TODO (2002-02-03)

******** todo ********

backends
--------
  * Add new backends (?)
    - hp4200 http://hp4200-backend.sourceforge.net/
    - v4l2 http://video.inodes.org/sane-v4l2/
    - Relisys Scorpio Super 3 SCSI II
      Mark Plowman <sane-devel@plowman.xs4all.nl>
      http://www.xs4all.nl/~plowman/
    - Linux Handscanner Ioctl Interface scanner by Harald
      Bauer <bauer-h@web.de>
    - viceo (Visioneer OneTouch 8600)
      http://www.littlecms.com/iphoto/otlinux.htm
    - Genius Vivid Pro USB, Colorado USB 19200, Visioneer OneTouch 7600 
      IBM IdeaScan 2000 USB 
      http://homepages.paradise.net.nz/stevenel/scanner/
    - Fujitsu M3091DCd support
      Frederik Ramm <frederik@remote.org>
      http://www.remote.org/frederik/projects/software/sane/
    - Canon FB620S flatbed scanner and FS2710 film scanner
      ftp://stthd0.pc.uni-koeln.de/pub/canon-1.08.tar.gz
      Ulrich Deiters <ukd@xenon.pc.Uni-Koeln.DE>
    - Hewlett-Packard ScanJet 3300C / 3400C and 4300C (wip)
      http://sourceforge.net/projects/hp3300backend

  * Update backends
    - Combine all the Fujitsu backends into one single backend
    
  * All backends should check for TL_X < BR_X and TL_Y < BR_Y to
    avoid segfaults or even scanner damage. This should NOT be done
    in sane_control_option, it should be possible to temporary set
    TL_X > BR_X or TL_ > BR, otherwise it is hard for a frontend to
    set the correct values.

  * Use DBG(...) instead of fprintf(stderr, ...) or printf
     - microtek

  * qcam:
     - implement auto mode for brightness and black-level (don't
       just advertise it!) Actually, implement an auto "backend" instead
       that can be plugged in front of any backend with brightness/contrast
       etc controls
     - figure out how/if to support bulb mode
     - convert to use sanei_pio functions instead of direct port
       access.
     - The result of locking isn't checked --> does it make sense at all?

  * dll: Rewrite to use libtool ltdl library

  * dc210, dc240, gphoto2, and jpeg stuff: move sanei_* functions to sanei/
    (if they are necessary). 

  * v4l: Problems (crash) with more than one video card. It looks like 
    the two different cards are identified as the same card.

  * Fix backends where sane_exit() does not release memory allocated by
    sane_get_devices().
      - abaton
      - agfafocus
      - apple
      - as6e
      - avision
      - bh
      - canon
      - coolscan
      - dmc
      - m3096
      - microtek
      - qcam
      - ricoh
      - s9036
      - sharp
      - sp15c
      - tamarack
      
      - etc?

  * as6e: attach: memory (dev + dev-sane.name) isn't freed if driver isn't
    found.

  * avision: line 1393: word isn't freed sometimes (maybe if  cp == line?)

  * net: add IPv6 support.

  * #include "../include/sane/config.h" should be the first include in every
    file (see doc/sane-backend-writing.txt for the lalloca exception):
    - umax_pp_low.c


doc
---
  * Add doxygen documentation for the remaining sanei files:
    - sanei_auth.c
    - sanei_codec*
    - sanei_config.c
    - sanei_config2.c
    - sanei_constrain_value.c
    - sanei_init_debug.c
    - sanei_net.c
    - sanei_pa4s2.c
    - sanei_pio.c
    - sanei_pv8630.c
    - sanei_scsi.c
    - sanei_thread.c
    - sanei_wire.c

  * sane.tex: Define the return values for sane_init?  Define the
    consequences if sane_init doesn't return SANE_STATUS_GOOD.

  * sane.tex: Add a warning/explanation about problems with 
    sane_get_select_fd, Unix select() calls and sane_cancel.

