Import iscan 2.30.4-2

7 files changed, 1544 insertions, 0 deletions

diff --git a/include/sane/sanei.h b/include/sane/sanei.h
new file mode 100644
index 0000000..ece1beb
--- /dev/null
+++ b/include/sane/sanei.h
@@ -0,0 +1,160 @@
+/* sane - Scanner Access Now Easy.
+   Copyright (C) 1996 David Mosberger-Tang and Andreas Beck
+   Copyright (C) 2002, 2003 Henning Meier-Geinitz
+
+   This file is part of the SANE package.
+
+   SANE is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   SANE is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with sane; see the file COPYING.  If not, write to the Free
+   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+   As a special exception, the authors of SANE give permission for
+   additional uses of the libraries contained in this release of SANE.
+   
+   The exception is that, if you link a SANE library with other files
+   to produce an executable, this does not by itself cause the
+   resulting executable to be covered by the GNU General Public
+   License.  Your use of that executable is in no way restricted on
+   account of linking the SANE library code into it.
+   
+   This exception does not, however, invalidate any other reasons why
+   the executable file might be covered by the GNU General Public
+   License.
+   
+   If you submit changes to SANE to the maintainers to be included in
+   a subsequent release, you agree by submitting the changes that
+   those changes may be distributed with this exception intact.
+   
+   If you write modifications of your own for SANE, it is your choice
+   whether to permit this exception to apply to your modifications.
+   If you do not wish that, delete this exception notice. 
+*/
+
+/** @file sanei.h
+ * Convenience macros and function declarations for backends
+ * @sa sanei_backend.h sanei_thread.h
+ */
+
+/* Doxygen documentation */
+
+/** @mainpage SANEI (SANE internal routines) documentation
+ *
+ * @image html sane-logo2.jpg
+ * @section intro Introduction
+ *
+ * The header files in the include/sane/ directory named sanei_*.h provide
+ * function declarations and macros that can be used by every SANE backend.
+ * Their implementations can be found in the sanei/ directory. The code aims
+ * to be platform-independent to avoid lots of \#ifdef code in the backends.
+ * Please use the SANEI functions wherever possible.
+ *
+ * This documentation was created by the use of doxygen, the 
+ * doc/doxygen-sanei.conf configuration file and documentation in the sanei_*.h
+ * files.
+ *
+ * This documentation is far from complete. Any help is appreciated.
+ *
+ * @section additional Additional documentation
+ * - The SANE standard can be found at <a 
+ *   href="http://www.sane-project.org/html/">the SANE webserver</a>,
+ *   though the PostScript version produced from the source may be more recent.
+ * - Information on how to write a backend: <a
+ *   href="../backend-writing.txt">backend-writing.txt</a>.
+ * - General SANE documentation is on <a
+ *   href="http://www.sane-project.org/docs.html">the SANE documentation
+ *   page</a>.
+ * 
+ * @section contact Contact 
+ *
+ * The common way to contact the developers of SANE is the sane-devel
+ * mailing list. See the <a
+ * href="http://www.sane-project.org/mailing-lists.html">mailing list webpage</a>
+ * for details. That's the place to ask questions, report bugs, or announce
+ * a new backend.
+ * 
+ */
+
+#ifndef sanei_h
+#define sanei_h
+
+#include <sane/sane.h>
+
+/** @name Public macros and functions
+ * @{
+ */
+/** @def STRINGIFY(x)
+ * Turn parameter into string.
+ */
+/** @def PASTE(x,y)
+ * Concatenate parameters.
+ *
+ */
+/** @def NELEMS(a)
+ * Return number of elements of an array.
+ *
+ */
+
+/** @fn extern SANE_Status sanei_check_value (const SANE_Option_Descriptor * opt, void * value);
+ * Check the constraints of a SANE option.
+ *
+ * @param opt   option to check
+ * @param value value of the option
+ *
+ * @return 
+ * - SANE_STATUS_GOOD     - on success
+ * - SANE_STATUS_INVAL    - if the value doesn't fit inside the constraint
+ *   or any other error occured
+ * @sa sanei_constrain_value()
+ */
+
+/** @fn extern SANE_Status sanei_constrain_value (const SANE_Option_Descriptor * opt, void * value, SANE_Word * info);
+ * Check the constraints of a SANE option and adjust its value if necessary.
+ *
+ * Depending on the type of the option and constraint, value is modified
+ * to fit inside constraint.
+ *
+ * @param opt   option to check
+ * @param value value of the option
+ * @param info  info is set to SANE_INFO_INEXACT if value was changed
+ *
+ * @return 
+ * - SANE_STATUS_GOOD     - on success
+ * - SANE_STATUS_INVAL    - if the function wasn't able to fit value into the
+ *   constraint or any other error occured
+ * @sa sanei_check_value()
+ */
+
+/* @} */
+
+/* A few convenience macros:  */
+/** @hideinitializer */
+#define NELEMS(a)	((int)(sizeof (a) / sizeof (a[0])))
+
+/** @hideinitializer */
+#define STRINGIFY1(x)	#x
+/** @hideinitializer */
+#define STRINGIFY(x)	STRINGIFY1(x)
+
+/** @hideinitializer */
+#define PASTE1(x,y)	x##y
+/** @hideinitializer */
+#define PASTE(x,y)	PASTE1(x,y)
+
+extern SANE_Status sanei_check_value (const SANE_Option_Descriptor * opt,
+				      void * value);
+
+extern SANE_Status sanei_constrain_value (const SANE_Option_Descriptor * opt,
+					  void * value, SANE_Word * info);
+
+
+#endif /* sanei_h */
diff --git a/include/sane/sanei_config.h b/include/sane/sanei_config.h
new file mode 100644
index 0000000..cf877cf
--- /dev/null
+++ b/include/sane/sanei_config.h
@@ -0,0 +1,175 @@
+/* sane - Scanner Access Now Easy.
+   Copyright (C) 1997 Jeffrey S. Freedman
+   This file is part of the SANE package.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+   MA 02111-1307, USA.
+
+   As a special exception, the authors of SANE give permission for
+   additional uses of the libraries contained in this release of SANE.
+
+   The exception is that, if you link a SANE library with other files
+   to produce an executable, this does not by itself cause the
+   resulting executable to be covered by the GNU General Public
+   License.  Your use of that executable is in no way restricted on
+   account of linking the SANE library code into it.
+
+   This exception does not, however, invalidate any other reasons why
+   the executable file might be covered by the GNU General Public
+   License.
+
+   If you submit changes to SANE to the maintainers to be included in
+   a subsequent release, you agree by submitting the changes that
+   those changes may be distributed with this exception intact.
+
+   If you write modifications of your own for SANE, it is your choice
+   whether to permit this exception to apply to your modifications.
+   If you do not wish that, delete this exception notice.
+*/
+
+/** @file sanei_config.h
+ * Generic configuration support.
+ *
+ * Use the functions of this header file if you want to read and analyze
+ * configuration files.
+*/
+
+#ifndef sanei_config_h
+#define sanei_config_h 1
+
+#include <stdio.h>
+#include <sane/sane.h>
+
+/** Search configuration file \a name along directory list and return file
+ * pointer if such a file exists.  
