CONTENT NETWORK OPTIMIZATION UTILIZING SOURCE MEDIA CHARACTERISTICS
Content is prepared for delivery to a user device by creating multiple encodings that are then stored in a content delivery network. Encodings range from a minimum-rate encoding to a maximum-rate encoding. For each segment of the content, a dynamics metric is compared to thresholds defining intervals of a dynamic range. The intervals, ranging from a minimum-dynamics interval to a maximum-dynamics interval, represent corresponding levels of dynamics and are mapped to corresponding encodings. The comparing results in selection of an encoding based on the dynamics metric, which may be a scene change count that reflects the number of independently renderable frames in the segment, available in MPEG encoding. Selections are included in download control data used by the user device to download the content. The user device selectively retrieves different encodings of segments, achieving lower bandwidth usage without sacrificing fidelity.
1 . A method of preparing content for segmented delivery to a user device over a network, comprising:
creating a plurality of encodings of a content item and storing the encodings in a content delivery network, the encodings ranging from a minimum-rate encoding to a maximum-rate encoding, the encodings being created on a segment basis and resulting in a set of different-rate encoded segments for each segment of the content item;
for each segment of the content item, comparing a dynamics metric for the segment to a set of thresholds defining intervals of a dynamic range of the content, the intervals ranging from a minimum-dynamics interval to a maximum-dynamics interval, the maximum-dynamics interval representing a maximum level of dynamics and being mapped to a corresponding one of the encodings, successively lower-dynamics intervals representing successively lower levels of dynamics in the content and being mapped to successively lower-rate ones of the encodings, the comparing resulting in selection of an encoding to which an interval containing the dynamics metric is mapped; and
creating download control data and making it available to the user device for use in downloading the content from the content delivery network for local rendering, the download control data including an identification of the selected encoding for each of the segments of the content item.
2 . A method according to claim 1 , wherein the content item is a video item and the dynamics metric is a scene change rate reflecting a number of independent video frames occurring in each segment.
3 . A method according to claim 1 , wherein each encoded segment is formed from a plurality of sub-segments, and wherein the comparing is performed for each sub-segment and the download control data includes an identification of a selected encoding for each of the sub-segments of the content item.
4 . A method according to claim 3 , wherein each segment represents an interval of the content item in the range of 1-10 seconds, and where there are two or more equal-duration sub-segments per segment.
5 . A method according to claim 1 , wherein the download control data is contained in a content description file stored in the content delivery network and retrievable therefrom by the user device.
6 . A method according to claim 1 , further including:
associating each encoding with a corresponding network bandwidth availability for downloading the content; and
including in the download control data the associations between the encodings and the network bandwidth availabilities to enable the user device to modify a selection of an encoding based on network bandwidth availability at a time of downloading a segment.
7 . A method according to claim 1 , wherein comparing the dynamics metric includes applying a scaling factor based on a known classification of the content item, the classification reflecting a general level of dynamics of the content item.
8 . A computer program storage apparatus comprising a non-transitory computer readable medium with a set of computer program instructions recorded thereon, the computer program instructions being operative, when executed by one or more computers of a computer system, to cause the computer system to perform a method of preparing content for segmented delivery to a user device over a network, the method including:
creating a plurality of encodings of a content item and storing the encodings in a content delivery network, the encodings ranging from a minimum-rate encoding to a maximum-rate encoding, the encodings being created on a segment basis and resulting in a set of different-rate encoded segments for each segment of the content item;
for each segment of the content item, comparing a dynamics metric for the segment to a set of thresholds defining intervals of a dynamic range of the content, the intervals ranging from a minimum-dynamics interval to a maximum-dynamics interval, the maximum-dynamics interval representing a maximum level of dynamics and being mapped to a corresponding one of the encodings, successively lower-dynamics intervals representing successively lower levels of dynamics in the content and being mapped to successively lower-rate ones of the encodings, the comparing resulting in selection of an encoding to which an interval containing the dynamics metric is mapped; and
creating download control data and making it available to the user device for use in downloading the content from the content delivery network for local rendering, the download control data including an identification of the selected encoding for each of the segments of the content item.
