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C++ png_crc_read函数代码示例

本文整理汇总了C++中png_crc_read函数的典型用法代码示例。如果您正苦于以下问题:C++ png_crc_read函数的具体用法?C++ png_crc_read怎么用?C++ png_crc_read使用的例子?那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。


在下文中一共展示了png_crc_read函数的15个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C++代码示例。

示例1: png_push_handle_unknown

/* This function is called when we haven't found a handler for this
 * chunk.  If there isn't a problem with the chunk itself (ie a bad chunk
 * name or a critical chunk), the chunk is (currently) silently ignored.
 */
void /* PRIVATE */
png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
   length)
{
   png_uint_32 skip=0;
   png_check_chunk_name(png_ptr, png_ptr->chunk_name);

   if (!(png_ptr->chunk_name[0] & 0x20))
   {
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
     if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
          PNG_HANDLE_CHUNK_ALWAYS
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
          && png_ptr->read_user_chunk_fn == NULL
#endif
        )
#endif
        png_chunk_error(png_ptr, "unknown critical chunk");

     (void) info_ptr; /* to quiet some compiler warnings */
   }

#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
   if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
   {
#ifdef PNG_MAX_MALLOC_64K
      if (length > (png_uint_32)65535L)
      {
          png_warning(png_ptr, "unknown chunk too large to fit in memory");
          skip = length - (png_uint_32)65535L;
          length = (png_uint_32)65535L;
      }
#endif
      png_strncpy((png_charp)png_ptr->unknown_chunk.name,
	 (png_charp)png_ptr->chunk_name, 5);
      png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
      png_ptr->unknown_chunk.size = (png_size_t)length;
      png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
      if(png_ptr->read_user_chunk_fn != NULL)
      {
         /* callback to user unknown chunk handler */
         int ret;
         ret = (*(png_ptr->read_user_chunk_fn))
           (png_ptr, &png_ptr->unknown_chunk);
         if (ret < 0)
            png_chunk_error(png_ptr, "error in user chunk");
         if (ret == 0)
         {
            if (!(png_ptr->chunk_name[0] & 0x20))
               if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
                    PNG_HANDLE_CHUNK_ALWAYS)
                  png_chunk_error(png_ptr, "unknown critical chunk");
            png_set_unknown_chunks(png_ptr, info_ptr,
               &png_ptr->unknown_chunk, 1);
         }
      }
#else
      png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
#endif
      png_free(png_ptr, png_ptr->unknown_chunk.data);
      png_ptr->unknown_chunk.data = NULL;
   }
   else
#endif
      skip=length;
   png_push_crc_skip(png_ptr, skip);
}
开发者ID:AGenews,项目名称:GUI,代码行数:72,代码来源:pngpread.c

示例2: png_push_read_chunk

void /* PRIVATE */
png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
{
#ifdef PNG_USE_LOCAL_ARRAYS
      PNG_CONST PNG_IHDR;
      PNG_CONST PNG_IDAT;
      PNG_CONST PNG_IEND;
      PNG_CONST PNG_PLTE;
#if defined(PNG_READ_bKGD_SUPPORTED)
      PNG_CONST PNG_bKGD;
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
      PNG_CONST PNG_cHRM;
#endif
#if defined(PNG_READ_gAMA_SUPPORTED)
      PNG_CONST PNG_gAMA;
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
      PNG_CONST PNG_hIST;
#endif
#if defined(PNG_READ_iCCP_SUPPORTED)
      PNG_CONST PNG_iCCP;
#endif
#if defined(PNG_READ_iTXt_SUPPORTED)
      PNG_CONST PNG_iTXt;
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
      PNG_CONST PNG_oFFs;
#endif
#if defined(PNG_READ_pCAL_SUPPORTED)
      PNG_CONST PNG_pCAL;
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
      PNG_CONST PNG_pHYs;
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
      PNG_CONST PNG_sBIT;
#endif
#if defined(PNG_READ_sCAL_SUPPORTED)
      PNG_CONST PNG_sCAL;
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
      PNG_CONST PNG_sRGB;
#endif
#if defined(PNG_READ_sPLT_SUPPORTED)
      PNG_CONST PNG_sPLT;
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
      PNG_CONST PNG_tEXt;
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
      PNG_CONST PNG_tIME;
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
      PNG_CONST PNG_tRNS;
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
      PNG_CONST 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->mode & PNG_HAVE_CHUNK_HEADER))
   {
      png_byte chunk_length[4];

