I managed to extract file from mini PTZ v2 , the procedure outlined by Mr. alastairstevenson ,by tftp.
It is very simple, if you read carefully said by Mr. alastairstevenson
mtdblok0 , mtdblok1 , mtdblok2 , mtdblok3 , mtdblok4, ...... it is necessary for recovery after a bad firmware,
mtdbok4...