+ *
+ * The following directory list is used:
+ *	1st: SANE_CONFIG_DIR environment variable.
+ *	2nd: PATH_SANE_CONFIG_DIR set during configuration.
+ *	3rd: Current directory.
+ * @param name filename with extension but without path (such as "mustek.conf")
+ *
+ * @return file pointer, or NULL if not found
+ *
+ */
+extern FILE *sanei_config_open (const char *name);
+
+/** Read a line from configuration file.
+ *
+ * Strips all unwanted chars.  Use this instead of fgets() to remove
+ * line ending chars on all known platforms.
+ *
+ * @param str points to the buffer for the line
+ * @param n size of the buffer
+ * @param stream file pointer
+ *
+ * @return \a str on success and NULL on error
+*/
+extern char *sanei_config_read (char *str, int n, FILE *stream);
+
+/** Remove all whitespace from the beginning of a string.
+ *
+ * @param str string
+ *
+ * @return string without leading whitespace
+ *
+ */
+extern const char *sanei_config_skip_whitespace (const char *str);
+
+
+/** Scan a string constant from a line of text and return a malloced copy
+ * of it.
+ *
+ * It's the responsibility of the caller to free the returned string constant
+ * at an appropriate time.  Whitespace in front of the string constant is
+ * ignored.  Whitespace can be included in the string constant by enclosing it
+ * in double-quotes.
+ *
+ * @param str line of text to scan for a string constant
+ * @param string_const copy of the string constant
+ *
+ * @return a pointer to the position in str where the scan stopped
+ */
+extern const char *sanei_config_get_string (const char *str,
+					    char **string_const);
+
+/** Expand device name patterns into a list of devices.
+ *
+ * Apart from a normal device name (such as /dev/sdb), this function currently
+ * supports SCSI device specifications of the form:
+ *
+ *	scsi VENDOR MODEL TYPE BUS CHANNEL ID LUN
+ *
+ * Where VENDOR is the desired vendor name.  MODEL is the desired model name.
+ * TYPE is the desired device type.  All of these can be set to * to match
+ * anything.  To include whitespace in these strings, enclose them in
+ * double-quotes (").  BUS, ID, and LUN are the desired SCSI bus, id, and
+ * logical-unit numbers.  These can be set to * or simply omitted to match
+ * anything.
+ *
+ * @param name device name pattern
+ * @param attach attach function
+ */
+extern void sanei_config_attach_matching_devices (const char *name,
+						  SANE_Status (*attach)
+						  (const char *dev));
+
+/** this structure holds the description of configuration options. There is
+ * a list for options and another for their values. 
+ * These lists are used when the configuration file is
+ * parsed. Read values are stored in Option_Value. Helpers functions are 
+ * provided to access values easily */
+typedef struct
+{
+  /** number of options */
+  SANE_Int count;
+
+  /** NULL terminated list of configuration option */
+  SANE_Option_Descriptor **descriptors;
+
+  /** values for the configuration options */
+  void **values;
+
+} SANEI_Config;
+
+/** Parse configuration file, reading configuration options and trying to
+ * attach devices found in file.
+ *
+ * The option are gathered in a single configuration structure. Each time
+ * a line holds a value that is not an option, the attach function is called
+ * with the name found and the configuration structure with it's current values.
+ *
+ * @param config_file name of the configuration file to read
+ * @param config configuration structure to be filled during configuration
+ *  	  parsing and passed to the attach callback function
+ * @param config_attach attach with config callback function
+ *
+ * @return SANE_STATUS_GOOD if no errors
+ *         SANE_STATUS_ACCESS_DENIED if configuration file can't be opened
+ */
+extern SANE_Status sanei_configure_attach (
+  const char *config_file,
+  SANEI_Config *config,
+  SANE_Status (*config_attach)(SANEI_Config *config, const char *devname)
+);
+
+/** Return the list of config directories, extracted from the SANE_CONFIG_DIR
+ * environment variable and the default paths.
+ * @return a string containing the configuration paths, separated by the
+ *         operating system's path separator
+ */
+extern const char *sanei_config_get_paths (void);
+
+#endif	/* sanei_config_h */
diff --git a/include/sane/sanei_debug.h b/include/sane/sanei_debug.h
new file mode 100644
index 0000000..557f8a7
--- /dev/null
+++ b/include/sane/sanei_debug.h
@@ -0,0 +1,153 @@
+/** @file sanei_debug.h
+ * Support for printing debug messages.
+ *
+ * Use the functions of this header file to print debug or warning messages.
+ */
+
+#ifndef _SANEI_DEBUG_H
+#define _SANEI_DEBUG_H
+
+#include <sane/sanei.h>
+
+/** @name Public macros
+ * These macros can be used in backends and other SANE-related
+ * code.
+ *
+ * Before including sanei_debug.h, the following macros must be set:
+ *
+ * - BACKEND_NAME - The name of your backend without double-quotes (must be set in any case)
+ * - STUBS - If this is defined, no macros will be included. Used in 
+ *   backends consisting of more than one .c file.
+ * - DEBUG_DECLARE_ONLY - Generates prototypes instead of functions. Used in 
+ *   backends consisting of more than one .c file.
+ * - DEBUG_NOT_STATIC - Doesn't generate static functions. Used in header files if
+ *   they are include in more than one .c file.
+ *
+ * @{ 
+ */
+
+/** @def DBG_INIT()
+ * Initialize sanei_debug.
+ *
+ * Call this function before you use any DBG function.
+ */
+
+/** @def DBG(level, fmt, ...)
+ * Print a message at debug level `level' or higher using a printf-like
+ * function. Example: DBG(1, "sane_open: opening fd \%d\\n", fd).
+ *
+ * @param level debug level
+ * @param fmt format (see man 3 printf for details)
+ * @param ... additional arguments
+ */
+
+/** @def IF_DBG(x)
+ * Compile code only if debugging is enabled.
+ *
+ * Expands to x if debug support is enabled at compile-time. If NDEBUG is 
+ * defined at compile-time this macro expands to nothing.
+ *
+ * @param x code to expand when debugging is enabled
+ */
+
+/**
+ * @def DBG_LEVEL
+ * Current debug level. 
+ *
+ * You can only read this "variable".
+ */
+
+/** @def ENTRY(name)
+ * Expands to sane_BACKEND_NAME_name.
+ *
+ * Example: ENTRY(init) in mustek.c will expand to sane_mustek_init.