  * sane.tex: Add new sane.type = "film scanner". Check the other well known
    strings for completeness.

  * sane-backends.html should state more clearly which backends are included
    in the distribution.


frontends
---------
  * saned:
     - saned times out after 60 minutes. Check if the
       watchdog timer is really necessary (e.g. to avoid blocking scanners
       by one user). Maybe add a command line option to saned to set the
       timeout. Otherwise turn on TCP keep alive (where available) and
       (maybe) check the connection from server side.
     - Add IPv6 support.

  * scanimage: Add i18n (NLS) support?

 [the remaining entries have been moved to the sane-frontends package]

sanei
-----
  * sanei_scsi: Think about a completely new interface. Details are in
    http://www.mostang.com/pipermail/sane-devel/2002-January/001995.html .

  * create sanei_parport_* and remove all inb, outb,... from all backends;
    use libieee1284 if available (see
    http://people.redhat.com/twaugh/libieee1284/). Or just include this
    library into sane.

  * Check if the device file has the right type before accessing it. E.g.
    check for major/minor numbers to avoid accessing a USB file as SCSI 
    device.

platform-specific
-----------------
  * Keep config.guess and config.sub up-to-date.

  * SCSI access doesn't seem to work on Linux/Sparc. See emails from
    Tomislav Renic on sane-devel (2001-09-21).

  * Really fix all the parport/inb/outb compilation issues which break
    porting to some non-i386 platforms.

  * Add AC_OBJEXT and AC_EXEEXT to configure.in for automatically adding
    the correct extensions (e.g. for OS/2). Also update the Makefiles
    accordingly.

  * Add support for semaphores also for OS/2 (currently used in snapscan).

  * Fix shared lib problem with NetBSD. Starting scanimage results in:
    "Cannot open "../backend/.libs/libsane.so". However, scanadf works.

  * Shared libs work with OpenBSD. However, they are named libsane.so.1.6
    instead of 1.0.6. Is this correct?

  * Check if a new version of libtool can fix the above mentioned issues.

  * Don't use -ansi for HPUX (see sane-devel).

misc
----
  * sane-config: add options "--exec-prefix=...." and "--prefix=..."
    compareable to gtk-config

  * Check include/sane/config.h.in for unnecessary macros.

  * Add configure option to enable only the net backend for users without
    local scanners. Install only sane-dll/sane-net (or even only sane-net).
    Maybe something like  --network-client-only or --disable-local-devices.

  * Make output of sane-find-scanner more flexible. See scanimage -f for
    details.

  * make distclean should remove *.orig, *.old, .#*, *.tar.gz, and similar
    files.


