Converting binary data

Hi I'm retriving some binary data from a Interbase blob field (a custom format to do some drawing) into a php variable like this: $blh = ibase_blob_open($row[4]); while ($blob = ibase_blob_get($blh, 400)) $Objects .= $blob; ibase_blob_close($blh); Now I want to tell php to get first 4 bytes (btw, is there something that returns size of integer - sizeof seems to work on arrays only), and convert them to integer Thanks Lucijan