Adaptive bitrate ladder optimization for live video streaming

A distributed computing system comprising:

• a database configured to store client stall event information and bitrates;
• and
• one or more processors configured to:
• receive, by an analytics server, a client-side input and an origin-side input during a first interval in a timeslot, the client-side input comprising a CDN log from a client, the origin-side input comprising a quality measure from an origin server on an encoding side of a network, the origin server implementing an origin agent and a live encoder, wherein the timeslot comprises a duration selected to avoid a late reaction to network bandwidth fluctuation on a client side;
• during the first interval, extract from the CDN log a frequency of requests for each bitrate in a set of bitrates in the timeslot and a duration of a recent stall event for the client's player;
• select, by the analytics server, during a second interval in the timeslot, an optimized bitrate ladder comprising an optimal set of bitrates (OSB) using an optimization function, the optimization function taking as input the quality measure and a coefficient value, the coefficient value being determined by calling a stall analysis algorithm to which an average duration of stalls in each timeslot and a stall dictionary comprising a coefficient value for each range of stall is provided, the coefficient value being based on the frequency of requests and the duration of the recent stall event;
• and
• send the optimized bitrate ladder to the origin server for live encoding a next segment.

A system for optimizing a bitrate ladder for live streaming, the system comprising:

• a processor;
• and
• a memory comprising program instructions executable by the processor to cause the processor to implement:
• an analytics server configured to receive a client request comprising stall event information and an origin server message from an origin server on an encoding side of a network, the origin server implementing a live encoder, the origin server message comprising a quality measure of a previously encoded segment, the analytics server further configured to select an optimal set of bitrates (OSB) using the stall event information and the quality measure during a timeslot comprising a duration selected to avoid a late reaction to network bandwidth fluctuation on a client side, the OSB being selected using an optimization function, the optimization function taking as input the quality measure and a coefficient value, the coefficient value being determined by calling a stall analysis algorithm to which an average duration of stalls in each timeslot and a stall dictionary comprising a coefficient value for each range of stall is provided, the quality measure during the timeslot being provided by the encoding side of the network;
• and
• an origin agent comprising a live encoder plug-in, the origin agent configured to measure perceptual quality of encoded segments and to request the encoder to adjust the bitrate ladder in accordance with the OSB selected by the analytics server.