezier
	{
		pathTypes.Add(PT_BEZIERTO);
		pathPoints.Add(p1);
		pathTypes.Add(PT_BEZIERTO);
		pathPoints.Add(p2);
		pathTypes.Add(PT_BEZIERTO);
		pathPoints.Add(o.pa[o.pa.GetCount()-1]);

		return;
	}

	COutline o1, o2;
	SplitOutline(o, o1, o2);
	AddSegment(o1, pathTypes, pathPoints);
	AddSegment(o2, pathTypes, pathPoints);
}

bool CVobSubImage::Polygonize(CAtlArray<BYTE>& pathTypes, CAtlArray<CPoint>& pathPoints, bool fSmooth, int scale)
{
	CPoint topleft;
	CAutoPtr<CAutoPtrList<COutline> > ol(GetOutlineList(topleft));
	if(!ol) return(false);

	POSITION pos;

	pos = ol->GetHeadPosition();
	while(pos)
	{
		CAtlArray<CPoint>& pa = ol->GetNext(pos)->pa;
		for(int i = 0; i < pa.GetCount(); i++)
		{
			pa[i].x = (pa[i].x-topleft.x)<<scale;
			pa[i].y = (pa[i].y-topleft.y)<<scale;
		}
	}

	pos = ol->GetHeadPosition();
	while(pos)
	{
		COutline& o = *ol->GetNext(pos), o2;

		if(fSmooth)
		{
			int i = 0, iFirst = -1;

			while(1)
			{
				i = GrabSegment(i, o, o2);

				if(i == iFirst) break;

				if(iFirst < 0) 
				{
					iFirst = i;
					pathTypes.Add(PT_MOVETO);
					pathPoints.Add(o2.pa[0]);
				}

				AddSegment(o2, pathTypes, pathPoints);
			}
		}
		else
		{
/*
			for(int i = 1, len = o.pa.GetSize(); i < len; i++)
			{
                if(int dir = o.da[i-1])
				{
					CPoint dir2 = o.pa[i] - o.pa[i-1];
					dir2.x /= 2; dir2.y /= 2;
					CPoint dir1 = dir > 0 ? CPoint(dir2.y, -dir2.x) : CPoint(-dir2.y, dir2.x);
					i = i;
					o.pa[i-1] -= dir1;
					o.pa.InsertAt(i, o.pa[i-1] + dir2);
					o.da.InsertAt(i, -dir);
					o.pa.InsertAt(i+1, o.pa[i] + dir1);
					o.da.InsertAt(i+1, dir);
					i += 2;
					len += 2;
				}
			}
*/
			pathTypes.Add(PT_MOVETO);
			pathPoints.Add(o.pa[0]);

			for(int i = 1, len = o.pa.GetCount(); i < len; i++)
			{
				pathTypes.Add(PT_LINETO);
				pathPoints.Add(o.pa[i]);
			}
		}
	}

	return !pathTypes.IsEmpty();
}

bool CVobSubImage::Polygonize(CStringW& assstr, bool fSmooth, int scale)
{
	CAtlArray<BYTE> pathTypes;
	CAtlArray<CPoint> pathPoints;

	if(!Polygonize(pathTypes, pathPoints, fSmooth, scale))
		return(false);

	assstr.Format(L"{\\an7\\pos(%d,%d)\\p%d}", rect.left, rect.top, 1+scale);
//	assstr.Format(L"{\\p%d}", 1+scale);

	BYTE lastType = 0;

	int nPoints = pathTypes.GetCount();

	for(int i = 0; i < nPoints; i++)
	{
		CStringW s;

		switch(pathTypes[i])
		{
		case PT_MOVETO: 
			if(lastType != PT_MOVETO) assstr += L"m ";
			s.Format(L"%d %d ", pathPoints[i].x, pathPoints[i].y); 
			break;
		case PT_MOVETONC: 
			if(lastType != PT_MOVETONC) assstr += L"n ";
			s.Format(L"%d %d ", pathPoints[i].x, pathPoints[i].y); 
			break;
		case PT_LINETO: 
			if(lastType != PT_LINETO) assstr += L"l ";
			s.Format(L"%d %d ", pathPoints[i].x, pathPoints[i].y); 
			break;
		case PT_BEZIERTO: 
			if(i < nPoints-2)
			{
				if(lastType != PT_BEZIERTO) assstr += L"b ";
				s.Format(L"%d %d %d %d %d %d ", pathPoints[i].x, pathPoints[i].y, pathPoints[i+1].x, pathPoints[i+1].y, pathPoints[i+2].x, pathPoints[i+2].y); 
				i+=2;
			}
			break;
		case PT_BSPLINETO: 
			if(i < nPoints-2)
			{
				if(lastType != PT_BSPLINETO) assstr += L"s ";
				s.Format(L"%d %d %d %d %d %d ", pathPoints[i].x, pathPoints[i].y, pathPoints[i+1].x, pathPoints[i+1].y, pathPoints[i+2].x, pathPoints[i+2].y); 
				i+=2;
			}
			break;
		case PT_BSPLINEPATCHTO: 
			if(lastType != PT_BSPLINEPATCHTO) assstr += L"p ";
			s.Format(L"%d %d ", pathPoints[i].x, pathPoints[i].y); 
			break;
		}

		lastType = pathTypes[i];

		assstr += s;
	}

	assstr += L"{\\p0}";

	return nPoints > 0;
}

void CVobSubImage::Scale2x()
{
	int w = rect.Width(), h = rect.Height();

	DWORD* src = (DWORD*)lpPixels;
	DWORD* dst = new DWORD[w*h];

	for(int y = 0; y < h; y++)
	{
		for(int x = 0; x < w; x++, src++, dst++)
		{
			DWORD E = *src;

			DWORD A = x > 0 && y > 0 ? src[-w-1] : E;
			DWORD B = y > 0 ? src[-w] : E;
			DWORD C = x < w-1 && y > 0 ? src[-w+1] : E;

			DWORD D = x > 0 ? src[-1] : E;;
			DWORD F = x < w-1 ? src[+1] : E;;

			DWORD G = x > 0 && y < h-1 ? src[+w-1] : E;
			DWORD H = y < h-1 ? src[+w] : E;
			DWORD I = x < w-1 && y < h-1 ? src[+w+1] : E;

			DWORD E0 = D == B && B != F && D != H ? D : E;
			DWORD E1 = B == F && B != D && F != H ? F : E;
			DWORD E2 = D == H && D != B && H != F ? D : E;
			DWORD E3 = H == F && D != H && B != F ? F : E;

			*dst = ((((E0&0x00ff00ff)+(E1&0x00ff00ff)+(E2&0x00ff00ff)+(E3&0x00ff00ff)+2)>>2)&0x00ff00ff)
				| (((((E0>>8)&0x00ff00ff)+((E1>>8)&0x00ff00ff)+((E2>>8)&0x00ff00ff)+((E3>>8)&0x00ff00ff)+2)<<6)&0xff00ff00);
		}
	}

	src -= w*h;
	dst -= w*h;

	memcpy(src, dst, w*h*4);

	delete [] dst;
}