Gumlet uses per-title-encoding to determine the lowest possible bitrate for a video by analyzing the material, maintaining the visual quality of the original video, and minimizing the size of the transcoded video.
As you can see in the above movies, the original video is
151 MB and the per-title encoded video is
104 MB, so per-title-encoding allows us to accomplish a 47 percent reduction in size while maintaining the same visual quality.
For more please read the In-depth article on Per-title encoding