Switch signaling methods providing improved switching between representations for adaptive HTTP streaming

Patent metadata

Field	Value
Publication number	US-9253233-B2
Application number	US-201213545697-A
Country	US
Kind code	B2
Filing date	Jul 10, 2012
Priority date	Aug 31, 2011
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

The switch signaling methods providing improved switching between representations for adaptive HTTP streaming described herein enable user experience and bandwidth efficiency improvements for adaptive HTTP streaming solutions, even when segment data is encrypted. The signaling methods include associating segment maps with segments of a representation, wherein a segment map comprises both temporal entry and temporal exit points within associated segments together with byte offset information and potentially other segment information, wherein segment maps may be generated with predictable time span patterns that are independent of the time spans of the associated segments. These embodiments can be used to enhance existing deployments in such a way that there is no need to change existing content encoding and formatting processes, and such that existing clients that receive and play out content are unaffected.

First claim

What is claimed is:

1. A method of signaling, in a media stream sent from a server to a client, for switching between representations for adaptive HTTP streaming, the method comprising:
generating a segment map for one or more segments of a representation, the segment map including one or more temporal entry points and byte offset information for each of the one or more temporal entry points, the segment map further including one or more temporal exit points and byte offset information for each of the one or more temporal exit points, wherein a temporal entry point indicates an entry frame and a corresponding byte offset within the representation at which a switch from one or more other representations to the representation can be made and at which the representation can be played out to any subsequent temporal exit point of the representation, wherein a temporal exit point indicates an exit frame and a corresponding byte offset within the representation at which a switch from the representation can be made to the one or more other representations, and wherein play out can start at any entry point of the representation previous to the temporal exit point and played out to the temporal exit point; and
associating the segment map with the one or more segments of the representation.

2. A method of formatting content that is streamed as a plurality of representations, wherein each of the plurality of representations is an alternative for an item of content, the method comprising:
organizing a first representation of the plurality of representations as a plurality of segments, wherein a segment comprises data relating to a portion of a representation that has a temporal order among other segments for the representation, and wherein a segment is usable by a receiver that does not have access to prior segments;
generating a segment map for one or more segments of the first representation, the segment map including one or more temporal entry points and byte offset information for each of the one or more temporal entry points, the segment map further including one or more temporal exit points and byte offset information for each of the one or more temporal exit points, wherein a temporal entry point indicates an entry frame and a corresponding byte offset within the first representation at which a switch from one or more other representations to the first representation can be made and at which the first representation can be played out to any subsequent temporal exit point of the first representation, wherein a temporal exit point indicates an exit frame and a corresponding byte offset within the first representation at which a switch from the first representation can be made to the one or more other representations, and wherein play out can start at any entry point of the first representation previous to the temporal exit point and played out to the temporal exit point; and
aligning the one or more temporal entry points and the one or more temporal exit points of the first representation with one or more temporal entry points and one or more temporal exit points of a second representation, wherein aligning results in a presentation time for a temporal entry point for a segment in the first representation matching a presentation time for a temporal exit point for a segment in the second representation.

3. The method of claim 2 , further comprising:
determining, for each segment, a filename; and
storing content of each segment as a plurality of files using the filename of each segment so stored.

4. The method of claim 3 , further comprising:
determining, at a client consuming content, a content request, wherein the content request specifies at least one representation and a presentation time range;
determining a set of one or more URLs for one or more files in the plurality of files that represent one or more segments corresponding to the content request;
requesting the one or more segments using the set of one or more URLs;
receiving the one or more segments; and
providing content from the one or more segments to a content consumer at the client.

5. A method of requesting content using a client device configured to connect to a network, make requests over the network, and present content having a nonzero playout time, the method comprising:
determining a content request, wherein the content request specifies at least one representation and a presentation time range, the presentation time range defining at least a portion of the representation being requested;
reading, from a stored media representation dataset, a request format template, a segment time length and a variable segment range, the variable segment range defining a variation in presentation time range for segments, the variation being relative to the segment time length stored in the media representation dataset;
comparing a value of the segment time length to a temporal entry point corresponding to a start of the presentation time range to determine an initial segment index, the temporal entry point indicating an entry frame and a corresponding byte offset within the representation at which a switch from one or more other representations to the representation can be made and at which the representation can be played out to any subsequent temporal exit point of the representation, wherein a temporal exit point indicates an exit frame and a corresponding byte offset within the representation at which a switch from the representation can be made to the one or more other representations, and wherein play out can start at any entry point of the representation previous to the temporal exit point and played out to the temporal exit point;
evaluating the initial segment index, the variable segment range, and the segment time length to determine a desired segment index;
generating a file request corresponding to the content request based on the desired segment index and the request format template; and
requesting at least one file using the file request.

6. The method of claim 5 , wherein the file request is a URL and requesting at least one file is performed using HTTP requests using the URL.

7. The method of claim 5 , wherein the initial segment index is determined by dividing the temporal entry point by the segment time length and the desired segment index is determined as the initial segment index when a remainder from the dividing is less than the variable segment range and is determined as a segment index immediately prior to the initial segment when a remainder from the dividing is equal to or greater than the variable segment range.

8. The method of claim 5 , further comprising repeating file requests until a segment is received that contains content with a temporal exit point corresponding to, or later than, an end of the presentation time range.

9. The method of claim 5 , wherein the variation being relative to the segment time length is a time range such that a segment presentation time is between the segment time length and the segment time length plus the time range of the variation, inclusive.

10. The method of claim 5 , wherein the variation being relative to the segment time length is a proportion, P, such that a segment presentation time is between 1.0 times the segment time length and 1+P times the segment time length, inclusive.

11. The method of claim 5 , wherein the variation being relative to the segment time length is a time range such that a segment presentation time can be greater than or less than the segment time length ranging over the time range of the variation.

12. The method of claim 11 , further comprising repeating file requests until a segment is received that contains content with a tempor

Assignees

• Luby Michael George
• Minder Lorenz Christoph
• Qualcomm Inc

Inventors

• Luby Michael George
• Minder Lorenz Christoph

Classifications

• H04L65/608

  Electricity · mapped topic

• H04L67/02

  based on web technology, e.g. hypertext transfer protocol [HTTP] · CPC title

• H04L65/602

  Electricity · mapped topic

• H04L65/80

  Responding to QoS · CPC title

• H04L65/60 Primary

  Network streaming of media packets · CPC title