QPA Plugin for offscreen capture

*Project description* Current QML application outputs some images, videos, rectangles (QML Image MediaPlayer, Rectangle, ...) to single screen. Current hardware is optionally Asus Tinker board or Odroid XU4 with QT 5.9.3. QT built from source. Application does NOT need to emit to HDMI port attached to board. Just to capture generated output to image files. *QPA plugin software Requirements* Create QT QPA platform plugin that will - use offscreen rendering - use H.264 hardware encoding - use GPU for OpenGL - save frames in separate files - configurable frames per second to be saved *Expected deliveries* - develop QPA plugin as listed in software requirements above - provide detailed step to compile developed QPA plugin - provide any steps to configure QT build / environments (if any specific)