CBR encoders have to be set to a bit rate close to the maximum bit-rate demand in order to avoid compression artefacts. Most of the time the encoder can cope with a lower bit rate. By sharing a common bit-rate capacity, encoders can free up bit rates to other channels during scenes of low criticality and obtain higher bit rates during critical scenes. By modelling the bit-rate demand for different content, the bit-rate saving of statistical multiplexing can be calculated.The bit-rate demand of MPEG-2 and MPEG-4 (AVC) encoders is strongly correlated although the bit-rate saving of MPEG-4 (AVC) increases for less critical scenes. Noise reduction frees up bit rate for other channels in the statistical multiplexing group.

Inspec keywords: video coding; data compression; statistical multiplexing; error statistics

Other keywords: statistical multiplexing; bit rate; MPEG-4; AVC; CBR encoders; MPEG-2; compression artefacts; Noise reduction

Subjects: Image and video coding