added support for mode 6 images.

diff --git a/src/png2swf.c b/src/png2swf.c
index 4736939..927504e 100644 (file)
--- a/src/png2swf.c
+++ b/src/png2swf.c
@@ -149,11 +149,11 @@ int png_read_header(FILE*fi, struct png_header*header)
            f = data[11];     // filter mode (0)
            i = data[12];     // interlace mode (0)
 
-           if(b!=2 && b!=3) {
+           if(b!=2 && b!=3 && b!=6) {
                fprintf(stderr, "Image mode %d not supported!\n", b);
                exit(1);
            }
-           if(a!=8 && b==2) {
+           if(a!=8 && (b==2 || b==6)) {
                fprintf(stderr, "Bpp %d in mode %d not supported!\n", a);
                exit(1);
            }
@@ -199,7 +199,7 @@ byte inline PaethPredictor (byte a,byte b,byte c)
         else return c;
 }
 
-void applyfilter(int mode, U8*src, U8*old, U8*dest, int width)
+void applyfilter3(int mode, U8*src, U8*old, U8*dest, int width)
 {
     int x;
     unsigned char lastr=0;
@@ -277,6 +277,89 @@ void applyfilter(int mode, U8*src, U8*old, U8*dest, int width)
 
 }
 
+void applyfilter4(int mode, U8*src, U8*old, U8*dest, int width)
+{
+    int x;
+    unsigned char lastr=0;
+    unsigned char lastg=0;
+    unsigned char lastb=0;
+    unsigned char lasta=0;
+    unsigned char upperlastr=0;
+    unsigned char upperlastg=0;
+    unsigned char upperlastb=0;
+    unsigned char upperlasta=0;
+
+    if(mode==0) {
+       for(x=0;x<width;x++) {
+           dest[0] = src[3];
+           dest[1] = src[0];
+           dest[2] = src[1];
+           dest[3] = src[2];
+           dest+=4;
+           src+=4;
+       }
+    }
+    else if(mode==1) {
+       for(x=0;x<width;x++) {
+           dest[0] = src[3]+lasta;
+           dest[1] = src[0]+lastr;
+           dest[2] = src[1]+lastg;
+           dest[3] = src[2]+lastb;
+           lasta = dest[0];
+           lastr = dest[1];
+           lastg = dest[2];
+           lastb = dest[3];
+           dest+=4;
+           src+=4;
+       }
+    }
+    else if(mode==2) {
+       for(x=0;x<width;x++) {
+           dest[0] = src[3]+old[0];
+           dest[1] = src[0]+old[1];
+           dest[2] = src[1]+old[2];
+           dest[3] = src[2]+old[3];
+           dest+=4;
+           old+=4;
+           src+=4;
+       }
+    }
+    else if(mode==3) {
+       for(x=0;x<width;x++) {
+           dest[0] = src[3]+(old[0]+lasta)/2;
+           dest[1] = src[0]+(old[1]+lastr)/2;
+           dest[2] = src[1]+(old[2]+lastg)/2;
+           dest[3] = src[2]+(old[3]+lastb)/2;
+           lastr = dest[1];
+           lastg = dest[2];
+           lastb = dest[3];
+           dest+=4;
+           old+=4;
+           src+=4;
+       }
+    }
+    else if(mode==4) {
+       for(x=0;x<width;x++) {
+           dest[0] = src[3]+PaethPredictor(lasta,old[0],upperlasta);
+           dest[1] = src[0]+PaethPredictor(lastr,old[1],upperlastr);
+           dest[2] = src[1]+PaethPredictor(lastg,old[2],upperlastg);
+           dest[3] = src[2]+PaethPredictor(lastb,old[3],upperlastb);
+           lasta = dest[0];
+           lastr = dest[1];
+           lastg = dest[2];
+           lastb = dest[3];
+           upperlastr = old[0];
+           upperlastr = old[1];
+           upperlastg = old[2];
+           upperlastb = old[3];
+           dest+=4;
+           old+=4;
+           src+=4;
+       }
+    }    
+
+}
+
 void applyfilter1(int mode, U8*src, U8*old, U8*dest, int width)
 {
     int x;
@@ -364,6 +447,8 @@ TAG *MovieAddFrame(SWF * swf, TAG * t, char *sname, int id)
     else
     if(header.mode == 2) bypp = 3;
     else
+    if(header.mode == 6) bypp = 4;
+    else
        return 0;
     imagedatalen = bypp * header.width * header.height + 65536;
     imagedata = malloc(imagedatalen);
@@ -421,12 +506,12 @@ TAG *MovieAddFrame(SWF * swf, TAG * t, char *sname, int id)
        t = swf_InsertTag(t, ST_DEFINEBITSLOSSLESS);
 
     swf_SetU16(t, id);         // id
-    if(header.mode == 2) {
+    if(header.mode == 2 || header.mode == 6) {
        U8*data2 = malloc(header.width*header.height*4);
        int i,s=0;
        int x,y;
        int pos=0;
-       /* 24->32 bit conversion */
+       /* in case for mode 2, the following also performs 24->32 bit conversion */
        for(y=0;y<header.height;y++) {
            int mode = imagedata[pos++]; //filter mode
            U8*src;
@@ -438,7 +523,7 @@ TAG *MovieAddFrame(SWF * swf, TAG * t, char *sname, int id)
            {
                /* one byte per pixel */
                src = &imagedata[pos];
-               pos+=header.width*3;
+               pos+=header.width*(header.mode==6?4:3);
            } else {
                /* not implemented yet */
                exit(1);
@@ -450,7 +535,10 @@ TAG *MovieAddFrame(SWF * swf, TAG * t, char *sname, int id)
            } else {
                old = &data2[(y-1)*header.width*4];
            }
-           applyfilter(mode, src, old, dest, header.width);
+           if(header.mode==6)
+               applyfilter4(mode, src, old, dest, header.width);
+           else
+               applyfilter3(mode, src, old, dest, header.width);
        }
        swf_SetLosslessBits(t, header.width, header.height, data2, BMF_32BIT);
        free(data2);