9 . A computer program storage apparatus according to claim 8 , wherein the content item is a video item and the dynamics metric is a scene change rate reflecting a number of independent video frames occurring in each segment.
10 . A computer program storage apparatus according to claim 8 , wherein each encoded segment is formed from a plurality of sub-segments, and wherein the comparing is performed for each sub-segment and the download control data includes an identification of a selected encoding for each of the sub-segments of the content item.
11 . A computer program storage apparatus according to claim 10 , wherein each segment represents an interval of the content item in the range of 1-10 seconds, and where there are two or more equal-duration sub-segments per segment.
12 . A computer program storage apparatus according to claim 8 , wherein the download control data is contained in a content description file stored in the content delivery network and retrievable therefrom by the user device.
13 . A computer program storage apparatus according to claim 8 , wherein the method performed by the computer program further includes:
associating each encoding with a corresponding network bandwidth availability for downloading the content; and
including in the download control data the associations between the encodings and the network bandwidth availabilities to enable the user device to modify a selection of an encoding based on network bandwidth availability at a time of downloading a segment.
14 . A computer program storage apparatus according to claim 8 , wherein comparing the dynamics metric includes applying a scaling factor based on a known classification of the content item, the classification reflecting a general level of dynamics of the content item.
15 . A computer system, comprising:
processing circuitry;
memory;
input/output circuitry; and
interconnect circuitry functionally interconnecting the processing circuitry, memory and input/output circuitry,
the memory storing a set of computer program instructions being operative, when executed by the processing circuitry, to cause the computer system to perform a method of preparing content for segmented delivery to a user device over a network, the method including:
creating a plurality of encodings of a content item and storing the encodings in a content delivery network, the encodings ranging from a minimum-rate encoding to a maximum-rate encoding, the encodings being created on a segment basis and resulting in a set of different-rate encoded segments for each segment of the content item;
for each segment of the content item, comparing a dynamics metric for the segment to a set of thresholds defining intervals of a dynamic range of the content, the intervals ranging from a minimum-dynamics interval to a maximum-dynamics interval, the maximum-dynamics interval representing a maximum level of dynamics and being mapped to a corresponding one of the encodings, successively lower-dynamics intervals representing successively lower levels of dynamics in the content and being mapped to successively lower-rate ones of the encodings, the comparing resulting in selection of an encoding to which an interval containing the dynamics metric is mapped; and
creating download control data and making it available to the user device for use in downloading the content from the content delivery network for local rendering, the download control data including an identification of the selected encoding for each of the segments of the content item.
16 . A computer system according to claim 15 , wherein the content item is a video item and the dynamics metric is a scene change rate reflecting a number of independent video frames occurring in each segment.
17 . A computer system according to claim 15 , wherein each encoded segment is formed from a plurality of sub-segments, and wherein the comparing is performed for each sub-segment and the download control data includes an identification of a selected encoding for each of the sub-segments of the content item.
18 . A computer system according to claim 17 , wherein each segment represents an interval of the content item in the range of 1-10 seconds, and where there are two or more equal-duration sub-segments per segment.
19 . A computer system according to claim 15 , wherein the download control data is contained in a content description file stored in the content delivery network and retrievable therefrom by the user device.
20 . A computer system according to claim 15 , wherein the method performed by the computer program further includes:
associating each encoding with a corresponding network bandwidth availability for downloading the content; and
including in the download control data the associations between the encodings and the network bandwidth availabilities to enable the user device to modify a selection of an encoding based on network bandwidth availability at a time of downloading a segment.
21 . A computer system according to claim 15 , wherein comparing the dynamics metric includes applying a scaling factor based on a known classification of the content item, the classification reflecting a general level of dynamics of the content item.