I have videos recording of class lectures, which obviously has a lot of inter-frame similarity. The current specs of the video is:
720P, H264 AVC, 30FPS, 2456kb/s and the file size is 920MB.
I could decrease the FPS to 24 and may be decrease the bit rate a little. But can this video, with low source complexity be compressed a "lot better" with some other codec. Meaning, is there any codec/"codec settings" known to perform well extremely well for such low source complexity.
Any codec would exploit the best of redundancy when it will be best at predicting as many pixels of the next picture as possible.
One of the best mechanism to achieve such techniques is multi hypothesis motion compensation. You can read this paper. http://iphome.hhi.de/wiegand/assets/pdfs/vcip00.pdf Basically you can predict any block very accurately by applying as an average of very large number of blocks.
In fact H.264 has full provision for this; only thing is most implementation might not be capable of fully exploiting this. You might just extend any codec to work on this and make the best. The encoder you are using may not be, but H.264 is still the best codec on the earth for your problem.