Method for encoding and transmission of real-time video conference data

摘要

Method and apparatus for encoding video data in a real-time face-to-face communication system. A video data signal comprising frames of facial images is input. Parts of a frame of the video data signal are classified as key parts or non-key parts of a facial image to form a key group and a non-key group. Each group is divided into macro-blocks to form key macro-blocks and non-key macro-blocks. Each key macro-block is encoded with reference to at least one macro-block only in said frame to define encoded key data which is output. For each non-key macro-bock the amount of correlation between the non-key macro-block and at least one comparison macro-block in at least one preceding frame is determined. If the amount of correlation is below a threshold the non-key macro-block is encoded with reference to at least one macro-block only in said frame to define first encoded non-key data which is output. If the amount of correlation is above the threshold the non-key macro housing block is encoded with reference to its respective comparison macro-block to define a second encoded non-key data which is output. The apparatus may further comprise two buffers and buffer monitors so that the type of encoding performed depends on the occupancy of the buffers.