implemented filtering for 8-bit pictures.

diff --git a/src/png2swf.c b/src/png2swf.c
index 0e584e3..0bf05a9 100644 (file)
--- a/src/png2swf.c
+++ b/src/png2swf.c
@@ -87,7 +87,6 @@ int png_read_chunk(char (*head)[4], int*destlen, U8**destdata, FILE*fi)
     if(!fread(head, 4, 1, fi))
        return 0;
     len = REVERSESWAP32(len);
-    printf("id: %.4s len: %d\n", head, len);
     if(destlen) *destlen = len;
     if(destdata) {
        if(len)
@@ -135,7 +134,8 @@ int png_read_header(FILE*fi, struct png_header*header)
    
     while(png_read_chunk(&id, &len, &data, fi))
     {
-       printf("%c%c%c%c %d\n", id[0],id[1],id[2],id[3],len);
+       if(VERBOSE(2))
+           printf("%c%c%c%c %d\n", id[0],id[1],id[2],id[3],len);
        if(!strncasecmp(id, "IHDR", 4)) {
            char a,b,c,f,i;
            if(len < 8) exit(1);
@@ -147,6 +147,15 @@ int png_read_header(FILE*fi, struct png_header*header)
            c = data[10];     // compression mode (0)
            f = data[11];     // filter mode (0)
            i = data[12];     // interlace mode (0)
+
+           if(b!=2 && b!=3) {
+               fprintf(stderr, "Image mode %d not supported!\n", b);
+               exit(1);
+           }
+           if(a!=8) {
+               fprintf(stderr, "Bpp %d not supported!\n", a);
+               exit(1);
+           }
            if(c!=0) {
                fprintf(stderr, "Compression mode %d not supported!\n", c);
                exit(1);
@@ -159,7 +168,8 @@ int png_read_header(FILE*fi, struct png_header*header)
                fprintf(stderr, "Interlace mode %d not supported!\n", i);
                exit(1);
            }
-           printf("%dx%d %d %d %d %d %d\n",header->width, header->height, a,b,c,f,i);
+           if(VERBOSE(2))
+               printf("%dx%d %d %d %d %d %d\n",header->width, header->height, a,b,c,f,i);
            header->bpp = a;
            header->mode = b;
            return 1;
@@ -267,6 +277,56 @@ void applyfilter(int mode, U8*src, U8*old, U8*dest, int width)
 
 }
 
+void applyfilter1(int mode, U8*src, U8*old, U8*dest, int width)
+{
+    int x;
+    unsigned char last=0;
+    unsigned char upperlast=0;
+
+    if(mode==0) {
+       for(x=0;x<width;x++) {
+           *dest = *src;
+           dest++;
+           src++;
+       }
+    }
+    else if(mode==1) {
+       for(x=0;x<width;x++) {
+           *dest = *src+last;
+           last = *dest;
+           dest++;
+           src++;
+       }
+    }
+    else if(mode==2) {
+       for(x=0;x<width;x++) {
+           *dest = *src+*old;
+           dest++;
+           old++;
+           src++;
+       }
+    }
+    else if(mode==3) {
+       for(x=0;x<width;x++) {
+           *dest = *src+(*old+last)/2;
+           dest++;
+           old++;
+           src++;
+       }
+    }
+    else if(mode==4) {
+       for(x=0;x<width;x++) {
+           *dest = *src+PaethPredictor(last,*old,upperlast);
+           last = *dest;
+           upperlast = *old;
+           dest++;
+           old++;
+           src++;
+       }
+    }    
+
+}
+
 TAG *MovieAddFrame(SWF * swf, TAG * t, char *sname, int id)
 {
     SHAPE *s;
@@ -316,14 +376,14 @@ TAG *MovieAddFrame(SWF * swf, TAG * t, char *sname, int id)
            palette = data;
            palettelen = len/3;
            data = 0;
-           printf("%d palette\n", len);
+           if(VERBOSE(2))
+               printf("%d colors in palette\n", palettelen);
        }
        if(!strncmp(tagid, "IDAT", 4)) {
            if(uncompress(imagedata, &imagedatalen, data, len) != Z_OK) {
                fprintf(stderr, "Couldn't uncompress %s!\n", sname);
                return 0;
            }
-           printf("IDAT %d -> %d\n", len, imagedatalen);
        }
        if(data)
            free(data);
@@ -357,7 +417,8 @@ TAG *MovieAddFrame(SWF * swf, TAG * t, char *sname, int id)
     }
     else {
        RGBA*rgba = (RGBA*)malloc(palettelen*sizeof(RGBA));
-       U8*data2 = malloc((header.width+4)*header.height);
+       int swf_width = BYTES_PER_SCANLINE(header.width);
+       U8*data2 = malloc(swf_width*header.height);
        int i,x,y;
        int pos=0;
        if(!palette) {
@@ -372,15 +433,18 @@ TAG *MovieAddFrame(SWF * swf, TAG * t, char *sname, int id)
            rgba[i].a = 255;
        }
        for(y=0;y<header.height;y++) {
-           int mode = imagedata[pos];
-           if(mode!=0) {
-               fprintf(stderr, "Warning: Filter mode %d\n", mode);
-           }
-           pos++; //filter mode
-           for(x=0;x<header.width;x++) {
-               data2[y*header.width+x] = 
-                   imagedata[pos++];
+           int mode = imagedata[pos++]; //filter mode
+           U8*src = &imagedata[pos];
+           U8*dest = &data2[y*swf_width];
+           U8*old;
+           if(!y) {
+               memset(data2,0,swf_width);
+               old = &data2[y*swf_width];
+           } else {
+               old = &data2[(y-1)*swf_width];
            }
+           applyfilter1(mode, src, old, dest, header.width);
+           pos+=header.width;
        }
        swf_SetLosslessBitsIndexed(t, header.width, header.height, data2, rgba, palettelen);
        free(rgba);
@@ -460,14 +524,6 @@ int CheckInputFile(char *fname, char **realname)
        fprintf(stderr, "%s is not a PNG file!\n", fname);
        return -1;
     }
-    if(head.mode!=2 && head.mode!=3) {
-       fprintf(stderr, "%s has unsupported mode %d\n", head.mode);
-       return -1;
-    }
-    if(head.bpp!=8) {
-       fprintf(stderr, "%s has unsupported bpp %d\n", head.bpp);
-       return -1;
-    }
 
     if (global.max_image_width < head.width)
        global.max_image_width = head.width;