Dash client and receiver with request cancellation capabilities

摘要

A receiver receives media for playing out using a presentation element of the receiver can make requests and wait for responses, but can also cancel requests, possibly reissuing new requests, to improve a user experience taking into account network and other conditions. The receiver can select a playback rate and make requests at that playback rate, monitor a presentation buffer that stores media data to be consumed by a presentation element, store an indication of a buffer level corresponding to how much of the presentation buffer is occupied by the media data that is received and not yet consumed by the presentation element, maintain a state of an issued request for downloading a selected first chunk of media data, and when an issued request is outstanding, determine, based on network conditions and the state of the issued request, whether to continue the request or cancel the request.

主权项

1. A method of determining a request action, performed by a receiver receiving media for playing out using a presentation element of the receiver, the playing out resulting in media being consumed from a presentation buffer at a playback rate, the method comprising:
monitoring the presentation buffer, wherein the presentation buffer stores media data at least between a time the media data is received and a time the media data is consumed by the presentation element associated with the receiver; storing an indication of a buffer level, wherein the buffer level corresponds to an amount of the presentation buffer occupied by the media data received and not yet consumed by the presentation element; determining that an issued request for downloading a selected first chunk of media data is outstanding; and when the issued request is outstanding, determining to cancel the issued request based on:
detecting a change in a download rate,determining that an estimated stall in playing out of the selected first chunk of media data is greater than an amount of time needed to cancel the issued request and issue a new request further based on:determining that a download of a remaining portion of the selected first chunk of media data cannot be completed in time for playback, anddetermining that a download of a second chunk of the media data can be completed in time for playback, wherein the second chunk has a start presentation time later than a start presentation time of the selected first chunk; and issuing the new request for the second chunk of the media data.