      if (png_ptr->buffer_size < 8)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_push_fill_buffer(png_ptr, chunk_length, 4);
      png_ptr->push_length = png_get_uint_31(png_ptr,chunk_length);
      png_reset_crc(png_ptr);
      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
   }

   if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
     if(png_ptr->mode & PNG_AFTER_IDAT)
        png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;

   if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }
      png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
   }
   else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
//.........这里部分代码省略.........
开发者ID:AGenews,项目名称:GUI,代码行数:101,代码来源:pngpread.c

示例3: png_push_read_iTXt

void /* PRIVATE */
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 key;
      int comp_flag;
      png_charp lang;
      png_charp lang_key;
      png_charp text;
      int ret;

      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

      key = png_ptr->current_text;

      for (lang = key; *lang; lang++)
         /* empty loop */ ;

      if (lang < key + png_ptr->current_text_size - 3)
         lang++;

      comp_flag = *lang++;
      lang++;     /* skip comp_type, always zero */

      for (lang_key = lang; *lang_key; lang_key++)
         /* empty loop */ ;
      lang_key++;        /* skip NUL separator */

      text=lang_key;
      if (lang_key < key + png_ptr->current_text_size - 1)
      {
        for (; *text; text++)
           /* empty loop */ ;
      }

      if (text < key + png_ptr->current_text_size)
         text++;

      text_ptr = (png_textp)png_malloc(png_ptr,
         (png_uint_32)png_sizeof(png_text));
      text_ptr->compression = comp_flag + 2;
      text_ptr->key = key;
      text_ptr->lang = lang;
      text_ptr->lang_key = lang_key;
      text_ptr->text = text;
      text_ptr->text_length = 0;
      text_ptr->itxt_length = png_strlen(text);

      ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);

      png_ptr->current_text = NULL;

      png_free(png_ptr, text_ptr);
      if (ret)
        png_warning(png_ptr, "Insufficient memory to store iTXt chunk.");
   }
}
开发者ID:AGenews,项目名称:GUI,代码行数:83,代码来源:pngpread.c

示例4: png_push_read_tEXt

void /* PRIVATE */
png_push_read_tEXt(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 key;
      int ret;

      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

      key = png_ptr->current_text;

      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)png_sizeof(png_text));
      text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
      text_ptr->key = key;
#ifdef PNG_iTXt_SUPPORTED
      text_ptr->lang = NULL;
      text_ptr->lang_key = NULL;
#endif
      text_ptr->text = text;

      ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);

      png_free(png_ptr, key);
      png_free(png_ptr, text_ptr);
      png_ptr->current_text = NULL;

      if (ret)
        png_warning(png_ptr, "Insufficient memory to store text chunk.");
   }
}
开发者ID:AGenews,项目名称:GUI,代码行数:63,代码来源:pngpread.c

示例5: png_push_read_zTXt

void /* PRIVATE */
png_push_read_zTXt(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_uint_32)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 key;
      int ret;
      png_size_t text_size, key_size;

      if (png_ptr->buffer_size < 4)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_push_crc_finish(png_ptr);

      key = png_ptr->current_text;

      for (text = key; *text; text++)
         /* empty loop */ ;

      /* zTXt can't have zero text */
      if (text >= key + png_ptr->current_text_size)
      {
         png_ptr->current_text = NULL;
         png_free(png_ptr, key);
         return;
      }

      text++;

      if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */
      {
         png_ptr->current_text = NULL;
         png_free(png_ptr, key);
         return;
      }

      text++;

      png_ptr->zstream.next_in = (png_bytep )text;
      png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
         (text - key));
      png_ptr->zstream.next_out = png_ptr->zbuf;
      png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;

      key_size = text - key;
      text_size = 0;
      text = NULL;
      ret = Z_STREAM_END;

