[pncrush] Version 1.7.51 (built with libpng-1.6.0 and zlib-1.2.7)v1.7.51

  Added "-noreduce" option, in preparation for "-reduce" becoming the
    default behaviour in version 1.8.0.  This turns off lossless bit depth,
    color type and palette reduction, and opaque alpha channel removal.
  Zero out the high byte of transparent color for color-type 0 and 2,
    when reducing from 16 bits to 8.
  Undefined a bunch of stuff in pngcrush.h that we do not use, saves about
    100 kbytes of executable file size in addition to about 50k saved by
    undefining the simplified API.
  Fixed double-underscore typo in an #ifdef in png.c
  If "-reduce" is on and the background index is larger than the reduced
    palette_length+1, reduce it to the palette_length+1.

2 files changed, 185 insertions, 55 deletions

diff --git a/pngcrush.c b/pngcrush.c
index 25958588e..453c1f8ec 100644
--- a/pngcrush.c
+++ b/pngcrush.c
@@ -80,7 +80,7 @@
  *
  */
 
-#define PNGCRUSH_VERSION "1.7.50"
+#define PNGCRUSH_VERSION "1.7.51"
 
 /* Experimental: define these if you wish, but, good luck.
 #define PNGCRUSH_COUNT_COLORS
@@ -88,6 +88,11 @@
 */
 #define PNGCRUSH_LARGE
 
+#define PNGCRUSH_ROWBYTES(pixel_bits, width) \
+    ((pixel_bits) >= 8 ? \
+    ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
+    (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
+
 /*
  * NOTICES
  *
@@ -162,7 +167,7 @@
  *      cp $1 temp-$$.png
  *      for w in 512 1 2 4 8 16 32
  *      do
- *      pngcrush -ow -w $w -brute temp-$$.png 
+ *      pngcrush -ow -w $w -brute temp-$$.png
  *      done
  *      mv temp-$$.png $2
  *
@@ -191,7 +196,8 @@
  *
  *      d. The simplest way might be to simply try all window sizes
  *      for all methods, just as the "pc" script above does.  This of
- *      course involves a lot more trial compressions.
+ *      course involves a lot more trial compressions, but it will catch
+ *      those instances where a smaller file will result.
  *
  *   2. Check for the possiblity of using the tRNS chunk instead of
  *      the full alpha channel.  If all of the transparent pixels are
@@ -272,10 +278,23 @@
 
 Change log:
 
+Version 1.7.51 (built with libpng-1.6.0 and zlib-1.2.7)
+  Added "-noreduce" option, in preparation for "-reduce" becoming the
+    default behaviour in version 1.8.0.  This turns off lossless bit depth,
+    color type and palette reduction, and opaque alpha channel removal.
+  Zero out the high byte of transparent color for color-type 0 and 2,
+    when reducing from 16 bits to 8.
+  Undefined a bunch of stuff in pngcrush.h that we do not use, saves about
+    100 kbytes of executable file size in addition to about 50k saved by
+    undefining the simplified API.
+  Fixed double-underscore typo in an #ifdef in png.c
+  If "-reduce" is on and the background index is larger than the reduced
+    palette_length+1, reduce it to the palette_length+1.
+
 Version 1.7.50 (built with libpng-1.6.0 and zlib-1.2.7)
   Removed completed items from the "To do" list.
   Ignore the argument of the "plte_len" argument and just set the
-     "reduce_palette" flag.
+    "reduce_palette" flag.
 
 Version 1.7.49 (built with libpng-1.5.14 and zlib-1.2.7)
   Use png_set_benign_errors() to allow certain errors in the input file
@@ -296,7 +315,7 @@ Version 1.7.48 (built with libpng-1.5.14 and zlib-1.2.7)
     conditions such as if the image is opaque or gray or can be losslessly
     reduced in bit depth, set flags in trial 0 and accomplish the
     transformations in the remaining trials (see the To do list starting
-    about line 200 in the pngcrush.c source).  
+    about line 200 in the pngcrush.c source).
   Removed "PNGCRUSH_COUNT_COLORS" blocks again.
 