******** done ********
* Don't use exit() in backends.
* sanei_scsi: Check return values of req_wait and cmd in case of
  SCSI DEVICE BUSY. Better specification of the behaviour of sanei_scsi
  functions (e.g. return values, timeout 10 min versus 1 min)?
* Documentation for sanei API
* Fix missing or wrong links to backend homepages (*.desc). If a homepage
  doesn't exist, add a contact address (where available).
* Check all backends which use fork/kill for the kill (-1,...) bug
  first found in the microtek2 backend.
* Add support for qt NLS (msg2qm) if possible without too much hassle.
* Add new backend primax http://primax.sourceforge.net/ (won't be ever a
  real sane backend)
* qcam: Check file handling in /tmp.
* Add a check in the frontends if the backend delivers more data than
  it announced by sane_get_parameters to avoid segfaults with bad 
  backends?
* Add installation procedure for translations of SANE backend's options.
* check memory leaks (checked with purify and mtrace (from glibc)):
* Test SANE on different os/platforms, fix possible compilation problems 
   Test methods: scanimage -d pnm:0 --filename=file.pnm -T
                 scanimage -d net:localhost:pnm:0 --filename=file.pnm -T
                 (start saned by inetd or saned -d before testing)
                 xscanimage / gimp with xscanimage plugin (where available)
   All the above with shared and static libraries.->backend-writing.txt
* Remove compiler warnings (>300 warnings even in disable-warnings mode,
  >700 with --enable-warnings)) ->backend-writing.txt
* Use #include "../include/sane/..." instead of #include <sane...>
  ->backend-writing.txt
* Use #include "../include/lalloca.h" instead of #include <lalloca.h>
  ->backend-writing.txt
* Update backend manpages (->backend-writing.txt).
* Add description of --enable-parport-directio.
* saned: Add documentation about the data connection.
* UMAX Astra 1220U  backend
  http://umax1220u-sane.sourceforge.net/
* There seems to be yet another race condition or other source for
  freezes in saned or net. Wheile scanning with pnm and auth, scanimage
  freezes. Last message from saned: "process_request: got request 2".
* Split configure option --enable-directio into --enable-scsi-directio and
  --enable-parport-directio to avoid confusion. Also add appropriate
  documentation.
* sanei_usb: Add sanei_usb_control_msg. 
* Add support for PV8630 USB chipset (as sanei interface):
* Fix libsocket problem (OS/2). libsocket must be linked when testing for
  libsyslog.
* Add bearpaw backend (Mustek BearPaw 1200 + maybe 2400)
  (will be supported by plustek backend)
* Must -ldl be added to sane-config.in?
* Use @LIBDIR@, @CONFIGDIR@ and the other @@ macros to refer to paths.
  These are updated when installing to a non-standard prefix.
* net: cancel doesn't work over the net at least with pnm and mustek.
* add Jochen Eisinger's net.c and sanei_wire.c fixes/additions.
* net.c: don't just ignore the byte-order for the image data (needed to
  support depths > 8 bits/channel)
* saned seems to have problems checking the peer name of incoming
  connections. This happens at least with glibc 2.2.4 if the
  name in saned.conf is not fully qualified. See sane-devel
  "saned.conf hostname format".
* If you mention sane-devel, also mention the website concerning
  subscription (http://www.mostang.com/sane/mail.html), because you can't
  write to sane-devel without subscribing.
  Or use your own mail address in the manual page.
* Check for logical errors and spelling
* Check .desc files:
* Check for formatting bugs in manual pages:
* Use #include "../include/assert.h" instead of #include <assert.h> to
  avoid problem with shared libraries on AIX.
* scanimage: Maybe add ADF extensions from Caskey Dickson (or add them to 
  scanadf if necessary).
* Add Mustek USB backend (1200UB, 1200CU, 1200CU Plus)
  http://www.meier-geinitz.de/sane/
  Henning Meier-Geinitz <henning@meier-geinitz.de>
* Add USB support for sane-find-scanner.
* move .desc files for backends that are not included in SANE to
  different directory (e.g. backends and external-backends)?
* create sanei_usb.* (maybe containing access for libusb and direct access
  for usb device files)? (sane-1.0.6)
* Add sane-usb manpage
* Check net/saned
   - sometimes saned+net freezes right after a scan (is this still
     occuring 2001-06-04?)
* add warning when prefix dir is not listed in /etc/ld.so.conf on 
