Example #1
0
/* flush the current output buffers now */
void
png_write_flush(png_structp png_ptr)
{
   int wrote_IDAT;

   png_debug(1, "in png_write_flush\n");
   /* We have already written out all of the data */
   if (png_ptr->row_number >= png_ptr->num_rows)
     return;

   do
   {
      int ret;

      /* compress the data */
      ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
      wrote_IDAT = 0;

      /* check for compression errors */
      if (ret != Z_OK)
      {
         if (png_ptr->zstream.msg != NULL)
            png_error(png_ptr, png_ptr->zstream.msg);
         else
            png_error(png_ptr, "zlib error");
      }

      if (!(png_ptr->zstream.avail_out))
      {
         /* write the IDAT and reset the zlib output buffer */
         png_write_IDAT(png_ptr, png_ptr->zbuf,
                        png_ptr->zbuf_size);
         png_ptr->zstream.next_out = png_ptr->zbuf;
         png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
         wrote_IDAT = 1;
      }
   } while(wrote_IDAT == 1);

   /* If there is any data left to be output, write it into a new IDAT */
   if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
   {
      /* write the IDAT and reset the zlib output buffer */
      png_write_IDAT(png_ptr, png_ptr->zbuf,
                     png_ptr->zbuf_size - png_ptr->zstream.avail_out);
      png_ptr->zstream.next_out = png_ptr->zbuf;
      png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
   }
   png_ptr->flush_rows = 0;
   png_flush(png_ptr);
}
Example #2
0
/* Writes the end of the PNG file.  If you don't want to write comments or
 * time information, you can pass NULL for info.  If you already wrote these
 * in png_write_info(), do not write them again here.  If you have long
 * comments, I suggest writing them here, and compressing them.
 */
void PNGAPI
png_write_end(png_structp png_ptr, png_infop info_ptr)
{
   png_debug(1, "in png_write_end");

   if (png_ptr == NULL)
      return;

   if (!(png_ptr->mode & PNG_HAVE_IDAT))
      png_error(png_ptr, "No IDATs written into file");

#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
   if (png_ptr->num_palette_max > png_ptr->num_palette)
      png_benign_error(png_ptr, "Wrote palette index exceeding num_palette");
#endif

   /* See if user wants us to write information chunks */
   if (info_ptr != NULL)
   {
#ifdef PNG_WRITE_TEXT_SUPPORTED
      int i; /* local index variable */
#endif
#ifdef PNG_WRITE_tIME_SUPPORTED
      /* Check to see if user has supplied a time chunk */
      if ((info_ptr->valid & PNG_INFO_tIME) &&
          !(png_ptr->mode & PNG_WROTE_tIME))
         png_write_tIME(png_ptr, &(info_ptr->mod_time));

#endif
#ifdef PNG_WRITE_TEXT_SUPPORTED
      /* Loop through comment chunks */
      for (i = 0; i < info_ptr->num_text; i++)
      {
         png_debug2(2, "Writing trailer text chunk %d, type %d", i,
            info_ptr->text[i].compression);
         /* An internationalized chunk? */
         if (info_ptr->text[i].compression > 0)
         {
#ifdef PNG_WRITE_iTXt_SUPPORTED
            /* Write international chunk */
            png_write_iTXt(png_ptr,
                info_ptr->text[i].compression,
                info_ptr->text[i].key,
                info_ptr->text[i].lang,
                info_ptr->text[i].lang_key,
                info_ptr->text[i].text);
            /* Mark this chunk as written */
            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
#else
            png_warning(png_ptr, "Unable to write international text");
#endif
         }

         else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
         {
#ifdef PNG_WRITE_zTXt_SUPPORTED
            /* Write compressed chunk */
            png_write_zTXt(png_ptr, info_ptr->text[i].key,
                info_ptr->text[i].text, 0,
                info_ptr->text[i].compression);
            /* Mark this chunk as written */
            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
#else
            png_warning(png_ptr, "Unable to write compressed text");
#endif
         }

         else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
         {
#ifdef PNG_WRITE_tEXt_SUPPORTED
            /* Write uncompressed chunk */
            png_write_tEXt(png_ptr, info_ptr->text[i].key,
                info_ptr->text[i].text, 0);
            /* Mark this chunk as written */
            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
#else
            png_warning(png_ptr, "Unable to write uncompressed text");
#endif
         }
      }
#endif
#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
   if (info_ptr->unknown_chunks_num)
   {
      png_unknown_chunk *up;

      png_debug(5, "writing extra chunks");

      for (up = info_ptr->unknown_chunks;
           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
           up++)
      {
         int keep = png_handle_as_unknown(png_ptr, up->name);
         if (keep != PNG_HANDLE_CHUNK_NEVER &&
             up->location &&
             (up->location & PNG_AFTER_IDAT) &&
             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
         {
            png_write_chunk(png_ptr, up->name, up->data, up->size);
         }
      }
   }
#endif
   }

   png_ptr->mode |= PNG_AFTER_IDAT;

   /* Write end of PNG file */
   png_write_IEND(png_ptr);
   /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
    * and restored again in libpng-1.2.30, may cause some applications that
    * do not set png_ptr->output_flush_fn to crash.  If your application
    * experiences a problem, please try building libpng with
    * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
    * png-mng-implement at lists.sf.net .
    */
#ifdef PNG_WRITE_FLUSH_SUPPORTED
#  ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
   png_flush(png_ptr);
#  endif
#endif
}