Initial commit

import from github

12 files changed, 2688 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..074bf52
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,32 @@
+#
+# O-3000 driver
+#
+
+cmake_minimum_required(VERSION 2.4)
+set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_SOURCE_DIR}/cmake)
+
+# find libusb library (version 1.0.19 or higher is needed!)
+find_package(LibUSB REQUIRED)
+
+include_directories(.)
+include_directories(${LIBUSB_INCLUDE_DIRS})
+
+add_library(				o3000 SHARED
+							o3000.c
+							o3000_private.h
+							o3000_xfer_handler.c
+							o3000_xfer_handler.h
+							)
+
+set_target_properties	(	o3000 PROPERTIES
+							OUTPUT_NAME "o3000"
+							VERSION 2.0.2
+							SOVERSION 2
+							LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+						)
+						
+target_compile_options(o3000 PRIVATE -Wall -g -ggdb -O3 -fPIC)
+target_link_libraries(o3000 pthread ${LIBUSB_LIBRARIES})
+
+install(TARGETS o3000 DESTINATION lib)
+install(DIRECTORY ../../include/o3000 DESTINATION include FILES_MATCHING PATTERN "*.h*")
diff --git a/ChangeLog b/ChangeLog
new file mode 100644
index 0000000..f1ec48c
--- /dev/null
+++ b/ChangeLog
@@ -0,0 +1,46 @@
+-------------------------------------------------------------------------------
+- ChangeLog O-3000 Host Driver
+-------------------------------------------------------------------------------
+
+Version 2.0.2
+	2018-04-11-PR
+	* Function handle_transfer() rewritten:
+	  The image frame synchronization was a bit hacky. Image frames were passed only to the
+	  overlaying application after the next image frame has been received. But when receiving a single
+	  snapshot, there won't follow an image. This causes a delay of one image until the application
+	  receives it. Now the function passes images to the application after a image is
+	  received completely without checking the preamble of the following image.
+	* Bug race condition at o3000_init() function:
+	  Accessing the session table for getting next free session and allocation session structure
+	  must be atomic.
+	* New function o3000_get_num_cam() added:
+	  This function returns the number of connected O-3000 cameras to the system.
+	* New loglevel O3000_LOG_VERBOSE added:
+	  This loglevel will set the libusb to debugging mode and is very useful for debugging purposes.
+
+Version 2.0.1
+	2015-08-11 -PR
+	* Bugfix in function handle_transfer(): A negative byte offset was calculated when the resolution 
+	  has changed during wrap-around. A SEGFAULT occured.
+    * Fields added to image header and image header version update to 4:
+	  - data rate in bytes/seconds
+	  - frames per seconds
+	  - field-of-view added used by lense distortion algorithm
+	* Short USB bulk transfers are supported now by the driver. Therefore the resolution
+	  doesn't have to be a multiple of 512 bytes anymore and binning is done correctly.
+	  There are following restrictions about image resolution settings:
+	  - Window size must start with an even pixel coordinate (see examples below)
+	  - Minimum image resolution is 640x480.
+	  - Binning is allowed at full-screen only (1280x960)
+	  E. g. valid window:		X = 110 to 1111, Y = 32 to 917
+	  E. g. invalid window:		X = 111 to 1111, Y = 33 to 917 	--> coordinate 111 and 33 are odd numbers
+	  
+	2016-03-01
+	* Calling convention added for Win32 and Win64.
+	 
+Version 2.0.0 - 2015-02-16
+	* PR: Multi camera sessions capability. The host can scan the number of cameras and establish a connection to
+	  each of them. Sending a XML message to the camera uses the synchronous API with OS dependet timeout handling.
+
+Version 1.0.0 - 2015-02-16
+	* PB: Inititial version
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..65c5ca8
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,165 @@
+                   GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+  This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
+  0. Additional Definitions.
+
+  As used herein, "this License" refers to version 3 of the GNU Lesser
+General Public License, and the "GNU GPL" refers to version 3 of the GNU
+General Public License.
+
+  "The Library" refers to a covered work governed by this License,
+other than an Application or a Combined Work as defined below.
+
+  An "Application" is any work that makes use of an interface provided
+by the Library, but which is not otherwise based on the Library.
+Defining a subclass of a class defined by the Library is deemed a mode
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+  A "Combined Work" is a work produced by combining or linking an
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+with which the Combined Work was made is also called the "Linked
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+
+  The "Minimal Corresponding Source" for a Combined Work means the
+Corresponding Source for the Combined Work, excluding any source code
+for portions of the Combined Work that, considered in isolation, are
+based on the Application, and not on the Linked Version.
+
+  The "Corresponding Application Code" for a Combined Work means the
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+and utility programs needed for reproducing the Combined Work from the
+Application, but excluding the System Libraries of the Combined Work.
+
+  1. Exception to Section 3 of the GNU GPL.
+
+  You may convey a covered work under sections 3 and 4 of this License
+without being bound by section 3 of the GNU GPL.
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+  2. Conveying Modified Versions.
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+  If you modify a copy of the Library, and, in your modifications, a
+facility refers to a function or data to be supplied by an Application
+that uses the facility (other than as an argument passed when the
+facility is invoked), then you may convey a copy of the modified
+version:
+
+   a) under this License, provided that you make a good faith effort to
+   ensure that, in the event an Application does not supply the
+   function or data, the facility still operates, and performs
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+
+   b) under the GNU GPL, with none of the additional permissions of
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+  3. Object Code Incorporating Material from Library Header Files.
+
+  The object code form of an Application may incorporate material from
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+(ten or fewer lines in length), you do both of the following:
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+   a) Give prominent notice with each copy of the object code that the
+   Library is used in it and that the Library and its use are
+   covered by this License.
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+   b) Accompany the object code with a copy of the GNU GPL and this license
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+  4. Combined Works.
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+  You may convey a Combined Work under terms of your choice that,
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+   the Library is used in it and that the Library and its use are
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+   c) For a Combined Work that displays copyright notices during
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+   these notices, as well as a reference directing the user to the
+   copies of the GNU GPL and this license document.
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+   d) Do one of the following:
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+   e) Provide Installation Information, but only if you would otherwise
+   be required to provide such information under section 6 of the
+   GNU GPL, and only to the extent that such information is
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+   Combined Work produced by recombining or relinking the
+   Application with a modified version of the Linked Version. (If
+   you use option 4d0, the Installation Information must accompany
+   the Minimal Corresponding Source and Corresponding Application
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+   Information in the manner specified by section 6 of the GNU GPL
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+  5. Combined Libraries.
+
+  You may place library facilities that are a work based on the
+Library side by side in a single library together with other library
+facilities that are not Applications and are not covered by this
+License, and convey such a combined library under terms of your
+choice, if you do both of the following:
+
+   a) Accompany the combined library with a copy of the same work based
+   on the Library, uncombined with any other library facilities,
+   conveyed under the terms of this License.
+
+   b) Give prominent notice with the combined library that part of it
+   is a work based on the Library, and explaining where to find the
+   accompanying uncombined form of the same work.
+
+  6. Revised Versions of the GNU Lesser General Public License.
+
+  The Free Software Foundation may publish revised and/or new versions
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+versions will be similar in spirit to the present version, but may
+differ in detail to address new problems or concerns.
+
+  Each version is given a distinguishing version number. If the
+Library as you received it specifies that a certain numbered version
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+conditions either of that published version or of any later version
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+  If the Library as you received it specifies that a proxy can decide
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+Library.
diff --git a/cmake/FindLibUSB.cmake b/cmake/FindLibUSB.cmake
new file mode 100644
index 0000000..6468937
--- /dev/null
+++ b/cmake/FindLibUSB.cmake
@@ -0,0 +1,30 @@
+# - Try to find libusb-1.0
+# Once done, this will define
+#
+#  LIBUSB_FOUND - system has libusb-1.0
+#  LIBUSB_INCLUDE_DIRS - the libusb-1.0 include directories
+#  LIBUSB_LIBRARIES - link these to use libusb-1.0
+
+include(LibFindMacros)
+
+# Use pkg-config to get hints about paths
+# libfind_pkg_check_modules(LIBUSB_PKGCONF libusb-1.0>=1.0.19)
+libfind_pkg_check_modules(LIBUSB_PKGCONF libusb-1.0)
+
+# Include dir
+find_path(LIBUSB_INCLUDE_DIR
+  NAMES libusb.h
+  PATHS ${LIBUSB_PKGCONF_INCLUDE_DIRS}
+)
+
+# Finally the library itself
+find_library(LIBUSB_LIBRARY
+  NAMES usb-1.0
+  PATHS ${LIBUSB_PKGCONF_LIBRARY_DIRS}
+)
+
+# Set the include dir variables and the libraries and let libfind_process do the rest.
+# NOTE: Singular variables for this library, plural for libraries this this lib depends on.
+set(LIBUSB_PROCESS_INCLUDES LIBUSB_INCLUDE_DIR)
+set(LIBUSB_PROCESS_LIBS LIBUSB_LIBRARY)
+libfind_process(LIBUSB)
diff --git a/cmake/LibFindMacros.cmake b/cmake/LibFindMacros.cmake
new file mode 100644
index 0000000..3ef5844
--- /dev/null
+++ b/cmake/LibFindMacros.cmake
@@ -0,0 +1,266 @@
+# Version 2.2
+# Public Domain, originally written by Lasse Kärkkäinen <tronic>
+# Maintained at https://github.com/Tronic/cmake-modules
+# Please send your improvements as pull requests on Github.
+
+# Find another package and make it a dependency of the current package.
+# This also automatically forwards the "REQUIRED" argument.
+# Usage: libfind_package(<prefix> <another package> [extra args to find_package])
+macro (libfind_package PREFIX PKG)
+  set(${PREFIX}_args ${PKG} ${ARGN})
+  if (${PREFIX}_FIND_REQUIRED)
+    set(${PREFIX}_args ${${PREFIX}_args} REQUIRED)
+  endif()
+  find_package(${${PREFIX}_args})
+  set(${PREFIX}_DEPENDENCIES ${${PREFIX}_DEPENDENCIES};${PKG})
+  unset(${PREFIX}_args)
+endmacro()
+
+# A simple wrapper to make pkg-config searches a bit easier.
+# Works the same as CMake's internal pkg_check_modules but is always quiet.
+macro (libfind_pkg_check_modules)
+  find_package(PkgConfig QUIET)
+  if (PKG_CONFIG_FOUND)
+    pkg_check_modules(${ARGN} QUIET)
+  endif()
+endmacro()
+
+# Avoid useless copy&pasta by doing what most simple libraries do anyway:
+# pkg-config, find headers, find library.
+# Usage: libfind_pkg_detect(<prefix> <pkg-config args> FIND_PATH <name> [other args] FIND_LIBRARY <name> [other args])
+# E.g. libfind_pkg_detect(SDL2 sdl2 FIND_PATH SDL.h PATH_SUFFIXES SDL2 FIND_LIBRARY SDL2)
+function (libfind_pkg_detect PREFIX)
+  # Parse arguments
+  set(argname pkgargs)
+  foreach (i ${ARGN})
+    if ("${i}" STREQUAL "FIND_PATH")
+      set(argname pathargs)
+    elseif ("${i}" STREQUAL "FIND_LIBRARY")
+      set(argname libraryargs)
+    else()
+      set(${argname} ${${argname}} ${i})
+    endif()
+  endforeach()
+  if (NOT pkgargs)
+    message(FATAL_ERROR "libfind_pkg_detect requires at least a pkg_config package name to be passed.")
+  endif()
+  # Find library
+  libfind_pkg_check_modules(${PREFIX}_PKGCONF ${pkgargs})
+  if (pathargs)
+    find_path(${PREFIX}_INCLUDE_DIR NAMES ${pathargs} HINTS ${${PREFIX}_PKGCONF_INCLUDE_DIRS})
+  endif()
+  if (libraryargs)
+    find_library(${PREFIX}_LIBRARY NAMES ${libraryargs} HINTS ${${PREFIX}_PKGCONF_LIBRARY_DIRS})
+  endif()
+endfunction()
+
+# Extracts a version #define from a version.h file, output stored to <PREFIX>_VERSION.
+# Usage: libfind_version_header(Foobar foobar/version.h FOOBAR_VERSION_STR)
+# Fourth argument "QUIET" may be used for silently testing different define names.
+# This function does nothing if the version variable is already defined.
+function (libfind_version_header PREFIX VERSION_H DEFINE_NAME)
+  # Skip processing if we already have a version or if the include dir was not found
+  if (${PREFIX}_VERSION OR NOT ${PREFIX}_INCLUDE_DIR)
+    return()
+  endif()
+  set(quiet ${${PREFIX}_FIND_QUIETLY})
+  # Process optional arguments
+  foreach(arg ${ARGN})
+    if (arg STREQUAL "QUIET")
+      set(quiet TRUE)
+    else()
+      message(AUTHOR_WARNING "Unknown argument ${arg} to libfind_version_header ignored.")
+    endif()
+  endforeach()
+  # Read the header and parse for version number
+  set(filename "${${PREFIX}_INCLUDE_DIR}/${VERSION_H}")
+  if (NOT EXISTS ${filename})
+    if (NOT quiet)
+      message(AUTHOR_WARNING "Unable to find ${${PREFIX}_INCLUDE_DIR}/${VERSION_H}")
+    endif()
+    return()
+  endif()
+  file(READ "${filename}" header)
+  string(REGEX REPLACE ".*#[ \t]*define[ \t]*${DEFINE_NAME}[ \t]*\"([^\n]*)\".*" "\\1" match "${header}")
+  # No regex match?
+  if (match STREQUAL header)
+    if (NOT quiet)
+      message(AUTHOR_WARNING "Unable to find \#define ${DEFINE_NAME} \"<version>\" from ${${PREFIX}_INCLUDE_DIR}/${VERSION_H}")
+    endif()
+    return()
+  endif()
+  # Export the version string
+  set(${PREFIX}_VERSION "${match}" PARENT_SCOPE)
+endfunction()
+
+# Do the final processing once the paths have been detected.
+# If include dirs are needed, ${PREFIX}_PROCESS_INCLUDES should be set to contain
+# all the variables, each of which contain one include directory.
+# Ditto for ${PREFIX}_PROCESS_LIBS and library files.
+# Will set ${PREFIX}_FOUND, ${PREFIX}_INCLUDE_DIRS and ${PREFIX}_LIBRARIES.
+# Also handles errors in case library detection was required, etc.
+function (libfind_process PREFIX)
+  # Skip processing if already processed during this configuration run
+  if (${PREFIX}_FOUND)
+    return()
+  endif()
+
+  set(found TRUE)  # Start with the assumption that the package was found
+
+  # Did we find any files? Did we miss includes? These are for formatting better error messages.
+  set(some_files FALSE)
+  set(missing_headers FALSE)
+
+  # Shorthands for some variables that we need often
+  set(quiet ${${PREFIX}_FIND_QUIETLY})
+  set(required ${${PREFIX}_FIND_REQUIRED})
+  set(exactver ${${PREFIX}_FIND_VERSION_EXACT})
+  set(findver "${${PREFIX}_FIND_VERSION}")
+  set(version "${${PREFIX}_VERSION}")
+
+  # Lists of config option names (all, includes, libs)
+  unset(configopts)
+  set(includeopts ${${PREFIX}_PROCESS_INCLUDES})
+  set(libraryopts ${${PREFIX}_PROCESS_LIBS})
+
+  # Process deps to add to 
+  foreach (i ${PREFIX} ${${PREFIX}_DEPENDENCIES})
+    if (DEFINED ${i}_INCLUDE_OPTS OR DEFINED ${i}_LIBRARY_OPTS)
+      # The package seems to export option lists that we can use, woohoo!
+      list(APPEND includeopts ${${i}_INCLUDE_OPTS})
+      list(APPEND libraryopts ${${i}_LIBRARY_OPTS})
+    else()
+      # If plural forms don't exist or they equal singular forms
+      if ((NOT DEFINED ${i}_INCLUDE_DIRS AND NOT DEFINED ${i}_LIBRARIES) OR
+          ({i}_INCLUDE_DIR STREQUAL ${i}_INCLUDE_DIRS AND ${i}_LIBRARY STREQUAL ${i}_LIBRARIES))
+        # Singular forms can be used
+        if (DEFINED ${i}_INCLUDE_DIR)
+          list(APPEND includeopts ${i}_INCLUDE_DIR)
+        endif()
+        if (DEFINED ${i}_LIBRARY)
+          list(APPEND libraryopts ${i}_LIBRARY)
+        endif()
+      else()
+        # Oh no, we don't know the option names
+        message(FATAL_ERROR "We couldn't determine config variable names for ${i} includes and libs. Aieeh!")
+      endif()
+    endif()
+  endforeach()
+  
+  if (includeopts)
+    list(REMOVE_DUPLICATES includeopts)
+  endif()
+  
+  if (libraryopts)
+    list(REMOVE_DUPLICATES libraryopts)
+  endif()
+
+  string(REGEX REPLACE ".*[ ;]([^ ;]*(_INCLUDE_DIRS|_LIBRARIES))" "\\1" tmp "${includeopts} ${libraryopts}")
+  if (NOT tmp STREQUAL "${includeopts} ${libraryopts}")
+    message(AUTHOR_WARNING "Plural form ${tmp} found in config options of ${PREFIX}. This works as before but is now deprecated. Please only use singular forms INCLUDE_DIR and LIBRARY, and update your find scripts for LibFindMacros > 2.0 automatic dependency system (most often you can simply remove the PROCESS variables entirely).")
+  endif()
+
+  # Include/library names separated by spaces (notice: not CMake lists)
+  unset(includes)
+  unset(libs)
+
+  # Process all includes and set found false if any are missing
+  foreach (i ${includeopts})
+    list(APPEND configopts ${i})
+    if (NOT "${${i}}" STREQUAL "${i}-NOTFOUND")
+      list(APPEND includes "${${i}}")
+    else()
+      set(found FALSE)
+      set(missing_headers TRUE)
+    endif()
+  endforeach()
+
+  # Process all libraries and set found false if any are missing
+  foreach (i ${libraryopts})
+    list(APPEND configopts ${i})
+    if (NOT "${${i}}" STREQUAL "${i}-NOTFOUND")
+      list(APPEND libs "${${i}}")
+    else()
+      set (found FALSE)
+    endif()
+  endforeach()
+
+  # Version checks
+  if (found AND findver)
+    if (NOT version)
+      message(WARNING "The find module for ${PREFIX} does not provide version information, so we'll just assume that it is OK. Please fix the module or remove package version requirements to get rid of this warning.")
+    elseif (version VERSION_LESS findver OR (exactver AND NOT version VERSION_EQUAL findver))
+      set(found FALSE)
+      set(version_unsuitable TRUE)
+    endif()
+  endif()
+
+  # If all-OK, hide all config options, export variables, print status and exit
+  if (found)
+    foreach (i ${configopts})
+      mark_as_advanced(${i})
+    endforeach()
+    if (NOT quiet)
+      message(STATUS "Found ${PREFIX} ${${PREFIX}_VERSION}")
+      if (LIBFIND_DEBUG)
+        message(STATUS "  ${PREFIX}_DEPENDENCIES=${${PREFIX}_DEPENDENCIES}")
+        message(STATUS "  ${PREFIX}_INCLUDE_OPTS=${includeopts}")
+        message(STATUS "  ${PREFIX}_INCLUDE_DIRS=${includes}")
+        message(STATUS "  ${PREFIX}_LIBRARY_OPTS=${libraryopts}")
+        message(STATUS "  ${PREFIX}_LIBRARIES=${libs}")
+      endif()
+      set (${PREFIX}_INCLUDE_OPTS ${includeopts} PARENT_SCOPE)
+      set (${PREFIX}_LIBRARY_OPTS ${libraryopts} PARENT_SCOPE)
+      set (${PREFIX}_INCLUDE_DIRS ${includes} PARENT_SCOPE)
+      set (${PREFIX}_LIBRARIES ${libs} PARENT_SCOPE)
+      set (${PREFIX}_FOUND TRUE PARENT_SCOPE)
+    endif()
+    return()    
+  endif()
+
+  # Format messages for debug info and the type of error
+  set(vars "Relevant CMake configuration variables:\n")
+  foreach (i ${configopts})
+    mark_as_advanced(CLEAR ${i})
+    set(val ${${i}})
+    if ("${val}" STREQUAL "${i}-NOTFOUND")
+      set (val "<not found>")
+    elseif (val AND NOT EXISTS ${val})
+      set (val "${val}  (does not exist)")
+    else()
+      set(some_files TRUE)
+    endif()
+    set(vars "${vars}  ${i}=${val}\n")
+  endforeach()
+  set(vars "${vars}You may use CMake GUI, cmake -D or ccmake to modify the values. Delete CMakeCache.txt to discard all values and force full re-detection if necessary.\n")
+  if (version_unsuitable)
+    set(msg "${PREFIX} ${${PREFIX}_VERSION} was found but")
+    if (exactver)
+      set(msg "${msg} only version ${findver} is acceptable.")
+    else()
+      set(msg "${msg} version ${findver} is the minimum requirement.")
+    endif()
+  else()
+    if (missing_headers)
+      set(msg "We could not find development headers for ${PREFIX}. Do you have the necessary dev package installed?")
+    elseif (some_files)
+      set(msg "We only found some files of ${PREFIX}, not all of them. Perhaps your installation is incomplete or maybe we just didn't look in the right place?")
+      if(findver)
+        set(msg "${msg} This could also be caused by incompatible version (if it helps, at least ${PREFIX} ${findver} should work).")
+      endif()
+    else()
+      set(msg "We were unable to find package ${PREFIX}.")
+    endif()
+  endif()
+
+  # Fatal error out if REQUIRED
+  if (required)
+    set(msg "REQUIRED PACKAGE NOT FOUND\n${msg} This package is REQUIRED and you need to install it or adjust CMake configuration in order to continue building ${CMAKE_PROJECT_NAME}.")
+    message(FATAL_ERROR "${msg}\n${vars}")
+  endif()
+  # Otherwise just print a nasty warning
+  if (NOT quiet)
+    message(WARNING "WARNING: MISSING PACKAGE\n${msg} This package is NOT REQUIRED and you may ignore this warning but by doing so you may miss some functionality of ${CMAKE_PROJECT_NAME}. \n${vars}")
+  endif()
+endfunction()
+
diff --git a/image_header.h b/image_header.h
new file mode 100644
index 0000000..dd752e7
--- /dev/null
+++ b/image_header.h
@@ -0,0 +1,157 @@
+/**