      while (png_ptr->zstream.avail_in)
      {
         ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
         if (ret != Z_OK && ret != Z_STREAM_END)
         {
            inflateReset(&png_ptr->zstream);
            png_ptr->zstream.avail_in = 0;
            png_ptr->current_text = NULL;
            png_free(png_ptr, key);
            png_free(png_ptr, text);
            return;
         }
         if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
         {
            if (text == NULL)
            {
               text = (png_charp)png_malloc(png_ptr,
                  (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
                     + key_size + 1));
               png_memcpy(text + key_size, png_ptr->zbuf,
                  png_ptr->zbuf_size - png_ptr->zstream.avail_out);
               png_memcpy(text, key, key_size);
               text_size = key_size + png_ptr->zbuf_size -
                  png_ptr->zstream.avail_out;
               *(text + text_size) = '\0';
            }
            else
            {
               png_charp tmp;

               tmp = text;
               text = (png_charp)png_malloc(png_ptr, text_size +
                  (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
                   + 1));
//.........这里部分代码省略.........
开发者ID:AGenews,项目名称:GUI,代码行数:101,代码来源:pngpread.c

示例6: png_read_row


//.........这里部分代码省略.........
               return;
            }
            break;
         case 6:
            if (!(png_ptr->row_number & 1))
            {
               png_read_finish_row(png_ptr);
               return;
            }
            break;
      }
   }
#endif

   if (!(png_ptr->mode & PNG_HAVE_IDAT))
      png_error(png_ptr, "Invalid attempt to read row data");

   png_ptr->zstream.next_out = png_ptr->row_buf;
   png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
   do
   {
      if (!(png_ptr->zstream.avail_in))
      {
         while (!png_ptr->idat_size)
         {
            png_byte chunk_length[4];

            png_crc_finish(png_ptr, 0);

            png_read_data(png_ptr, chunk_length, 4);
            png_ptr->idat_size = png_get_uint_32(chunk_length);

            png_reset_crc(png_ptr);
            png_crc_read(png_ptr, png_ptr->chunk_name, 4);
            if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
               png_error(png_ptr, "Not enough image data");
         }
         png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
         png_ptr->zstream.next_in = png_ptr->zbuf;
         if (png_ptr->zbuf_size > png_ptr->idat_size)
            png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
         png_crc_read(png_ptr, png_ptr->zbuf,
            (png_size_t)png_ptr->zstream.avail_in);
         png_ptr->idat_size -= png_ptr->zstream.avail_in;
      }
      ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
      if (ret == Z_STREAM_END)
      {
         if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
            png_ptr->idat_size)
            png_error(png_ptr, "Extra compressed data");
         png_ptr->mode |= PNG_AFTER_IDAT;
         png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
         break;
      }
      if (ret != Z_OK)
         png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
                   "Decompression error");

   } while (png_ptr->zstream.avail_out);

   png_ptr->row_info.color_type = png_ptr->color_type;
   png_ptr->row_info.width = png_ptr->iwidth;
   png_ptr->row_info.channels = png_ptr->channels;
   png_ptr->row_info.bit_depth = png_ptr->bit_depth;
   png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
开发者ID:RaymondLiao,项目名称:elektronika,代码行数:67,代码来源:pngread.c

示例7: png_read_end

/* Read the end of the PNG file.  Will not read past the end of the
 * file, will verify the end is accurate, and will read any comments
 * or time information at the end of the file, if info is not NULL.
 */
void PNGAPI
png_read_end(png_structp png_ptr, png_infop info_ptr)
{
   png_byte chunk_length[4];
   png_uint_32 length;

   png_debug(1, "in png_read_end\n");
   if(png_ptr == NULL) return;
   png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */

   do
   {
#ifdef PNG_USE_LOCAL_ARRAYS
      PNG_CONST PNG_IHDR;
      PNG_CONST PNG_IDAT;
      PNG_CONST PNG_IEND;
      PNG_CONST PNG_PLTE;
#if defined(PNG_READ_bKGD_SUPPORTED)
      PNG_CONST PNG_bKGD;
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
      PNG_CONST PNG_cHRM;
#endif
#if defined(PNG_READ_gAMA_SUPPORTED)
      PNG_CONST PNG_gAMA;
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
      PNG_CONST PNG_hIST;
#endif
#if defined(PNG_READ_iCCP_SUPPORTED)
      PNG_CONST PNG_iCCP;
#endif
#if defined(PNG_READ_iTXt_SUPPORTED)
      PNG_CONST PNG_iTXt;
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
      PNG_CONST PNG_oFFs;
#endif
#if defined(PNG_READ_pCAL_SUPPORTED)
      PNG_CONST PNG_pCAL;
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
      PNG_CONST PNG_pHYs;
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
      PNG_CONST PNG_sBIT;
#endif
#if defined(PNG_READ_sCAL_SUPPORTED)
      PNG_CONST PNG_sCAL;
#endif
#if defined(PNG_READ_sPLT_SUPPORTED)
      PNG_CONST PNG_sPLT;
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
      PNG_CONST PNG_sRGB;
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
      PNG_CONST PNG_tEXt;
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
      PNG_CONST PNG_tIME;
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
      PNG_CONST PNG_tRNS;
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
      PNG_CONST PNG_zTXt;
#endif
#endif /* PNG_USE_LOCAL_ARRAYS */