  linux systems may be there is a general way to test this if the
  destination library directory is in the search path of the
  linker. [The correct fix is to use -R (on Solaris) and -rpath
  (on the rest?) to include the dynamic link path in the binaries
  / libraries. pere 2001-02-09 -- I believe this is partly fixed
  in tools/sane-config.in 2001-05-18]
* Add links to sane(7) in all maual pages
* Check AIX/gcc shared lib loading problem: When starting scanimage,
    only dll is loaded.
    Backend libraries can't be loaded:
    [dll] load: dlopen() failed (Symbol resolution failed for
       /tmp/sane-bin/lib/sane/libsane-umax.so.1 because:
       Symbol __eprintf (number 55) is not exported from dependent
       module scanimage.
    This happens in most libraries. The reason is assert() e.g. in
    sanei_scsci.c. As assert() is in libgcc.a it can't be linked at runtime.
* Don't export any other symbols than sane_* and sanei_*
* nec:
   - Remove references to sharp backend (grep for "JX").
   - Check for HAVE_SYS_SHM_H before including sys/shm.h and
     disable shared memory support if necessary.
* lines like "if (config_line[len - 1] == '\n')" can cause segfaults and
  should be removed (removing "\n" is already done in sanei_config_read).
  This ist just a fast grep. Check all backends!
* add additions/bug fixes to microtek2 from Karsten Festag
  <karsten.festag@t-online.de> (partially done)
* include snapscan updates http://sourceforge.net/projects/snapscan
* as6e: change :new status to :alpha, :beta, or :stable.
* Check Tru64 Unix compilation problems with u_int* types. They are already
  defined in sys/bitypes.h but this file isn't checked with AC_CHECK_TYPE.
  (-> include sys/bitypes.h in these cases).
* Fix HP-UX problems in isfdtype.c (and maybe others). sys/stat.h doesn't
  seem to define stuct stat (not a bug, make was used instead of gmake).
* Polaroid SprintScan 35 LE [should be included into microtek] 
* Maybe add script to deinstall existing sane versions
  - make uninstall
  - install sane-uninstall script. Advantage: uninstall possible
    without sourcecode (I think that's not necessary because you usually
    have the sourcecode of a newer version if you want to uninstall. hmg)
* Add sane manpage (this is work in progress: Henning Meier-Geinitz 
                    <henning@meier-geinitz.de>)
   - versioning system?
   - SANE API (maybe summary only?)
   - point to backends and other information?
* Add backend UMAX 1220P/2000P & HP 320C http://umax1220p.sourceforge.net
* install all documentation that's available
* Add a check for installed sane versions.
  - Print a warning when already a sane version is installed
  - If SANE is installed at a different location, ask user to
    remove old installation first
* epson: backend tries to detect usb scanners by default. This breaks with
  non-epson scanners like the LM9831 bases Mustek Bearpaw 1200. The epson
  backend freezes if such a scanner is plugged in. Try to make the test safe
  or don't test without user interaction.
* pnm: add more options for testing (e.g. arrays and read-only options)
* sanei_scsi.c: OS/2: struct param breaks compilation with --enable-warnings.
  (probably fixed by testing for os2.h in configure).
* Check all manpages for references to find-scanner (->sane-find-scanner).
* net.c doesn't compile on Irix because socklen_t isn't known
* Add new backends: bh http://www.martoneconsulting.com/sane-bh.html
* Add manpage for find-scanner.
* Should find-scanner be installed?
* net backend segfaults sometimes when connected to localhost. Enabling
  debug output sometimes prevents segfaults. Cause of the problem:
  Copying SANE_TYPE_STRINGs up to their maximum size in 
  SANE_Option_Descriptor (strings may be shorter then size).
* Compilation of most backends break with OS/2 and gcc because the
  option -ansi doesn't seem to like sigset_t ?
* Check for shm.h in configure
* Add a global PATH_MAX macro somewhere (config.h ?) if it's not defined
  by the system.
* sanei_scsi.c: Add patch from FreeBSD ports (sanei_scsi_find_devices)
  (after 1.0.4).
* update libtool versioning system
  - in /usr/local/lib/libsane.la "installed=no" is set, isn't 
    "installed=yes" the correct entry?
* plustek-share.h: remove //
* as6e: Check result of stat for errors to avoid false recognitions of the
  as6edriver.
