Blind GOP structure analysis of MPEG-2 and H.264/AVC decoded video

In this paper, we provide a simple method for analyzing the GOP structure of an MPEG-2 or H.264/AVC decoded video without having access to the bitstream. Noise estimation is applied on the decoded frames and the variance of the noise in the different I-, P-, and B-frames is measured. After the encoding process, the noise variance in the video sequence shows a periodic pattern, which helps in the extraction of the GOP period, as well as the type of frames. This algorithm can be used along with other algorithms to blindly analyze the encoding history of a video sequence. The method has been tested on several MPEG-2 DVB and DVD streams, as well as on H.264/AVC encoded sequences, and shows successful results in both cases.