Well, I don't think so. For unknown reasons, in low light the FPS decreases (with enough ambient light the FPS stay at 30). There must be a way to force FPS be constant 30 FPS even in low light somewhere, either in kernel or by decompiling camera app, I just don't know where (and how)...
Sony Xperia M dual [C2004]
ROM: 15.5.A.1.5 (stock)
Android version: 4.3 (rooted)
Bootloader: locked (unlockable)