Imported from pngcrush-1.2.1.tar

2025-07-10 18:04:09 +02:00 · 1999-12-07 09:44:50 -06:00
parent 713ac5ec17
commit ce85ad6640
22 changed files with 2638 additions and 690 deletions
--- a/pngpread.c
+++ b/pngpread.c
@@ -1,7 +1,7 @@

 /* pngpread.c - read a png file in push mode
 *
- * libpng 1.0.5a - October 23, 1999
+ * libpng 1.0.5f - December 6, 1999
 * For conditions of distribution and use, see copyright notice in png.h
 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
 * Copyright (c) 1996, 1997 Andreas Dilger
@@ -13,6 +13,17 @@

 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED

+/* push model modes */
+#define PNG_READ_SIG_MODE   0
+#define PNG_READ_CHUNK_MODE 1
+#define PNG_READ_IDAT_MODE  2
+#define PNG_SKIP_MODE       3
+#define PNG_READ_tEXt_MODE  4
+#define PNG_READ_zTXt_MODE  5
+#define PNG_READ_DONE_MODE  6
+#define PNG_READ_iTXt_MODE  7
+#define PNG_ERROR_MODE      8
+
 void
 png_process_data(png_structp png_ptr, png_infop info_ptr,
   png_bytep buffer, png_size_t buffer_size)
@@ -61,6 +72,13 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr)
         png_push_read_zTXt(png_ptr, info_ptr);
         break;
      }
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+      case PNG_READ_iTXt_MODE:
+      {
+         png_push_read_iTXt(png_ptr, info_ptr);
+         break;
+      }
 #endif
      case PNG_SKIP_MODE:
      {
@@ -116,13 +134,58 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
 void
 png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 {
+#ifdef PNG_USE_LOCAL_ARRAYS
+      PNG_IHDR;
+      PNG_IDAT;
+      PNG_IEND;
+      PNG_PLTE;
+#if defined(PNG_READ_bKGD_SUPPORTED)
+      PNG_bKGD;
+#endif
+#if defined(PNG_READ_cHRM_SUPPORTED)
+      PNG_cHRM;
+#endif
+#if defined(PNG_READ_gAMA_SUPPORTED)
+      PNG_gAMA;
+#endif
+#if defined(PNG_READ_hIST_SUPPORTED)
+      PNG_hIST;
+#endif
+#if defined(PNG_READ_oFFs_SUPPORTED)
+      PNG_oFFs;
+#endif
+#if defined(PNG_READ_pCAL_SUPPORTED)
+      PNG_pCAL;
+#endif
+#if defined(PNG_READ_pHYs_SUPPORTED)
+      PNG_pHYs;
+#endif
+#if defined(PNG_READ_sBIT_SUPPORTED)
+      PNG_sBIT;
+#endif
+#if defined(PNG_READ_sRGB_SUPPORTED)
+      PNG_sRGB;
+#endif
+#if defined(PNG_READ_tEXt_SUPPORTED)
+      PNG_tEXt;
+#endif
+#if defined(PNG_READ_tIME_SUPPORTED)
+      PNG_tIME;
+#endif
+#if defined(PNG_READ_tRNS_SUPPORTED)
+      PNG_tRNS;
+#endif
+#if defined(PNG_READ_zTXt_SUPPORTED)
+      PNG_zTXt;
+#endif
+#endif /* PNG_USE_LOCAL_ARRAYS */
   /* First we make sure we have enough data for the 4 byte chunk name
    * and the 4 byte chunk length before proceeding with decoding the
    * chunk data.  To fully decode each of these chunks, we also make
    * sure we have enough data in the buffer for the 4 byte CRC at the
    * end of every chunk (except IDAT, which is handled separately).
    */
-   if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER))
+   if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
   {
      png_byte chunk_length[4];

@@ -136,7 +199,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
      png_ptr->push_length = png_get_uint_32(chunk_length);
      png_reset_crc(png_ptr);
      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
-      png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER;
+      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
   }

   if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
@@ -159,7 +222,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)

      png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
   }
-   else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+   else if (!png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
   {
      /* If we reach an IDAT chunk, this means we have read all of the
       * header chunks, and we can start reading the image (or if this
@@ -337,13 +400,19 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
   {
      png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
   }
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+   else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
+   {
+      png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
+   }
 #endif
   else
   {
      png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
   }

-   png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER;
+   png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
 }

 void
@@ -496,7 +565,10 @@ png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
 void
 png_push_read_IDAT(png_structp png_ptr)
 {
-   if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER))
+#ifdef PNG_USE_LOCAL_ARRAYS
+   PNG_IDAT;
+#endif
+   if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
   {
      png_byte chunk_length[4];

@@ -511,9 +583,9 @@ png_push_read_IDAT(png_structp png_ptr)

      png_reset_crc(png_ptr);
      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
-      png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER;
+      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;