      png_read_data(png_ptr, chunk_length, 4);
      length = png_get_uint_31(png_ptr,chunk_length);

      png_reset_crc(png_ptr);
      png_crc_read(png_ptr, png_ptr->chunk_name, 4);

      png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name);

      if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
         png_handle_IHDR(png_ptr, info_ptr, length);
      else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
         png_handle_IEND(png_ptr, info_ptr, length);
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
      else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
      {
         if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
         {
            if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
               png_error(png_ptr, "Too many IDAT's found");
         }
         png_handle_unknown(png_ptr, info_ptr, length);
         if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
            png_ptr->mode |= PNG_HAVE_PLTE;
      }
#endif
      else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
//.........这里部分代码省略.........
开发者ID:My-Source,项目名称:root,代码行数:101,代码来源:pngread.c

示例8: png_push_read_chunk

void /* PRIVATE */
png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
{
   png_uint_32 chunk_name;
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
   int keep; /* unknown handling method */
#endif

   /* 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->mode & PNG_HAVE_CHUNK_HEADER) == 0)
   {
      png_byte chunk_length[4];
      png_byte chunk_tag[4];

      PNG_PUSH_SAVE_BUFFER_IF_LT(8)
      png_push_fill_buffer(png_ptr, chunk_length, 4);
      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
      png_reset_crc(png_ptr);
      png_crc_read(png_ptr, chunk_tag, 4);
      png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
      png_check_chunk_name(png_ptr, png_ptr->chunk_name);
      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
   }

   chunk_name = png_ptr->chunk_name;

   if (chunk_name == png_IDAT)
   {
      if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
         png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;

      /* 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
       * is called after the image has been read - we have an error).
       */
      if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
         png_error(png_ptr, "Missing IHDR before IDAT");

      else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
          (png_ptr->mode & PNG_HAVE_PLTE) == 0)
         png_error(png_ptr, "Missing PLTE before IDAT");

      png_ptr->mode |= PNG_HAVE_IDAT;
      png_ptr->process_mode = PNG_READ_IDAT_MODE;

      if ((png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) == 0)
         if (png_ptr->push_length == 0)
            return;

      if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
         png_benign_error(png_ptr, "Too many IDATs found");
   }

   if (chunk_name == png_IHDR)
   {
      if (png_ptr->push_length != 13)
         png_error(png_ptr, "Invalid IHDR length");

      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
   }

   else if (chunk_name == png_IEND)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);

      png_ptr->process_mode = PNG_READ_DONE_MODE;
      png_push_have_end(png_ptr, info_ptr);
   }

#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
   else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);

      if (chunk_name == png_PLTE)
         png_ptr->mode |= PNG_HAVE_PLTE;
   }
#endif

   else if (chunk_name == png_PLTE)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
   }

   else if (chunk_name == png_IDAT)
   {
      png_ptr->idat_size = png_ptr->push_length;
      png_ptr->process_mode = PNG_READ_IDAT_MODE;
      png_push_have_info(png_ptr, info_ptr);
      png_ptr->zstream.avail_out =
          (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
//.........这里部分代码省略.........
开发者ID:007Indian,项目名称:opencv,代码行数:101,代码来源:pngpread.c

示例9: png_push_read_IDAT

void /* PRIVATE */
png_push_read_IDAT(png_structrp png_ptr)
{
   if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0)
   {
      png_byte chunk_length[4];
      png_byte chunk_tag[4];

