***************************************************************************

  Unified Gutenprint/CUPS Backend for various Dye-Sublimation photo printers

  (c) 2007-2014 Solomon Peachy <pizza@shaftnet.org>

  The latest version can be found at
  
    http://git.shaftnet.org/cgit/selphy_print.git

  For a list of known bugs and development plans, see:

    http://bugs.shaftnet.org/index.php?project=4

 ***************************************************************************
 
  Supported Printers:

   Canon SELPHY ES series
   Canon SELPHY CP series (except CP520, CP820, and CP910)
   Kodak Professional 1400
   Kodak 605 Photo Printer
   Kodak 805 Photo Printer
   Kodak 6800 Photo Printer
   Kodak 6850 Photo Printer
   Shinko CHC-S2145 (aka "Sinfonia S2")
   Sony UP-DR150
   DNP DS40
   DNP DS80 

 Work-in-progress printers:

   Mitsubishi CP-D70DW, CP-D707DW and CP-K60DW
   Sony UP-DR200

 ***************************************************************************

  This intelligent backend is needed to utilize many common dye-sublimation
  photo printers under Linux, OSX, and other UNIX-like operating systems.

  Although these printers advertise themselves as standard USB Printer Class
  devices, they do not actually obey those specifications, and require 
  two-way communications in order to successfully print.

  If you do not have one of the printers listed above, this backend is
  not relevant for you and you can just ignore everything below.

  In order to properly utilize this backend, you must have an up-to-date
  version of Gutenprint (5.2.10) installed.

  Once Gutenprint and this backend are installed, if you are using up-to-date
  versions of CUPS (1.6.4 or newer) on Linux, then your system will 
  automatically select this backend if you plug in one of its supported 
  printers.  No further intervention on the user's part should be necessary.

  Unfortunately, if you are using an older version of CUPS or a non-Linux
  system (particularly OSX) then you will probably need to manually 
  configure the use of this backend, as the system may attempt to use the 
  default usb backend which does not work properly with these printers.

  To check which backend your printers are using, run the 'lpstat -s' command.
  Below is an example of its output:

    device for Canon_SELPHY_ES1: gutenprint52+usb://Canon/SELPHY%20ES1?serial=221CD10131&backend=canonselphy
    device for Canon_SELPHY_ES3: usb://Canon/Canon%20SELPHY%20ES3

  In this example, the SELPHY ES1 is using the correct gutenprint backend, but
  the ES3 is using the incorrect 'usb' backend. In order for the ES3 to 
  function properly, you need to configure it to use the correct backend.

  The most expedient way to accomplish this is to remove the printer via your
  system's printer configuration interface, then manually add a new one, taking
  care to select the correct backend ("gutenprint52+usb").  This backend name
  is present in the device URI for the printer, as demonstrated in the above
  example.  An alternative to the system printer configuration interface is to
  use your local system's CUPS web interface, if it is enabled. Step-by-step
  instructions for using any of these interfaces is beyond the scope of this
  document.

  Once the printer is properly configured, this backend will be automatically
  invoked as needed; the user will never invoke the backend directly.

 ***************************************************************************

  This backend also supports a "standalone" mode that performs various 
  utility functions for selected printers, such as querying status.
  The exact commands supported for each printer are documented below.

 ***************************************************************************
  Compilation:

     You will need libusbx to build this tool.

     Fedora/RedHat:
	yum install libusbx-devel
     Debian/Ubuntu
	apt-get install libusbx-dev

   And all you need to do after that is type 'make'

 ***************************************************************************
  CUPS backend usage:

   DEVICE_URI=someuri \
       gutenprint52+usb job-id user title num-copies options [ filename ]

 ***************************************************************************
  Standalone usage:

    This backend is set up as a multi-call executable; that is to say
    behaivor changes based on the name used to invoke the executable.
    When compiled, a set of symlinks are created, corresponding to each
    of the internal backends.  Alternatively you may set the BACKEND
    environment variable to force a specific backend to be used:

        BACKEND=backend \
    	  gutenprint52+usb [ args ]

      (OR)
 
	backend [ args ]

     That said, all internal backends support these invocation options

  	backend filename
	backend - < filename
	somecommand | backend -
        backend [ backend-specific-argument ]

      The 'filename' here refers to the raw spool data generated by
      Gutenprint (eg via its gimp plugin) or the Windows print-to-file 
      output.

      You can enable full data dumps by defining the DYESUB_DEBUG 
      environment variable.

      If there is more than one device present that the backend handles,
      the backend will choose the first supported device it finds. If you
      wish to specify the specific device when operating in standalone 
      mode, set the 'DEVICE' environment variable to the target device's
      serial number. For example:

  	  DEVICE=N782 backend filename

      All backends support an additional operational mode, to test out
      unknown models. To use this mode, specify the VID, PID and its 
      type as environment variables. For example:

 	  EXTRA_VID=04a9 EXTRA_PID=3ab1 EXTRA_TYPE=3 backend filename

	EXTRA_VID is the USB VID, in hex
	EXTRA_PID is the USB PID, in hex
	EXTRA_TYPE is:	4 for SELPHY CP520/820/910 (or other CP-series model)
			(See P_ANY enum in backend_common.h for more types)

      If you have a model the spooler doesn't recognize but it works with
      a VID/PID/TYPE specification, please let me know via e-mail.

