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Coding-Gain-Based
complexity control for motion compensation in H.264 video decoder Video Applications in mobile devices
become more and more popular. The latest video compression standard H.264/AVC
provides various coding tools to achieve high coding efficiency at the
expense of high computational complexity. Because the computation capability
of a mobile device is generally constrained, the full-scale H.264 video
decoding may be not allowed for a mobile device. Therefore, a complexity
control mechanism which adjusts the complexity of video coding computational
complexity and maintains the Rate-Distortion (RD) performance is important. Most studies on complexity control
focus on the encoding side. However, we propose a complexity control
mechanism for video decoders because decoders are more popularly used. Motion
compensation (MC) is the most complexity-consuming operation in H.264 video
decoding, the complexity control of MC is critical and the first one to be
considered in our work. This research proposes a Coding-Gain-Based layer
(CGL) mechanism which controls MC complexity of the decoder by controlling
allowable search point locations and partition modes in the encoder. The
computational overhead of the proposed mechanism is totally just in the
encoder. The simulation results show that the proposed mechanism can reduce
decoding time up to 37% with less than 0.44 dB video quality degradation
compared with no complexity constrained case. It can efficiently control the
decoding complexity with only 2.43% error rate on average. Keywords:
video coding, complexity control, motion compensation, coding gain |