-      if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+      if (png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
      {
         png_ptr->process_mode = PNG_READ_CHUNK_MODE;
         if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
@@ -576,7 +648,7 @@ png_push_read_IDAT(png_structp png_ptr)
      }

      png_crc_finish(png_ptr, 0);
-      png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER;
+      png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
   }
 }

@@ -767,6 +839,32 @@ png_push_process_row(png_structp png_ptr)
 void
 png_read_push_finish_row(png_structp png_ptr)
 {
+#ifdef PNG_USE_LOCAL_ARRAYS
+   /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+   
+   /* start of interlace block */
+   const int png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+   
+   /* offset to next interlace block */
+   const int png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+   
+   /* start of interlace block in the y direction */
+   const int png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+   
+   /* offset to next interlace block in the y direction */
+   const int png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
+   
+   /* Width of interlace block.  This is not currently used - if you need
+    * it, uncomment it here and in png.h
+   const int png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
+   */
+   
+   /* Height of interlace block.  This is not currently used - if you need
+    * it, uncomment it here and in png.h
+   const int png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
+   */
+#endif
+   
   png_ptr->row_number++;
   if (png_ptr->row_number < png_ptr->num_rows)
      return;
@@ -878,6 +976,7 @@ png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)

      text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
      text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
+      text_ptr->lang = (char *)NULL;
      text_ptr->key = key;
      text_ptr->text = text;

@@ -1057,6 +1156,101 @@ png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)

      text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
      text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
+      text_ptr->lang = (char *)NULL;
+      text_ptr->key = key;
+      text_ptr->text = text;
+
+      png_set_text(png_ptr, info_ptr, text_ptr, 1);
+
+      png_free(png_ptr, text_ptr);
+   }
+}
+#endif
+
+#if defined(PNG_READ_iTXt_SUPPORTED)
+void
+png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   if (png_ptr->mode == PNG_BEFORE_IHDR || png_ptr->mode & PNG_HAVE_IEND)
+      {
+         png_error(png_ptr, "Out of place iTXt");
+         /* to quiet some compiler warnings */
+         if(info_ptr == NULL) return;
+      }
+
+#ifdef PNG_MAX_MALLOC_64K
+   png_ptr->skip_length = 0;  /* This may not be necessary */
+
+   if (length > (png_uint_32)65535L) /* Can't hold the entire string in memory */
+   {
+      png_warning(png_ptr, "iTXt chunk too large to fit in memory");
+      png_ptr->skip_length = length - (png_uint_32)65535L;
+      length = (png_uint_32)65535L;
+   }
+#endif
+
+   png_ptr->current_text = (png_charp)png_malloc(png_ptr,
+         (png_uint_32)(length+1));
+   png_ptr->current_text[length] = '\0';
+   png_ptr->current_text_ptr = png_ptr->current_text;
+   png_ptr->current_text_size = (png_size_t)length;
+   png_ptr->current_text_left = (png_size_t)length;
+   png_ptr->process_mode = PNG_READ_iTXt_MODE;
+}
+
+void
+png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr->buffer_size && png_ptr->current_text_left)
+   {
+      png_size_t text_size;
+
+      if (png_ptr->buffer_size < png_ptr->current_text_left)
+         text_size = png_ptr->buffer_size;
+      else
+         text_size = png_ptr->current_text_left;
+      png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
+      png_ptr->current_text_left -= text_size;
+      png_ptr->current_text_ptr += text_size;
+   }
+   if (!(png_ptr->current_text_left))
+   {
+      png_textp text_ptr;
+      png_charp text;
+      png_charp lang;
+      png_charp key;
+
+      if (png_ptr->buffer_size < 4)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+
+      png_push_crc_finish(png_ptr);
+
+#if defined(PNG_MAX_MALLOC_64K)
+      if (png_ptr->skip_length)
+         return;
+#endif
+
+      lang = png_ptr->current_text;
+      png_ptr->current_text = 0;
+
+      for (key = lang; *key; key++)
+         /* empty loop */ ;
+
+      if (key != lang + png_ptr->current_text_size)
+         key++;
+
+      for (text = key; *text; text++)
+         /* empty loop */ ;
+
+      if (text != key + png_ptr->current_text_size)
+         text++;
+
+      text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
+      text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
+      text_ptr->lang = lang;
      text_ptr->key = key;
      text_ptr->text = text;

@@ -1115,6 +1309,9 @@ void
 png_progressive_combine_row (png_structp png_ptr,
   png_bytep old_row, png_bytep new_row)
 {
+#ifdef PNG_USE_LOCAL_ARRAYS
+   const int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
+#endif
   if (new_row != NULL)    /* new_row must == png_ptr->row_buf here. */
      png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
 }