Transmission parameter control for segment delivery

Patent metadata

Field	Value
Publication number	US-2019342591-A1
Application number	US-201716473784-A
Country	US
Kind code	A1
Filing date	Dec 13, 2017
Priority date	Dec 29, 2016
Publication date	Nov 7, 2019
Grant date	—

Abstract

A method of delivering a video sequence in a network, the sequence including a plurality of temporal segments encoded at a plurality of qualities, the method including storing a dataset indicating the relative size of segments of the video stream; computing in dependence on that dataset a time schedule for delivery of the segments, the time schedule indicating a target delivery time for each segment sufficient to deliver all the segments in the sequence in time for decoding and being independent of the encoded quality of each segment; for each segment: setting one or more transmission parameters for the segment in dependence on the target delivery time for the segment and the relative size of the segment; and delivering the segment over the network using the one or more transmission parameters.

First claim

1 . A method of delivering a video sequence in a network, the video sequence comprising a plurality of temporal segments each encoded at a plurality of qualities, the method comprising:
computing a dataset indicating a relative size of the plurality of temporal segments of the video sequence; computing a representative decoding schedule for the plurality of temporal segments of the video sequence as a cumulative function of the relative size of plurality of temporal segments of the video sequence; computing in dependence on the representative decoding schedule a representative delivery schedule for delivery of the plurality of temporal segments of the video sequence, the representative delivery schedule indicating a target delivery time for each temporal segment of the video sequence, each target delivery time being no later than a decoding time of the temporal segment indicated by the representative decoding schedule, and each target delivery time being independent of the encoded quality of each temporal segment; and for each temporal segment: setting one or more transmission parameters for the temporal segment in dependence on the target delivery time for the temporal segment and the relative size of the temporal segment; and delivering the temporal segment over the network using the one or more transmission parameters.

2 . The method as claimed in claim 1 , wherein the one or more transmission parameters comprise a quality at which the temporal segment is encoded.

3 . The method as claimed in 1 , wherein the one or more transmission parameters comprises a congestion window size for transmitting the temporal segment.

4 . The method as claimed in claim 1 , wherein the representative delivery schedule is a piecewise linear curve with a monotonically decreasing slope.

5 . The method as claimed in claim 1 , wherein the method further comprises, for each temporal segment subsequent to a first temporal segment of the plurality of temporal segments:
determining one or more delivery parameters associated with delivery of a previously delivered temporal segment; and setting the one or more transmission parameters further in dependence on the delivery parameter for the previously delivered temporal segment.

6 . The method as claimed in claim 5 , wherein the one or more delivery parameters comprises a parameter indicative of a difference between a delivery time of the previously delivered temporal segment and the target delivery time of the previously delivered temporal segment.

7 . The method as claimed in claim 5 , wherein the one or more delivery parameters comprises a packet loss rate associated with the delivery of the previously delivered temporal segment.

8 . The method as claimed in claim 1 , wherein the dataset is a representative set of relative segment sizes for the plurality of qualities that indicates a representative relative size for each temporal segment.

9 . The method as claimed in claim 8 , wherein the method further comprises: generating, from a plurality of sets of segment sizes each indicating the relative size of the temporal segments at a respective quality, the representative set of relative segment sizes for the plurality of qualities; and storing the representative set as the dataset.

10 . The method as claimed in claim 9 , wherein the representative set is generated from a mathematical average of the sets of segment sizes for the plurality of qualities.

11 . The method as claimed in claim 8 , wherein the size of each temporal segment in the representative set is selected from one of the sets of segment sizes indicating the relative size of the temporal segments at a respective quality.

12 . The method as claimed in claim 1 , wherein the method further comprises updating the time schedule during delivery of the temporal segments to revise the target delivery times for temporal segments yet to be delivered over the network.

13 . The method as claimed in claim 11 , wherein the time schedule is updated in response to a segment being delivered at a time after the target delivery time.

14 . The method as claimed in claim 12 , wherein the time schedule is updated using a linear interpolation from the delivery time of a most recently delivered temporal segment to the target delivery time of a critical segment next occurring in the video sequence, wherein a critical segment is such that transmission rates for temporal segments subsequent to the critical segment calculated from the initial time schedule are less than calculated transmission rates for temporal segments prior to the critical segment.

15 . The method as claimed in claim 13 , wherein the time schedule is updated so that the revised target delivery time for a segment n to be delivered, RTD(n), is calculated as

RTD


(
n
)

=

ATD


(
m
)

+

(

TD


(
n
)

-

TD


(
m
)

)

×

TD
Cp

-

ATD


(
m
)

TD
CP

-

TD


(
m
)

,

where ATD(m) is an actual time of delivery for a segment m delivered after its target delivery time TD(m), TD(n) is a prior target delivery time for the segment n, and TD CP is a delivery time of the next critical segment in the video sequence.

16 . A data transmitter configured to deliver a video sequence comprising a plurality of temporal segments encoded at a plurality of qualities over a network, the data transmitter comprising:
a parameter calculation unit configured to:
compute a representative decoding

Assignees

• British Telecomm

Inventors

• Nilsson Michael
• Humeida Yousif
• Appleby Stephen

Classifications

• H04N21/8456

  by decomposing the content in the time domain, e.g. in time segments · CPC title

• H04N21/26216

  involving the channel capacity, e.g. network bandwidth (admission control, resource allocation in open networks H04L12/5692; flow control in packet networks H04L47/10; establishing a schedule or organising the servicing of application requests taking into account QoS H04L67/61) · CPC title

• H04N21/26233

  involving content or additional data duration or size, e.g. length of a movie, size of an executable file · CPC title

• H04N21/2402 Primary

  Monitoring of the downstream path of the transmission network, e.g. bandwidth available (traffic monitoring in data switching networks H04L43/00; monitoring data switching networks utilization H04L43/0876) · CPC title

• H04N21/2407

  Monitoring of transmitted content, e.g. distribution time, number of downloads (arrangements for monitoring programmes for broadcast or for distribution combined with broadcast H04H20/14) · CPC title