Simple AVC-based codecs with spatial scalability

Proposed is a coder that produces a layered video representation with layers corresponding to different spatial resolutions. A coder consists of based subcoders with independent motion estimation and compensation. Improved motion-vector encoding is provided for the enhancement layer. Other codec features include adaptive interpolation from the base layer, full AVC-compatibility of the base layer and syntax compatibility of the enhancement-layer bitstream. Interpolated reconstructed base-layer frames are used as additional reference frames in the enhancement layer. The respective prediction modes are embedded into prediction strategy of AVC. Experimental results prove that improved motion-vector encoding results in bitrate reduction of up to 13% of the enhancement-layer bitrate for motion vectors. As measured for all layers together, compression efficiency is significantly higher than for simulcast, but scalable codec complexity is only slightly higher than complexity of the respective simulcast codec.