 Version 1.7.47 (built with libpng-1.5.13 and zlib-1.2.7)
@@ -531,7 +550,7 @@ Version 1.7.7  (built with libpng-1.4.0 and zlib-1.2.3.4)
 Version 1.7.6  (built with libpng-1.4.0rc02 and zlib-1.2.3.2)
   Change some "#if defined(X)" to "#ifdef X" according to libpng coding style.
   Added some defines to suppress pedantic warnings from libpng-1.2.41beta15
-    and later.  A warning about deprecated access to png_ptr->zstream is 
+    and later.  A warning about deprecated access to png_ptr->zstream is
     otherwise unavoidable.  When building the embedded libpng, a warning
     about png_default_error() returning is also otherwise unavoidable.
   Write premultiplied alpha if output extension is .ppng and
@@ -833,7 +852,7 @@ Version 1.4.5 (built with libpng-1.0.7rc2 and cexcept-1.0.0)
   or grayscale when fewer than 257 RGBA combinations are present,
   and no color is present that requires 16-bit precision.  For now,
   it only reports the frequencies.
-  
+
   Added "-fix" option, for fixing bad CRCs and other correctable
   conditions.
 
@@ -924,7 +943,7 @@ Version 1.3.3 (built with libpng-1.0.5m)
   arithmetic is not enabled.
 
 Version 1.3.2 (built with libpng-1.0.5k)
-  
+
   Renamed "dirname" to "directory_name" to avoid conflict with "dirname"
   that appears in string.h on some platforms.
 
@@ -1007,7 +1026,7 @@ Version 1.1.4: added ability to restrict brute_force to one or more filter
 #ifdef PNG_LIBPNG_VER
 #define PNGCRUSH_LIBPNG_VER PNG_LIBPNG_VER
 #else
-/* 
+/*
  * This must agree with PNG_LIBPNG_VER; you have to define it manually
  * here if you are using libpng-1.0.6h or earlier
  */
@@ -1249,7 +1268,7 @@ png_uint_32 pngcrush_crc;
 
 #if defined(__DJGPP__) && ((__DJGPP__ == 2) && (__DJGPP_MINOR__ == 0))
 #  include <libc/dosio.h>     /* for _USE_LFN, djgpp 2.0 only */
-#endif 
+#endif
 
 #if ( defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||  \
    defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__) || \
@@ -1360,6 +1379,8 @@ static int found_cHRM = 0;
 #endif
 
 static int premultiply = 0;
+static int interlace_method = 0;
+png_alloc_size_t max_bytes;
 
        /* 0: not premultipled
         * 1: premultiplied input (input has .ppng suffix)
@@ -1437,7 +1458,7 @@ static int trial;
 static int last_trial = 0;
 static png_uint_32 pngcrush_write_byte_count;
 static png_uint_32 pngcrush_best_byte_count=0xffffffff;
-            
+
 static int verbose = 1;
 static int fix = 0;
 static int bail = 0; /* if 0, bail out of trials early */
@@ -1517,6 +1538,7 @@ static int have_bkgd = 0;
 static png_uint_16 bkgd_red = 0;
 static png_uint_16 bkgd_green = 0;
 static png_uint_16 bkgd_blue = 0;
+static png_byte bkgd_index = 0;
 
 static png_colorp palette;
 static int num_palette;
@@ -1926,7 +1948,7 @@ static void png_cexcept_error(png_structp png_ptr, png_const_charp err_msg)
  * a benign error, "Too many IDATs found".
  */
 #if PNG_LIBPNG_VER < 10400
-#  ifdef PNGCRUSH_H 
+#  ifdef PNGCRUSH_H
     if (!strcmp(err_msg, "Too many IDAT's found")) {
 #    ifdef PNG_CONSOLE_IO_SUPPORTED
         fprintf(stderr, "\nIn %s, correcting ", inname);
@@ -2380,7 +2402,7 @@ static void pngcrush_flush(png_structp png_ptr)
 void pngcrush_examine_pixels_fn(png_structp png_ptr, png_row_infop
     row_info, png_bytep data)
 {
-   
+
 
    if (blacken == 1 || make_gray == 1 || make_opaque == 1)
    {
@@ -2403,13 +2425,13 @@ void pngcrush_examine_pixels_fn(png_structp png_ptr, png_row_infop
        */
 
       int i;
-   
+
       if (row_info->color_type < 4)
       {
         blacken = 3;  /* It doesn't have an alpha channel */
         make_opaque = 3;
       }
-   
+
       if (row_info->color_type == 0 || row_info->color_type == 4)
         make_gray = 3; /* It's already gray! */
 
