A Spatially Enhanced Error Concealment Technique and its Potential Alternative Application to Reduce H.264 Stream Sizes

With more and more video content being transmitted digitally and with user expectations continually rising, error concealment is becoming an increasingly important part of streaming media. Often overlooked in the past, even now manufacturers are often only doing the bare minimum necessary in order to avoid complexity. This paper first presents a combination of simple techniques that when combined produce an extremely effective concealment method that maintains spatially correlated edges throughout any lost data; this in turn gives an increase in both mathematical and visual performance when compared against the commonly used bilinear concealment technique. Secondly this paper looks at an alternative use of the bilinear passive error concealment algorithm that is often used by H.264 decoders. Occasionally a concealed macroblock is mathematically closer to the original than an encoded and decoded one, by removing these from the stream at the encoder and thus forcing the decoder to conceal the missing data, a significant reduction in the bit stream size (up to 5%) can be achieved with almost no loss in quality

Direct macroblock coding for predictive (P) pictures in the H.264 standard

In this paper we introduce a new Inter Macroblock type within the H.264 (or MPEG-4 AVC) video coding standard that can further improve coding efficiency by exploiting the temporal correlation of motion within a sequence. This leads to a reduction in the bits required for encoding motion information, while retaining or even improving quality under a Rate Distortion Optimization Framework. An extension of this concept within the skip macroblock type of the same standard is also presented. Simulation results show that the proposed semantic changes can lead to up to 7.6 % average bitrate reduction or equivalently 0.39dB quality improvement over the current H.264 standard