added pre-multiplying / un-premultiplying stuff.

[swftools.git] / lib / modules / swfbits.c

diff --git a/lib/modules/swfbits.c b/lib/modules/swfbits.c
index 66b61f4..409ed96 100644 (file)
--- a/lib/modules/swfbits.c
+++ b/lib/modules/swfbits.c
@@ -37,6 +37,30 @@ int swf_ImageHasAlpha(RGBA*img, int width, int height)
     return hasalpha;
 }
 
+int swf_ImageGetNumberOfPaletteEntries2(RGBA*_img, int width, int height)
+{
+    int len = width*height;
+    int t;
+    U32* img = (U32*)_img;
+    U32 color1 = img[0];
+    U32 color2 = 0;
+    for(t=1;t<len;t++) {
+       if(img[t] != color1) {
+           color2 = img[t];
+           break;
+       }
+    }
+    if(t==len)
+       return 1;
+
+    for(;t<len;t++) {
+       if(img[t] != color1 && img[t] != color2) {
+           return width*height;
+       }
+    }
+    return 2;
+}
+
 /*int swf_ImageGetNumberOfPaletteEntries(RGBA*img, int width, int height, RGBA*palette)
 {
     int len = width*height;
@@ -101,15 +125,17 @@ int swf_ImageGetNumberOfPaletteEntries(RGBA*img, int width, int height, RGBA*pal
        RGBA col = img[t];
        U32 col32 = *(U32*)&img[t];
        int i;
+       int csize;
        U32 hash;
+       U32* cpal;
        if(col32 == lastcol32)
            continue;
        hash = (col32 >> 17) ^ col32;
        hash ^= ((hash>>8) + 1) ^ hash;
        hash &= 255;
 
-       int csize = size[hash];
-       U32* cpal = &pal[hash*256];
+       csize = size[hash];
+       cpal = &pal[hash*256];
        for(i=0;i<csize;i++) {
            if(col32 == cpal[i])
                break;
@@ -681,24 +707,36 @@ int swf_SetLosslessBitsGrayscale(TAG * t, U16 width, U16 height, U8 * bitmap)
     return swf_SetLosslessBitsIndexed(t, width, height, bitmap, NULL, 256);
 }
 
+void swf_PreMultiplyAlpha(RGBA*data, int width, int height)
+{
+    int num = width*height;
+    int t;
+    for(t=0;t<num;t++) {
+       data[t].r = ((int)data[t].r*data[t].a)/255;
+       data[t].g = ((int)data[t].g*data[t].a)/255;
+       data[t].b = ((int)data[t].b*data[t].a)/255;
+    }
+}
+
 void swf_SetLosslessImage(TAG*tag, RGBA*data, int width, int height)
 {
     int hasalpha = swf_ImageHasAlpha(data, width, height);
+    int num;
     if(!hasalpha) {
        tag->id = ST_DEFINEBITSLOSSLESS;
     } else {
        tag->id = ST_DEFINEBITSLOSSLESS2;
-       /* TODO: premultiply alpha? */
+       swf_PreMultiplyAlpha(data, width, height);
     }
-    int num = swf_ImageGetNumberOfPaletteEntries(data, width, height, 0);
+    num = swf_ImageGetNumberOfPaletteEntries(data, width, height, 0);
     if(num>1 && num<=256) {
        RGBA*palette = (RGBA*)malloc(sizeof(RGBA)*num);
-       swf_ImageGetNumberOfPaletteEntries(data, width, height, palette);
        int width2 = BYTES_PER_SCANLINE(width);
        U8*data2 = (U8*)malloc(width2*height);
        int len = width*height;
        int x,y;
        int r;
+       swf_ImageGetNumberOfPaletteEntries(data, width, height, palette);
        for(y=0;y<height;y++) {
            RGBA*src = &data[width*y];
            U8*dest = &data2[width2*y];
@@ -798,6 +836,8 @@ RGBA *swf_DefineLosslessBitsTagToImage(TAG * tag, int *dwidth, int *dheight)
            palette[t].b = data[pos++];
            if (alpha) {
                palette[t].a = data[pos++];
+           } else {
+               palette[t].a = 255;
            }
        }
     }
@@ -817,10 +857,13 @@ RGBA *swf_DefineLosslessBitsTagToImage(TAG * tag, int *dwidth, int *dheight)
                }
            } else {
                for (x = 0; x < width; x++) {
-                   /* TODO: un-premultiply alpha? */
-                   dest[pos2].r = data[pos + 1];
-                   dest[pos2].g = data[pos + 2];
-                   dest[pos2].b = data[pos + 3];
+                   /* TODO: is un-premultiplying alpha the right thing to do?
+                      dest[pos2].r = data[pos + 1];
+                      dest[pos2].g = data[pos + 2];
+                      dest[pos2].b = data[pos + 3];*/
+                   dest[pos2].r = ((int)data[pos + 1]*255)/(int)data[pos+0];
+                   dest[pos2].g = ((int)data[pos + 2]*255)/(int)data[pos+0];
+                   dest[pos2].b = ((int)data[pos + 3]*255)/(int)data[pos+0];
                    dest[pos2].a = data[pos + 0];       //alpha
                    pos2++;
                    pos += 4;
@@ -1010,12 +1053,13 @@ void swf_RemoveJPEGTables(SWF * swf)
     tag = swf->firstTag;
     while (tag) {
        if (tag->id == ST_DEFINEBITSJPEG) {
-           void *data = rfx_alloc(tag->len);
+           int len = tag->len;
+           void *data = rfx_alloc(len);
            swf_GetBlock(tag, data, tag->len);
            swf_ResetTag(tag, ST_DEFINEBITSJPEG2);
            swf_SetBlock(tag, &((U8*)data)[0], 2); //id
            swf_SetBlock(tag, tables_tag->data, tables_tag->len);
-           swf_SetBlock(tag, &((U8*)data)[2], tag->len-2);
+           swf_SetBlock(tag, &((U8*)data)[2], len-2);
            free(data);
        }
        tag = tag->next;
@@ -1047,7 +1091,6 @@ static scale_lookup_t**make_scale_lookup(int width, int newwidth)
 