@@ -2431,11 +2453,11 @@ void pngcrush_examine_pixels_fn(png_structp png_ptr, png_row_infop
                  {
                    make_gray = 2;
                  }
-               
+
                i-=3;
             }
           }
-   
+
         else /* bit depth == 16 */
           {
             for ( ; i > 0 ; )
@@ -2469,7 +2491,7 @@ void pngcrush_examine_pixels_fn(png_structp png_ptr, png_row_infop
                i-=2;
             }
           }
-   
+
         else /* bit depth == 16 */
           {
             for ( ; i > 0 ; )
@@ -2487,7 +2509,7 @@ void pngcrush_examine_pixels_fn(png_structp png_ptr, png_row_infop
             }
           }
       }
-   
+
       /* color_type == 6, RGBA */
       else if (row_info->color_type == 6 && (blacken == 1 || make_gray == 1 ||
                make_opaque == 1))
@@ -2511,11 +2533,11 @@ void pngcrush_examine_pixels_fn(png_structp png_ptr, png_row_infop
                  {
                    make_opaque = 2;
                  }
-               
+
                i-=4;
             }
           }
-   
+
         else /* bit depth == 16 */
           {
             for ( ; i > 0 ; )
@@ -2596,14 +2618,14 @@ void pngcrush_examine_pixels_fn(png_structp png_ptr, png_row_infop
 void pngcrush_transform_pixels_fn(png_structp png_ptr, png_row_infop row_info,
      png_bytep data)
 {
-   
+
    int i;
 
    if (blacken == 2)
    {
    /* change the underlying color of any fully transparent pixels to black */
       i=(int) row_info->rowbytes-1;
-   
+
       if (row_info->color_type == 4) /* GA */
       {
         if (row_info->bit_depth == 8)
@@ -2617,7 +2639,7 @@ void pngcrush_transform_pixels_fn(png_structp png_ptr, png_row_infop row_info,
                i-=2;
             }
           }
-   
+
         else /* bit depth == 16 */
           {
             for ( ; i > 0 ; )
@@ -2632,7 +2654,7 @@ void pngcrush_transform_pixels_fn(png_structp png_ptr, png_row_infop row_info,
             }
           }
       }
-   
+
       else /* color_type == 6, RGBA */
       {
         if (row_info->bit_depth == 8)
@@ -2649,7 +2671,7 @@ void pngcrush_transform_pixels_fn(png_structp png_ptr, png_row_infop row_info,
                i-=4;
             }
           }
-   
+
         else /* bit depth == 16 */
           {
             for ( ; i > 0 ; )
@@ -2873,7 +2895,7 @@ int main(int argc, char *argv[])
 
         else if (!strncmp(argv[i], "-bail", 5))
             bail=0;
- 
+
         else if (!strncmp(argv[i], "-nobail", 7))
             bail=1;
 
@@ -2885,6 +2907,7 @@ int main(int argc, char *argv[])
             bkgd_red = (png_uint_16) atoi(argv[++i]);
             bkgd_green = (png_uint_16) atoi(argv[++i]);
             bkgd_blue = (png_uint_16) atoi(argv[++i]);
+            bkgd_index = 0;
         }
 
         else if (!strncmp(argv[i], "-blacken", 8))
@@ -3183,6 +3206,14 @@ int main(int argc, char *argv[])
             no_limits++;
         }
 