+ */
+
+/* @} */
+
+
+                                  /** @hideinitializer*/
+#define ENTRY(name)     PASTE(PASTE(PASTE(sane_,BACKEND_NAME),_),name)
+
+#ifdef NDEBUG
+  
+extern void sanei_debug_ndebug (int level, const char *msg, ...);
+	
+# define DBG_LEVEL	(0)
+# define DBG_INIT()
+# define DBG		sanei_debug_ndebug
+# define IF_DBG(x)
+	
+#else /* !NDEBUG */
+	
+                                  /** @hideinitializer*/
+# define DBG_LEVEL      PASTE(sanei_debug_,BACKEND_NAME)
+
+# if defined(BACKEND_NAME) && !defined(STUBS)
+#  ifdef DEBUG_DECLARE_ONLY
+extern int DBG_LEVEL;
+#  else /* !DEBUG_DECLARE_ONLY */
+int DBG_LEVEL = 0;
+#  endif /* DEBUG_DECLARE_ONLY */
+# endif /* BACKEND_NAME && !STUBS */
+
+                                  /** @hideinitializer*/
+# define DBG_INIT()                                     \
+  sanei_init_debug (STRINGIFY(BACKEND_NAME), &DBG_LEVEL)
+
+                                  /** @hideinitializer*/
+# define DBG_LOCAL	PASTE(DBG_LEVEL,_call)
+
+
+# ifndef STUBS
+
+#  ifdef DEBUG_DECLARE_ONLY
+
+extern void DBG_LOCAL (int level, const char *msg, ...) 
+#ifdef __GNUC__
+__attribute__ ((format (printf, 2, 3)))
+#endif
+;
+
+#  else /* !DEBUG_DECLARE_ONLY */
+
+#   include <stdarg.h>
+	
+extern void sanei_debug_msg 
+  (int level, int max_level, const char *be, const char *fmt, va_list ap);
+
+#ifdef __GNUC__
+#   ifndef DEBUG_NOT_STATIC
+static
+#   endif /* !DEBUG_NOT_STATIC */
+void DBG_LOCAL (int level, const char *msg, ...) __attribute__ ((format (printf, 2, 3)));
+#endif /* __GNUC__ */
+
+#   ifndef DEBUG_NOT_STATIC
+static
+#   endif /* !DEBUG_NOT_STATIC */
+void
+DBG_LOCAL (int level, const char *msg, ...)
+{
+  va_list ap;
+
+  va_start (ap, msg);
+  sanei_debug_msg (level, DBG_LEVEL, STRINGIFY(BACKEND_NAME), msg, ap);
+  va_end (ap);
+}
+
+#  endif /* DEBUG_DECLARE_ONLY */
+
+# endif /* !STUBS */
+
+                                  /** @hideinitializer*/
+# define DBG            DBG_LOCAL
+
+extern void sanei_init_debug (const char * backend, int * debug_level_var);
+  
+                                  /** @hideinitializer*/
+# define IF_DBG(x)      x
+
+#endif /* NDEBUG */
+
+#endif /* _SANEI_DEBUG_H */
diff --git a/include/sane/sanei_magic.h b/include/sane/sanei_magic.h
new file mode 100644
index 0000000..9e87e00
--- /dev/null
+++ b/include/sane/sanei_magic.h
@@ -0,0 +1,154 @@
+/* sane - Scanner Access Now Easy.
+ 
+   Copyright (C) 2009 m. allan noah
+
+   This file is part of the SANE package.
+
+   SANE is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   SANE is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with sane; see the file COPYING.  If not, write to the Free
+   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+   As a special exception, the authors of SANE give permission for
+   additional uses of the libraries contained in this release of SANE.
+
+   The exception is that, if you link a SANE library with other files
+   to produce an executable, this does not by itself cause the
+   resulting executable to be covered by the GNU General Public
+   License.  Your use of that executable is in no way restricted on
+   account of linking the SANE library code into it.
+
+   This exception does not, however, invalidate any other reasons why
+   the executable file might be covered by the GNU General Public
+   License.
+
+   If you submit changes to SANE to the maintainers to be included in
+   a subsequent release, you agree by submitting the changes that
+   those changes may be distributed with this exception intact.
+
+   If you write modifications of your own for SANE, it is your choice
+   whether to permit this exception to apply to your modifications.
+   If you do not wish that, delete this exception notice.
+*/
+
+/** @file sanei_magic.h
+ * This file provides an interface to simple image post-processing functions
+ *
+ * Currently, three operations are provided:
+ * - Deskew (correct rotated scans, by detecting media edges)
+ * - Autocrop (reduce image size to minimum rectangle containing media)
+ * - Despeckle (replace dots of significantly different color with background)
+ *
+ * Note that these functions are simplistic, and are expected to change.
+ * Patches and suggestions are welcome.
+ */
+
+#ifndef SANEI_MAGIC_H
+#define SANEI_MAGIC_H
+
+/** Initialize sanei_magic.
+ *
+ * Call this before any other sanei_magic function.
+ */
+extern void sanei_magic_init( void );
+
+/** Update the image buffer, replacing dots with surrounding background color
+ *
+ * @param params describes image
+ * @param buffer contains image data
+ * @param diam maximum dot diameter to remove
+ *
+ * @return
+ * - SANE_STATUS_GOOD - success
+ * - SANE_STATUS_INVAL - invalid image parameters
+ */
+extern SANE_Status
+sanei_magic_despeck (SANE_Parameters * params, SANE_Byte * buffer,
+  SANE_Int diam);
+
+/** Find the skew of the media inside the image, via edge detection.
+ *
+ * @param params describes image
+ * @param buffer contains image data
+ * @param dpiX horizontal resolution
+ * @param dpiY vertical resolution
+ * @param[out] centerX horizontal coordinate of center of rotation
+ * @param[out] centerY vertical coordinate of center of rotation
+ * @param[out] finSlope slope of rotation
+ *
+ * @return
+ * - SANE_STATUS_GOOD - success
+ * - SANE_STATUS_NO_MEM - not enough memory
+ * - SANE_STATUS_INVAL - invalid image parameters
+ * - SANE_STATUS_UNSUPPORTED - slope angle too shallow to detect
+ */
+extern SANE_Status
+sanei_magic_findSkew(const SANE_Parameters * params, const SANE_Byte * buffer,
+  int dpiX, int dpiY, int * centerX, int * centerY, double * finSlope);
+
+/** Correct the skew of the media inside the image, via simple rotation
+ *
+ * @param params describes image
+ * @param buffer contains image data
+ * @param centerX horizontal coordinate of center of rotation
+ * @param centerY vertical coordinate of center of rotation
+ * @param slope slope of rotation
+ * @param bg_color the replacement color for edges exposed by rotation
+ *
+ * @return
+ * - SANE_STATUS_GOOD - success
+ * - SANE_STATUS_NO_MEM - not enough memory
+ * - SANE_STATUS_INVAL - invalid image parameters
+ */
+extern SANE_Status
+sanei_magic_rotate (SANE_Parameters * params, SANE_Byte * buffer,
+  int centerX, int centerY, double slope, int bg_color);
+
+/** Find the edges of the media inside the image, parallel to image edges
+ *
+ * @param params describes image
+ * @param buffer contains image data
+ * @param dpiX horizontal resolution
+ * @param dpiY vertical resolution
+ * @param[out] top vertical offset to upper edge of media
+ * @param[out] bot vertical offset to lower edge of media
+ * @param[out] left horizontal offset to left edge of media
+ * @param[out] right horizontal offset to right edge of media
+ *
+ * @return
+ * - SANE_STATUS_GOOD - success
+ * - SANE_STATUS_NO_MEM - not enough memory
+ * - SANE_STATUS_UNSUPPORTED - edges could not be detected
+ */
+extern SANE_Status
+sanei_magic_findEdges(const SANE_Parameters * params, const SANE_Byte * buffer,
+  int dpiX, int dpiY, int * top, int * bot, int * left, int * right);
+
+/** Crop the image, parallel to image edges
+ *
+ * @param params describes image
+ * @param buffer contains image data
+ * @param top vertical offset to upper edge of crop
+ * @param bot vertical offset to lower edge of crop
+ * @param left horizontal offset to left edge of crop 
+ * @param right horizontal offset to right edge of crop
+ *
+ * @return
+ * - SANE_STATUS_GOOD - success
+ * - SANE_STATUS_NO_MEM - not enough memory
+ * - SANE_STATUS_INVAL - invalid image parameters
+ */
+extern SANE_Status
+sanei_magic_crop(SANE_Parameters * params, SANE_Byte * buffer,
+  int top, int bot, int left, int right);
+
+#endif /* SANEI_MAGIC_H */
diff --git a/include/sane/sanei_pio.h b/include/sane/sanei_pio.h
new file mode 100644
index 0000000..61ac414
--- /dev/null
+++ b/include/sane/sanei_pio.h
@@ -0,0 +1,55 @@
+/* sane - Scanner Access Now Easy.
