Patent ID: 8743958

Claim:
Compressed video data stream switching method for the transmission of a first data stream corresponding to a first video sequence, followed by, in a given switching point of this first stream, a second data stream corresponding to a second video sequence—each sequence being coded according to a GOP (Group of Pictures) structure—each GOP comprising intra type pictures coded in intra, predictive type pictures coded in inter and bidirectional type pictures coded in inter, the method comprising: modifying the second data stream prior to its transmission, by replacing bidirectional type pictures, pictures following the intra picture of the first GOP of the second sequence following the switching point, when one considers the coding order of the pictures, by bidirectional pictures, called commutation pictures, which have forward prediction and backward prediction modes that are predefined by attributing to their blocks a null motion vector, a null residue and a weighting rate relative to the predictions regarding one or several reference pictures that is related to the temporal location of the commutation pictures in relation to the reference picture and is also related to the position of the blocks in the picture.