VobSubImage.cpp

/* 
 *      Copyright (C) 2003-2005 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, tr;

        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)])

COutlineList* 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;

        COutlineList* ol = new COutlineList();
        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.GetSize() > 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.GetSize();
        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.GetSize();

        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.GetSize();

        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 
{
        CPointArray& pa = o.pa;

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

        CPointArray& pa = o.pa;

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

        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];

        CArray<double,double&> pl;
        pl.SetSize(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.GetSize();
        
        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.GetSize();
        if(len < 4) return;

        CUIntArray 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.GetSize(); i++)
        {
                if(maxlen < la[i])
                {
                        maxlen = la[i];
                        maxidx = i;
                }

                if(maxlen2 < la[i] && i > 0 && i < la.GetSize()-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, CByteArray& pathTypes, CPointArray& pathPoints)
{
        int i, len = o.pa.GetSize();
        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.GetSize()-1]);

                return;
        }

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

bool CVobSubImage::Polygonize(CByteArray& pathTypes, CPointArray& pathPoints, bool fSmooth, int scale)
{
        CPoint topleft;
        CAutoPtr<COutlineList> ol(GetOutlineList(topleft));
        if(!ol) return(false);

        POSITION pos;

        pos = ol->GetHeadPosition();
        while(pos)
        {
                CPointArray& pa = ol->GetNext(pos)->pa;
                for(int i = 0; i < pa.GetSize(); 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.GetSize(); i < len; i++)
                        {
                                pathTypes.Add(PT_LINETO);
                                pathPoints.Add(o.pa[i]);
                        }
                }
        }

        return(pathTypes.GetSize() > 0);
}

bool CVobSubImage::Polygonize(CStringW& assstr, bool fSmooth, int scale)
{
        CByteArray pathTypes;
        CPointArray 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.GetSize();

        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;
}

---