Network based instant replay and time shifted playback

• US 20070130597A1
• Filed: 12/02/2005
• Published: 06/07/2007
• Est. Priority Date: 12/02/2005
• Status: Abandoned Application

• Current Assignee: Alcatel SA (Nokia Corporation)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Dion, Gino, Furlong, Jeff, Parker, Alistair, Higgins, Sean
• Application Number:
  US11/292,345
• Publication Number:
  US 20070130597A1
• Time in Patent Office: Days
• US Class Current: 725/94
• CPC Class Codes: H04H 20/38 Arrangements for distribution where lower stations, e.g. receivers, interact with the broadcast
• CPC Class Codes: H04H 20/82 using signals not modulated onto a carrier
• CPC Class Codes: H04H 2201/33 via the broadcast channel
• CPC Class Codes: H04H 60/27 Arrangements for recording or accumulating broadcast information or broadcast-related information
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• CPC Class Codes: H04L 65/613 for the control of the source by the destination control signals issued by the client directed to the server or network components specially adapted for selective content distribution H04N21/637
• CPC Class Codes: H04L 65/765 intermediate
• CPC Class Codes: H04N 21/21 Server components or server architectures
• CPC Class Codes: H04N 21/23 Processing of content or additional data; Elementary server operations; Server middleware
• CPC Class Codes: H04N 21/23406 involving management of server-side video buffer
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/2625 for delaying content or additional data distribution, e.g. because of an extended sport event
• CPC Class Codes: H04N 21/6377 directed to server one-way streaming services wherein the source is controlled by the destination H04L65/613
• CPC Class Codes: H04N 21/6408 Unicasting
• CPC Class Codes: H04N 21/658 Transmission by the client directed to the server
• CPC Class Codes: H04N 21/6587 Control parameters, e.g. trick play commands, viewpoint selection
• CPC Class Codes: H04N 5/76 Television signal recording
• CPC Class Codes: H04N 5/765 Interface circuits between an apparatus for recording and another apparatus
• CPC Class Codes: H04N 5/781 on disks or drums
• CPC Class Codes: H04N 7/17318 : Direct or substantially direct transmission and handling of requests
• CPC Class Codes: H04N 9/8042 : involving data reduction

Abstract

A circular buffer in a video delivery server tracks a second copy of a live video stream to provide instant replay capability. When an end-user initiates the instant replay function, the circular buffer is copied to an instant-replay buffer, from which a replay of the video is sent to the end-user. During replay the end-user can use playback functions such as pause, slow-play, freeze frame, etc. Upon leaving the replay function the end user rejoins the live stream. The circular buffer also enables transmission of delayed copies of the live stream, time-shifted by predetermined intervals, which copies are multicasted to end-users. Upon request, an end-user may join a delayed version of interest. This allows the user to replay interesting content by jumping to a time-delayed version without missing the show and to catch up with real-time during e.g. commercial breaks.

Claims

1. At a video delivery server for distributing multimedia content streams to a plurality of subscriber premise equipment (SPE) units, where SPE units select and join multimedia content streams using interactive program guide capabilities at said server, a time-shift unit comprising:

a circular buffer for storing multimedia content received in a live multimedia content stream;

a first sender for bypassing said circular buffer and multicasting said live multimedia content stream directly to said SPE units; and

a second sender for accessing said multimedia content from a specific position in said circular buffer, and multicasting a time-shifted variant of said live multimedia content stream to said SPE units,

wherein said specific position in said circular buffer confers a predetermined time-shift for said variant of said live multimedia content stream with respect to said live multimedia content stream.

2. The video delivery server of claim 1, further comprising a time-shift controller for receiving a time-shift request message from said SPE unit and providing said SPE unit with a multicast address for said time-shifted variant of said live multimedia content stream.

3. The video delivery server of claim 1, further comprising additional senders for accessing said multimedia content from different specific positions in said circular buffer for providing different predetermined time-shifts Dn, each said additional sender multicasting a respective time-shifted variant of said live multimedia content stream to said SPE units,

wherein a SPE unit selects to join either one of said live multimedia content stream and said time-shifted variants of said multimedia content stream for playback of the content in said live stream directly or with a respective predetermined time-shift Dn.