+   Copyright (C) 1998 Christian Bucher
+   Copyright (C) 1998 Kling & Hautzinger GmbH
+   This file is part of the SANE package.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+   MA 02111-1307, USA.
+
+   As a special exception, the authors of SANE give permission for
+   additional uses of the libraries contained in this release of SANE.
+
+   The exception is that, if you link a SANE library with other files
+   to produce an executable, this does not by itself cause the
+   resulting executable to be covered by the GNU General Public
+   License.  Your use of that executable is in no way restricted on
+   account of linking the SANE library code into it.
+
+   This exception does not, however, invalidate any other reasons why
+   the executable file might be covered by the GNU General Public
+   License.
+
+   If you submit changes to SANE to the maintainers to be included in
+   a subsequent release, you agree by submitting the changes that
+   those changes may be distributed with this exception intact.
+
+   If you write modifications of your own for SANE, it is your choice
+   whether to permit this exception to apply to your modifications.
+   If you do not wish that, delete this exception notice.  */
+
+#ifndef sanei_pio_h
+#define sanei_pio_h
+
+#include <sys/types.h>
+
+#include <sane/sane.h>
+
+extern SANE_Status	sanei_pio_open  (const char * dev, int * fd);
+extern void		sanei_pio_close (int fd);
+extern int		sanei_pio_read  (int fd, u_char * buf, int n);
+extern int		sanei_pio_write (int fd, const u_char * buf, int n);
+
+#endif /* sanei_pio_h */
+
diff --git a/include/sane/sanei_scsi.h b/include/sane/sanei_scsi.h
new file mode 100644
index 0000000..21c4561
--- /dev/null
+++ b/include/sane/sanei_scsi.h
@@ -0,0 +1,332 @@
+/* sane - Scanner Access Now Easy.
+   Copyright (C) 1996, 1997 David Mosberger-Tang
+   This file is part of the SANE package.
+
+   SANE is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   SANE is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with sane; see the file COPYING.  If not, write to the Free
+   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+   As a special exception, the authors of SANE give permission for
+   additional uses of the libraries contained in this release of SANE.
+
+   The exception is that, if you link a SANE library with other files
+   to produce an executable, this does not by itself cause the
+   resulting executable to be covered by the GNU General Public
+   License.  Your use of that executable is in no way restricted on
+   account of linking the SANE library code into it.
+
+   This exception does not, however, invalidate any other reasons why
+   the executable file might be covered by the GNU General Public
+   License.
+
+   If you submit changes to SANE to the maintainers to be included in
+   a subsequent release, you agree by submitting the changes that
+   those changes may be distributed with this exception intact.
+
+   If you write modifications of your own for SANE, it is your choice
+   whether to permit this exception to apply to your modifications.
+   If you do not wish that, delete this exception notice.
+*/
+
+/** @file sanei_scsi.h
+ *  Generic interface to SCSI drivers.  
+ *  @sa sanei_usb.h, sanei_ab306.h,sanei_lm983x.h, sanei_pa4s2.h, sanei_pio.h,
+ *  and man sane-scsi(5) for user-oriented documentation
+ */
+
+#ifndef sanei_scsi_h
+#define sanei_scsi_h
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <sys/types.h>
+
+#include <sane/sane.h>
+
+/** Sense handler
+ *
+ * The sense handler can be implemented in backends. It's for deciding
+ * which sense codes should be considered an error and which shouldn't.
+ *
+ * @param fd file descriptor
+ * @param sense_buffer pointer to buffer containing sense codes
+ * @param arg pointer to data buffer
+ *
+ * @return
+ * - SANE_STATUS_GOOD - on success (sense isn't regarded as error)
+ * - any other status if sense code is regarded as error
+ */
+typedef SANE_Status (*SANEI_SCSI_Sense_Handler) (int fd,
+						 u_char *sense_buffer,
+						 void *arg);
+/** Maximum size of a SCSI request
+ */
+extern int sanei_scsi_max_request_size;
+
+/** Find SCSI devices.
+ *
+ * Find each SCSI device that matches the pattern specified by the
+ * arguments.  String arguments can be "omitted" by passing NULL,
+ * integer arguments can be "omitted" by passing -1.  
+ * 
+ *   Example: vendor="HP" model=NULL, type=NULL, bus=3, id=-1, lun=-1 would
+ *	    attach all HP devices on SCSI bus 3.
+ *
+ * @param vendor
+ * @param model
+ * @param type
+ * @param bus
+ * @param channel
+ * @param id
+ * @param lun
+ * @param attach callback invoked once for each device, dev is the real devicename (passed to attach callback)
+ *
+ */
+extern void sanei_scsi_find_devices (const char *vendor, const char *model,
+				     const char *type,
+				     int bus, int channel, int id, int lun,
+				     SANE_Status (*attach) (const char *dev));
+
+
+/** Open a SCSI device
+ *
+ * Opens a SCSI device by its device filename and returns a file descriptor.
+ * If it's necessary to adjust the SCSI buffer size, use 
+ * sanei_scsi_open_extended().
+ *
+ * @param device_name name of the devicefile, e.g. "/dev/sg0"
+ * @param fd file descriptor
+ * @param sense_handler called whenever the SCSI driver returns a sense buffer
+ * @param sense_arg pointer to data for the sense handler
+ * 
+ * @return 
+ * - SANE_STATUS_GOOD - on success
+ * - SANE_STATUS_ACCESS_DENIED - if the file couldn't be accessed due to
+ *   permissions
+ * - SANE_STATUS_NO_MEM - if malloc failed (not enough memory)
+ * - SANE_STATUS_INVAL - if the filename was invalid or an unknown error occured
+ *
+ * @sa sanei_scsi_open_extended(), HAVE_SANEI_SCSI_OPEN_EXTENDED
+ */
+extern SANE_Status sanei_scsi_open (const char * device_name, int * fd,
+				    SANEI_SCSI_Sense_Handler sense_handler,
+				    void *sense_arg);
+
+/** Open a SCSI device and set the buffer size
+ *
+ * The extended open call allows a backend to ask for a specific buffer
+ * size. sanei_scsi_open_extended() tries to allocate a buffer of the size
+ * given by *buffersize upon entry to this function. If
+ * sanei_scsi_open_extended returns successfully, *buffersize contains the
+ * available buffer size. This value may be both smaller or larger than the
+ * value requested by the backend; it can even be zero. The backend must
+ * decide, if it got enough buffer memory to work.
