Method of transcoding video data with fusion of coding units, computer program, transcoding module and telecommunications equipment associated therewith

A transcoding module adapted to transcode a bitstream (FBI) containing video data in a first format (F1) into a bitstream (FB2) containing said video data in a second format (F2), the video data comprising frames (T1i, T2i), said frames being divided in the first format into first coding units (uc1) each covering a region of the frame and defining a first coding structure (SC1i) for each frame, and being divided in the second format (F2) into second coding units (uc2) defining a second coding structure (SC2i) for each frame, the transcoding module comprising:

• a decoding module (6) adapted to decode the bitstream, providing decoded video data, data representative of the first coding structures and, for some or all of the first coding units, prediction data, the prediction data of at least one coding unit comprising a motion vector, and
• a re-encoding module (8) adapted to encode the decoded video data in the second format (F2),
• characterized in that the re-encoding module (8) is configured for:
• constructing, for at least one frame of decoded video data in the first format (F1), an intermediate coding structure (SCIi) comprising intermediate coding units (uci) each constructed to correspond to the merging of one or more first coding units (uc1) covered by said intermediate coding unit (uci) when a first condition (C1) is satisfied, the first condition being whether at least one dissimilarity metric (M) associated with the intermediate coding unit in question and determined from motion vectors of said first coding units is less than a predetermined threshold (T), at least one intermediate coding unit (uci) corresponding to the merging of at least two first coding units (uc1),
• assigning, to each of the intermediate coding units (uci), prediction data constructed from prediction data of the first coding unit or units merged to form said intermediate coding unit, and
• re-encoding the decoded video data in the second format (F2) by constructing the second coding structure (SC2i) based on the intermediate coding structure (SC1i).