+* @file			image_header.h

+* @brief		Image header definition

+* @author		Patrick Brunner - brunner@stettbacher.ch

+* @author		Patrick Roth - roth@stettbacher.ch

+* @version		1.1

+* @date			2016-03-01

+* @copyright	2012-2016 Stettbacher Signal Processing AG

+* 

+* @remarks

+*

+* <PRE>

+* This library is free software; you can redistribute it and/or

+* modify it under the terms of the GNU Lesser General Public

+* License as published by the Free Software Foundation; either

+* version 2.1 of the License, or (at your option) any later version.

+*

+* This library 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

+* Lesser General Public License for more details.

+*

+* You should have received a copy of the GNU Lesser General Public

+* License along with this library; if not, write to the Free Software

+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

+* </PRE>

+*

+*/

+

+

+#ifndef _IMAGE_HEADER_H

+#define _IMAGE_HEADER_H

+

+#include "o3000/o3000_portable.h"

+

+#define O3000_IMG_HEADER_VERSION			4		///< O-3000 image header version

+

+/**

+ * Image header size in bytes

+ * 

+ * @note The struct img_header_t defined below must be a multiple of 512 bytes.

+ * The macro @ref IMAGE_HEADER_SIZE just helps to verify the header size, as done with

+ * the assert command in image_header_init. Unfortunately, assertions in C can only

+ * be performed at runtime, not at compile-time...

+ */

+#define IMAGE_HEADER_SIZE	512

+

+/**

+ * Image data format.

+ * These are all possible values for the field format in struct img_header_t.

+ */

+enum enumDataFormat_t {

+	DF_RAW_MONO_8 = 0,		///< monochrome image with 8 bit per pixel

+	DF_RAW_MONO_12,			///< monochrome image with 12 bit per pixel

+	DF_RAW_BAYER_8,			///< bayer image with 8 bit per pixel

+	DF_RAW_BAYER_12,		///< bayer image with 12 bit per pixel

+	DF_HDR_MONO_20_COMP,	///< 20 bit HDR monochrome image compressed to 12 bits

+	DF_HDR_BAYER_20_COMP,	///< 20 bit HDR bayer image compressed to 12 bits

+};

+

+/**

+ * Bayer pattern color order.

+ * These are all possible values for the field bayer pattern in struct img_header_t.

+ * The individual values describe the order of the pixels in the image data array.

+ * Depending on the start coordinate, the pattern starts with a red, 

+ * green (2 possibilities), or blue pixel.

+ * The pattern then repeats every 2 pixels in the X- and Y-direction.

+ * 

+ * @code

+ *  X   |	Y   | 1st row      | 2nd row      | enum value

+ * -----+-------+--------------+--------------+-----------

+ * even | even	| Gr, R, Gr, R | B, Gb, B, Gb | BP_GR

+ *  odd | even	| R, Gr, R, Gr | Gb, B, Gb, B | BP_RG

+ * even |  odd	| B, Gb, B, Gb | Gr, R, Gr, R | BP_BG

+ *  odd |  odd	| Gb, B, Gb, B | R, Gr, R, Gr | BP_GB

+ * 1st row: first row data within the region of interest

+ * 

+ * R:  red pixel

+ * Gr: green pixel, adjacent to red pixel

+ * Gb: green pixel, adjacent to blue pixel

+ * B:  blue pixel

+ * @endcode

+ */

+enum enumBayerPattern_t {

+	BP_GR = 0,		///< first row: green-red-green-red-...

+	BP_RG,			///< first row: red-green-red-green-...

+	BP_BG,			///< first row: blue-green-blue-green-...

+	BP_GB,			///< first row: green-blue-green-blue-...

+};

+

+

+/**

+ * Image header (must be a multiple of 512 bytes)

+ * 

+ * @code

+ * 

+ * X/Y coordinate system

+ * 

+ *   +---------------------------------> x-axis

+ *   |0/0		1/0		2/0

+ *   |0/1		1/1		2/1

+ *   |

+ *   |        +-----------------+

+ *   |        |                 |        

+ *   |        |  field of view  |

+ *   |        |                 |

+ *   |        +-----------------+

+ *   v

+ * y-axis

+ * 

+ * @endcode

+ * 

+ * - upper left corner starts with coordinate 0/0

+ * - the image width defines the maximum horizontal view in x-direction

+ * - the image height defines the maximum vertical view y-direction

+ * 

+ * As the sensor data may contain embedded statistics which should be ignored

+ * by the application, image_start defines the offset in bytes of the actual image

+ * data.  The payload size contains the regular image size plus the size 

+ * of the embedded data. If there is no embedded data, image start offset 

+ * is 0 and the payload and image size are equal.

+ * 

+ * @note Embedded data not only contains statistics lines at the beginning, 

+ * but also at the end of the image. The field @ref bayer_pattern is defined for bayer-based

+ * data formats only (e.g. DF_RAW_BAYER_8).

+ */

+struct img_header_t {

+	

+	// since image header version 1

+	uint32_t	preamble[2]; 	///< constant preamble 											(8 bytes)

+	uint32_t	version;		///< header version number 										(4 bytes)

+	uint32_t	payload_size;	///< payload size (in bytes)									(4 bytes)

+	uint32_t	image_start;	///< image start offset (in bytes)										(4 bytes)

+	uint32_t	image_size;		///< image size (in bytes) 										(4 bytes)

+	uint32_t	width;			///< current image width (x-direction) (in pixels) 				(4 bytes)

+	uint32_t	height;			///< current image height (y-direction) (in pixels) 			(4 bytes)

+	uint32_t	format;			///< image data format (see @ref enumDataFormat_t)				(4 bytes)

+	uint32_t	frame_count;	///< frame sequence number 										(4 bytes)

+	

+	// since image header version 2

+	uint32_t	bayer_pattern;	///< bayer pattern color order (see @ref enumBayerPattern_t)	(4 bytes)

+	

+	// since image header version 3

+	uint32_t	datarate;		///< USB data rate in bytes per seconds							(4 bytes)

+	float		fps;			///< frames per seconds											(4 bytes)

+	

+	// since image header version 4

+	uint16_t	fov_x_start;	///< start x-cooredinate of current field of view				(2 bytes)

+	uint16_t	fov_x_end;		///< end x-cooredinate of current field of view					(2 bytes)

+	uint16_t	fov_y_start;	///< start y-cooredinate of current field of view				(2 bytes)

+	uint16_t	fov_y_end;		///< end y-cooredinate of current field of view					(2 bytes)

+	

+	uint8_t		padding[452];	///< padding bytes to fill header								(452 bytes)

+} __packed__;

+

+

+#endif // _IMAGE_HEADER_H

diff --git a/o3000.c b/o3000.c
new file mode 100644
index 0000000..1ad5676
--- /dev/null
+++ b/o3000.c
@@ -0,0 +1,1431 @@
+/**
+* @file			o3000.c
+* @brief		O-3000 Camera driver
+* @author		Patrick Brunner - brunner@stettbacher.ch
+* @author		Patrick Roth - roth@stettbacher.ch
+* @version		1.1
+* @date			2016-03-01
+* @copyright	2012-2016 Stettbacher Signal Processing AG
+* 
+* @remarks
+*
+* <PRE>
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU Lesser General Public
+* License as published by the Free Software Foundation; either
+* version 2.1 of the License, or (at your option) any later version.
+*
+* This library 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
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public
+* License along with this library; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+* </PRE>
+*
+*/
+
+
+/**
+
+@mainpage O-3000 camera driver
+ 
+@section intro Introduction
+
+This document describes the Application Programming Interface (API) for the
+<b>Stettbacher Signal Processing USB O-3000 Camera</b>, further referenced as "the camera".</p>
+The driver delivers a generic user interface for accessing the camera and runs on different operating system like:
+<ul>
+<li> Linux </li>
+<li> Windows </li>
+<li> MAC </li>
+</ul>
+The driver supports session handling. Therfore it's able to handle several camera session on the same host system accessing from one
+or several user applications.
+
+@section api API
+
+Two groups of functions represent the interface:
+<ol>
+<li>	A set of functions provided by the camera API which can be called from
+		the user application (see @ref api_fun). </li>
+<li>	A set of callback functions the user application must implement and
+		register with the camera API (see @ref cb_fun). </li>
+</ol>
+
+@subsection api_fun API functions
+
+The basic approach using the camera driver is:
+<ol>
+<li> Implementing all required callback functions, see @ref cb_fun. </li>
+<li> Initialising the camera driver, see o3000_init(). </li>
+<li> Connecting to the camera driver, see o3000_connect(). </li>
+</ol>
+
+Once the user application is connected to the driver by calling o3000_connect(), it will block until:
+<ul>
+<li> The driver exits by calling o3000_exit(). </li>
+<li> The camera is disconnected from the system. </li>
+</ul>
+
+XML messages are transfered to the camera by calling o3000_send_xml(). If the camera sends a XML message to the host, the 
+driver triggers the @ref xml_cb. The same concept is used, when the camera sends video data to the host. After receving a complete frame, the driver calls the 
+@ref video_cb.
+
+@note The video driver triggers any callback from the thread context, where o3000_connect() is called from. This means that the o3000_send_xml() function should
+never be called from the Video, XML or Logging callback. Otherwise the driver will lock. It's important, that any XML message sent with o3000_send_xml() to the camera
+is called from a different thread context.
+
+
+
+@subsection cb_fun Callback functions
+
+@subsubsection video_cb Video handler
+
+The video handler is called by the camera driver whenever a complete frame 
+is received. The video handler holds a pointer to the image
+data (the frame) and a pointer to a structure describing the image format. 
+This handler is mandatory.
+
+@subsubsection xml_cb XML handler
+
+The XML handler is called by the camera driver whenever a XML message is 
+received. The XML handler holds a pointer to a string buffer
+containing the XML message, and the length of that message. This handler is
+mandatory.
+
+@subsubsection log_cb Logging handler
+
+The Logging handler is called by the driver to print debug messages.
+The handler contains a pointer to a (zero-terminated) string buffer
+containing the log message. This handler is optional.
+@note The verbosity of the messages depends on the log level and is defined from @ref O3000_LOG_NONE to @ref O3000_LOG_VERBOSE.
+
+@section example Example
+
+A simplified example with C is shown below, focussing on the order in which the various
+camera driver functions should be called. It's up to the user to implement
+multithreading in order to avoid a deadlock due to the blocking nature of o3000_connect()!
+
+@code
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <o3000/o3000.h>
+
+
+static char xml_msg[] = {"<camera><stream></stream></camera>"};
+
+static void xml_handling(int id, char* msg, int len) {
+	// insert your code here
+}
+
+static void video_handling(int id, unsigned char* buf, struct img_header_t* img_header) {
+	// insert your code here
+}
+
+static void log_handling(int id, char* msg) {
+	// insert your code here
+}
+
+int main(int argc, char **argv) {
+	
+	int ret = 0;
+	int num_camera, i;
+	int cam_session;
+	
+	
+	// setup camera session with 4 MByte video cache
+	cam_session = o3000_init(O3000_VID, O3000_PID, 1024*1024*4, xml_handling, video_handling, log_handling, O3000_LOG_ERROR);
+	if(cam_session < 0) {
+		exit(1);
+	}
+	
+	num_camera = o3000_device_discovery(cam_session);
+	if(num_camera < 0) {
+		o3000_exit(cam_session);
+		exit(1);
+	}
+	
+	if(num_camera == 0) {
+		printf("%s: no camera connected to the system\n", __func__);
+		o3000_exit(cam_session);
+		exit(1);
+	}
+	
+	// establish connection to first available camera
+	for(i = 0; i < num_camera; i++) {
+		printf("%s: establish connection to camera %d\n", __func__, i);
+		ret = o3000_connect(cam_session, i, xml_msg, strlen(xml_msg));
+		if(ret == O3000_ERROR_BUSY) {
+			printf("%s: device %d is already in use\n", __func__, i);
+		}
+		else {
+			break;
+		}
+	}
+	
+	o3000_exit(cam_session);
+    exit(0);
+}
+
+@endcode
+
+*/
+
+/* Video buffering concept
+
+At program initialisation, a number of transfer buffers is sent to libusb.
+Libusb handles the low-level interactions with the kernel. A transfer is split
+into a number of URBs. These URBs are sent to the kernel and returned to libusb 
+with the data received. As soon as enough data was received, libusb calls the
+transfer callback, which processes the data. In this case, the transfer handler
+is called. As soon as the transfer is handled, the transfer is resubmitted to
+libusb, ready to be filled again.
+
+Each transfer points to a buffer, where received data is copied to. All transfer
+buffers T(x) and the frame buffer FB (see below) are contiguous, i.e. starting 
+from T(0) (transfer 0) to the end of the frame buffer a linear memory region 
+without holes is allocated.
+
+Memory Layout:
+
++---- start of video cache
+|                                         +---- start of frame buffer
+|                                         |
+|                                         |
+V                                         V
++------+------+------+------+------+------+--------------------+
+| T(0) | T(1) | T(2) | T(3) | .... | T(n) | Frame buffer       |
++------+------+------+------+------+------+--------------------+
+
+The transfers are submitted starting from T(0). As they are queued, the order
+T(0), T(1), etc. is always maintained. After filling the last buffer T(n),
+the sequence starts over with T(0). No double-buffering takes place, as by the
+strict sequence order and the fact that a received buffer is processed first 
+before resubmission there is no risk of overwriting unprocessed data.
+
+The transfer handler scans through the data received. Whenever a complete frame
+is found in the buffers, the video callback is called, which is supposed to
+process the frame.
+
+A special case applies, if an incomplete frame remains at the end of T(n), which
+will be continued with T(0) (and maybe subsequent transfers). In that situation,
+if the frame is completely received, the second part, starting from T(0) will
+be copied to the frame buffer. As the frame buffer is linked directly after T(n),
+the frame is now located in a linear part of the memory, which is a condition for
+the video callback function which expects a pointer to a linear buffer, holding
+the frame.
+
+An other special case occurs, when a snapshot is sent. The last portion of a snapshot
+is usually sent as a short bulk transfer packet, which means, that a subsequent snapshot
+or streaming frame will be aligned to the start of a transfer, leaving a gap of invalid
+data between two frames in the video cache.
+
+Depending on the transfer size chosen, a frame may extend over several transfers,
+or a transfer may contain several frames.
+
+*/
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+
+#include "o3000/o3000_portable.h"
+#include "o3000_private.h"
+#include "o3000/o3000.h"
+#include "o3000_xfer_handler.h"
+
+
+#define CAM_IN_EP	(1 | LIBUSB_ENDPOINT_IN)	///< endpoint for video data
+#define XML_IN_EP	(2 | LIBUSB_ENDPOINT_IN)	///< endpoint for inbound XML messages
+#define XML_OUT_EP	(1)							///< endpoint for outbound XML messages
+
+
+
+/**
+ * Inbound XML messages size
+ */
+#define XML_IN_BUF_SIZE		16384	
+
+
+/**
+ * Maximum image size ever expected.
+ * 
+ * @note The size must be a multiple of 512 bytes!
+ */
+#define MAX_IMAGE_SIZE						(1280*964*2+IMAGE_HEADER_SIZE)
+
+/**
+ * Minimum video cache size.
+ * It's the double of the maximum image size ever expected.
+ */
+#define MIN_VIDEO_CACHE_SIZE				(MAX_IMAGE_SIZE)
+
+
+/**
+ * maximum number of camera sessions
+ */
+#define MAX_NUM_SESSION						16
+
+
+/**
+ * The video cache is divided into several USB transfer queued at at kernel.
+ */
+#define NUM_USB_VIDEO_TRANSFER				10
+
+
+/**
+ * Session table
+ * Each table entry points to an active session. If the entry is NULL it's not used and can be used for a new session.
+ */
+static struct o3000_session_t *session_table[MAX_NUM_SESSION];
+
+/*
+ * Thread synchronization mutex
+ */
+static o3000_mutex_static_t session_lock = O3000_MUTEX_INITIALIZER;
+
+/**
+ * Maps loglevel numbers to descriptive strings
+ */
+static const char *dbg_strlevel[] = {
+	"NONE",
+	"ERROR",
+	"WARNING",
+	"INFO",
+	"DEBUG"
+};
+
+
+
+/**
+ * Return session by ID
+ * 
+ * @param id session ID
+ * @return adress to session or NULL if not available
+ */
+static struct o3000_session_t *get_session(int id) {
+	
+	struct o3000_session_t *session;
+	
+	if(id < 0 || id >= MAX_NUM_SESSION) {
+		return NULL;
+	}
+	session = session_table[id];
+	if(session == NULL) {
+		return NULL;
+	}
+	return session;
+}
+
+
+/**
+ * Cleanup given session.
+ * Everything is cleaned up like:
+ * - closing current session
+ * - release USB transfers
+ * - release video cache and XML message buffer
+ * 
+ * In the end, the current session is freed.
+ * 
+ */
+static void cleanup(int id) {
+	
+	struct o3000_session_t *session;
+	int i;
+	
+	
+	session = get_session(id);
+	if(session == NULL) {
+		return;
+	}
+	
+	// release device list
+	if(session->device_list != NULL) {
+		o3000_log(session, O3000_LOG_DEBUG, "%s: cleanup USB device discovery list\n", __func__);
+		libusb_free_device_list(session->device_list, 1);
+		session->device_list = NULL;
+		session->num_device_list = 0;
+	}
+	
+	// close USB device
+	if(session->dev != NULL) {
+		o3000_log(session, O3000_LOG_DEBUG, "%s: close USB device handler\n", __func__);
+		libusb_close(session->dev);
+		session->dev = NULL;
+	}
+	
+	// release USB video transfer
+	for(i = 0; i < NUM_USB_VIDEO_TRANSFER; i++) {
+		if(session->transfer_data[i] != NULL) {
+			o3000_log(session, O3000_LOG_DEBUG, "%s: release USB video transfers %d\n", __func__, i);
+			libusb_free_transfer(session->transfer_data[i]);
+			session->transfer_data[i] = NULL;
+		}
+	}
+	
+	// release USB transfer transfer array
+	if(session->transfer_data != NULL) {
+		o3000_log(session, O3000_LOG_DEBUG, "%s: release USB transfer array\n", __func__);
+		free(session->transfer_data);
+		session->transfer_data = NULL;
+	}
+	
+	// release USB XML transfer for incoming messages
+	if(session->transfer_xml_in != NULL) {
+		o3000_log(session, O3000_LOG_DEBUG, "%s: release USB XML transfer for incoming messages\n", __func__);
+		libusb_free_transfer(session->transfer_xml_in);
+		session->transfer_xml_in = NULL;
+	}
+	
+	// release XML buffer
+	if(session->xml_in_buf != NULL) {
+		o3000_log(session, O3000_LOG_DEBUG, "%s: release XML message buffer\n", __func__);
+		free(session->xml_in_buf);
+		session->xml_in_buf = NULL;
+	}
+	
+	// release video cache
+	if(session->video_cache != NULL) {
+		o3000_log(session, O3000_LOG_DEBUG, "%s: release video cache\n", __func__);
+		free(session->video_cache);
+		session->video_cache = NULL;
+	}
+	
+	
+	
+	// add more cleanup code here...
+	// ..
+	
+	
+	
+	// close libusb context
+	if(session->libusb_ctx != NULL) {
+		o3000_log(session, O3000_LOG_DEBUG, "%s: release USB context\n", __func__);
+		libusb_exit(session->libusb_ctx);
+		session->libusb_ctx = NULL;
+	}
+	
+	// finally release this session
+	if(session_table[id] != NULL) {
+		o3000_log(session, O3000_LOG_DEBUG, "%s: release USB session\n", __func__);
+		free(session_table[id]);
+		session_table[id] = NULL;
+	}
+}
+
+
+
+/**
+ * Check wether given USB device is a camera
+ * 
+ * @param session session pointer
+ * @param device USB device to check
+ * @return TRUE if it's a camera otherwise FALSE
+ */
+static int is_camera(struct o3000_session_t *session, libusb_device *device) {
+	
+	int ret, dev_of_interest;
+	struct libusb_device_descriptor desc;
+	
+	ret = libusb_get_device_descriptor(device, &desc);
+	if(ret != 0) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: getting USB descriptor failed (code %d)\n", __func__, ret);
+		return FALSE;
+	}
+	
+	dev_of_interest = FALSE;
+	if((desc.idVendor == session->vid) && (desc.idProduct == session->pid)) {
+		dev_of_interest = TRUE;
+	}
+	
+	o3000_log(session, O3000_LOG_DEBUG, "%s: USB device detected (Device class %d, VID:PID 0x%x:0x%x, S/N %d) - %s\n",
+			  __func__, desc.bDeviceClass, desc.idVendor, desc.idProduct, desc.iSerialNumber, dev_of_interest == TRUE ? "camera":"no camera");
+	
+	return dev_of_interest;
+}
+
+
+/**
+ * Print a meaningful message for given transfer result.
+ * 
+ * @param result libusb submit transfer return code.
+ * @return o3000 error code translation (see @ref o3000.h)
+ */
+static int print_transfer_result(struct o3000_session_t *session, int result) {
+	
+	int error_code = O3000_ERROR_OTHER;
+	
+	switch(result) {
+		case 0:
+			o3000_log(session, O3000_LOG_DEBUG, "%s: transfer successfully completed\n", __func__);
+			error_code = O3000_SUCCESS;
+			break;
+			
+		case LIBUSB_ERROR_NO_DEVICE:
+			o3000_log(session, O3000_LOG_ERROR, "%s: device has been disconnected\n", __func__);
+			error_code = O3000_ERROR_NODEV;
+			break;
+			
+		case LIBUSB_ERROR_BUSY:
+			o3000_log(session, O3000_LOG_ERROR, "%s: transfer has already been submitted\n", __func__);
+			error_code = O3000_ERROR_BUSY;
+			break;
+			
+		case LIBUSB_ERROR_NOT_SUPPORTED:
+			o3000_log(session, O3000_LOG_ERROR, "%s: transfer flags not supported by the OS\n", __func__);
+			break;
+			
+		default:
+			o3000_log(session, O3000_LOG_ERROR, "%s: other error (code %d)\n",__func__, result);
+	}
+	return error_code;
+}
+
+
+/**
+ * Print a meaningful message for given transfer status.
+ * 
+ * @param status libusb status code
+ */
+static void print_transfer_status(struct o3000_session_t *session, enum libusb_transfer_status status) {
+	switch(status) {
+		case LIBUSB_TRANSFER_COMPLETED:
+			o3000_log(session, O3000_LOG_DEBUG, "%s: transfer successfully completed\n", __func__);
+			break;
+		case LIBUSB_TRANSFER_ERROR:
+			o3000_log(session, O3000_LOG_DEBUG, "%s: Error: transfer failed\n", __func__);
+			break;
+		case LIBUSB_TRANSFER_TIMED_OUT:
+			o3000_log(session, O3000_LOG_DEBUG, "transfer timed out\n", __func__);
+			break;
+		case LIBUSB_TRANSFER_CANCELLED:
+			o3000_log(session, O3000_LOG_DEBUG, "transfer was cancelled\n", __func__);
+			break;
+		case LIBUSB_TRANSFER_STALL:
+			o3000_log(session, O3000_LOG_DEBUG, "%s: endpoint stalled\n", __func__);
+			break;
+		case LIBUSB_TRANSFER_NO_DEVICE:
+			o3000_log(session, O3000_LOG_DEBUG, "%s: device has been disconnected\n", __func__);
+			break;
+		case LIBUSB_TRANSFER_OVERFLOW:
+			o3000_log(session, O3000_LOG_DEBUG, "%s: device sent more data than requested\n", __func__);
+			break;
+		default:
+			o3000_log(session, O3000_LOG_DEBUG, "%s: Error: unknown\n", __func__);
+	}
+}
+
+
+/**
+ * Check whether all transfers are cleanuped (freed).
+ * This includes all video transfers and the XML transfer.
+ *
+ * @param session current session
+ * @return FALSE if any transfer is pending for cleaning up; TRUE if all transfers are cleanuped
+ */
+static int allTransfersCleanup(struct o3000_session_t *session) {
+	int i;
+	
+	if(session->transfer_xml_in != NULL) {
+		return FALSE;
+	}
+	
+	for(i = 0; i < NUM_USB_VIDEO_TRANSFER; i++) {
+		if(session->transfer_data[i] != NULL) {
+			return FALSE;
+		}
+	}
+	return TRUE;
+}
+
+
+/**
+ * Cleanup current USB transfer (XML or video transfer).
+ *
+ * @param transfer current transfer to clean up
+ */
+static void cleanup_transfer(struct libusb_transfer *transfer) {
+	
+	int i;
+	struct o3000_session_t *session = transfer->user_data;
+	
+	
+	session->cleanup_transfers = TRUE;
+	
+	// print transfer status for debugging purposes
+	print_transfer_status(session, transfer->status);
+	
+	
+	if(transfer == session->transfer_xml_in) {
+		// release USB XML transfer
+		if(session->transfer_xml_in != NULL) {
+			libusb_free_transfer(session->transfer_xml_in);
+			o3000_log(session, O3000_LOG_INFO, "%s: cleanup XML transfer (%p)\n", __func__, session->transfer_xml_in);
+			session->transfer_xml_in = NULL;
+			transfer = NULL;
+		}
+	}
+	else {
+		// release USB video transfer
+		for(i = 0; i < NUM_USB_VIDEO_TRANSFER; i++) {
+			if(session->transfer_data[i] == transfer) {
+				libusb_free_transfer(session->transfer_data[i]);
+				o3000_log(session, O3000_LOG_INFO, "%s: cleanup video transfer %d (%p)\n", __func__, i, session->transfer_data[i]);
+				session->transfer_data[i] = NULL;
+				transfer = NULL;
+				break;
+			}
+		}
+	}
+	
+	if(transfer != NULL) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: FIXME: This transfer %p should be cleaned!\n", __func__, transfer);
+	}
+	
+	// reset running flag only when all transfers are cleaned up
+	if(allTransfersCleanup(session)) {
+		o3000_log(session, O3000_LOG_INFO, "%s: all USB transfers are cleaned up\n", __func__);
+		session->running = FALSE;
+	}
+}
+
+
+/**
+ * Transfer done callback for inbound XML.
+ * 
+ * @note Transfer done only means submitted, not actually completed!
+ * 
+ * @param  transfer Pointer to XML transfer which has been submitted
+ */
+static void LIBUSB_CALL cb_xml_in_xfer_done(struct libusb_transfer *transfer) {
+	
+	int retval;
+	struct o3000_session_t *session = transfer->user_data;
+	
+	
+	if(transfer->status == LIBUSB_TRANSFER_COMPLETED) {
+		
+		// check whether string length is out of range
+		if(transfer->actual_length < 0 || transfer->actual_length >= XML_IN_BUF_SIZE) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: invalid XML message length (len = %d)\n", __func__, transfer->actual_length);
+		}
+		else {
+			session->xml_in_buf[transfer->actual_length] = '\0';
+			session->xml_cb(session->id, session->xml_in_buf, transfer->actual_length);
+		}
+		
+		// resubmit transfer only if driver isn't cleaning up
+		if(session->cleanup_transfers == FALSE) {
+			retval = libusb_submit_transfer(session->transfer_xml_in);
+			if(retval != 0) {				
+				o3000_log(session, O3000_LOG_ERROR, "%s: resubmit XML transfer failed (code %d) --> cleanup\n", __func__, retval);
+				print_transfer_result(session, retval);
+				cleanup_transfer(transfer);
+			}
+		}
+		else {
+			o3000_log(session, O3000_LOG_INFO, "%s: cleaning up in progress\n", __func__);
+			cleanup_transfer(transfer);
+		}
+	}
+	else {
+		/*
+		 * USB transfer is not completed!
+		 * Do only clean up the transfer if the device has been disconnected or cleaning-up flag is set.
+		 * Otherwise skip error and resubmit current transfer.
+		 */
+		if(transfer->status == LIBUSB_TRANSFER_NO_DEVICE || session->cleanup_transfers == TRUE) {
+			o3000_log(session, O3000_LOG_INFO, "%s: cleaning up in progress (%s), no device (%s)\n",
+					  __func__, session->cleanup_transfers == TRUE ? "yes":"no", transfer->status == LIBUSB_TRANSFER_NO_DEVICE ? "yes":"no");
+			cleanup_transfer(transfer);
+		}
+		else {
+			retval = libusb_submit_transfer(session->transfer_xml_in);
+			if(retval != 0) {
+				o3000_log(session, O3000_LOG_ERROR, "%s: Could resubmit XML transfer (code %d)\n", __func__, retval);
+				print_transfer_result(session, retval);
+				cleanup_transfer(transfer);
+			}
+		}
+	}
+}
+
+
+/**
+ * Transfer done callback for video data.
+ * 
+ * @note Transfer done only means submitted, not actually completed!
+ * 
+ * @param transfer Pointer to transfer which just has been submitted
+ */
+static void LIBUSB_CALL cb_video_xfer_done(struct libusb_transfer *transfer) {
+
+	int retval;
+	struct o3000_session_t *session = transfer->user_data;
+	
+	
+	if(transfer->status == LIBUSB_TRANSFER_COMPLETED) {
+
+		if(transfer->actual_length > 0) {
+			handle_transfer(session, (uint8_t*)(transfer->buffer), transfer->actual_length);	
+		}
+		
+		// resubmit transfer only if driver is not exiting
+		if(session->cleanup_transfers == FALSE) {
+			retval = libusb_submit_transfer(transfer);
+			if(retval != 0) {
+				o3000_log(session, O3000_LOG_ERROR, "%s: Could resubmit video transfer (code %d)\n", __func__, retval);
+				print_transfer_result(session, retval);
+				cleanup_transfer(transfer);
+			}
+		}
+		else {
+			o3000_log(session, O3000_LOG_INFO, "%s: cleaning up in progress\n", __func__);
+			cleanup_transfer(transfer);
+		}
+	} 
+	else {
+		/*
+		 * USB transfer is not completed!
+		 * Do only clean up the transfer if the device has been disconnected or cleaning-up flag is set.
+		 * Otherwise skip error and resubmit current transfer.
+		 */
+		if(transfer->status == LIBUSB_TRANSFER_NO_DEVICE || session->cleanup_transfers == TRUE) {
+			o3000_log(session, O3000_LOG_INFO, "%s: cleaning up in progress (%s), no device (%s)\n",
+					  __func__, session->cleanup_transfers == TRUE ? "yes":"no", transfer->status == LIBUSB_TRANSFER_NO_DEVICE ? "yes":"no");
+			cleanup_transfer(transfer);
+		}
+		else {
+			retval = libusb_submit_transfer(transfer);
+			if(retval != 0) {
+				o3000_log(session, O3000_LOG_ERROR, "%s: Could resubmit video transfer (code %d)\n", __func__, retval);
+				print_transfer_result(session, retval);
+				cleanup_transfer(transfer);
+			}
+		}
+	}
+}
+
+
+/**
+ * Prepare USB transfers to receive video data and XML messages from device.
+ * 
+ * @param session session pointer
+ * @return 0 on success, or error code (see @ref o3000.h)
+ */
+static int prepare_usb_transfers(struct o3000_session_t *session) {
+	
+	int i, retval;
+	struct libusb_transfer *new_transfer;
+	int error_code = O3000_ERROR_OTHER;
+	uint8_t *xfer_buf;
+	
+	
+	// paranoia check
+	if(session->transfer_data == NULL) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: FIXME: pointer array used for video transfer is not allocated!\n", __func__);
+		return O3000_ERROR_OTHER;
+	}
+		
+	/*
+	 * setup video transfer array
+	 */
+	for(i = 0; i < NUM_USB_VIDEO_TRANSFER; i++) {
+		
+		// Allocate transfer
+		new_transfer = libusb_alloc_transfer(0);
+		if(new_transfer == NULL) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: Could not allocate video transfer %d\n", __func__, i);
+			error_code = O3000_ERROR_NOMEM;
+			goto _prepare_usb_transfer_abort;
+		}
+		session->transfer_data[i] = new_transfer;
+		
+		// Video transfers are using the same callback but with own user data pointer pointing to current session definition.
+		xfer_buf = session->video_cache + i*(session->video_chunk_size);
+		libusb_fill_bulk_transfer(new_transfer, session->dev, CAM_IN_EP, xfer_buf, session->video_chunk_size, cb_video_xfer_done, session, 0);
+
+		// Submit transfer
+		retval = libusb_submit_transfer(new_transfer);
+		if(retval != 0) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: Could not submit video transfer %d (code %d)\n", __func__, i, retval);
+			error_code = print_transfer_result(session, retval);
+			goto _prepare_usb_transfer_abort;
+		}
+		o3000_log(session, O3000_LOG_DEBUG, "%s: video transfer %d allocated and submitted (%p)\n", __func__, i, new_transfer);
+	}
+		
+	/*
+	 * setup single XML transfer
+	 */
+	new_transfer = libusb_alloc_transfer(0);
+	if(new_transfer == NULL) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: Could not allocate XML transfer\n", __func__);
+		error_code = O3000_ERROR_NOMEM;
+		goto _prepare_usb_transfer_abort;
+	}
+	session->transfer_xml_in = new_transfer;
+	
+	// prepare and submit transfer
+	libusb_fill_bulk_transfer(new_transfer, session->dev, XML_IN_EP, (unsigned char*)(session->xml_in_buf), XML_IN_BUF_SIZE, cb_xml_in_xfer_done, session, 0);
+	retval = libusb_submit_transfer(new_transfer);
+	if(retval != 0) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: Could not submit XML transfer (code %d)\n", __func__, retval);
+		error_code = print_transfer_result(session, retval);
+		goto _prepare_usb_transfer_abort;
+	}
+	
+	o3000_log(session, O3000_LOG_DEBUG, "%s: XML transfer allocated and submitted (%p)\n", __func__, new_transfer);
+	return 0;
+	
+	
+_prepare_usb_transfer_abort:
+	return error_code;
+}
+
+
+/**
+ * Send XML message to device.
+ * 
+ * @param session current session
+ * @param msg message content
+ * @param msg_len message content length
+ * @return 0 on success, or error code (see @ref o3000.h)
+ */
+static int send_xml(struct o3000_session_t *session, const char *msg, int msg_len) {
+	
+	int xml_msg_transferred, retval, ret_code;
+	
+	// use timeout of 1 second
+	ret_code = 0;
+	retval = libusb_bulk_transfer(session->dev, XML_OUT_EP, (unsigned char*)msg, msg_len, &xml_msg_transferred, 1000); 	
+	if(retval != 0) {
+		if(retval == LIBUSB_ERROR_TIMEOUT) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: sending XML message failed (timeout)\n", __func__, retval);
+			ret_code = O3000_ERROR_USB_TRANSFER_TIMEOUT;
+		}
+		else if(retval == LIBUSB_ERROR_PIPE) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: sending XML message failed (pipe error)\n", __func__, retval);
+			ret_code = O3000_ERROR_USB_EP_HALTED;
+		}
+		else if(retval == LIBUSB_ERROR_NO_DEVICE) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: sending XML message failed (no device)\n", __func__, retval);
+			ret_code = O3000_ERROR_NODEV;
+		}
+		else {
+			o3000_log(session, O3000_LOG_ERROR, "%s: sending XML message failed (code %d)\n", __func__, retval);
+			ret_code = O3000_ERROR_OTHER;
+		}
+	}
+	else if(xml_msg_transferred != msg_len) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: less data are transfered to the device than expected (%d of %d bytes)\n", __func__, xml_msg_transferred, msg_len);
+		ret_code = O3000_ERROR_LESS_DATA;
+	}
+	return ret_code;
+}
+
+
+/**
+ * Send XML packet from host to device.
+ * 
+ * @note Never call this function from the thread context  o3000_connect() is called from!
+ * 
+ * @param id session ID
+ * @param msg message content
+ * @param msg_len message content length
+ * @return 0 on success, or error code (see @ref o3000.h)
+ */
+int __stdcall o3000_send_xml(int id, const char *msg, int msg_len) {
+	
+	struct o3000_session_t *session;	
+	
+	session = get_session(id);
+	if(session == NULL) {
+		return O3000_ERROR_INVALID_SESSION_ID;
+	}
+	
+	if(msg == NULL) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: no message defined\n", __func__);
+		return O3000_ERROR_OTHER;
+	}
+	
+	if(msg_len <= 0) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: invalid message length %d\n", __func__, msg_len);
+		return O3000_ERROR_OTHER;
+	}
+	
+	if(session->running == FALSE) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: driver is not running\n", __func__);
+		return O3000_ERROR_DRV_NOT_CONNECTED;
+	}
+	
+	if(session->cleanup_transfers == TRUE) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: driver is cleaning up\n", __func__);
+		return O3000_ERROR_DRV_NOT_CONNECTED;
+	}
+	
+	return (send_xml(session, msg, msg_len));
+}
+
+
+/**
+ * Disconnect a currently claimed USB connection.
+ * Use this function if the driver is connected to an USB device. The o3000_connect() function-call is blocking now.
+ * After disconnecting, the function o3000_connect() returns. The session is not cleaned-up due to the driver is ready the reconnect
+ * to the same USB device by calling o3000_connect() again.
+ * 
+ * @param id session ID
+ * @return 0 on success, or error code defined at @ref o3000.h.
+ */
+int __stdcall o3000_disconnect(int id) {
+	
+	struct o3000_session_t *session;
+	int retval;
+	
+	
+	session = get_session(id);
+	if(session == NULL) {
+		return O3000_ERROR_INVALID_SESSION_ID;
+	}
+	
+	if(session->running == FALSE) {
+		o3000_log(session, O3000_LOG_WARNING, "%s: driver is not connected!\n", __func__);
+		return O3000_ERROR_DRV_NOT_CONNECTED;
+	}
+	
+	o3000_log(session, O3000_LOG_DEBUG, "%s: disconnect USB device (release interface)\n", __func__);
+	session->cleanup_transfers = TRUE;
+	session->disconnect_dev = TRUE;
+	retval = libusb_release_interface(session->dev, 0);
+	if(retval == LIBUSB_ERROR_NOT_FOUND) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: releasing interface failed: interface not claimed\n", __func__);
+	}
+	else if(retval == LIBUSB_ERROR_NO_DEVICE) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: releasing interface failed: device has been disconnected\n", __func__);
+	}
+	else if(retval != 0) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: releasing interface failed (code %d)\n", __func__, retval);
+	}
+	return retval;
+}
+
+
+/**
+ * Estabslish a connection to an existing device.
+ * If several devices are available on the same system, the device number is used. The number of devices are requested
+ * by o3000_get_num_device().
+ * 
+ * NOTE
+ * This function will block until the USB device is disconnected manually or the driver is stopped by calling o3000_exit().
+ * 
+ * @param id session ID
+ * @param device_nr device number to connect (use 0 to connect to first available device)
+ * @param config_msg configuration message to be sent to device after successful connection, or NULL if not used
+ * @param config_msg_len configuration message length
+ * @return 0 is returned only after calling dmm_exit() or dmm_disconnect(). Otherwise the error code defined at @ref o3000.h.
+ */
+int __stdcall o3000_connect(int id, int device_nr, char *config_msg, int config_msg_len) {
+	
+	struct o3000_session_t *session;
+	int ret, i, dev_cnt, completed;
+	libusb_device *device;
+	libusb_device_handle *handle;
+	int error_code = 0;
+	
+	
+	session = get_session(id);
+	if(session == NULL) {
+		return O3000_ERROR_INVALID_SESSION_ID;
+	}
+	
+	// reset all flags here
+	session->cleanup_transfers = FALSE;
+	session->disconnect_dev = FALSE;
+	session->release_session = FALSE;
+	
+	// check whether device list is defined
+	if(session->device_list == NULL) {
+		ret = o3000_device_discovery(id);
+		if(ret < 0) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: device discovery failed\n", __func__);
+			return ret;
+		}
+	}
+	
+	// look for device in question
+	dev_cnt = 0;
+	device = NULL;
+	for(i = 0; i < session->num_device_list; i++) {
+		if(is_camera(session, session->device_list[i]) == TRUE) {
+			if(device_nr == dev_cnt) {
+				device = session->device_list[i];
+				break;
+			}
+			dev_cnt++;
+		}
+	}
+	
+	if(device == NULL) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: USB device not available\n", __func__);
+		error_code = O3000_ERROR_NODEV;
+		goto _connect_abort;
+	}
+	
+	// now open the device
+	ret = libusb_open(device, &handle);
+	if(ret != 0) {
+		if(ret == LIBUSB_ERROR_NO_MEM) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: opening device failed: no memory\n", __func__);
+			error_code = O3000_ERROR_NOMEM;
+		}
+		else if(ret == LIBUSB_ERROR_ACCESS) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: opening device failed: no permission\n", __func__);
+			error_code =  O3000_ERROR_ACCESS;
+		}
+		else if(ret == LIBUSB_ERROR_NO_DEVICE) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: opening device failed: no such device\n", __func__);
+			error_code =  O3000_ERROR_NODEV;
+		}
+		else {
+			o3000_log(session, O3000_LOG_ERROR, "%s: opening device failed: other\n", __func__);
+			error_code =  O3000_ERROR_OTHER;
+		}
+		goto _connect_abort;
+	}
+	session->dev = handle;
+	
+	// now claim the interface
+	ret = libusb_claim_interface(handle, 0);
+	if(ret != 0) {
+		if(ret == LIBUSB_ERROR_NOT_FOUND) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: claiming device failed: requested device does not exist\n", __func__);
+			error_code = O3000_ERROR_NODEV;
+		}
+		else if(ret == LIBUSB_ERROR_BUSY) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: claiming device failed: device already in use\n", __func__);
+			error_code = O3000_ERROR_BUSY;
+		}
+		else if(ret == LIBUSB_ERROR_NO_DEVICE) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: claiming device failed: device has been disconnected\n", __func__);
+			error_code = O3000_ERROR_NODEV;
+		}
+		else {
+			o3000_log(session, O3000_LOG_ERROR, "%s: claiming device failed:other\n", __func__);
+			error_code = O3000_ERROR_OTHER;
+		}
+		goto _connect_abort;
+	}
+	
+	// setup all USB transfers (video and XML)
+	if(prepare_usb_transfers(session)) {
+		o3000_log(session, O3000_LOG_ERROR, "%s: preparing USB transfers failed\n", __func__);
+		error_code = O3000_ERROR_OTHER;
+		goto _connect_abort;
+	}
+	
+	/*
+	 * Send configuration message to device if available
+	 */
+	if(config_msg != NULL && config_msg_len > 0) {
+		o3000_log(session, O3000_LOG_INFO, "%s: send configuration string\n", __func__);
+		ret = send_xml(session, config_msg, config_msg_len);
+		if(ret != 0) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: sending configuration string failed (code %d)\n", __func__, ret);
+		}
+	}
+	
+	/*
+	 * Finally enter main-loop
+	 */
+	o3000_log(session, O3000_LOG_INFO, "%s: enter blocking loop for event handling\n", __func__);
+	session->running = TRUE;
+	while(session->running == TRUE) {
+		completed = 0;
+		ret = libusb_handle_events_completed(session->libusb_ctx, &completed);
+		if(ret != 0) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: USB event handling error (code %d)\n", __func__, ret);
+			break;
+		}
+	}
+	
+	
+	/*
+	 * There are following reasons to get here:
+	 * 
+	 * 1. o3000_disconnect() was called
+	 * 2. o3000_exit() was called
+	 * 3. the device isn't available anymore because it was unplugged, it does an USB hardware reset
+	 * 
+	 * The current session is cleaned-up only if o3000_exit() has been called. Otherwise the session will further exist and a reconnection with o3000_connect() will be allowed.
+	 * Actually, it doesn't make any sense to connect to an unavailable device. But to keep it simple, a session is cleaned-up only with o3000_exit() without any exception.
+	 */
+	if(session->release_session == FALSE && session->disconnect_dev == FALSE) {
+		// device was unplugged (see reason 3 few lines above)
+		o3000_log(session, O3000_LOG_DEBUG, "%s: release interface\n", __func__);
+		ret = libusb_release_interface(session->dev, 0);
+		if(ret != 0) {
+			o3000_log(session, O3000_LOG_ERROR, "%s: releasing interface failed (error code %d)\n", __func__, ret);
+		}
+		ret = O3000_ERROR_NODEV;
+	}
+	
+	// close USB device
+	if(session->dev != NULL) {
+		o3000_log(session, O3000_LOG_DEBUG, "%s: close USB device handler\n", __func__);
+		libusb_close(session->dev);
+		session->dev = NULL;
+	}
+	
+	// release session due to o3000_exit() call
+	if(session->release_session == TRUE) {
+		o3000_log(session, O3000_LOG_DEBUG, "%s: cleanup session\n", __func__);
+		session->release_session = FALSE;
+		cleanup(id);
+	}
+	return ret;
+	
+_connect_abort:
+	// close USB device
+	if(session->dev != NULL) {
+		o3000_log(session, O3000_LOG_DEBUG, "%s: close USB device handler\n", __func__);
+		libusb_close(session->dev);
+		session->dev = NULL;
+	}
+	return error_code;
+}
+
+
+/**
+ * The device discovery returns the number of USB devices in question.
+ * In fact, the number of devices with the session PID/VID are counted. After knowing the number of devices, any connection can be
+ * established with o3000_connect().
+ * 
+ * @param id valid session ID
+ * @return number of USB device or a negative return code
+ */
+int __stdcall o3000_device_discovery(int id) {
+	
+	int num_device, i, num_camera;
+	struct o3000_session_t *session;
+	
+	
+	session = get_session(id);
+	if(session == NULL) {
+		return O3000_ERROR_INVALID_SESSION_ID;
+	}
+	
+	// check whether device list is allocated already
+	if(session->device_list != NULL) {
+		libusb_free_device_list(session->device_list, 1);
+		session->device_list = NULL;
+	}
+		
+	// get list with all USB device currently attached to the system
+	session->num_device_list = 0;
+	num_device = libusb_get_device_list(session->libusb_ctx, &(session->device_list));
+	o3000_log(session, O3000_LOG_DEBUG, "%s: %d USB connected to the system\n", __func__, num_device);
+	
+	if(num_device < 0) {
+		o3000_log(session, O3000_LOG_WARNING, "%s: currently no USB device attached to the system (code %d)\n", __func__, num_device);
+		return O3000_ERROR_NODEV;
+	}
+	session->num_device_list = num_device;
+	
+	// count number of devices in question
+	num_camera = 0;
+	for(i = 0; i < num_device; i++) {
+		if(is_camera(session, session->device_list[i]) == TRUE) {
+			num_camera++;
+		}
+	}
+	
+	o3000_log(session, O3000_LOG_INFO, "%s: number of cameras found: %d\n", __func__, num_camera);
+	return num_camera;
+}
+
+
+/**
+ * Get number of connected O-3000 cameras to the system.
+ * 
+ * This function is thread save and can be called without an already opened
+ * session.
+ * 
+ * @return number of connected cameras or negative error code (see @ref o3000.h)
+ */
+int __stdcall o3000_get_num_cam(void) {
+	
+	libusb_context *libusb_ctx;
+	libusb_device **device_list;
+	int num_device, num_camera, i;
+	struct libusb_device_descriptor desc;
+	
+	if(libusb_init(&libusb_ctx)) {
+		return O3000_ERROR_OTHER;
+	}
+	
+	num_device = libusb_get_device_list(libusb_ctx, &device_list);
+	
+	if(num_device < 0) {
+		libusb_exit(libusb_ctx);
+		return O3000_ERROR_NODEV;
+	}
+	
+	// count number of devices in question
+	num_camera = 0;
+	for(i = 0; i < num_device; i++) {
+		if(libusb_get_device_descriptor(device_list[i], &desc)) {
+			libusb_free_device_list(device_list, 1);
+			libusb_exit(libusb_ctx);
+			return O3000_ERROR_OTHER;
+		}
+		if((desc.idVendor != O3000_VID) || (desc.idProduct != O3000_PID)) {
+			continue;
+		}
+		num_camera++;
+	}
+	
+	libusb_free_device_list(device_list, 1);
+	libusb_exit(libusb_ctx);
+	return num_camera;
+}
+
+
+/**
+ * Logging function.
+ * 
+ * Concatenates level and message and forwards the resulting string to the logging function.
+ * 
+ * @param session session pointer
+ * @param level The logging level (from @ref O3000_LOG_NONE to @ref O3000_LOG_DEBUG)
+ * @param fmt The format string
+ */
+void __stdcall o3000_log(struct o3000_session_t *session, const int level, const char *fmt, ...) {
+	
+	va_list	args;
+	char str[1024];
+	char *str_ptr = str;
+	int level_int;
+	int max_level;
+
+	if(level > session->loglevel) {
+		return; // ignore messages beyond session loglevel
+	}
+
+	if(session->log_cb == NULL) {
+		// session has no callback registered; ignore request
+		return;
+	}
+	
+	if(fmt == NULL) {
+		return;
+	}
+
+	// check range of level and limit (clamp) it
+	max_level = sizeof(dbg_strlevel)/sizeof(char*)-1;
+	level_int = (level > max_level) ? max_level : level;
+	
+	str_ptr += sprintf(str_ptr, "%s: ", dbg_strlevel[level_int]);
+	
+	va_start(args, fmt);
+	vsprintf(str, fmt, args);
+	va_end(args);
+	
+	session->log_cb(session->id, str);
+}
+
+
+/**
+ * Initialize O-3000 session.
+ * A new O-3000 session is initialized by calling this function. Several buffers are allocated and the USB context is setup.
+ * The driver automatically divides the video cache to @ref NUM_USB_VIDEO_TRANSFER USB transfers. The video cache size must be at least
+ * an image frame size. It's recommended that the size is more the 2 times the maximum expected image size.
+ * 
+ * A suitable video cache size is calculated by following example:
+ * Maximum expected image resolution:		1280x960 with 2 bytes/pixel
+ * Recommended video cache size:			1280*960*2*3 = 3686400 bytes = 3.5 MByte (3 times the image size)
+ * 
+ * NOTE
+ * This function must be called before connecting to any O-3000 camera.
+ * 
+ * @param vid USB vendor ID; use default VID if 0
+ * @param pid USB product ID; use default PID if 0
+ * @param video_cache_size Requested video cache size (in bytes); note: might be adjusted by the driver
+ * @param xml_cb XML receive callback
+ * @param video_cb	Video receive callback
+ * @param log_cb Logging callback, or NULL if not used
+ * @param loglevel logging level (from @ref O3000_LOG_NONE to @ref O3000_LOG_VERBOSE)
+ * @return positive session ID starting from 0, or error code (see @ref o3000.h)
+ */
+int __stdcall o3000_init(int vid, int pid, unsigned int video_cache_size,
+						 void __stdcall (*xml_cb)(int id, char* buf, int len),
+						 void __stdcall (*video_cb)(int id, unsigned char* buf, struct img_header_t* img_header),
+						 void __stdcall (*log_cb)(int id, char* msg),
+						 int loglevel) {
+	
+	int i, new_session_id, ret;
+	struct o3000_session_t *new_session;
+	int error_code = O3000_ERROR_OTHER;
+	int transfer_size, total_buffer_size;
+	
+	
+	// Validate callbacks
+	if(xml_cb == NULL || video_cb == NULL) {
+		return O3000_ERROR_NOCALLBACK;
+	}
+	
+	/*
+	 * Look for next free session
+	 * Session table access must be atmic
+	 */
+	new_session_id = -1;
+	o3000_mutex_static_lock(&session_lock);
+	for(i = 0; i < MAX_NUM_SESSION; i++) {
+		if(session_table[i] == NULL) {
+			new_session_id = i;
+			break;
+		}
+	}
+	
+	if(new_session_id == -1) {
+		return O3000_ERROR_NO_FREE_SESSION;
+	}
+	
+	// allocate session and save session data
+	new_session = calloc(1, sizeof(struct o3000_session_t));
+	if(new_session == NULL) {
+		return O3000_ERROR_NOMEM;
+	}
+	session_table[new_session_id] = new_session;
+	o3000_mutex_static_unlock(&session_lock);
+	
+	new_session->id = new_session_id;
+	new_session->vid = ((vid == 0) ? O3000_VID : vid); // set default if vid not set
+	new_session->pid = ((pid == 0) ? O3000_PID : pid); // set default if vid not set
+	
+	if(loglevel < O3000_LOG_NONE || loglevel > O3000_LOG_VERBOSE) {
+		new_session->loglevel = O3000_LOG_NONE;
+	}
+	else{
+		new_session->loglevel = loglevel;
+	}
+	
+	new_session->xml_cb = xml_cb;
+	new_session->video_cb = video_cb;
+	new_session->log_cb = log_cb;
+	
+	
+	// open libusb context
+	ret = libusb_init(&(new_session->libusb_ctx));
+	if(ret != 0) {
+		o3000_log(new_session, O3000_LOG_ERROR, "%s: initializing libusb context failed (code %d)\n", __func__, ret);
+		error_code = O3000_ERROR_OTHER;
+		goto _o3000_init_abort;
+	}
+	
+	/*
+	 * If loglevel is set to O3000_LOG_VERBOSE, do set libusb loglevel to debug.
+	 * This will flood the logging handler and is useful for debugging purposes only!
+	 */
+	if(loglevel == O3000_LOG_VERBOSE) {
+		libusb_set_debug(new_session->libusb_ctx, LIBUSB_LOG_LEVEL_DEBUG);
+	}
+	else {
+		libusb_set_debug(new_session->libusb_ctx, LIBUSB_LOG_LEVEL_NONE);
+	}
+	
+	// allocate XML buffer
+	if((new_session->xml_in_buf = malloc(XML_IN_BUF_SIZE)) == NULL) {
+		o3000_log(new_session, O3000_LOG_ERROR, "%s: failed to allocate XML buffer\n", __func__);
+		error_code = O3000_ERROR_NOMEM;
+		goto _o3000_init_abort;
+	}
+	
+	
+	/*
+	 * The image size must be larger or equal to the maximum image size ever to be expected. The
+	 * video cache is divided in several adjacent bulk transfers.
+	 */
+	if(video_cache_size < MIN_VIDEO_CACHE_SIZE) {
+		video_cache_size = MIN_VIDEO_CACHE_SIZE;
+	}
+	
+	
+	// calculate video cache
+	transfer_size = video_cache_size/NUM_USB_VIDEO_TRANSFER;
+	if(transfer_size % 512) {
+		/*
+		 * Do adjust USB bulk transfer size to a multiple of 512 bytes which is 
+		 * equal to the bulk payload size (at high-speed). 
+		 */
+		transfer_size = ((transfer_size/512)+1)*512;
+	}
+	video_cache_size = NUM_USB_VIDEO_TRANSFER * transfer_size;
+
+	// calculate and allocate total buffer size
+	total_buffer_size = video_cache_size + MAX_IMAGE_SIZE;
+	if((new_session->video_cache = malloc(total_buffer_size)) == NULL) {
+		o3000_log(new_session, O3000_LOG_ERROR, "%s: failed to allocate video cache\n", __func__);
+		error_code = O3000_ERROR_NOMEM;
+		goto _o3000_init_abort;
+	}
+	new_session->frame_buf = new_session->video_cache + video_cache_size;
+	new_session->video_cache_size = video_cache_size;
+	new_session->video_chunk_size = transfer_size;
+	o3000_log(new_session, O3000_LOG_DEBUG, "%s: video cache %d bytes (divided into %d chunks of %d bytes)\n",
+			  __func__, video_cache_size, NUM_USB_VIDEO_TRANSFER, transfer_size);
+	
+	// allocate video transfer array
+	new_session->transfer_data = calloc(1, sizeof(struct libusb_transfer*)*NUM_USB_VIDEO_TRANSFER);
+	if(new_session->transfer_data == NULL) {
+		o3000_log(new_session, O3000_LOG_ERROR, "%s: allocating USB video transfers failed\n", __func__);
+		error_code = O3000_ERROR_NOMEM;
+		goto _o3000_init_abort;
+	}
+	
+	o3000_log(new_session, O3000_LOG_INFO, "%s: new session initialized (ID %d, video cache %d bytes, video chunk  %d x %d bytes)\n",
+			  __func__, new_session_id, video_cache_size, NUM_USB_VIDEO_TRANSFER, new_session->video_chunk_size);
+	
+	// finally return the valid session ID
+	return new_session_id;
+	
+_o3000_init_abort:
+	cleanup(new_session_id);
+	return error_code;
+}
+
+
+/**
+ * Exit O-3000 session.
+ * This function closes an active session and releases all system resources.
+ * 
+ * @param id session ID
+ */
+void __stdcall o3000_exit(int id) {
+	
+	struct o3000_session_t *session;
+	
+	
+	session = get_session(id);
+	if(session == NULL) {
+		return;
+	}
+	
+	if(session->running == FALSE) {
+		o3000_log(session, O3000_LOG_INFO, "%s: driver not at main-loop --> cleanup session\n", __func__, id);
+		cleanup(id);
+	}
+	else {
+		o3000_log(session, O3000_LOG_DEBUG, "%s: driver at main-loop --> release USB interface\n", __func__, id);
+		session->release_session = TRUE;
+		o3000_disconnect(id);
+	}
+}
+
+/** @} */
diff --git a/o3000.h b/o3000.h
new file mode 100644
index 0000000..b13b767
--- /dev/null
+++ b/o3000.h
@@ -0,0 +1,101 @@
+/**

+* @file			o3000.h

+* @brief		O-3000 Camera driver API

+* @author		Patrick Brunner - brunner@stettbacher.ch

+* @author		Patrick Roth - roth@stettbacher.ch

+* @version		1.1

+* @date			2016-03-01

+* @copyright	2012-2016 Stettbacher Signal Processing AG

+* 

+* @remarks

+*

+* <PRE>

+* This library is free software; you can redistribute it and/or

+* modify it under the terms of the GNU Lesser General Public

+* License as published by the Free Software Foundation; either

+* version 2.1 of the License, or (at your option) any later version.

+*

+* This library 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

+* Lesser General Public License for more details.

+*

+* You should have received a copy of the GNU Lesser General Public

+* License along with this library; if not, write to the Free Software

+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

+* </PRE>

+*

+*/

+

+#ifndef _O3000_H

+#define _O3000_H

+

+#include "o3000/o3000_portable.h"

+#include "o3000/image_header.h"

+

+/**

+ * O-3000 library version

+ */

+#define O3000_VERSION				"2.0.2"

+

+#define O3000_VID	0x0483			///< O3000 vendor ID

+#define O3000_PID	0xA098			///< O3000 product ID

+

+

+/*

+ * All possible error codes

+ */

+#define O3000_SUCCESS						0 				///< success (no error)

+#define O3000_ERROR_NOCALLBACK				-1				///< one or more callback functions are missing

+#define O3000_ERROR_NOMEM					-2				///< failed to allocate memory

+#define O3000_ERROR_NODEV					-3				///< device not found

+#define O3000_ERROR_NO_FREE_SESSION			-4				///< all session are in used

+#define O3000_ERROR_INVALID_SESSION_ID		-5				///< session ID is invalid

+#define O3000_ERROR_ACCESS					-6				///< user has insufficient permissions

+#define O3000_ERROR_BUSY					-7				///< another program or driver has claimed the device

+#define O3000_ERROR_DRV_NOT_CONNECTED		-8				///< O-3000 driver is not running (call o3000_connect() first)

+#define O3000_ERROR_XML_XFER_RUNNING		-9				///< XML transfer to device in progress

+#define O3000_ERROR_USB_TRANSFER_TIMEOUT	-10				///< USB transfer timeout

+#define O3000_ERROR_USB_EP_HALTED			-11				///< USB endpoint halted

+#define O3000_ERROR_LESS_DATA				-12				///< USB received less data than expected

+

+#define O3000_ERROR_OTHER					-1000			///< other (unspecified) error

+

+

+/*

+ * All possible logging levels (don't touch it!!)

+ */

+#define	O3000_LOG_NONE			0		///< nothing is logged

+#define	O3000_LOG_ERROR			1		///< error message (top priority log message)

+#define	O3000_LOG_WARNING		2 		///< warning message

+#define O3000_LOG_INFO			3		///< info message

+#define O3000_LOG_DEBUG			4		///< debug message

+#define O3000_LOG_VERBOSE		5		///< verbose debug message, libusb is debugging too (lowest priority log message)

+

+

+#if defined(__cplusplus) || defined(c_plusplus)

+extern "C" {

+#endif

+

+

+int __stdcall o3000_init(int vid, int pid, unsigned int video_cache_size,

+						 void __stdcall (*xml_cb)(int id, char* buf, int len),

+						 void __stdcall (*video_cb)(int id, unsigned char* buf, struct img_header_t* img_header),

+						 void __stdcall (*log_cb)(int id, char* msg),

+						 int loglevel);

+

+void __stdcall o3000_exit(int id);

+

+int __stdcall o3000_get_num_cam(void);

+int __stdcall o3000_device_discovery(int id);

+int __stdcall o3000_connect(int id, int device_nr, char *config_msg, int config_msg_len);

+int __stdcall o3000_disconnect(int id);

+

+int __stdcall o3000_send_xml(int id, const char *msg, int msg_len);

+

+

+#if defined(__cplusplus) || defined(c_plusplus)

+} // extern "C"

+#endif

+

+#endif // _O3000_H

diff --git a/o3000_portable.h b/o3000_portable.h
new file mode 100644
index 0000000..4e7da6a
--- /dev/null
+++ b/o3000_portable.h
@@ -0,0 +1,144 @@
+/**

+* @file			o3000_portable.h

+* @brief		O-3000 definitions to make portable platform-independent code

+* @author		Patrick Roth - roth@stettbacher.ch

+* @author		Christian Jaeggi - jaeggi@stettbacher.ch

+* @version		1.0

+* @date			2016-03-01

+* @copyright	2012-2016 Stettbacher Signal Processing AG

+* 

+* @remarks

+*

+* <PRE>

+* This library is free software; you can redistribute it and/or

+* modify it under the terms of the GNU Lesser General Public

+* License as published by the Free Software Foundation; either

+* version 2.1 of the License, or (at your option) any later version.

+*

+* This library 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

+* Lesser General Public License for more details.

+*

+* You should have received a copy of the GNU Lesser General Public

+* License along with this library; if not, write to the Free Software

+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

+* </PRE>

+*

+*/

+

+

+#ifndef _O3000_PORTABLE_H

+#define _O3000_PORTABLE_H

+

+

+/* stdint.h is not available on older MSVC */

+#if defined(_MSC_VER) && (_MSC_VER < 1600) && (!defined(_STDINT)) && (!defined(_STDINT_H))

+

+typedef unsigned __int8   uint8_t;

+typedef unsigned __int16  uint16_t;

+typedef unsigned __int32  uint32_t;

+typedef unsigned __int64  uint64_t;

+

+#else

+

+#include <stdint.h>

+

+#endif // defined(_MSC_VER) && (_MSC_VER < 1600) && (!defined(_STDINT)) && (!defined(_STDINT_H))

+

+

+

+/*

+ * Calling conventions

+ * The System V ABI is one of the major ABIs in use today and is virtually universal among Unix

+ * systems. It is the calling convention used by toolchains such as i686-elf-gcc and x86_64-elf-gcc. 

+ * 

+ * Windows builds often use "project files" and are less transparent and more ad hoc than Makefiles.

+ * As an example, the driver crashes by calling a callback previously register via .NET. Therfore 

+ * on MSVC, the calling ABI is defined. On other system (UNIX), the macros below are left

+ * empty.

+ * 

+ * _WIN32 is always defined for Win32 or Win64 applications.

+ */

+#ifndef _WIN32

+

+#define __cdecl    	/* nothing */

+#define __stdcall  	/* nothing */

+#define __fastcall 	/* nothing */

+

+#else

+

+#include <windows.h>

+

+#endif // _WIN32

+

+

+/*

+ * aligned malloc functiions

+ */

+#ifndef _WIN32

+

+#define ALIGNED_ALLOC(align, size)	aligned_alloc(align, size)

+#define ALIGNED_FREE(buf)			free(buf)

+

+#else

+

+#include <malloc.h>

+#define ALIGNED_ALLOC(align, size)	_aligned_malloc(size, align)

+#define ALIGNED_FREE(buf)			_aligned_free(buf)

+

+#endif // _WIN32

+

+

+/*

+ * structure packing macros

+ */

+#if defined(_MSC_VER)

+

+#define __func__					__FUNCTION__

+#define __packed__					__packed

+

+#else

+

+/* define nothing for __func__ because it's used as default macro at source code */

+#define __packed__ 					__attribute__ ((packed))

+

+#endif // defined(_MSC_VER)

+

+

+/*

+ * mutexes

+ * 

+ * copied from libusb project see files os/threads_windows.* and os/threads_poxix.*

+ */

+#if defined(_MSC_VER)

+

+#define O3000_MUTEX_INITIALIZER		0L

+typedef LONG						o3000_mutex_static_t;

+static inline void o3000_mutex_static_lock(o3000_mutex_static_t *mutex) {

+	while (InterlockedExchange(mutex, 1L) == 1L)

+		SleepEx(0, TRUE);

+}

+static inline void o3000_mutex_static_unlock(o3000_mutex_static_t *mutex) {

+	InterlockedExchange(mutex, 0L);

+}

+

+#else

+

+#include <pthread.h>

+

+#define O3000_MUTEX_INITIALIZER		PTHREAD_MUTEX_INITIALIZER

+typedef pthread_mutex_t				o3000_mutex_static_t;

+static inline void o3000_mutex_static_lock(o3000_mutex_static_t *mutex) {

+	(void)pthread_mutex_lock(mutex);

+}

+static inline void o3000_mutex_static_unlock(o3000_mutex_static_t *mutex) {

+	(void)pthread_mutex_unlock(mutex);

+}

+

+#endif // defined(_MSC_VER)

+

+

+#endif // _O3000_PORTABLE_H

+

+

diff --git a/o3000_private.h b/o3000_private.h
new file mode 100644
index 0000000..7087d46
--- /dev/null
+++ b/o3000_private.h
@@ -0,0 +1,102 @@
+/**
+* @file			o3000_private.h
+* @brief		O-3000 Camera driver API (internal)
+* @author		Patrick Brunner - brunner@stettbacher.ch
+* @author		Patrick Roth - roth@stettbacher.ch
+* @version		1.1
+* @date			2016-03-01
+* @copyright	2012-2016 Stettbacher Signal Processing AG
+* 
+* @remarks
+*
+* <PRE>
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU Lesser General Public
+* License as published by the Free Software Foundation; either
+* version 2.1 of the License, or (at your option) any later version.
+*
+* This library 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
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public
+* License along with this library; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+* </PRE>
+*
+*/
+
+
+#ifndef __O3000_PRIVATE_H
+#define __O3000_PRIVATE_H
+
+#include <libusb-1.0/libusb.h>
+#include "o3000/o3000_portable.h"
+#include "o3000/image_header.h"
+
+
+#define TRUE	1			///< TRUE value (not 0)
+#define FALSE	0			///< FALSE value must be 0
+
+
+
+/**
+ * Image frame synchronization state
+ */
+enum image_frame_state_t {
+	IMG_FRAME_STATE_NOSYNC = 0,			///< not synchronized (preamble not found)
+	IMG_FRAME_STATE_SYNC,				///< synchronized (preamble found)
+};
+
+
+/**
+ * O-3000 session description
+ * 
+ * Each session descripes a connection between the camera and the user application.
+ * 
+ * @note These data are used internally and are not accessible from the user application.
+ */
+struct o3000_session_t {
+	int id;								///< session ID
+	libusb_context *libusb_ctx;			///< libusb context pointer
+	struct libusb_device_handle	*dev;	///< the USB device handler (a connection to this device is established)
+	int running;						///< running flag: TRUE if driver is connected and at main-loop (function o3000_connect() is blocking)
+	int cleanup_transfers;				///< TRUE if driver is cleaning up all USB transfers
+	int disconnect_dev;					///< TRUE if the user wants to disconnect the USB device by software. This flag is set by o3000_disconnect().
+	int release_session;				///< TRUE indicates to release session when leaving main-loop (see function o3000_connect()). This flag is set by o3000_exit().
+	
+	int vid;							///< USB vendor ID used for this session
+	int pid;							///< USB product ID used for this session
+	libusb_device **device_list;		///< USB device list with pid and vid defined above
+	int num_device_list;				///< number of entries at device list
+	
+	int loglevel;						///< logging level (from @ref O3000_LOG_NONE to @ref O3000_LOG_DEBUG)
+	
+	void __stdcall (*xml_cb)(int id, char* buf, int len);										///< XML callback
+	void __stdcall (*video_cb)(int id, unsigned char* buf, struct img_header_t* img_header);	///< video callback
+	void __stdcall (*log_cb)(int id, char* msg);												//< logging callback
+	
+	
+	char *xml_in_buf;					///< buffer for inbound XML messages
+	uint8_t *video_cache;				///< video data buffer
+	int video_chunk_size;				///< chunk size of one video transfer in bytes
+	uint8_t *frame_buf;					///< start of frame buffer, memory-adjacent to video cache
+	unsigned int video_cache_size;		///< actual video cache size in bytes
+	
+	struct libusb_transfer **transfer_data;			///< generic USB transfer structures for incoming video data (dyn. allocated array of transfers)
+	struct libusb_transfer *transfer_xml_in;		///< generic USB transfer structures for incoming XML messages
+	
+	enum image_frame_state_t frame_state;			///< current image frame synchronization state
+	uint8_t *frame_start;							///< start address of image frame (in case if @ref IMG_FRAME_STATE_SYNC)
+	int frame_rx_cnt;								///< image frame payload counter, image received if @ref frame_payload_cnt is more or equal @ref frame_size
+	struct img_header_t	*frame_img_header;			///< start address of current image header
+	uint8_t *image_start;							///< start address of pixel data
+	int frame_size;									///< image frame size (including image header)
+};
+
+
+
+void __stdcall o3000_log(struct o3000_session_t *session, const int level, const char *fmt, ...);
+
+#endif // __O3000_PRIVATE_H
diff --git a/o3000_xfer_handler.c b/o3000_xfer_handler.c
new file mode 100644
index 0000000..4ae8b2f
--- /dev/null
+++ b/o3000_xfer_handler.c
@@ -0,0 +1,175 @@
+/**

+* @file			o3000_xfer_handler.c

+* @brief		O-3000 USB transfer handler

+* @author		Patrick Brunner - brunner@stettbacher.ch

+* @author		Patrick Roth - roth@stettbacher.ch

+* @version		1.1

+* @date			2016-03-01

+* @copyright	2012-2016 Stettbacher Signal Processing AG

+* 

+* @remarks

+*

+* <PRE>

+* This library is free software; you can redistribute it and/or

+* modify it under the terms of the GNU Lesser General Public

+* License as published by the Free Software Foundation; either

+* version 2.1 of the License, or (at your option) any later version.

+*

+* This library 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

+* Lesser General Public License for more details.

+*

+* You should have received a copy of the GNU Lesser General Public

+* License along with this library; if not, write to the Free Software

+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

+* </PRE>

+*

+*/

+

+

+#include <string.h>

+

+#include "o3000/o3000.h"

+#include "o3000_private.h"

+

+

+/**

+ * The preamble, used to detect the beginning of a new frame

+ */

+static const uint8_t preamble[] = {0xaa, 0x55, 0xde, 0xad, 0xbe, 0xef, 0x55, 0xaa};

+

+/**

+ * Check whether the argument points to a valid preamble.

+ * 

+ * @param p Memory pointer

+ * @return TRUE: points to valid preamble, FALSE: no valid preamble

+ */

+static int is_preamble(uint8_t *p) {

+	if( (*p == preamble[7]) &&

+		(*(p+1) == preamble[6]) &&

+		(*(p+2) == preamble[5]) &&

+		(*(p+3) == preamble[4])	&&

+		(*(p+4) == preamble[3])	&&

+		(*(p+5) == preamble[2])	&&

+		(*(p+6) == preamble[1])	&&

+		(*(p+7) == preamble[0])) {

+		return TRUE;

+	}

+	else {

+		return FALSE;

+	}

+}

+

+

+/**

+ * Scan for the preamble in the buffer specified.

+ * 

+ * @param buf Buffer start address

+ * @param size Buffer size

+ * @return preamble offset in bytes (w.r.t. to start address) or -1 if not found

+ */

+static int scan_for_preamble(uint8_t *buf, int size) {

+	

+	int	i, size_preamble, end;

+	

+	size_preamble = sizeof(((struct img_header_t*)0)->preamble);

+	end = size - size_preamble;

+	

+	for(i = 0; i < end; i++) {

+		if(is_preamble(buf+i) == TRUE) {

+			return i; // preamble found at offset i

+		}

+	}

+	return -1; // preamble not found	

+}

+

+/**

+ * Video transfer handler

+ * 

+ * This function recursively scans through a video transfer (video data chunk).

+ * Incomplete image frames are tracked continuously. Whenever an image frame is completed, the video callback handler is called.

+ * 

+ * NOTE

+ * The video-cache consists of severalf memory-adjacent USB transfers plus an adjacent framebuffer. In case of a wrap-around

+ * the end of the image frame (located at the start of the video-cache) is copied to the framebuffer. So this frame won't be fragmented.

+ * In case of receiving short USB transfers, two image frames won't be adjacent at the video-cache. Therfore, after handling a image

+ * the state machine is set to not-synced state.

+ * 

+ * @param session current session (is never NULL otherwise SEGFAULT)

+ * @param addr Start address of block to be scanned.

+ * @param len Lenght of block.

+ */

+void handle_transfer(struct o3000_session_t *session, uint8_t *addr, int len) {

+	

+	int offset;

+	struct img_header_t	*img_header;		// points to current image header structure

+	int wraparound_chunk_size;				// chunk size (bytes) at wrap-around to copy to frame buffer

+	int frame_data_remain;					// remaining image frame data to process in bytes

+	

+	if(session->frame_state == IMG_FRAME_STATE_NOSYNC) {

+		offset = scan_for_preamble(addr, len);

+		if(offset < 0) {

+			o3000_log(session, O3000_LOG_WARNING, "%s: preamble not found (start address=%p, len=%d)\n",

+					  __func__, addr - session->video_cache, len);

+			return;

+		}

+		

+		// preamble found, we are synchronized now!

+		session->frame_state = IMG_FRAME_STATE_SYNC;

+		session->frame_start = addr + offset;			// set start address of image frame

+		session->frame_rx_cnt = 0;						// reset data counter

+		len -= offset;									// skip image data located before preamble

+		

+		o3000_log(session, O3000_LOG_DEBUG, "%s: preamble found at address offset %d, remaining data of current image frame %d bytes\n",

+				  __func__, session->frame_start - session->video_cache, len);

+		

+		// parse image header

+		img_header = (struct img_header_t*)(session->frame_start);

+		session->frame_img_header = img_header;

+		session->image_start = session->frame_start + IMAGE_HEADER_SIZE + img_header->image_start;

+		session->frame_size = img_header->payload_size + IMAGE_HEADER_SIZE;

+	}

+	

+	

+	if(session->frame_state == IMG_FRAME_STATE_SYNC) {

+		session->frame_rx_cnt += len;

+		

+		o3000_log(session, O3000_LOG_DEBUG, "%s: sync: %d bytes of %d bytes (image size) received\n",

+				  __func__, session->frame_rx_cnt, session->frame_size);

+		

+		// checking whether whole image frame is received

+		if(session->frame_rx_cnt >= session->frame_size) {

+			

+			o3000_log(session, O3000_LOG_DEBUG, "%s: sync: image frame received\n", __func__);

+			

+			if(session->frame_start > addr) {

+				/*

+				 * We have a wrap-around to resolve. Do copy part of the image frame which resides at the

+				 * start of the video cache to the frame buffer. Note that the frame buffer is memory-adjacent

+				 * to the video cache.

+				 */

+				wraparound_chunk_size = session->frame_size - (session->frame_buf - session->frame_start);

+				o3000_log(session, O3000_LOG_DEBUG, "%s: wrap-around, copy %d bytes to frame buffer\n", __func__, wraparound_chunk_size);

+				memcpy(session->frame_buf, session->video_cache, wraparound_chunk_size);

+			}

+			

+			// delegate image to overlaying application

+			session->video_cb(session->id, session->image_start, session->frame_img_header);

+			

+			/*

+			 * Image frame is processed. 

+			 * The following image may won't be memory-adjacent to this one. Because a snapshot

+			 * is sent with zero packet. The easiest way is to change state to NOT SYNC to trigger 

+			 * syncronization part again.

+			 */

+			session->frame_state = IMG_FRAME_STATE_NOSYNC;

+			frame_data_remain = session->frame_rx_cnt - session->frame_size;

+			o3000_log(session, O3000_LOG_DEBUG, "%s: sync: %d bytes remaining from next image frame\n", __func__, frame_data_remain);

+			if(frame_data_remain > 0) {

+				handle_transfer(session, addr+(len-frame_data_remain), frame_data_remain);

+			}

+		}

+	}

+}

+

diff --git a/o3000_xfer_handler.h b/o3000_xfer_handler.h
new file mode 100644
index 0000000..09fdb3b
--- /dev/null
+++ b/o3000_xfer_handler.h
@@ -0,0 +1,39 @@
+/**
+* @file			o3000_xfer_handler.h
+* @brief		O-3000 USB transfer handler
+* @author		Patrick Brunner - brunner@stettbacher.ch
+* @author		Patrick Roth - roth@stettbacher.ch
+* @version		1.1
+* @date			2016-03-01
+* @copyright	2012-2016 Stettbacher Signal Processing AG
+* 
+* @remarks
+*
+* <PRE>
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU Lesser General Public
+* License as published by the Free Software Foundation; either
+* version 2.1 of the License, or (at your option) any later version.
+*
+* This library 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
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public
+* License along with this library; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+* </PRE>
+*
+*/
+
+
+#ifndef __O3000_XFER_HANDLER_H
+#define __O3000_XFER_HANDLER_H
+
+#include "o3000/o3000_portable.h"
+#include "o3000_private.h"
+
+void handle_transfer(struct o3000_session_t *session, uint8_t *addr, int len);
+
+#endif // __O3000_XFER_HANDLER_H