FS#925 memory-limit checking in fetch.php too restrictive

Backend

• 

  2006-09-26 thomask77

  When i try to automatically resize big images (like 3072x2304 from my digital camera), GD resize will fail because
  
   if(!is_mem_available(($from_w * $from_h * 4) + ($to_w * $to_h * 4))){
     return false;
   }
  
  in fetch.php will return false, which seems to be the wanted behaviour (it's called with 28430156 bytes and memory_limit is set to 8M in php.ini).
  
  but: if i comment out the above lines, everything will work fine. So resize_imageGD seems to use less memory than expected, and the check is too restrictive.
  
• 

  2006-10-21 gb

  Cannot reproduce this (using RC2, RC3 and current) with pictures of exactly the same size. I even can't reproduce it on an other wiki running Release 2006-03-09. Which version are you using? Can you please make a test with RC3 version (available from DokuWiki website) and report back?
  
  Thanks
• 

  2007-01-06 andi

  I just did some testing using the memory_get_peak_usage() function - if this works as I understand it, libGD seems to use *much* fewer RAM then assumed in the mentioned check.
  
  But I'm not sure what the right way to estimate the needed memory is. I'm open to suggestions.
• 

  2010-08-27 andi

  see also http://stackoverflow.com/questions/3554397/estimate-required-memory-for-libgd-operation
• 

  2010-09-03 gb

  This bug is so old that I doubt we should keep it opened if we cannot confirm the reported issue.
• 

  2010-09-03 gb

  "bug is so old" -> our fault of course :-(
• 

  2010-09-03 andi

  The comments linked in the stackoverflow answer aren't as helpful as I thought initially. Their calculations are even higher than my naive approach. I guess unless someone digs through the gdlib code to find the *real* way they allocate memory we should leave it as is.
• 

  2010-09-09 andi

  closed until someone sends a patch