+ *
+ * Note that the value of *buffersize may differ for different files.
+ *
+ * @param device_name name of the devicefile, e.g. "/dev/sg0"
+ * @param fd file descriptor
+ * @param sense_handler called whenever the SCSI driver returns a sense buffer
+ * @param sense_arg pointer to data for the sense handler
+ * @param buffersize size of the SCAI request buffer (in bytes)
+ * 
+ * @return 
+ * - SANE_STATUS_GOOD - on success
+ * - SANE_STATUS_ACCESS_DENIED - if the file couldn't be accessed due to
+ *   permissions
+ * - SANE_STATUS_NO_MEM - if malloc failed (not enough memory)
+ * - SANE_STATUS_INVAL - if the filename was invalid or an unknown error occured
+ *
+ * @sa sanei_scsi_open(), HAVE_SANEI_SCSI_OPEN_EXTENDED
+ */
+extern SANE_Status sanei_scsi_open_extended (
+       const char * device_name, int * fd,
+       SANEI_SCSI_Sense_Handler sense_handler,
+       void *sense_arg, int *buffersize);
+
+/** Do we have sanei_scsi_open_extended()?
+ *
+ * Let backends decide, which open call to use: if
+ * HAVE_SANEI_SCSI_OPEN_EXTENDED is defined, sanei_scsi_open_extended may be
+ * used.  May also be used to decide, if sanei_scsi_req_flush_all or
+ * sanei_scsi_req_flush_all_extended() should be used.
+ *
+ * @sa sanei_scsi_open(), sanei_scsi_open_extended()
+*/
+#define HAVE_SANEI_SCSI_OPEN_EXTENDED
+
+/** Enqueue SCSI command
+ *
+ * One or more scsi commands can be enqueued by calling sanei_scsi_req_enter().
+ *
+ * NOTE: Some systems may not support multiple outstanding commands.  On such
+ * systems, sanei_scsi_req_enter() may block.  In other words, it is not proper
+ * to assume that enter() is a non-blocking routine.
+ *
+ * @param fd file descriptor
+ * @param src pointer to the SCSI command and associated write data (if any)
+ * @param src_size length of the command and data
+ * @param dst pointer to a buffer in which data is returned; NULL if no data is
+ *   returned
+ * @param dst_size  on input, the size of the buffer pointed to by dst, on exit,
+ *   set to the number of bytes returned in the buffer (which is less than or equal
+ *   to the buffer size; may be NULL if no data is expected
+ * @param idp pointer to a void* that uniquely identifies the entered request
+ *
+ * @return
+ * - SANE_STATUS_GOOD - on success
+ * - SANE_STATUS_IO_ERROR - if an error was received from the SCSI driver
+ * - SANE_STATUS_NO_MEM - if malloc failed (not enough memory)
+ * - SANE_STATUS_INVAL - if a locking or an unknown error occured
+ * @sa sanei_scsi_req_enter2()
+ *
+*/
+extern SANE_Status sanei_scsi_req_enter (int fd,
+					 const void * src, size_t src_size,
+					 void * dst, size_t * dst_size,
+					 void **idp);
+
+/** Enqueue SCSI command and separated data 
+ *
+ * Same as sanei_scsi_req_enter(), but with separate buffers for the SCSI
+ * command and for the data to be sent to the device.
+ *
+ * With sanei_scsi_req_enter(), the length of te SCSI command block must be
+ * guessed. While that works in most cases, Canon scanners for example use the
+ * vendor specific commands 0xd4, 0xd5 and 0xd6. The Canon scanners want to
+ * get 6 byte command blocks for these commands, but sanei_scsi_req_enter() and
+ * sanei_scsi_cmd() send 12 bytes.
+ *
+ * If dst_size and *dst_size are non-zero, a "read command" (ie, data transfer
+ * from the device to the host) is assumed.
+ *
+ * @param fd file descriptor
+ * @param cmd pointer to SCSI command
+ * @param cmd_size size of the command
+ * @param src pointer to the buffer with data to be sent to the scanner
+ * @param src_size size of src buffer
+ * @param dst pointer to a buffer in which data is returned; NULL if no data is
+ *   returned
+ * @param dst_size  on input, the size of the buffer pointed to by dst, on exit,
+ *   set to the number of bytes returned in the buffer (which is less than or equal
+ *   to the buffer size; may be NULL if no data is expected
+ * @param idp pointer to a void* that uniquely identifies the entered request
+ * @return
+ * - SANE_STATUS_GOOD - on success
+ * - SANE_STATUS_IO_ERROR - if an error was received from the SCSI driver
+ * - SANE_STATUS_NO_MEM - if malloc failed (not enough memory)
+ * - SANE_STATUS_INVAL - if a locking or an unknown error occured
+ * @sa sanei_scsi_req_enter()
+ */
+extern SANE_Status sanei_scsi_req_enter2 (int fd,
+					 const void * cmd, size_t cmd_size,
+					 const void * src, size_t src_size,
+					 void * dst, size_t * dst_size,
+					 void **idp);
+
+/** Wait for SCSI command
+ *
+ * Wait for the completion of the SCSI command with id ID.  
+ *
+ * @param id id used in sanei_scsi_req_enter()
+ *
+ * @return
+ * - SANE_STATUS_GOOD - on success
+ * - SANE_STATUS_DEVICE_BUSY - if the device is busy (try again later)
+ * - SANE_STATUS_IO_ERROR - if an error was received from the SCSI driver
+*/
+extern SANE_Status sanei_scsi_req_wait (void *id);
+
+/** Send SCSI command
+ *
+ * This is a convenience function that is equivalent to a pair of
+ * sanei_scsi_req_enter()/sanei_scsi_req_wait() calls.
+ *
+ * @param fd file descriptor
+ * @param src pointer to the SCSI command and associated write data (if any)
+ * @param src_size length of the command and data
+ * @param dst pointer to a buffer in which data is returned; NULL if no data is
+ *   returned
+ * @param dst_size  on input, the size of the buffer pointed to by dst, on exit,
+ *   set to the number of bytes returned in the buffer (which is less than or equal
+ *   to the buffer size; may be NULL if no data is expected
+ *
+ * @return
+ * - SANE_STATUS_GOOD - on success
+ * - SANE_STATUS_IO_ERROR - if an error was received from the SCSI driver
+ * - SANE_STATUS_NO_MEM - if malloc failed (not enough memory)
+ * - SANE_STATUS_INVAL - if a locking or an unknown error occured
+ *
+ * @sa sanei_scsi_cmd2(), sanei_scsi_req_enter(), sanei_scsi_req_wait()
+ */
+extern SANE_Status sanei_scsi_cmd (int fd,
+				   const void * src, size_t src_size,
+				   void * dst, size_t * dst_size);
+
+/** Send SCSI command and separated data
+ *
+ * This is a convenience function that is equivalent to a pair of
+ * sanei_scsi_req_enter2()/sanei_scsi_req_wait() calls.