* artec: O_SYNC is not Posix. Breaks compilation on FreeBSD and (maybe) OS/2.
* use strchr() instead of index() in mustek_pp to avoid problems when
  icluding strings.h or string.h.
* Add test for PTAL to acinclude.m4/configure.in
* build on Irix fails because of problems with the jpeg library. If this
  is removed in configure, build works. It complains about functions like
  (typename) functionname (). It doesn't like the brackets which result
  from expanding the macros EXTERN(x), METHODDEF(x), and GLOBAL(x) to
  (x). Defining something like EXTERN(x) x seems to work.  Same for dc210.c
  Something like --disable-jpeg for configure would be nice.
* addition to hp backend (support for SCL-based HP OfficeJets)
  http://hpoj.sourceforge.net
* Libtool: 
  - -version-info is used but with the current version number system 
    -release should be used. (We should not change the version syntax
     within an existing sane-standard, so we leave this)
  - look for AIX problems (overwriting shared libs with eachother
    because all libs are named libsane.so.1) (solved)
  - look for Irix/cc problems (program searches for libsane.so.2 instead
    of libsane.so.1). (Patch works for existing sane standard)
* getopt.c and umax.c seem to use gettext? Can cause crash if frontends
  are linked to libintl, too.
* libdl is used in dll backend but -ldl is not added to LDFLAGS?
* use strchr() instead of index() in sanei_auth, scanimage, saned
  to avoid problems when icluding strings.h or string.h.
* Remove frontends (at least xscanimage/xcam) from distribution. 
* build on AIX does only work for static libraries. The shared libraries
  seem to overwrite each other.
* add sanei_authorize (function for all backends)
* make authorization_callback work in net-backend and saned. Try to 
  avoid plain text passwords?
* Add as6e http://as6edriver.sourceforge.net/
* stiff.c: Tiff header not written correctly: "Jaeger, Gerhard"
  <gjaeger@sysgo.de> writes: When writing the TIFF header, you have to
  specify the TAG "BitsPerSample", which tells a reader how many bits each
  sample has. The current version only specifies one value (8 or 16). This
  is wrong, as we have to specify one value for each channel (i.e for a
  24bit RGB pic we must specify 8,8,8, see TIFF6.0 spec, [...]
* don't install sanei_* headers
* Add sane-pie (Pacific Image Electronics series of ScanAce SCSI scanners, and
  the Devcom 9636/9630 BlackWidow) http://www.munton.demon.co.uk/sane
* configure --without-x doesn't work (doesn't matter when frontends
  are removed from package)
* Create new package for frontends. 
* 0 is white for sane in lineart and halftone, however, 0 is black for
  the other modes. Possible reason: pnm data format. The SANE standard
  doesn't talk about this (added point to SANE standard)
* add ADF and TA entries to .desc files (not done, probably webpage gets 
  too wide)
* check DBG problems for non gcc compilers:
  - no backend name output
  - only global debug level
* dll: make it robust against it being listed in the configuration
  file (currently bad things will happen if dll attempts to load itself)
* scanimage: add information about backend:devicename in the man
  page and scanimage --help.
* scanimage: check if devicename starts with a / and print a warning
  message
* scanimage: if no devices are detected print a message
* use sanei_config_read() instead of fgets()
* use #include "sane/..." instead of #include <sane/...>
* Update LEVEL2 file. Ideas:
* xscanimage: Fix "Gtk-CRITICAL **: file gtkmain.c: line 534 ..." bug
  when no SANE devices found
+ PREVIEW: maybe there should be an option to limit the preview
  scan to the selected area? YES => this will also make it easier
  to avoid the scan area selection to get confused when the user
  resizes the preview area in a way that changes the aspect ratio;
  in essence we want to allow for the preview-image to be a subregion
  of the preview-window (done in xsane)
+ xcam: allow disabling of advanced options and tooltips
+ man page for xcam
+ scanimage: support depths > 8 bits/channel
+ upgrade to GTK 1.2 (but stay backwards compatible to 1.0 if possible)
+ saned: check_host() consider using strncasecmp()
+ GTK: changing the length unit causes dirty pixels in the unit-labels
  of the "Geometry Group"
+ preview: image data doesn't get preserved properly when changing
  scan area size (reproducable by changing Mustek Scan source to TA)
