Method and system for recording streams

• US 9,038,116 B1
• Filed: 12/24/2010
• Issued: 05/19/2015
• Est. Priority Date: 12/28/2009
• 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 Jaiprakash
• Primary Examiner(s): Shang, Annan
• Application Number:
  US12/978,468
• Time in Patent Office: 1,607 Days
• Field of Search: 725 87-120, 725131-134, 725139-142, 725151-153, 709217-232
• US Class Current: 725/89
• CPC Class Codes: H04L 12/2805 Home Audio Video Interoperability [HAVI] networks
• CPC Class Codes: H04L 65/60 Network streaming of media packets
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04N 21/2187 Live feed
• CPC Class Codes: H04N 21/222 Secondary servers, e.g. proxy server, cable television Head-end provisioning of proxy services in data packet switching networks H04L67/56
• 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 21/234318 by decomposing into objects, e.g. MPEG-4 objects
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/2389 Multiplex stream processing, e.g. multiplex stream encrypting
• CPC Class Codes: H04N 21/2747 Remote storage of video programs received via the downstream path, e.g. from the server

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.

Claims

1. Apparatus, comprising:

a set of interconnected machines, each machine comprising a processor, and computer memory for holding computer program instructions executed by the processor to manage a stream, the computer program instructions comprising;

first program code to receive the stream in a source format;

second program code distinct from the first program code to demux the stream from the source format into an intermediate format comprising file fragments and associated index information, wherein a file fragment represents a given time period of the stream, the second program code operative with respect to a given portion of the stream in the source format to generate an intermediate format header, package the given portion in the source format into an intermediate format body associated with the intermediate format header to generate an intermediate format file fragment, and to output the intermediate format file fragment so generated; and

third program code distinct from the second program code to record the intermediate format file fragments demuxed from the stream and output from the second program code;

wherein the third program code also caches a predetermined number of file fragments to a temporary data storage unit for live playback of the stream.

2. The apparatus as described in claim 1 wherein the third program code to record the stream also archives the file fragments to a persistent data store after a given time period associated with the live playback.

3. The apparatus as described in claim 1 wherein the third program code to record the stream also periodically creates a new fragment index file.

4. The apparatus as described in claim 1 wherein the stream is received in one or more versions.

5. The apparatus as described in claim 4 wherein the one or more versions comprise distinct bitrate versions of the stream in the source format.

6. The apparatus as described in claim 5 wherein the bitrate versions are multiplexed over a single connection.

7. The apparatus as described in claim 1 wherein redundant copies of the predetermined number of file fragments are cached to the temporary data store.

8. The apparatus as described in claim 1 wherein the stream is received from an encoder.

9. The apparatus as described in claim 1 wherein the intermediate format is a fragmented MP4 format.

10. The apparatus as described in claim 1 wherein the second program code determines an optimal size of an intermediate format file fragment.

11. The apparatus as described in claim 1 wherein the second program code determines and pushes key frame information.

12. The apparatus as described in claim 11 wherein the key frame information is a key frame location within a given data packet in the source format.