      /* TODO: this code can be commoned up with the same code in push_read */
      PNG_PUSH_SAVE_BUFFER_IF_LT(8)
      png_push_fill_buffer(png_ptr, chunk_length, 4);
      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
      png_reset_crc(png_ptr);
      png_crc_read(png_ptr, chunk_tag, 4);
      png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;

      if (png_ptr->chunk_name != png_IDAT)
      {
         png_ptr->process_mode = PNG_READ_CHUNK_MODE;

         if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
            png_error(png_ptr, "Not enough compressed data");

         return;
      }

      png_ptr->idat_size = png_ptr->push_length;
   }

   if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0)
   {
      png_size_t save_size = png_ptr->save_buffer_size;
      png_uint_32 idat_size = png_ptr->idat_size;

      /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
       * are of different types and we don't know which variable has the fewest
       * bits.  Carefully select the smaller and cast it to the type of the
       * larger - this cannot overflow.  Do not cast in the following test - it
       * will break on either 16-bit or 64-bit platforms.
       */
      if (idat_size < save_size)
         save_size = (png_size_t)idat_size;

      else
         idat_size = (png_uint_32)save_size;

      png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);

      png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);

      png_ptr->idat_size -= idat_size;
      png_ptr->buffer_size -= save_size;
      png_ptr->save_buffer_size -= save_size;
      png_ptr->save_buffer_ptr += save_size;
   }

   if (png_ptr->idat_size != 0 && png_ptr->current_buffer_size != 0)
   {
      png_size_t save_size = png_ptr->current_buffer_size;
      png_uint_32 idat_size = png_ptr->idat_size;

      /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
       * are of different types and we don't know which variable has the fewest
       * bits.  Carefully select the smaller and cast it to the type of the
       * larger - this cannot overflow.
       */
      if (idat_size < save_size)
         save_size = (png_size_t)idat_size;

      else
         idat_size = (png_uint_32)save_size;

      png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);

      png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);

      png_ptr->idat_size -= idat_size;
      png_ptr->buffer_size -= save_size;
      png_ptr->current_buffer_size -= save_size;
      png_ptr->current_buffer_ptr += save_size;
   }

   if (png_ptr->idat_size == 0)
   {
      PNG_PUSH_SAVE_BUFFER_IF_LT(4)
      png_crc_finish(png_ptr, 0);
      png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
      png_ptr->mode |= PNG_AFTER_IDAT;
      png_ptr->zowner = 0;
   }
}
开发者ID:007Indian,项目名称:opencv,代码行数:92,代码来源:pngpread.c

示例10: png_push_read_IDAT

void /* PRIVATE */
png_push_read_IDAT(png_structp png_ptr)
{
   PNG_IDAT;
   if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
   {
      png_byte chunk_length[4];

      if (png_ptr->buffer_size < 8)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_push_fill_buffer(png_ptr, chunk_length, 4);
      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
      png_reset_crc(png_ptr);
      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;

      if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
      {
         png_ptr->process_mode = PNG_READ_CHUNK_MODE;

         if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
            png_error(png_ptr, "Not enough compressed data");

         return;
      }

      png_ptr->idat_size = png_ptr->push_length;
   }
   if (png_ptr->idat_size && png_ptr->save_buffer_size)
   {
      png_size_t save_size = png_ptr->save_buffer_size;
      png_uint_32 idat_size = png_ptr->idat_size;

      /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
       * are of different types and we don't know which variable has the fewest
       * bits.  Carefully select the smaller and cast it to the type of the
       * larger - this cannot overflow.  Do not cast in the following test - it
       * will break on either 16 or 64 bit platforms.
       */
      if (idat_size < save_size)
         save_size = (png_size_t)idat_size;

      else
         idat_size = (png_uint_32)save_size;

      png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);

      png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);

      png_ptr->idat_size -= idat_size;
      png_ptr->buffer_size -= save_size;
      png_ptr->save_buffer_size -= save_size;
      png_ptr->save_buffer_ptr += save_size;
   }

   if (png_ptr->idat_size && png_ptr->current_buffer_size)
   {
      png_size_t save_size = png_ptr->current_buffer_size;
      png_uint_32 idat_size = png_ptr->idat_size;