+        else if (!strncmp(argv[i], "-noreduce", 9))
+        {
+            make_opaque = 0;
+            make_gray = 0;
+            make_8_bit = 0;
+            reduce_palette = 0;
+        }
+
         else if (!strncmp(argv[i], "-nosave", 2))
         {
             /* no save; I just use this for testing decode speed */
@@ -3769,7 +3800,7 @@ int main(int argc, char *argv[])
 #ifdef PNGCRUSH_LOCO
             if (new_mng)
             {
-           
+
 #  ifdef PNG_USER_MEM_SUPPORTED
                mng_ptr = png_create_write_struct_2(PNG_LIBPNG_VER_STRING,
                  (png_voidp) NULL, (png_error_ptr) png_cexcept_error,
@@ -3783,7 +3814,7 @@ int main(int argc, char *argv[])
 #  endif
                if (mng_ptr == NULL)
                   fprintf(STDERR, "pngcrush could not create mng_ptr");
-                  
+
                if ((mng_out = FOPEN(mngname, "wb")) == NULL)
                {
                   fprintf(STDERR, "Could not open output file %s\n",
@@ -3815,7 +3846,7 @@ int main(int argc, char *argv[])
 
             if (verbose > 0)
             {
-                
+
                 fprintf(STDERR, "   Recompressing %s\n", inname);
                 fprintf(STDERR,
                   "   Total length of data found in critical chunks = %8lu\n",
@@ -4567,7 +4598,7 @@ int main(int argc, char *argv[])
                  *  - unknown chunks
                  */
                 {
-                    int interlace_method, compression_method,
+                    int compression_method,
                         filter_method;
 
                     P1( "Transferring info struct\n");
@@ -4772,7 +4803,7 @@ int main(int argc, char *argv[])
                                 if (nosave == 0 && last_trial == 1)
                                    png_permit_mng_features(write_ptr,
                                        PNG_FLAG_MNG_FILTER_64);
-                       
+
                             }
                         } else
                             filter_method = 0;
@@ -4843,6 +4874,7 @@ int main(int argc, char *argv[])
                         backgrnd->green = bkgd_green;
                         backgrnd->blue = bkgd_blue;
                         backgrnd->gray = backgrnd->green;
+                        backgrnd->index = bkgd_index;
                         png_set_bKGD(write_ptr, write_info_ptr,
                                      backgrnd);
                     }
@@ -5013,11 +5045,13 @@ int main(int argc, char *argv[])
                                 fprintf(STDERR, "   Ignoring sRGB request; "
 #  ifdef PNG_FIXED_POINT_SUPPORTED
                                   "gamma=(%lu/100000)"
+                                  " is not approx. 0.455\n",
+                                  (unsigned long)file_gamma);
 #  else
                                   "gamma=%f"
-#  endif
                                   " is not approx. 0.455\n",
-                                  (unsigned long)file_gamma);
+                                  file_gamma);
+#  endif
                             }
                         }
 #endif /* PNG_gAMA_SUPPORTED */
@@ -5149,7 +5183,7 @@ int main(int argc, char *argv[])
                                      res_y, unit_type);
                         if (verbose > 0 && last_trial)
                             fprintf(STDERR, "   Added pHYs %lu %lu 1 chunk\n",
-                            (unsigned long)res_x, 
+                            (unsigned long)res_x,
                             (unsigned long)res_y);
                     }
                 }
@@ -5214,11 +5248,25 @@ int main(int argc, char *argv[])
                                 }
                                 num_trans = last_nonmax + 1;
                             }
+                            else
+                            {
+                               /* color type is 0 or 2 */
+                               if (input_bit_depth == 16 &&
+                                   output_bit_depth == 8)
+                               {
+                                 /* zero out the high byte */
+                                 trans_values->red &= 0x00ff;
+                                 trans_values->green &= 0x00ff;
+                                 trans_values->blue &= 0x00ff;
+                                 trans_values->gray &= 0x00ff;
+                               }
+
+                            }
                             if (verbose > 1)
                                 fprintf(STDERR,
                                   "   png_set_tRNS, num_trans=%d\n",
                                   num_trans);
-                            if (output_color_type != 3 || num_trans)
+                            if (output_color_type < 3 || num_trans)
                                 png_set_tRNS(write_ptr, write_info_ptr,
                                              trans, num_trans,
                                              trans_values);
@@ -5770,10 +5818,54 @@ int main(int argc, char *argv[])
                         if (output_color_type == 6)
                             channels = 4;
 
