High Efficiency Video Coding

Posts By: Mathias Wien

Deblocking Filter Example

Example for deblocking of 2×2 CTBs.

Besides the original area of the picture from the test sequence and the corresponding decoded reconstruction, the samples along the prediction block and transform block boundaries which are modified by the deblocking filter are visualized. For comparison, the same region without the application of the deblocking filter is shown as well.

(CB: solid lines, PB: dashed lines, TB: dotted lines)

The Hybrid Video Coding Scheme

Hybrid Video Coding SchemeThe block diagram presents the basic concept of the hybrid video coding scheme. This scheme has been the basis for all video coding standards since ITU-T H.261 in 1989.

The pictures of the input video sequence are fed to the encoder. A prediction signal generated from information available both, encoder and decoder is subtracted from the input signal. The residual, representing the resulting prediction error, is transformed, quantized, and encoded into the bitstream. The prediction parameters needed to reproduce the prediction signal at the decoder side are encoded into the bitstream as well. Under the assumption of error-free transmission, the encoder and decoder sides are synchronized since the encoder includes the complete prediction structure of the decoder. In the figure, the building blocks which are included in both encoder and decoder are
marked by a gray box.

(Acronyms: CTB: coding tree block; ME: motion estimation; PB: prediction block; Q: quantization; TB: transform block; TR: transform)