Systems and methods for selective retrieval of adaptive bitrate streaming media
Methods and apparatus that enable a subscriber of an adaptive bitrate streaming service provider to begin viewing a live program already in progress, and further have the ability to pause, rewind or start the program over from the beginning of the program regardless of its actual length or the manifest window defined by an encoder. Selective retrieval of a live media stream is provided by storing, at a server, a plurality of media fragments beginning at an initial time along with a server manifest for the media stream. In response to a client request for a start time later than the initial time, the server generates a program-specific manifest based on the server manifest.
1. A method of providing selective retrieval of a live media stream in progress at a current time, the media stream formed of a plurality of fragments, the method comprising:
storing, for the plurality of fragments corresponding to a program having a beginning at an initial time, archival manifest information comprising at least one manifest for the media stream beginning at the initial time;
receiving, from a client device, a request for a portion of the media stream beginning at a selected late-start time later than the initial time and earlier than the current time;
in one or more computer processors, automatically generating a program-specific late-start time-specific manifest based on the archival manifest information and comprising a subset of the archival manifest information, wherein a chronologically-earliest manifest entry for a chronologically-earliest fragment in the program-specific late-start time-specific manifest corresponds to a selected fragment in the plurality of fragments at the selected late-start time, and wherein a chronologically-latest manifest entry for a chronologically-latest fragment in the program-specific late-start time-specific manifest corresponds to a current fragment in the plurality of fragments; and
providing the program-specific late-start time-specific manifest to the client device.
2. The method of claim 1 , further comprising receiving the plurality of fragments from a media server.
3. The method of claim 1 , further comprising receiving the archival manifest information from a media server.
4. The method of claim 2 , wherein the media server is an adaptive bitrate streaming server.
5. The method of claim 1 , further comprising providing a request URL for the portion of the media stream to the client device.
6. The method of claim 5 , wherein the request URL comprises a token that identifies the portion of the media stream.
7. The method of claim 6 , wherein the token identifies the selected late-start time.
8. The method of claim 6 , wherein the token identifies a rewind window from a current time to the selected late-start time.
9. The method of claim 6 , wherein the token comprises an authorization to provide the portion of the media stream.
10. The method of claim 5 , wherein the request URL is provided by an interface server.
11. The method of claim 1 , further comprising periodically generating the archival manifest information for a preselected number of the plurality of fragments, prior to storing the archival manifest information.
12. The method of claim 1 , wherein generating the program-specific late-start time-specific manifest further comprises inserting at least one manifest entry for a media fragment related to a different media stream.
13. The method of claim 1 , wherein the media stream is an HTTP Live Streaming stream, wherein the archival manifest information comprises a plurality of manifests each relating to a manifest window, and wherein the program-specific late-start time-specific manifest is generated by identifying a subset of the plurality of manifests that contain fragments beginning at the selected late-start time, and extracting the manifest entries beginning at the selected late-start time from the subset.
14. The method of claim 1 , wherein the media stream is a Smooth Streaming stream, wherein the archival manifest information comprises an initial manifest, and wherein the program-specific late-start time-specific manifest is generated beginning from the initial manifest using the plurality of fragments.
15. A manifest modification server for providing selective retrieval over a data network of a live media stream in progress at a current time, the media stream formed of a plurality of fragments, the fragments stored at a media server beginning at an initial time, the server comprising:
a network interface operatively coupled to the data network;
a memory; and
a processor operatively coupled to the memory and the network interface, the processor configured to:
store, for the plurality of fragments corresponding to a program having a beginning at an initial time, archival manifest information comprising at least one manifest for the media stream beginning at the initial time;
receive, from a client device, a request for a portion of the media stream beginning at a selected late-start time later than the initial time and earlier than the current time;
automatically generate a program-specific late-start time-specific manifest based on the archival manifest information and comprising a subset of the archival manifest information, wherein a chronologically-earliest manifest entry for a chronologically-earliest fragment in the program-specific late-start time-specific manifest corresponds to a selected fragment in the plurality of fragments at the selected late-start time, and wherein a chronologically-latest manifest entry for a chronologically-latest fragment in the program-specific late-start time-specific manifest corresponds to a current fragment in the plurality of fragments; and
transmit the program-specific late-start time-specific manifest to the client device.
16. A non-transitory computer readable medium for storing instructions executable by a computer processor, the instructions when executed for causing the computer processor to perform a method of providing selective retrieval of a live media stream in progress at a current time, the media stream formed of a plurality of fragments, the method comprising:
storing, for the plurality of fragments corresponding to a program having a beginning at an initial time, archival manifest information comprising at least one manifest for the media stream beginning at the initial time;
receiving, from a client device, a request for a portion of the media stream beginning at a selected late-start time later than the initial time and earlier than the current time;
automatically generating a program-specific late-start time-specific manifest based on the archival manifest information and comprising a subset of the archival manifest information, wherein a chronologically-earliest manifest entry for a chronologically-earliest fragment in the program-specific late-start time-specific manifest corresponds to a selected fragment in the plurality of fragments at the selected late-start time, and wherein a chronologically-latest manifest entry for a chronologically-latest fragment in the program-specific late-start time-specific manifest corresponds to a current fragment in the plurality of fragments; and
providing the program-specific late-start time-specific manifest to the client device.