      /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
       * are of different types and we don't know which variable has the fewest
       * bits.  Carefully select the smaller and cast it to the type of the
       * larger - this cannot overflow.
       */
      if (idat_size < save_size)
         save_size = (png_size_t)idat_size;

      else
         idat_size = (png_uint_32)save_size;

      png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);

      png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);

      png_ptr->idat_size -= idat_size;
      png_ptr->buffer_size -= save_size;
      png_ptr->current_buffer_size -= save_size;
      png_ptr->current_buffer_ptr += save_size;
   }
   if (!png_ptr->idat_size)
   {
      if (png_ptr->buffer_size < 4)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_crc_finish(png_ptr, 0);
      png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
      png_ptr->mode |= PNG_AFTER_IDAT;
   }
}
开发者ID:Amalerd,项目名称:SoxPlayer,代码行数:97,代码来源:pngpread.c

示例11: png_push_read_IDAT

void /* PRIVATE */
png_push_read_IDAT(png_structrp png_ptr)
{
    if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0)
    {
        png_byte chunk_length[4];
        png_byte chunk_tag[4];

        /* TODO: this code can be commoned up with the same code in push_read */
#ifdef PNG_READ_APNG_SUPPORTED
        PNG_PUSH_SAVE_BUFFER_IF_LT(12)
#else
        PNG_PUSH_SAVE_BUFFER_IF_LT(8)
#endif
        png_push_fill_buffer(png_ptr, chunk_length, 4);
        png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
        png_reset_crc(png_ptr);
        png_crc_read(png_ptr, chunk_tag, 4);
        png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
        png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;

#ifdef PNG_READ_APNG_SUPPORTED
        if (png_ptr->chunk_name != png_fdAT && png_ptr->num_frames_read > 0)
        {
            if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) != 0)
            {
                png_ptr->process_mode = PNG_READ_CHUNK_MODE;
                if (png_ptr->frame_end_fn != NULL)
                    (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read);
                png_ptr->num_frames_read++;
                return;
            }
            else
            {
                if (png_ptr->chunk_name == png_IEND)
                    png_error(png_ptr, "Not enough image data");
                PNG_PUSH_SAVE_BUFFER_IF_FULL
                png_warning(png_ptr, "Skipping (ignoring) a chunk between "
                            "APNG chunks");
                png_crc_finish(png_ptr, png_ptr->push_length);
                png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
                return;
            }
        }
        else
#endif
#ifdef PNG_READ_APNG_SUPPORTED
            if (png_ptr->chunk_name != png_IDAT && png_ptr->num_frames_read == 0)
#else
            if (png_ptr->chunk_name != png_IDAT)
#endif
            {
                png_ptr->process_mode = PNG_READ_CHUNK_MODE;

                if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
                    png_error(png_ptr, "Not enough compressed data");

#ifdef PNG_READ_APNG_SUPPORTED
                if (png_ptr->frame_end_fn != NULL)
                    (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read);
                png_ptr->num_frames_read++;
#endif

                return;
            }

        png_ptr->idat_size = png_ptr->push_length;

#ifdef PNG_READ_APNG_SUPPORTED
        if (png_ptr->num_frames_read > 0)
        {
            png_ensure_sequence_number(png_ptr, 4);
            png_ptr->idat_size -= 4;
        }
#endif
    }

    if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0)
    {
        png_size_t save_size = png_ptr->save_buffer_size;
        png_uint_32 idat_size = png_ptr->idat_size;

        /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
         * are of different types and we don't know which variable has the fewest
         * bits.  Carefully select the smaller and cast it to the type of the
         * larger - this cannot overflow.  Do not cast in the following test - it
         * will break on either 16-bit or 64-bit platforms.
         */
        if (idat_size < save_size)
            save_size = (png_size_t)idat_size;

        else
            idat_size = (png_uint_32)save_size;

        png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);

        png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);

        png_ptr->idat_size -= idat_size;
        png_ptr->buffer_size -= save_size;
//.........这里部分代码省略.........
开发者ID:subsevenx2001,项目名称:gecko-dev,代码行数:101,代码来源:pngpread.c

