fixed handling of alpha palettes in PNG extraction.

diff --git a/src/swfextract.c b/src/swfextract.c
index a4a2ded..ee15f62 100644 (file)
--- a/src/swfextract.c
+++ b/src/swfextract.c
@@ -830,12 +830,21 @@ void handlelossless(TAG*tag)
             png_write_byte(fi,palette[t].b);
         }
        png_end_chunk(fi);
+
+       if(alpha) {
+           /* write alpha palette */
+           png_start_chunk(fi, "tRNS", 256);
+           for(t=0;t<256;t++) {
+               png_write_byte(fi,palette[t].a);
+           }
+           png_end_chunk(fi);
+       }
     }
     {
        int pos2 = 0;
        int x,y;
        int srcwidth = width * (bpp/8);
-       datalen3 = width*height*4;
+       datalen3 = (width*4+5)*height;
        data3 = (U8*)malloc(datalen3);
        for(y=0;y<height;y++)
        {