4. The video delivery server of claim 3, further comprising a time-shift controller for receiving a request message from said SPE unit specifying a preferred time-shift and providing said SPE unit with a respective address enabling said SPE unit to join one of said time-shifted variants of said live multimedia content stream that provides said preferred time-shift.

5. The video delivery server of claim 3, wherein said time-shifts Dn are in the order of tenths of minutes.

6. The video delivery server of claim 3, wherein said time-shifts Dn are in the order of minutes.

7. The video server of claim 1 further comprising an instant reply unit for enabling a SPE unit with instant reply functionality.

8. The video server of claim 7 wherein said instant reply unit comprises:

a replay buffer for storing a length T of multimedia content;

an instant replay controller for receiving an instant reply request from said CPE unit, taking a snapshot copy of length T of the multimedia content from said circular buffer to said reply buffer and directing a pointer associated with said SPE unit to said reply buffer; and

a sender associated with said replay buffer for transmitting said snapshot copy to said SPE unit from said reply buffer.

9. The video server of claim 8 wherein said sender associated with said replay buffer transmits said snapshot copy using a unicast transmission protocol.

10. The video server of claim 8, wherein said length T is in the order of tens of seconds.

11. The video server of claim 8, wherein said instant reply request is implemented using the real time streaming protocol (RTSP).

12. The video server of claim 7 wherein said instant reply unit comprises:

a plurality of replay buffers, each for storing a distinct length Tn of multimedia content;

an instant replay controller for receiving an instant reply request from said CPE unit specifying a preferred length T of an instant replay sequence, taking a snapshot copy of length T of the multimedia content from said circular buffer to one of said reply buffers according to length T; and

a sender associated with said replay buffer selected based on length T for transmitting said snapshot copy of length D to said SPE unit from said reply buffer.

13. A method for distributing multimedia content streams to a plurality of subscriber premise equipment (SPE) units, where SPE units select and join multimedia content streams using interactive program guide capabilities at said server, comprising:

continuously storing multimedia content received in a live multimedia content stream into a circular buffer;

identifying a specific access point in said circular buffer that provides a predetermined time-shift of multimedia content in said circular buffer from the access point of multimedia content in said live multimedia content stream; and

accessing said multimedia content from said specific offset in said circular buffer, and multicasting a time-shifted variant of said live multimedia content stream to said SPE units from said specific access point.

14. The method of claim 13, further comprising bypassing said circular buffer and multicasting said live multimedia content stream directly to said SPE units.

15. The method of claim 13, further comprising receiving a time-shift request message from a SPE unit and providing said SPE unit with a multicast address for said time-shifted variant of said live multimedia content stream.

16. The method of claim 13, further comprising:

identifying additional specific access points in said circular buffer for additional predetermined time-shifts Dn of multimedia content in said circular buffer from the access point of multimedia content in said live multimedia content stream; and

accessing said multimedia content from each said specific access point in said circular buffer, and multicasting additional time-shifted variants of said live multimedia content stream to said SPE units from said additional specific access points.

17. The method of claim 13, further comprising:

receiving an instant reply request from said CPE unit;

taking a snapshot copy of length T of the multimedia content from said circular buffer to a reply buffer and directing a pointer associated with said SPE unit to said reply buffer; and

transmitting said snapshot copy to said SPE unit from said reply buffer.

18. The method of claim 17, wherein said snapshot copy is provided to said SPE unit using a unicast transmission protocol.

19. The method of claim 13, further comprising:

providing a plurality of reply buffers of various lengths Tn;

receiving an instant reply request from said CPE unit, wherein said instant reply specifies a length T for instant reply of selected content of interest;

identifying a certain reply buffer from said plurality of reply buffers that can store content of said length T;

taking a snapshot copy of length T of the multimedia content from said circular buffer to said certain reply buffer and directing a pointer associated with said SPE unit to said certain reply buffer; and

transmitting said instant reply content of interest to said SPE unit.

20. The method of claim 19, further comprising performing trick play operations on said instant reply content of interest in said certain reply buffer.