Method and system for HTTP-based stream delivery

• US 9,537,967 B2
• Filed: 08/17/2010
• Issued: 01/03/2017
• Est. Priority Date: 08/17/2009
• Status: Active Grant

• Current Assignee: Akamai Technologies, Inc.
• Original Assignee: Akamai Technologies, Inc.
• Inventors: Knox, Christopher R., Lisiecki, Philip A., Mutton, James, Bernard, Chuck, Lalwani, Ashok, Law, Will, Devanneaux, Thomas
• Primary Examiner(s): Tiv, Backhean
• Assistant Examiner(s): Chou, Alan S
• Application Number:
  US12/858,177
• Publication Number:
  US 20110173345A1
• Time in Patent Office: 2,331 Days
• Field of Search: 709/231, 709/246
• US Class Current: 1/1
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 65/765 intermediate
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/565 Conversion or adaptation of application format or content adding application control or application functional data H04L67/561
• CPC Class Codes: H04L 67/566 Grouping or aggregating service requests, e.g. for unified processing
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04N 21/23106 involving caching operations prefetching while addressing of a memory level in which the access to the desired data or data block requires associative addressing means within memory systems or architectures G06F12/0862; caching at an intermediate stage in a data network H04L67/568
• CPC Class Codes: H04N 21/2343 involving reformatting operations of video signals for distribution or compliance with end-user requests or end-user device requirements video transcoding H04N19/40; media packet handling at the source H04L65/762
• CPC Class Codes: H04N 21/2747 Remote storage of video programs received via the downstream path, e.g. from the server
• CPC Class Codes: H04N 21/8456 by decomposing the content in the time domain, e.g. in time segments

Abstract

A method of delivering a live stream is implemented within a content delivery network (CDN) and includes the high level functions of recording the stream using a recording tier, and playing the stream using a player tier. The step of recording the stream includes a set of sub-steps that begins when the stream is received at a CDN entry point in a source format. The stream is then converted into an intermediate format (IF), which is an internal format for delivering the stream within the CDN and comprises a stream manifest, a set of one or more fragment indexes (FI), and a set of IF fragments. The player process begins when a requesting client is associated with a CDN HTTP proxy. In response to receipt at the HTTP proxy of a request for the stream or a portion thereof, the HTTP proxy retrieves (either from the archive or the data store) the stream manifest and at least one fragment index. Using the fragment index, the IF fragments are retrieved to the HTTP proxy, converted to a target format, and then served in response to the client request. The source format may be the same or different from the target format. Preferably, all fragments are accessed, cached and served by the HTTP proxy via HTTP. In another embodiment, a method of delivering a stream on-demand (VOD) uses a translation tier (in lieu of the recording tier) to manage the creation and/or handling of the IF components.

Claims

1. A method of streaming in a content delivery network (CDN) having a set of interconnected machines, comprising:

recording a stream by the following sub-steps;

receiving at an entry point a stream in a source format;

converting the stream into an intermediate format (IF), wherein the intermediate format is an internal format for transporting and storing the stream within the CDN and comprises a stream manifest, a set of one or more fragment indexes (FI), and a set of IF fragments that, within the CDN, are individually managed from one another, the intermediate format being distinct from the source format; and

archiving, in an archiver, a predetermined number of the IF fragments of the stream in the intermediate format in association with a current fragment index, the predetermined number of the IF fragments of the stream adapted for live playback, wherein, as the predetermined number of the IF fragments of the stream age-out, the current fragment index is closed and the predetermined number of the IF fragments associated therewith are then transferred to and stored in a storage system associated with the CDN and distinct from the archiver, the archiving operation being repeated continuously as the stream continues to be received; and

playing the stream by the following sub-steps;

in response to receipt at an edge server process of a request for the stream or a portion thereof, retrieving the stream manifest and at least one fragment index to the edge server process;

using the fragment index, retrieving to the edge server process the IF fragments, wherein the IF fragments are retrieved (i) from the archiver when the request is for a portion of the stream that is then available for live playback, or (ii) from the storage system when the at least one fragment index is associated with any IF fragments that were previously transferred to and stored in the distinct storage system;

converting the IF fragments to a target format, the target format also being distinct from the intermediate format; and

serving the stream in the target format via HTTP.

2. The method as described in claim 1 wherein the source format and the target format are a same format.

3. The method as described in claim 1 wherein the IF fragments are retrieved to the edge server process via HTTP.

4. The method as described in claim 1 wherein the archiving is performed via HTTP.

5. The method as described in claim 1 wherein the stream is one of:

a live stream, and a DVR stream.

6. The method as described in claim 1 further including caching a predetermined number of IF fragments for live stream playback.

7. Apparatus, comprising:

a set of interconnected machines, each machine comprising a processor, and computer memory for holding computer program instructions that when executed by the processor facilitate a method of HTTP-based delivery of a stream, the method comprising;

converting the stream from a source format into an intermediate format (IF), wherein the intermediate format is an internal format for transporting and storing the stream within the set of interconnected machines, the intermediate format comprising a stream manifest, a set of one or more fragment indexes (FI), and a set of IF fragments that, within the set of interconnected machines, are individually managed from one another and optimally sized for caching, the intermediate format being distinct from the source format;

storing, in an archiver, the stream manifest, the set of one or more fragment indexes, and the set of IF fragments, wherein IF fragments associated with at least an aged-out portion of the stream are stored in a separate storage distinct from the archiver, the archiver storing IF fragments representing a live playback of the stream;

in response to receipt of a request for the stream or a portion thereof, retrieving the stream manifest and at least one fragment index;

using the fragment index, retrieving, via HTTP, one or more IF fragments, wherein when the request is for a portion of the stream that is then available for live playback the at least one IP fragment is retrieved from the archiver, and when the request is for a portion of the stream that is not then available for live playback at least one IF fragment is retrieved from the separate storage instead of the archiver;

converting the retrieved IF fragments to a target format, the target format also being distinct from the intermediate format; and

serving, via HTTP, the stream in the target format in response to the request for the stream or the portion thereof.

8. The apparatus as described in claim 7 wherein the stream is one of:

a live stream, a DVR stream, and VOD.

9. The apparatus as described in claim 7 wherein the source format and the target format are a same format.

10. The apparatus as described in claim 8 wherein, for a live stream, the method includes archiving a current portion of the stream in the intermediate format.

11. The apparatus as described in claim 8 wherein, for a live stream, the method includes archiving at a first machine IF fragments that constitute a first portion of the stream, and storing at a second machine IF fragments that constitute a second portion of the stream, the second portion being less recent than the first portion.