+ *
+ * @param fd file descriptor
+ * @param cmd pointer to SCSI command
+ * @param cmd_size size of the command
+ * @param src pointer to the buffer with data to be sent to the scanner
+ * @param src_size size of src buffer
+ * @param dst pointer to a buffer in which data is returned; NULL if no data is
+ *   returned
+ * @param dst_size  on input, the size of the buffer pointed to by dst, on exit,
+ *   set to the number of bytes returned in the buffer (which is less than or equal
+ *   to the buffer size; may be NULL if no data is expected
+ * @return
+ * - SANE_STATUS_GOOD - on success
+ * - SANE_STATUS_IO_ERROR - if an error was received from the SCSI driver
+ * - SANE_STATUS_NO_MEM - if malloc failed (not enough memory)
+ * - SANE_STATUS_INVAL - if a locking or an unknown error occured
+ *
+ * @sa sanei_scsi_cmd(), sanei_scsi_req_enter(), sanei_scsi_req_wait()
+ */
+extern SANE_Status sanei_scsi_cmd2 (int fd,
+				   const void * cmd, size_t cmd_size,
+				   const void * src, size_t src_size,
+				   void * dst, size_t * dst_size);
+
+/** Flush queue
+ *
+ * Flush all pending SCSI commands. This function work only, if zero or one
+ * SCSI file handles are open.
+ *
+ * @sa sanei_scsi_req_flush_all_extended()
+*/
+extern void sanei_scsi_req_flush_all (void);
+
+/** Flush queue for handle
+ *
+ * Flush all SCSI commands pending for one handle
+ *
+ * @param fd file descriptor
+ *
+ * @sa sanei_scsi_req_flush_all()
+ */
+extern void sanei_scsi_req_flush_all_extended (int fd);
+
+/** Close a SCSI device
+ *
+ * @param fd file descriptor
+ *
+ */
+extern void sanei_scsi_close (int fd);
+
+#endif /* sanei_scsi_h */
diff --git a/include/sane/sanei_usb.h b/include/sane/sanei_usb.h
new file mode 100644
index 0000000..c84e4b0
--- /dev/null
+++ b/include/sane/sanei_usb.h
@@ -0,0 +1,515 @@
+/* sane - Scanner Access Now Easy.
+   Copyright (C) 2001, 2002 Henning Meier-Geinitz
+   Copyright (C) 2003, 2005 Rene Rebe (sanei_read_int,sanei_set_timeout)
+   Copyright (C) 2008 m. allan noah (sanei_usb_clear_halt)
+   Copyright (C) 2011 Reinhold Kainhofer (sanei_usb_set_endpoint)
+   This file is part of the SANE package.
+
+   SANE is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   SANE is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with sane; see the file COPYING.  If not, write to the Free
+   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+   As a special exception, the authors of SANE give permission for
+   additional uses of the libraries contained in this release of SANE.
+
+   The exception is that, if you link a SANE library with other files
+   to produce an executable, this does not by itself cause the
+   resulting executable to be covered by the GNU General Public
+   License.  Your use of that executable is in no way restricted on
+   account of linking the SANE library code into it.
+
+   This exception does not, however, invalidate any other reasons why
+   the executable file might be covered by the GNU General Public
+   License.
+
+   If you submit changes to SANE to the maintainers to be included in
+   a subsequent release, you agree by submitting the changes that
+   those changes may be distributed with this exception intact.
+
+   If you write modifications of your own for SANE, it is your choice
+   whether to permit this exception to apply to your modifications.
+   If you do not wish that, delete this exception notice.
+*/
+
+/** @file sanei_usb.h
+ * This file provides a generic USB interface.  
+ *
+ * Currently, two access methods to USB devices are provided:
+ * - Access to device
+ * files as used by the Linux kernel USB scanner driver is supported. FreeBSD
+ * and OpenBSD with their uscanner drivers also work this way. However, 
+ * detection and control messages aren't supported on these platforms.
+ * - Access using libusb (where available). 
+ *
+ * A general remark: Do not mix sanei_usb functions with "normal" file-related
+ * libc functions like open() or close.  The device numbers used in sanei_usb
+ * are not file descriptors.
+ *
+ * @sa sanei_lm983x.h, sanei_pa4s2.h, sanei_pio.h, sanei_scsi.h, and <a 
+ * href="http://www.sane-project.org/man/sane-usb.5.html">man sane-usb(5)</a>
+ * for user-oriented documentation
+ */
+
+#ifndef sanei_usb_h
+#define sanei_usb_h
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <sane/sane.h>
+
+#include <stdlib.h> /* for size_t */
+
+/* USB spec defines */
+#ifndef USB_CLASS_PER_INTERFACE
+/* Also defined in libusb */
+/** @name Device and/or interface class codes */
+/* @{ */
+#define USB_CLASS_PER_INTERFACE         0x00
+#define USB_CLASS_AUDIO                 0x01
+#define USB_CLASS_COMM                  0x02
+#define USB_CLASS_HID                   0x03
+#define USB_CLASS_PRINTER               0x07
+#define USB_CLASS_MASS_STORAGE          0x08
+#define USB_CLASS_HUB                   0x09
+#define USB_CLASS_DATA                  0x0a
+#define USB_CLASS_VENDOR_SPEC           0xff
+/* @} */
+
+/** @name USB descriptor types */
+/* @{ */
+#define USB_DT_DEVICE                   0x01
+#define USB_DT_CONFIG                   0x02
+#define USB_DT_STRING                   0x03
+#define USB_DT_INTERFACE                0x04
+#define USB_DT_ENDPOINT                 0x05
+#define USB_DT_HID                      0x21
+#define USB_DT_REPORT                   0x22
+#define USB_DT_PHYSICAL                 0x23
+#define USB_DT_HUB                      0x29
+/* @} */
+
+/** @name Descriptor sizes per descriptor type */
+/* @{ */
+#define USB_DT_DEVICE_SIZE              18
+#define USB_DT_CONFIG_SIZE              9
+#define USB_DT_INTERFACE_SIZE           9
+#define USB_DT_ENDPOINT_SIZE            7
+#define USB_DT_ENDPOINT_AUDIO_SIZE      9
+#define USB_DT_HUB_NONVAR_SIZE          7
+/* @} */
+
+/** @name Endpoint descriptors */
+/* @{ */
+#define USB_ENDPOINT_ADDRESS_MASK       0x0f
+#define USB_ENDPOINT_DIR_MASK           0x80
+#define USB_ENDPOINT_TYPE_MASK          0x03
+#define USB_ENDPOINT_TYPE_CONTROL       0
