Patent ID: 9313243
Filing Date: 2016-04-12
CPC Classification: H04L,H04N

Claim Text:
1. A method for delivering encoded content data over a network, the content data being encoded at one or more quality levels, the method comprising: determining one or more respective data rates required to deliver the encoded content data at the one or more quality levels; and selecting a quality level for delivery in dependence on at least the one or more determined respective data rates; the method being characterised in that the determining of a data rate for a particular quality level comprises: being provided with pre-calculated data defining one or more critical points of a first type on a decoding schedule of the encoded content data of the particular quality, the critical points of the first type being points at which, for one or more other points on the decoding schedule and assuming that when delivery occurs from those points a minimum threshold amount of encoded content data is buffered, a constant bit rate delivery schedule calculated for the one or more other points such that buffer underflow does not occur is substantially equal to the decoding schedule; wherein when actual delivery of the encoded content data is behind a piecewise monotonic decreasing constant bit rate delivery schedule required to deliver the encoded content data from the start so that buffer underflow does not occur, and at least the minimum threshold amount of content is buffered, calculating the data rate required for delivery of remaining encoded data at the particular quality level is performed in dependence on at least the critical points of the first type.