Options
2016
Conference Paper
Titel
Step response metric for video encoder rate control characterisation
Abstract
Adaptive streaming is a widely-used solution to avoid playback interruptions and compensate for insufficient bandwidth or momentary congestion. A temporary reduction in bitrate results in less or no video break-up and rebuffering. The rate control mechanism of a codec implementation allows the selection of a target bitrate and tries to meet this target within certain constraints e.g. number of frames, with a certain percentage overshoot. However the target bitrate is not always instantaneously achievable, and the number of bits required to encode a frame are highly content-dependent. In this paper the Codec Step Response metric is proposed to measure the effectiveness of a codec rate control at responding to instantaneous rate variations. This metric allows the measurements of the suitability of a rate control implementation for an application or access network.