     if(newwidth<=width) {
        for(x=0;x<newwidth;x++) {
-           lblockx[x] = p_x;
            double ex = px + fx;
            int fromx = (int)px;
            int tox = (int)ex;
@@ -1056,6 +1099,7 @@ static scale_lookup_t**make_scale_lookup(int width, int newwidth)
            int xweight = (int)(rem*256/fx);
            int xx;
            int w = 0;
+           lblockx[x] = p_x;
            if(tox>=width) tox = width-1;
            for(xx=fromx;xx<=tox;xx++) {
                if(xx==fromx && xx==tox) p_x->weight = 256;
@@ -1070,11 +1114,11 @@ static scale_lookup_t**make_scale_lookup(int width, int newwidth)
        }
     } else {
        for(x=0;x<newwidth;x++) {
-           lblockx[x] = p_x;
            int ix1 = (int)px;
            int ix2 = ((int)px)+1;
-           if(ix2>=width) ix2=width-1;
            double r = px-ix1;
+           if(ix2>=width) ix2=width-1;
+           lblockx[x] = p_x;
            if(bicubic)
                r = -2*r*r*r+3*r*r;
            p_x[0].weight = (int)(256*(1-r));
@@ -1088,15 +1132,24 @@ static scale_lookup_t**make_scale_lookup(int width, int newwidth)
     lblockx[newwidth] = p_x;
     return lblockx;
 }
-
 RGBA* swf_ImageScale(RGBA*data, int width, int height, int newwidth, int newheight)
 {
-    if(newwidth<1 || newheight<1)
-       return 0;
     int x,y;
-    RGBA* newdata= (RGBA*)malloc(newwidth*newheight*sizeof(RGBA));
+    RGBA* newdata; 
     scale_lookup_t *p, **lblockx,**lblocky;
-    rgba_int_t*tmpline = (rgba_int_t*)malloc(width*sizeof(rgba_int_t));
+    rgba_int_t*tmpline;
+    
+    if(newwidth<1 || newheight<1)
+       return 0;
+
+    /* this is bad because this scaler doesn't yet handle monochrome
+       images with 2 colors in a way that the final image hasn't more
+       than 256 colors */
+    if(swf_ImageGetNumberOfPaletteEntries2(data, width, height) == 2)
+       fprintf(stderr, "Warning: scaling monochrome image\n");
+
+    tmpline = (rgba_int_t*)malloc(width*sizeof(rgba_int_t));
+    newdata = (RGBA*)malloc(newwidth*newheight*sizeof(RGBA));
   
     lblockx = make_scale_lookup(width, newwidth);
     lblocky = make_scale_lookup(height, newheight);
@@ -1109,7 +1162,7 @@ RGBA* swf_ImageScale(RGBA*data, int width, int height, int newwidth, int newheig
        
        /* create lookup table for y */
        rgba_int_t*l = tmpline;
-       scale_lookup_t*p_y;
+       scale_lookup_t*p_y,*p_x;
        memset(tmpline, 0, width*sizeof(rgba_int_t));
        for(p_y=lblocky[y];p_y<lblocky[y+1];p_y++) {
            RGBA*line = &data[p_y->pos];
@@ -1124,7 +1177,7 @@ RGBA* swf_ImageScale(RGBA*data, int width, int height, int newwidth, int newheig
        }
 
        /* process x direction */
-       scale_lookup_t*p_x = lblockx[0];
+       p_x = lblockx[0];
        for(x=0;x<newwidth;x++) {
            unsigned int r=0,g=0,b=0,a=0;
            scale_lookup_t*p_x_to = lblockx[x+1];