-                        required_window =
-                            (png_uint_32) (height *
-                                           ((width * channels * bit_depth +
-                                             15) >> 3) + 262);
+                        /* This method was copied from libpng to find maximum
+                         * data size.  Only return sizes up to the maximum of
+                         * a png_uint_32, by limiting the width and height used
+                         * to 15 bits.
+                         */
+                        png_uint_32 rowbytes;
+                        png_uint_32 h = height;
+
+                        rowbytes = png_get_rowbytes(read_ptr, read_info_ptr);
+                        if (rowbytes < 16384 && h < 16384)
+                        {
+                          if (rowbytes * h < 16384)
+                          {
+                             if (interlace_method)
+                             {
+                                /* Interlacing makes the image larger because of
+                                 * the replication of both the filter byte and the
+                                 * padding to a byte boundary.
+                                 */
+                                png_uint_32 w = width;
+                                unsigned int pd = channels * output_bit_depth;
+                                png_alloc_size_t cb_base;
+                                int interlace_pass;
+
+                                for (cb_base=0, interlace_pass=0;
+                                     interlace_pass<=6; ++interlace_pass)
+                                {
+                                   png_uint_32 pw = PNG_PASS_COLS(w, interlace_pass);
+
+                                   if (pw > 0)
+                                      cb_base += (PNGCRUSH_ROWBYTES(pd, pw)+1) *
+                                          PNG_PASS_ROWS(h, interlace_pass);
+                                }
+
+                                max_bytes = cb_base;
+                             }
+
+                             else
+                                max_bytes = (rowbytes+1) * h;
+                          }
+                          else
+                             max_bytes = 0x3fffffffU;
+                        }
+
+                        else
+                           max_bytes = 0x3fffffffU;
+
+                        required_window = (png_uint_32) (max_bytes + 262);
 
                         zbuf_size =
                             png_get_compression_buffer_size(write_ptr);
@@ -6011,9 +6103,19 @@ int main(int argc, char *argv[])
                          png_color_16p bkgd;
                          if (png_get_bKGD(read_ptr, read_info_ptr, &bkgd))
                          {
-                           P1("bKGD index = %d\n", bkgd->index);
+                           bkgd_index = bkgd->index;
+                           P1("bKGD index = %d\n", bkgd_index);
+#if 1
+                           if (bkgd_index > palette_length+1)
+                           {
+                              bkgd_index = palette_length+1;
+                              have_bkgd = 1;
+                              fprintf(STDERR,
+                                  "   New bKGD index = %d\n", bkgd_index);
+                           }
+#endif
                            if (bkgd->index > palette_length)
-                              palette_length = (int) bkgd->index;
+                              palette_length = (int) bkgd_index+1;
                            P1("Total    palette length = %d\n", palette_length);
                          }
                        }
@@ -6193,7 +6295,7 @@ int main(int argc, char *argv[])
                                     text_compression[ntext];
                                 png_set_text(write_ptr, write_end_info_ptr,
                                              added_text, 1);
-  
+
                                 if (verbose > 0 && last_trial)
                                 {
                                   if (added_text[0].compression < 0)
@@ -6379,9 +6481,9 @@ int main(int argc, char *argv[])
                      (unsigned long)idat_length[trial]);
                 fflush(STDERR);
             }
-            
+
         } /* end of trial-loop */
-       
+
         P1("\n\nFINISHED MAIN LOOP OVER %d METHODS\n\n\n", MAX_METHODS);
 
         /* ////////////////////////////////////////////////////////////////////
@@ -6400,7 +6502,7 @@ int main(int argc, char *argv[])
             FCLOSE(fpout);
             setfiletype(outname);
         }
-        
+
         if (last_trial && nosave == 0 && overwrite != 0)
         {
             /* rename the new file , outname = inname */
@@ -6455,7 +6557,7 @@ int main(int argc, char *argv[])
                 {
                 fprintf(STDERR,
                   "   Best pngcrush method        =   %d "
-                  "(ws %d fm %d zl %d zs %d) = %8lu\n      for %s\n", best, 
+                  "(ws %d fm %d zl %d zs %d) = %8lu\n      for %s\n", best,
                   compression_window, fm[best], lv[best], zs[best],
                   (unsigned long)idat_length[best], outname);
                 }
@@ -7238,6 +7340,11 @@ struct options_help pngcrush_options[] = {
     {2, ""},
 #endif
 