+#define USB_ENDPOINT_TYPE_ISOCHRONOUS   1
+#define USB_ENDPOINT_TYPE_BULK          2
+#define USB_ENDPOINT_TYPE_INTERRUPT     3
+/* @} */
+
+/** @name Standard requests */
+/* @{ */
+#define USB_REQ_GET_STATUS              0x00
+#define USB_REQ_CLEAR_FEATURE           0x01
+#define USB_REQ_SET_FEATURE             0x03
+#define USB_REQ_SET_ADDRESS             0x05
+#define USB_REQ_GET_DESCRIPTOR          0x06
+#define USB_REQ_SET_DESCRIPTOR          0x07
+#define USB_REQ_GET_CONFIGURATION       0x08
+#define USB_REQ_SET_CONFIGURATION       0x09
+#define USB_REQ_GET_INTERFACE           0x0A
+#define USB_REQ_SET_INTERFACE           0x0B
+#define USB_REQ_SYNCH_FRAME             0x0C
+/* @} */
+
+/** @name USB types */
+/* @{ */
+#define USB_TYPE_STANDARD               (0x00 << 5)
+#define USB_TYPE_CLASS                  (0x01 << 5)
+#define USB_TYPE_VENDOR                 (0x02 << 5)
+#define USB_TYPE_RESERVED               (0x03 << 5)
+/* @} */
+
+/** @name USB recipients */
+/* @{ */
+#define USB_RECIP_DEVICE                0x00
+#define USB_RECIP_INTERFACE             0x01
+#define USB_RECIP_ENDPOINT              0x02
+#define USB_RECIP_OTHER                 0x03
+/* @} */
+
+#endif /* not USB_CLASS_PER_INTERFACE */
+
+/* Not defined in libsub */
+/** @name USB Masks */
+/* @{ */
+#define USB_TYPE_MASK                   (0x03 << 5)
+#define USB_RECIP_MASK                  0x1f
+/* @} */
+
+/** @name USB directions */
+/* @{ */
+#define USB_DIR_OUT                     0x00
+#define USB_DIR_IN                      0x80
+/* @} */
+
+/** */
+struct sanei_usb_dev_descriptor
+{
+	SANE_Byte    desc_type;
+	unsigned int bcd_usb;
+	unsigned int bcd_dev;
+	SANE_Byte    dev_class;
+	SANE_Byte    dev_sub_class;
+	SANE_Byte    dev_protocol;
+	SANE_Byte    max_packet_size;
+};
+
+/** Initialize sanei_usb.
+ *
+ * Call this before any other sanei_usb function.
+ */
+extern void sanei_usb_init (void);
+
+/** Get the vendor and product ids by device name.
+ *
+ * @param devname 
+ * @param vendor vendor id
+ * @param product product id
+ *
+ * @return
+ * - SANE_STATUS_GOOD - if the ids could be determined
+ * - SANE_STATUS_INVAL - if the device is not found
+ * - SANE_STATUS_UNSUPPORTED - if this method is not supported with the current
+ *   access method
+ */
+SANE_Status
+sanei_usb_get_vendor_product_byname (SANE_String_Const devname,
+				     SANE_Word * vendor, SANE_Word * product);
+
+/** Get the vendor and product ids.
+ *
+ * Currently, only libusb devices and scanners supported by the Linux USB 
+ * scanner module can be found.  For the latter method, the Linux version
+ * must be 2.4.8 or higher. 
+ *
+ * @param dn device number of an already sanei_usb_opened device
+ * @param vendor vendor id
+ * @param product product id
+ *
+ * @return 
+ * - SANE_STATUS_GOOD - if the ids could be determined
+ * - SANE_STATUS_UNSUPPORTED - if the OS doesn't support detection of ids
+ */
+extern SANE_Status
+sanei_usb_get_vendor_product (SANE_Int dn, SANE_Word * vendor,
+			      SANE_Word * product);
+
+/** Find devices that match given vendor and product ids.
+ *
+ * For limitations, see function sanei_usb_get_vendor_product().
+ * The function attach is called for every device which has been found.
+ *
+ * @param vendor vendor id
+ * @param product product id
+ * @param attach attach function
+ *
+ * @return SANE_STATUS_GOOD - on success (even if no scanner was found)
+ */
+extern SANE_Status
+sanei_usb_find_devices (SANE_Int vendor, SANE_Int product,
+			SANE_Status (*attach) (SANE_String_Const devname));
+
+/** Open a USB device.
+ *
+ * The device is opened by its name devname and the device number is
+ * returned in dn on success.  
+ *
+ * Device names can be either device file names for direct access over
+ * kernel drivers (like /dev/usb/scanner) or libusb names. The libusb format
+ * looks like this: "libusb:bus-id:device-id". Bus-id and device-id are
+ * platform-dependent. An example could look like this: "libusb:001:002"
+ * (Linux).
+ *
+ * @param devname name of the device to open
+ * @param dn device number
+ *
+ * @return
+ * - SANE_STATUS_GOOD - on success
+ * - SANE_STATUS_ACCESS_DENIED - if the file couldn't be accessed due to
+ *   permissions
+ * - SANE_STATUS_INVAL - on every other error
+ */
+extern SANE_Status sanei_usb_open (SANE_String_Const devname, SANE_Int * dn);
+
+/** Set the endpoint for the USB communication
+ *
+ * Allows to switch to a different endpoint for the USB communication than
+ * the default (auto-detected) endpoint. This function can only be called
+ * after sanei_usb_open.
+ *
+ * @param dn device number
+ * @param ep_type type of endpoint to set (bitwise or of USB_DIR_IN/OUT and
+ *                USB_ENDPOINT_TYPE_BULK/CONTROL/INTERRUPT/ISOCHRONOUS
+ * @param ep endpoint to use for the given type
+ *
+ */
+extern void sanei_usb_set_endpoint (SANE_Int dn, SANE_Int ep_type, SANE_Int ep);
+
+/** Retrieve the endpoint used for the USB communication
+ *
+ * Returns the endpoint used for the USB communication of the given type.
+ * This function can only be called after sanei_usb_open.
+ *
+ * @param dn device number
+ * @param ep_type type of endpoint to retrieve (bitwise or of USB_DIR_IN/OUT
+ *                and USB_ENDPOINT_TYPE_BULK/CONTROL/INTERRUPT/ISOCHRONOUS
+ * @return endpoint used for the given type
+ *
+ */
+extern SANE_Int sanei_usb_get_endpoint (SANE_Int dn, SANE_Int ep_type);
+
+/** Close a USB device.
+ * 
+ * @param dn device number
+ */
+extern void sanei_usb_close (SANE_Int dn);
+
+/** Set the libusb timeout for bulk and interrupt reads.
+ * 
+ * @param timeout the new timeout in ms
+ */
+extern void sanei_usb_set_timeout (SANE_Int timeout);
+
+/** Check if sanei_usb_set_timeout() is available.
+ */
+#define HAVE_SANEI_USB_SET_TIMEOUT
+
+/** Clear halt condition on bulk endpoints
+ * 
+ * @param dn device number
+ */
+extern SANE_Status sanei_usb_clear_halt (SANE_Int dn);
+
+/** Check if sanei_usb_clear_halt() is available.
