1. A method of processing a compressed video signal that includes a succession of image frames and that is a compressed version of an original source video signal, the method comprising: analyzing the compressed video signal in a digital video encoder to generate one or more compression statistics; identifying in the digital video encoder a scene of the compressed video signal for re-encoding  based on at least one of the compressed video signal and the compression statistics; selecting in the digital video encoder a target bit rate for re-encoding the identified scene based on the compression statistics and applicable compression constraints; determining in the digital video encoder compression parameters for the identified scene based on the identified scene's compression statistics and the selected target bit rate; re-encoding in the digital video encoder image frames for the identified scene from the original source video signal based on the determined compression parameters, thereby generating a new compressed scene; checking in the digital video encoder a visual quality of the new compressed scene; and integrating in the digital video encoder the new compressed scene into the compressed video signal if the visual quality is sufficient.