+    {0, "            -n (no save; doesn't do compression or write output PNG)"},
+    {2, ""},
+    {2, "               Useful in conjunction with -v option to get info."},
+    {2, ""},
+
     {0, " -newtimestamp (Reset file modification time [default])"},
     {2, ""},
 
@@ -7259,9 +7366,12 @@ struct options_help pngcrush_options[] = {
     {2, "               Instead, the user limits are inherited from libpng."},
     {2, ""},
 
+    {0, "     -noreduce (turns off \"-reduce\" operations)"},
+    {2, ""},
+
     {0, " -oldtimestamp (Do not reset file modification time)"},
     {2, ""},
-    
+
     {0, "           -ow (Overwrite)"},
     {2, ""},
     {2, "               Overwrite the input file.  The input file is "},
@@ -7269,11 +7379,6 @@ struct options_help pngcrush_options[] = {
     {2, "               is renamed to the input file after recompression"},
     {2, "               and therefore they must reside on the same filesystem"},
     {2, ""},
-    
-    {0, "            -n (no save; doesn't do compression or write output PNG)"},
-    {2, ""},
-    {2, "               Useful in conjunction with -v option to get info."},
-    {2, ""},
 
     {0, "     -plte_len n (obsolete, n is ignored, sets automatic reduction)"},
     {2, ""},
@@ -7283,7 +7388,9 @@ struct options_help pngcrush_options[] = {
 
     {0, "       -reduce (do lossless color-type or bit-depth reduction)"},
     {2, ""},
-    {2, "               (if possible)"},
+    {2, "               (if possible).  Also reduces palette length if"},
+    {2, "               if possible.  Currently only attempts to reduce the"},
+    {2, "               bit depth from 16 to 8"},
     {2, ""},
 
     {0, "          -rem chunkname (or \"alla\" or \"allb\")"},
diff --git a/pngcrush.h b/pngcrush.h
index 1cce42e5d..ea3cd11ca 100644
--- a/pngcrush.h
+++ b/pngcrush.h
@@ -5,12 +5,35 @@
  * license (see LICENSE, in pngcrush.c).
  */
 
-/* Special defines for pngcrush version 1.7.50 */
+/* Special defines for pngcrush version 1.7.51 */
 
 #ifndef PNGCRUSH_H
 #define PNGCRUSH_H
 
+/* Do not build stuff we will not use */
+#undef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+#undef PNG_EASY_ACCESS_SUPPORTED
+#undef PNG_FIXED_POINT_SUPPORTED
+#undef PNG_INCH_CONVERSIONS_SUPPORTED
 #undef PNG_PROGRESSIVE_READ_SUPPORTED
+#undef PNG_READ_ALPHA_MODE_SUPPORTED
+#undef PNG_READ_BGR_SUPPORTED
+#undef PNG_READ_COMPOSITE_NODIV_SUPPORTED
+#undef PNG_READ_GAMMA_SUPPORTED
+#undef PNG_READ_STRIP_16_TO_8_SUPPORTED
+#undef PNG_READ_SWAP_ALPHA_SUPPORTED
+#undef PNG_READ_SWAP_SUPPORTED
+#undef PNG_READ_INVERT_ALPHA_SUPPORTED
+#undef PNG_READ_INVERT_SUPPORTED
+#undef PNG_READ_QUANTIZE_SUPPORTED
+#undef PNG_TIME_RFC1123_SUPPORTED
+#undef PNG_WRITE_BGR_SUPPORTED
+#undef PNG_WRITE_GET_PALETTE_MAX_SUPPORTED
+#undef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+#undef PNG_WRITE_INVERT_SUPPORTED
+#undef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+#undef PNG_WRITE_SWAP_SUPPORTED
+#undef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
 
 #if PNG_LIBPNG_VER >= 10600
 #  undef PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED