vcap: Initial implementation

This UPM module captures a still frame from a Linux V4L device, such
as a USB webcam, and and then allows you to save it as a JPEG image
into a file.

The camera and driver in use must support streaming, mmap-able buffers
and must provide data in YUYV format.  This should encompass most
video cameras out there.  It has been tested with a few off the shelf
USB cameras without any problems.

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

examples/c++/CMakeLists.txt

@@ -264,6 +264,7 @@ if (BACNET_FOUND)
   include_directories(${PROJECT_SOURCE_DIR}/src/bacnetmstp)
   add_example (e50hx)
 endif()
+add_example (vcap)
 
 # These are special cases where you specify example binary, source file and module(s)
 include_directories (${PROJECT_SOURCE_DIR}/src)

examples/c++/vcap.cxx

@@ -0,0 +1,70 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <unistd.h>
+#include <iostream>
+
+#include "vcap.hpp"
+
+using namespace std;
+
+int main(int argc, char **argv)
+{
+//! [Interesting]
+
+  string defaultDev = "/dev/video0";
+
+  // if an argument was specified, use it as the device instead
+  if (argc > 1)
+    defaultDev = string(argv[1]);
+
+  cout << "Using device " << defaultDev << endl;
+  cout << "Initializing..." << endl;
+
+  // Instantiate an VCAP instance, using the specified video device
+  upm::VCAP *sensor = new upm::VCAP(defaultDev);
+
+  // enable some debug/verbose output
+  sensor->setDebug(true);
+
+  // This is just a hint.  The kernel can change this to a lower
+  // resolution that the hardware supports.  Use getWidth() and
+  // getHeight() methods to see what the kernel actually chose if you
+  // care.
+  sensor->setResolution(1920, 1080);
+
+  // capture an image
+  sensor->captureImage();
+
+  // convert and save it as a jpeg
+  sensor->saveImage("video-img1.jpg");
+
+  cout << "Exiting..." << endl;
+
+  delete sensor;
+
+//! [Interesting]
+
+  return 0;
+}