示例12: png_push_read_chunk

void
png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
{
   /* 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))
   {
      png_byte chunk_length[4];

      if (png_ptr->buffer_size < 8)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_push_fill_buffer(png_ptr, chunk_length, 4);
      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;
   }

   if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
   }
   else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
   }
   else if (!png_memcmp(png_ptr->chunk_name, 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
       * is called after the image has been read - we have an error).
       */
      if (png_ptr->mode & PNG_HAVE_IDAT)
      {
         if (png_ptr->push_length == 0)
            return;

         if (png_ptr->mode & PNG_AFTER_IDAT)
            png_error(png_ptr, "Too many IDAT's found");
      }

      png_ptr->idat_size = png_ptr->push_length;
      png_ptr->mode |= PNG_HAVE_IDAT;
      png_ptr->process_mode = PNG_READ_IDAT_MODE;
      png_push_have_info(png_ptr, info_ptr);
      png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
      png_ptr->zstream.next_out = png_ptr->row_buf;
      return;
   }
   else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
      png_ptr->process_mode = PNG_READ_DONE_MODE;
      png_push_have_end(png_ptr, info_ptr);
   }
#if defined(PNG_READ_gAMA_SUPPORTED)
   else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
   }
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
   else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
//.........这里部分代码省略.........
开发者ID:devoworm,项目名称:Morphozoic,代码行数:101,代码来源:pngpread.c

示例13: png_push_read_chunk

void /* PRIVATE */
png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
{
   png_uint_32 chunk_name;
#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
   int keep; /* unknown handling method */
#endif

   /* 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->mode & PNG_HAVE_CHUNK_HEADER))
   {
      png_byte chunk_length[4];
      png_byte chunk_tag[4];

      if (png_ptr->buffer_size < 8)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_push_fill_buffer(png_ptr, chunk_length, 4);
      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
      png_reset_crc(png_ptr);
      png_crc_read(png_ptr, chunk_tag, 4);
      png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
      png_check_chunk_name(png_ptr, png_ptr->chunk_name);
      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
   }

   chunk_name = png_ptr->chunk_name;

#ifdef PNG_READ_APNG_SUPPORTED
   if (png_ptr->num_frames_read > 0 &&
       png_ptr->num_frames_read < info_ptr->num_frames)
   {
      if (chunk_name == png_IDAT)
      {
         /* Discard trailing IDATs for the first frame */
         if (png_ptr->mode & PNG_HAVE_fcTL || png_ptr->num_frames_read > 1)
            png_error(png_ptr, "out of place IDAT");

         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
         {
            png_push_save_buffer(png_ptr);
            return;
         }

         png_push_crc_skip(png_ptr, png_ptr->push_length);
         png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
         return;
      }
      else if (chunk_name == png_fdAT)
      {
         if (png_ptr->buffer_size < 4)
         {
            png_push_save_buffer(png_ptr);
            return;
         }

         png_ensure_sequence_number(png_ptr, 4);

         if (!(png_ptr->mode & PNG_HAVE_fcTL))
         {
            /* Discard trailing fdATs for frames other than the first */
            if (png_ptr->num_frames_read < 2)
               png_error(png_ptr, "out of place fdAT");

            if (png_ptr->push_length + 4 > png_ptr->buffer_size)
            {
               png_push_save_buffer(png_ptr);
               return;
            }

            png_push_crc_skip(png_ptr, png_ptr->push_length);
            png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
            return;
         }

         else
         {
            /* frame data follows */
            png_ptr->idat_size = png_ptr->push_length - 4;
            png_ptr->mode |= PNG_HAVE_IDAT;
            png_ptr->process_mode = PNG_READ_IDAT_MODE;

            return;
         }
      }

      else if (chunk_name == png_fcTL)
      {
         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
         {
            png_push_save_buffer(png_ptr);
            return;
//.........这里部分代码省略.........
开发者ID:blue119,项目名称:gecko-dev,代码行数:101,代码来源:pngpread.c