      Finally, some backends may support additional arguments; see below:

 *************************************************************************** 
  BACKEND=canonselphy

   Verified supported printers:
  
     ES1, ES2, ES3, ES30, ES40, CP-10, CP-100, CP-200, CP-300, CP-330, 
     CP400, CP500, CP510, CP710, CP720, CP730, CP740, CP750, CP760, CP770, 
     CP780, CP790, CP800, CP900

   Unverified/untested, but should work:

     ES20, CP-220, CP530, CP600, CP810

   NOT currently supported by libusb backend:  (USB PIDs unknown) 
	
     CP520, CP820, CP910

   This backend does not support additional commands

 *************************************************************************** 
  BACKEND=kodak1400

   Verified supported printers:

     Kodak 1400
     Kodak 805

   This backend supports additional commands:

      kodak1400 [command [arg] ]

   Valid commands:

     -stc filename      Set tone curve [1]

  Notes:

    [1]  Format of curvedata file:

    	 256 entries each of Yellow, Magenta, Cyan mappings:
	 Values are unsigned 16-bit big endian, between 0 and ???
	 (unsure as to the bit usage)

 *************************************************************************** 
  BACKEND=kodak6800

   Verified supported printers:

     Kodak 6800
     Kodak 6850

   This backend supports additional commands:

      kodak6800 [command [arg] ]

   Valid commands:

     -qtc filename      Query tone curve [1]
     -stc filename      Set tone curve   [1]

  Notes:

    [1]  Format of curvedata file:

    	 256 entries each of Yellow, Magenta, Cyan mappings:
	 Values are unsigned 16-bit big endian, between 0 and 16383
	 (ie 14-bit)

 *************************************************************************** 
  BACKEND=kodak605

   Verified supported printers:

     Kodak 605

   Valid commands:

     -qs                 Query printer status (Not fully decoded yet)
     -qm		 Query supported media (Not fully decoded yet)
     -stc filename       Set tone curve [1]

  Notes:

    [1]  Format of curvedata file:

    	 256 entries each of Yellow, Magenta, Cyan mappings:
	 Values are unsigned 16-bit big endian, between 0 and ???
	 (unsure as to the bit usage)

 *************************************************************************** 
  BACKEND=shinkos2145

   Verified supported printers:

     Shinko/Sinfonia CHC-S2145 (aka "S2")

   Development was sponsored by:

        LiveLink Technology [ www.livelinktechnology.net ]

   In order to use this backend, you will need to ensure the printer is
   configured to use the 'DRV' (as opposed to 'DLL') operating mode.  See 
   the printer documentation for details on how to set this.

   This backend supports additional commands:

      shinkos2145 [command [arg] ]

   Valid commands:

     -qs                Query printer status
     -qm		Query media information
     -qf		Query firmware version
     -qe		Query Error log
     -qu		Query User String
     -qtu filename	Query User tone curve (stored in flash)  [2]
     -qtc filename	Query Current tone curve (stored in RAM) [2]
     -su  somestring    Set User String to 'somestring'
     -stu filename      Set User tone curve (stored in flash)    [2]
     -stc filename      Set Current tone curve (stored in RAM)   [2]
     -pc  id            Cancel print job 'id'                    [1]
     -fl  		Flash printer LEDs for five seconds.
     -ru		Reset User tone curve to default         [3]
     -rp		Reset printer to factory defaults
     -b1		Enable printer control panel buttons
     -b0		Disable printer control panel buttons
     -f 		Enable fast return                       [4]

  Notes:

    [1]  Job ID is the Internal Job ID (reported via status)
    	   This cancels a multi-copy print job.
	   To see which jobs are active/pending, see the output of the
	   '-qs' command, specifically the 'Bank' output.

    [2]  Format of curvedata file:

	 256 entries each of Yellow, Magenta, Cyan mappings:
	 Values are unsigned 16-bit big endian, between 0 and 2047 
	 (ie only 11 bits used)

    [3]  Default printer tone curve is a linear 'val << 3'

    [4]  This terminates the backend as soon as the printer has acknowledged
         the print job, without waiting for the print job to complete.
         This can also be enabled by setting the 'FAST_RETURN' environment
         variable.

 *************************************************************************** 
  BACKEND=sonyupdr150

   Verified supported printers:

    Sony UP-DR150

   Theoretically supportable printers: (Unknown USB PID)

    Sony UP-DR200

   This backend does not support additional commands

 *************************************************************************** 
  BACKEND=mitsu70x

   NOTE:  This backend is not yet present in mainline Gutenprint

   Theoretically supported printers:  (Untested)

    Mitsubishi CP-D70DW
    Mitsubishi CP-D707DW

   Theoretically supportable printers: (Unknown USB PID)

    Mitsubishi CP-K60DW-S

   This backend supports additional commands:

      mitsu70x [command [arg] ]

   Valid commands:

     -qs                 Query printer status (Not fully decoded yet)

 *************************************************************************** 
  BACKEND=dnpds40

   Verified supported printers:

    DNP DS40
    DNP DS80

   Development was sponsored by:

        Marco Di Antonio and ilgruppodigitale.com

   This backend supports additional commands:

      dnpds40 [command [arg] ]

   Valid commands:

     -qs                 Query printer status
     -qi		 Query printer info (resolution, etc)
     -qc		 Query printer counters
     -cca		 Clear 'A' Counter
     -ccb		 Clear 'B' Counter
     -ccm		 Clear 'M' Counter
     -scp num		 Set 'P' Counter to 'num'