Hi, I have a couple of somewhat related problems regarding sane_get_devices(), sane_init() and SANE_Authorization_Callback().
1) sane_get_devices() does not update the available devices list without calling sane_init(). I asked about this some time ago and got the answer that it was a bug. With the version in (K)Ubuntu Lucid and the pashazz-sane PPA, I still have the problem that the scanner is not found if turned on after sane_init(). I use the epson2 and v4l backends. With epson2 I get a crash if the scanner is on the first time but is turned off before the second sane_get_devices(). Do you have any hints on where to start digging? 2) With sane_get_devices() I can get the vendor, model, type and backend names for the available scanners. Is there a way to get the same information about the currently opened device? I do not find an API for that. Have I missed something? The problem is that I can specify a backend like "test" and sane_open() will open either "test:0" or "test:1", but I do not know which one and I do not get the vendor, model and type strings. 3) libksane can be used in multi threaded applications and at the moment I'm making sure that sane_exit() is only called when the last instance exits, as sane_exit() will invalidate the other running instances. Should I do the same for sane_init()?. So far it has not resulted in problems, but when I tried a workaround for the sane_get_devices() problem I noticed that I got unwanted behavior. 4) Again in a multi threaded application there might be two scanners that require authentication. The resource string that is provided to SANE_Authorization_Callback() contains the backend name and a md5 hash, but it does not contain the same ":libusb:001:004" extra info type of sting that sane_get_devices() returns for the backend. How should I identify the different scanners with the same backend? Or is the authorization restricted to the backend with the same authentication for all the scanners with the same backend? Thanks in advance, K?re
