I need to synchronize records, say a list of clients, between a local and distant database. The database on both sides has the same structure. I've thought of using some kind of marker (date field, hash/checksum on field values...) but what would you advise ?

Edit: Distant database is on web hosting so PHP will be needed for transferring data.


Question: Detecting scene transitions in a video
Answer: Scenes generally exhibit a fade-to-black transition. You could capture those frames with simple image processing tools, which are found in many libraries, such as OpenCV.

If you want to rely on the change of the mis-an-scene to be robust against sudden changes, then of cours algorithms for detecting temporal differences is more appropriate. For that, you might want to consider:

http://vis.uky.edu/~cheung/courses/ee639_fall04/readings/spie99.pdf
http://www.mitsubishi-electric-itce.fr/uk-rce/pubdocs/VIL07-D071.pdf

If you want a simple algorithm do as described here:
http://stackoverflow.com/questions/4801053/video-scene-detection-implementation

For harder cases, you might even try GMM-like background models to test if the transition was a temporarily quick shot or a complete change.