On 10/30/07, jazz_johnson at verizon.net <jazz_johnson at verizon.net> wrote: > I've finally got the major features of the IS450 working > but would appreciate some advice on implementing reading duplex window data > in SANE. > > I need to read two windows of data but have the sane-frontend realize that > the data > is to be saved into a frontside and backside for each sheet and not just one > long page.
you need to buffer the backside data, and return it (instead of scanning) after the second call to sane_start. there is no way to tell the frontend that half the data you are sending should be held for later. > I have an sp15c which duplexes so I've been looking over the sp15c backend > which uses threads and arrays of pipes neither of which my backend uses. > look at the fujitsu backend. it is single threaded, but does duplex, using an (unfortunately large) buffer. It could also be implemented with temp files, but i'd make it a user option. allan -- "The truth is an offense, but not a sin"