+ preview: when popping up the preview window, the current scan area is
  not visible
+ qcam: test b&w support (need volunteer!)
+ hp: convert to use pixel-unit commands only; HP 5P doesn't support
  decipoint commands
+ mustek: the MFS-06000SP with firmware v3.12 does not seem to need any
  line-distance correction at all!?!
+ scanimage/xscanimage: when a scanner is busy while probing for devices,
  the device is dropped silently from the list of available devices; this
  is confusing particularly when remote controlling a device; it should
  be possible to distinguish between a device that's busy and one that's
  absent
+ xscanimage: program crashes when preview window is popped down while
  preview is being acquired!
+ Mustek backend crashes when invoked via xscanimage through the network
  backend.  It does not crash if there are no saved device settings.
+ gtkglue: support vectors (requires a "graph" widget; see gimp/app/curves.c)
+ xscan: make scrollbar wider
+ xscan: at startup or after rebuilding the dialog, the notebook widget
  displays both the standard and advanced options simultaneously
+ xscan: pnm backend causes crash when hitting "Defaults" button
+ scan: add three pass scanning support
+ xscan: double-clicking selection should imply OK
+ xscan: enabling the gtk_rc_parse() code causes segfault when scanning in
  three-pass mode (pnm backend) => bug in gtkstyle.c (patch submitted)
+ qcam: implement "christmas light" filter
+ xscan/qcam: after scanning a preview, the original scan area seems to
  get lost somehow => bug in restoring the scan area settings
+ qcam: image always comes out black until the blacklevel has been modified;
  why is this? => send dummy black-level after qc_reset()
+ xscan: provide access option doc strings
+ xscan: in GIMP mode, RED/GREEN/BLUE frames are not handled properly yet.
+ preview: bit-depth is currently ignored (makes lineart etc fail)
+ sanei: allow saving/restoring options on a per-device and per-user basis
+ xcam: replace ugly top-left/bottom-right corner coordinates with something
	more useful => they're advanced options now
+ preview: modifying the scan area coordinates should update the selection
+ preview: should we allow saving the current preview image? => yes
+ xscan: make it possible to build with gtk alone (i.e., without gimp libs)
+ xscan: use same scan-logic as preview (select-based, if possible);
  should be able to share most of the code
+ replace params.first_frame with params.last_frame---i don't know how to
  use the former, the latter would be useful for xcam to implement support
  for individual R/G/B frames
+ saned: add multi-host capabilities (selection-phase ... how ??).
+ saned: add authorization
+ ensure frontend never link sanei_*() functions dynamically
+ always define unique names in backends and define weak-aliases for
  generic names where elf_alias is available---this should make it
  easy to add "pre-load" support to dll.c (either for faster loading or
  for systems that don't have dl*())
+ make install: don't overwrite existing configuration files
+ xcam: let user be able to type in a device string
+ mustek: make sane_close() hang around until sane_cancel() has finished
+ net: implement it: socket-based backend [Andy is working on this]
+ need a camera front end (to allow recording video & audio)
+ qcam: allow changing all parameters "on-the-fly" (while scanning)
+ qcam backend: implement sane_set_io_mode() and sane_get_select_fd()
+ make "scan" print current value of each option
+ make "scan" apply any options before printing help message
+ initialize backend debug level through environment variable (e.g.,
  SANE_DEBUG_LEVEL)
+ allow abbreviating string values and make them case-insensitive (as long
  as they're unique) => see sanei_constrain_value()
+ add support to "scan" for setting options to "automatic"
+ update documentation and convert to latex & html
+ add --width/--height support
+ update Mustek backend with new notion of inactive options
+ in verbose multibit mode print min/max graylevel value 
+ Mustek segfaults after ctrl-C => need -Bsymbolic to ensure mustek backend's
  references to sane_foo() get resolved within backend
+ test parsing of boolean options
+ --mode Gray causes segfault
+ change scan to use getopt_long
+ make Mustek backend work without having to first call get_devices()
+ implement meta backend
+ bring pnm backend up to speed