+ */
+#define HAVE_SANEI_USB_CLEAR_HALT
+
+/** Reset device
+ * 
+ * @param dn device number
+ */
+extern SANE_Status sanei_usb_reset (SANE_Int dn);
+
+/** Initiate a bulk transfer read.
+ *
+ * Read up to size bytes from the device to buffer. After the read, size
+ * contains the number of bytes actually read.
+ *
+ * @param dn device number
+ * @param buffer buffer to store read data in
+ * @param size size of the data
+ *
+ * @return 
+ * - SANE_STATUS_GOOD - on succes
+ * - SANE_STATUS_EOF - if zero bytes have been read
+ * - SANE_STATUS_IO_ERROR - if an error occured during the read
+ * - SANE_STATUS_INVAL - on every other error
+ *
+ */
+extern SANE_Status
+sanei_usb_read_bulk (SANE_Int dn, SANE_Byte * buffer, size_t * size);
+
+/** Initiate a bulk transfer write.
+ *
+ * Write up to size bytes from buffer to the device. After the write size
+ * contains the number of bytes actually written.
+ *
+ * @param dn device number
+ * @param buffer buffer to write to device
+ * @param size size of the data
+ *
+ * @return 
+ * - SANE_STATUS_GOOD - on succes
+ * - SANE_STATUS_IO_ERROR - if an error occured during the write
+ * - SANE_STATUS_INVAL - on every other error
+ */
+extern SANE_Status
+sanei_usb_write_bulk (SANE_Int dn, const SANE_Byte * buffer, size_t * size);
+
+/** Send/receive a control message to/from a USB device.
+ *
+ * This function is only supported for libusb devices and kernel acces with
+ * Linux 2.4.13 and newer.
+ * For a detailed explanation of the parameters, have a look at the USB
+ * specification at the <a href="http://www.usb.org/developers/docs/">
+ * www.usb.org developers information page</a>.
+ * 
+ * @param dn device number
+ * @param rtype specifies the characteristics of the request (e.g. data
+ *    direction)
+ * @param req actual request
+ * @param value parameter specific to the request
+ * @param index parameter specific to the request (often used to select
+ *     endpoint)
+ * @param len length of data to send/receive
+ * @param data buffer to send/receive data
+ *
+ * @return
+ * - SANE_STATUS_GOOD - on success
+ * - SANE_STATUS_IO_ERROR - on error
+ * - SANE_STATUS_UNSUPPORTED - if the feature is not supported by the OS or
+ *   SANE.
+ */
+extern SANE_Status
+sanei_usb_control_msg (SANE_Int dn, SANE_Int rtype, SANE_Int req,
+		       SANE_Int value, SANE_Int index, size_t * size,
+		       SANE_Byte * data);
+
+/** Initiate a interrupt transfer read.
+ *
+ * Read up to size bytes from the interrupt endpoint from the device to
+ * buffer. After the read, size contains the number of bytes actually read.
+ *
+ * @param dn device number
+ * @param buffer buffer to store read data in
+ * @param size size of the data
+ *
+ * @return 
+ * - SANE_STATUS_GOOD - on succes
+ * - SANE_STATUS_EOF - if zero bytes have been read
+ * - SANE_STATUS_IO_ERROR - if an error occured during the read
+ * - SANE_STATUS_INVAL - on every other error
+ *
+ */
+
+extern SANE_Status
+sanei_usb_read_int (SANE_Int dn, SANE_Byte * buffer, size_t * size);
+
+/** Expand device name patterns into a list of devices.
+ *
+ * Apart from a normal device name (such as /dev/usb/scanner0 or
+ * libusb:002:003), this function currently supports USB device
+ * specifications of the form:
+ *
+ *	usb VENDOR PRODUCT
+ *
+ * VENDOR and PRODUCT are non-negative integer numbers in decimal or
+ * hexadecimal format. A similar function for SCSI devices can be found
+ * in include/sane/config.h.
+ *
+ * @param name device name pattern
+ * @param attach attach function
+ *
+ */
+extern void
+sanei_usb_attach_matching_devices (const char *name,
+				   SANE_Status (*attach) (const char *dev));
+
+/** Initiate set configuration.
+ *
+ * Change set configuration
+ *
+ * @param dn device number
+ * @param configuration, configuration nummber
+ *
+ * @return 
+ * - SANE_STATUS_GOOD - on succes
+ * - SANE_STATUS_EOF - if zero bytes have been read
+ * - SANE_STATUS_IO_ERROR - if an error occured during the read
+ * - SANE_STATUS_INVAL - on every other error
+ *
+ */
+
+extern SANE_Status
+sanei_usb_set_configuration (SANE_Int dn, SANE_Int configuration);
+
+/** Initiate claim interface.
+ *
+ * Change claim interface
+ *
+ * @param dn device number
+ * @param interface_number interface number
+ *
+ * @return 
+ * - SANE_STATUS_GOOD - on succes
+ * - SANE_STATUS_EOF - if zero bytes have been read
+ * - SANE_STATUS_IO_ERROR - if an error occured during the read
+ * - SANE_STATUS_INVAL - on every other error
+ *
+ */
+
+extern SANE_Status
+sanei_usb_claim_interface (SANE_Int dn, SANE_Int interface_number);
+
+/** Initiate release interface.
+ *
+ * Change release interface
+ *
+ * @param dn device number
+ * @param interface_number interface number
+ *
+ * @return 
+ * - SANE_STATUS_GOOD - on succes
+ * - SANE_STATUS_EOF - if zero bytes have been read
+ * - SANE_STATUS_IO_ERROR - if an error occured during the read
+ * - SANE_STATUS_INVAL - on every other error
+ *
+ */
+
+extern SANE_Status
+sanei_usb_release_interface (SANE_Int dn, SANE_Int interface_number);
+
+/** Initiate a set altinterface.
+ *
+ * Change set alternate
+ *
+ * @param dn device number
+ * @param alternate, alternate nummber
+ *
+ * @return 
+ * - SANE_STATUS_GOOD - on succes
+ * - SANE_STATUS_EOF - if zero bytes have been read
+ * - SANE_STATUS_IO_ERROR - if an error occured during the read
+ * - SANE_STATUS_INVAL - on every other error
+ *
+ */
+
+extern SANE_Status
+sanei_usb_set_altinterface (SANE_Int dn, SANE_Int alternate);
+
+/** Get some information from the device descriptor
+ *
+ * Sometimes it's useful to know something about revisions and
+ * other stuff reported by the USB system
+ *
+ * @param dn device number
+ * @param desc where to put the information to
+ *
+ * @return 
+ * - SANE_STATUS_GOOD - on succes
+ * - SANE_STATUS_UNSUPPORTED - if the feature is not supported by the OS or
+ *   SANE.
+ * - SANE_STATUS_INVAL - on every other error
+ *
+ */
+
+extern SANE_Status
+sanei_usb_get_descriptor( SANE_Int dn, struct sanei_usb_dev_descriptor *desc );
+
+/*------------------------------------------------------*/
+#endif /* sanei_usb_h */