sane-project-backends/TODO

TODO (2001-06-05)

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

backends
--------
  * Configuration problems:
    - add options "--exec-prefix=...." and "--prefix=..." compareable
      to gtk-config

    - 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 new backends (?)
    - primax http://primax.sourceforge.net/
    - hp4200 http://hp4200-backend.sourceforge.net/
    - v4l2 http://video.inodes.org/sane-v4l2/
    - Relisys Scorpio Super 3 SCSI II
      Mark Plowman <mplowman@wxs.nl>
    - Linux Handscanner Ioctl Interface scanner by Harald
      Bauer <bauer-h@web.de>
    - viceo (Visioneer OneTouch 8600)
      http://www.abaforum.es/martim/bird/otlinux.htm
    - Mustek 1200 UB backend
      ftp://ftp.mustek.com.tw/pub/driver/1200UB/Linux/
    - bearpaw (Mustek BearPaw 1200 + maybe 2400)
      Henning Meier-Geinitz <hmg@gmx.de>
    - 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>

  * Update backends
    - Combine all the Fujitsu backends into one single backend

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

  * Check net/saned
     - sometimes saned+net freezes right after a scan (is this still
       occuring 2001-06-04?)
     - don't just ignore the byte-order for the image data (needed to
       support depths > 8 bits/channel)
     - saned times out after 5 minutes (now 60 minutes). Check if the
       watchdog timer is really necessary (e.g. to avoid blocking scanners
       by one user). Maybe add an 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.

  * 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.
     - Check file handling in /tmp.

  * dc210 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() do 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 diver isn't
    found.

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

  * add a contact address for each backend (in backend.desc).

doc
---
  * Add sane-usb manpage

  * Documentation for sanei API
    - any ideas for this?
    - Options:
      - Doxygen, <URL:http://www.stack.nl/~dimitri/doxygen/>
      - ROBODoc, <URL:http://www.xs4all.nl/~rfsber/Robo/>

  * sane.tex: Define the return values for sane_init?  Define the
    consequences if sane_init do not return SANE_STATUS_GOOD.

  * Add links to sane(7) in all maual pages
 
frontends
---------
  * dll: Rewrite to use libtool ltdl library

  * 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?

  * scanimage: Maybe add ADF extensions from Caskey Dickson (or add them to 
    scanadf if necessary).

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

sanei
-----
  * create sanei_parport_* and remove all inb, outb,... from all backends
   (for sane-1.0.6)

  * create sanei_usb.* (maybe containing access for libusb and direct access
    for usb device files)? (sane-1.0.6)

misc
----
  * Remove compiler warnings (>300 warnings even in disable-warnings mode,
    >700 with --enable-warnings))

  * 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.

  * move .desc files for backends that are not included in SANE to
    different directory (e.g. backends and external-backends)?

  * Use #include "../include/sane/..." instead of #include <sane...>

  * Use #include "../include/lalloca.h" instead of #include <lalloca.h>

  * 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.

  * Add USB support for sane-find-scanner.

  * check memory leaks (checked with purify and mtrace (from glibc)):

  * Use #include "../include/assert.h" instead of #include <assert.h> to
    avoid problem with shared libraries on AIX.

  * Add installation procedure for translations of SANE backend's options.

******** done ********
* 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