示例14: png_read_end

/* Read the end of the PNG file.  Will not read past the end of the
 * file, will verify the end is accurate, and will read any comments
 * or time information at the end of the file, if info is not NULL.
 */
void
png_read_end(png_structp png_ptr, png_infop info_ptr)
{
   png_byte chunk_length[4];
   png_uint_32 length;

   png_debug(1, "in png_read_end\n");
   /* save jump buffer and error functions */
   png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */

   do
   {
      png_read_data(png_ptr, chunk_length, 4);
      length = png_get_uint_32(chunk_length);

      png_reset_crc(png_ptr);
      png_crc_read(png_ptr, png_ptr->chunk_name, 4);

      png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name);

      if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
         png_handle_IHDR(png_ptr, info_ptr, length);
      else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
      {
         /* Zero length IDATs are legal after the last IDAT has been
          * read, but not after other chunks have been read.
          */
         if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
            png_error(png_ptr, "Too many IDAT's found");
         else
            png_crc_finish(png_ptr, 0);
      }
      else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
         png_handle_PLTE(png_ptr, info_ptr, length);
      else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
         png_handle_IEND(png_ptr, info_ptr, length);
#if defined(PNG_READ_bKGD_SUPPORTED)
      else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
         png_handle_bKGD(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
      else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
         png_handle_cHRM(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_gAMA_SUPPORTED)
      else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
         png_handle_gAMA(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
      else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
         png_handle_hIST(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
      else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
         png_handle_oFFs(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_pCAL_SUPPORTED)
      else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
         png_handle_pCAL(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
      else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
         png_handle_pHYs(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
      else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
         png_handle_sBIT(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
      else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
         png_handle_sRGB(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
      else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
         png_handle_tEXt(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
      else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
         png_handle_tIME(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
      else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
         png_handle_tRNS(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
      else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
         png_handle_zTXt(png_ptr, info_ptr, length);
#endif
      else
         png_handle_unknown(png_ptr, info_ptr, length);
   } while (!(png_ptr->mode & PNG_HAVE_IEND));
}
开发者ID:RaymondLiao,项目名称:elektronika,代码行数:96,代码来源:pngread.c

示例15: png_push_read_IDAT

void /* PRIVATE */
png_push_read_IDAT(png_structp png_ptr)
{
#ifdef PNG_USE_LOCAL_ARRAYS
   PNG_CONST PNG_IDAT;
#endif
   if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
   {
      png_byte chunk_length[4];

      if (png_ptr->buffer_size < 8)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_push_fill_buffer(png_ptr, chunk_length, 4);
      png_ptr->push_length = png_get_uint_31(png_ptr,chunk_length);
      png_reset_crc(png_ptr);
      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;

      if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
      {
         png_ptr->process_mode = PNG_READ_CHUNK_MODE;
         if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
            png_error(png_ptr, "Not enough compressed data");
         return;
      }

      png_ptr->idat_size = png_ptr->push_length;
   }
   if (png_ptr->idat_size && png_ptr->save_buffer_size)
   {
      png_size_t save_size;

      if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
      {
         save_size = (png_size_t)png_ptr->idat_size;
         /* check for overflow */
         if((png_uint_32)save_size != png_ptr->idat_size)
            png_error(png_ptr, "save_size overflowed in pngpread");
      }
      else
         save_size = png_ptr->save_buffer_size;

      png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
      if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
         png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
      png_ptr->idat_size -= save_size;
      png_ptr->buffer_size -= save_size;
      png_ptr->save_buffer_size -= save_size;
      png_ptr->save_buffer_ptr += save_size;
   }
   if (png_ptr->idat_size && png_ptr->current_buffer_size)
   {
      png_size_t save_size;

      if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
      {
         save_size = (png_size_t)png_ptr->idat_size;
         /* check for overflow */
         if((png_uint_32)save_size != png_ptr->idat_size)
            png_error(png_ptr, "save_size overflowed in pngpread");
      }
      else
         save_size = png_ptr->current_buffer_size;

      png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
      if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
        png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);

      png_ptr->idat_size -= save_size;
      png_ptr->buffer_size -= save_size;
      png_ptr->current_buffer_size -= save_size;
      png_ptr->current_buffer_ptr += save_size;
   }
   if (!png_ptr->idat_size)
   {
      if (png_ptr->buffer_size < 4)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_crc_finish(png_ptr, 0);
      png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
      png_ptr->mode |= PNG_AFTER_IDAT;
   }
}
开发者ID:AGenews,项目名称:GUI,代码行数:90,代码来源:pngpread.c


注:本文中的png_crc_read函数示例由纯净天空整理自Github/MSDocs等开源代码及文档管理平台,相关代码片段筛选自各路编程大神贡献的开源项目,源码版权归原作者所有,传播和使用请参考对应项目的License;未经允许,请勿转载。