I am starting out on a project in which I need to build a customized annotation tool for movies and video. Some person (not technically minded) will need to pop open a GUI that I create, open either a video file or a directory of frames that result from chopping up a video file, and then use a window (much like QuickTime or VLC player, etc., i.e. a video window with a simple slider bar allowing the user to move back and forth at will). In this window, the user will be able to click on interesting points, give them semantic labels and meta-data (such as whether or not the point is occluded by something else in the picture), and then basically “press go” and start a tracker. The tracker will follow the points, frame by frame and the user can press the space bar or something to move forward and backward. The idea is to allow the human to intervene any time the tracker gets confused, but hopefully the tracker works well enough that humans don’t have to hand-label every frame in an entire multi-thousand frame video sequence.
I am planning to do this all in Python, (a) because it is the language I know best for non-trivial programming, (b) I have easy access to both OpenCV Python (for image processing algorithms) and PyQt which seems to have a powerful enough GUI toolbox for what I want to do and (c) some other aspects of this same project are being developed by other programmers to work in Python and with MySQL databases. Python just seems like the natural choice to streamline it all together.
I am experienced using computer vision algorithms for the tracking, and I am reasonably sure that I can figure out simple PyQt GUI devices for making points clickable, buttons, entering simple text data, etc. However, the part I am having trouble understanding is how to actually construct my own video window with a slider bar that either moves ahead according to a frame’s number or else is actually manipulating a video file. Can I leverage other movie players like VLC from within PyQt when programming in Python? Any suggestions or links that describe similar movie/video editing GUIs and how to develop them at home would be greatly appreciated.
Qt(PyQt) has a good multimedia support via Phonon module. You can easily use that module to achieve Video window, it can provide an easy-to-use video player and you can get playing position etc.