When I use plupload to chunk files (setting option chunk_size), I get a separate PHP request for each chunk. Looking at $_FILES variable, each chun
chunk_size
$_FILES
In the end I used the code from official example bundled with plupload-1.5.2 (examples/upload.php):
http://github.com/moxiecode/plupload/blob/master/examples/upload.php