Video multiplexer system providing low-latency VCR-like effects and program changes

• US 8,161,519 B2
• Filed: 05/06/2005
• Issued: 04/17/2012
• Est. Priority Date: 08/29/2003
• Status: Active Grant

• Current Assignee: Imagine Communications Limited (Gores Broadcast Holdings LLC)
• Original Assignee: RGB Networks, Inc. (Gores Broadcast Holdings LLC)
• Inventors: Krause, Edward A., Monta, Peter, Tom, Adam
• Primary Examiner(s): Kumar, Pankaj
• Assistant Examiner(s): ANDRAMUNO, FRANKLIN S
• Application Number:
  US11/123,780
• Publication Number:
  US 20050190794A1
• Time in Patent Office: 2,538 Days
• Field of Search: 725/138, 725/144
• US Class Current: 725/138
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• 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 65/765 intermediate
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04N 19/146 Data rate or code amount at the encoder output
• CPC Class Codes: H04N 19/40 using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream
• CPC Class Codes: H04N 19/48 using compressed domain processing techniques other than decoding, e.g. modification of transform coefficients, variable length coding [VLC] data or run-length data motion estimation in a transform domain H04N19/547; processing of decoded motion vectors H04N19/513
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 21/2225 Local VOD servers
• CPC Class Codes: H04N 21/23103 using load balancing strategies, e.g. by placing or distributing content on different disks, different memories or different servers storage management G06F3/0604; allocation of resources considering the load in multiprogramming arrangements G06F9/505; techniques for rebalancing the load in a distributed system G06F9/5083; access to distributed or replicated servers, e.g. load balancing, in data networks H04L67/1001
• CPC Class Codes: H04N 21/23424 involving splicing one content stream with another content stream, e.g. for inserting or substituting an advertisement
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/23608 Remultiplexing multiplex streams, e.g. involving modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/2365 Multiplexing of several video streams
• CPC Class Codes: H04N 21/23655 Statistical multiplexing, e.g. by controlling the encoder to alter its bitrate to optimize the bandwidth utilization
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/2385 Channel allocation H04N21/266 takes precedence; Bandwidth allocation H04N21/24 takes precedence ; allocation of channels according to the instantaneous demands of the users in time-division multiplex systems H04J3/1682; admission control, resource allocation in open networks H04L12/5692; arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896; negotiating bandwidth in wireless networks H04W28/16
• CPC Class Codes: H04N 21/2405 Monitoring of the internal components or processes of the server, e.g. server load allocation of resources in multiprogramming arrangements G06F9/50; performance measurement of computer activity G06F11/34
• CPC Class Codes: H04N 21/26216 involving the channel capacity, e.g. network bandwidth admission control, resource allocation in open networks H04L12/5692; flow control in packet networks H04L47/10; establishing a schedule or organising the servicing of application requests taking into account QoS H04L67/61
• CPC Class Codes: H04N 21/26606 : for generating or managing entitlement messages, e.g. Entitlement Control Message [ECM] or Entitlement Management Message [EMM] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 21/26613 : for generating or managing keys in general key distribution for secret or secure communication involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP] H04L9/083; network support of key management H04L63/06; key management for network security in communication control or processing H04W12/04
• CPC Class Codes: H04N 21/4344 : Remultiplexing of multiplex streams, e.g. by modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/4347 : Demultiplexing of several video streams
• CPC Class Codes: H04N 21/44016 : involving splicing one content stream with another content stream, e.g. for substituting a video clip
• CPC Class Codes: H04N 21/47202 : for requesting content on demand, e.g. video on demand
• CPC Class Codes: H04N 21/6118 : involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/63345 : by transmitting keys key distribution for secret or secure communication H04L9/08; network support of key management H04L63/06
• CPC Class Codes: H04N 21/812 : involving advertisement data advertising per se G06Q30/02
• CPC Class Codes: H04N 7/1675 : Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58
• CPC Class Codes: H04N 7/17318 : Direct or substantially direct transmission and handling of requests
• CPC Class Codes: H04N 7/17336 : Handling of requests in head-ends

Abstract

An advanced multiplexer designed and optimized for next generation on-demand video distribution is described. Features and capabilities include low-latency client interactions, quality of service management, session based encryption management, support for multiple video formats, and support for multiple video decoding standards. Indicators are embedded in new video segments to identify start-of-segment transition points, enabling rapid transitions from one video segment to another. Low-latency operation is achieved by rapid switching, and by coordinating flushing of video buffers and buffer restoration.

Claims

1. A video multiplexer system characterized by:

a session manager for identifying digital video content to be provided;

a video server, responsive to said session manager, for providing said digital video content, said video content being further characterized by a plurality of video segments;

a multiplexer for selecting and combining video segments into one or more multi-channel multiplexes;

means for a client to request that said server transition from a current video segment to a new video segment at any point in the current video segment;

means within said video server for defining a start point of said new video segment in response to said client request and inserting a start point identifier in the new video segment indicative of said start point; and

means within said multiplexer and responsive to said start point identifier for effecting a smooth transition to the new video segment synchronized to said start point of the new video segment.

2. A video multiplexer system according to claim 1, wherein:

said start point is indicated by a cueing message packet.

3. A video multiplexer system according to claim 2, wherein:

said cueing message packet has a fixed packet ID (PID).

4. A video multiplexer according to claim 2, wherein:

said cueing message packet conforms to ANSI/SCTE 35, and is a splice_insert message with a splice_immediate indication set to 1.

5. A video multiplexer system according to claim 1, wherein:

said video server provides said start point of said new video segment at a reference frame within said video segment.

6. A video multiplexer system according to claim 5, wherein:

said reference frame is characterized by a sequence header and MPEG I-Frame.

7. A video multiplexer system according to claim 1, wherein:

said multiplexer delays effecting the transition to the new video segment after said start point until a reference frame is detected within said new video segment.

20. A video multiplexer system according to claim 1, further characterized by:

buffering means within said multiplexer for maintaining a predetermined buffer level of video segment information;

means within said multiplexer for discarding buffered video segment data from said current video segment after effecting the transition to the new video segment; and

means within said video server for providing data from said new video segment at a rate sufficient after said transition to restore buffering of said new video segment data within said multiplexer to said predetermined level.

8. A video multiplexer system characterized by:

a session manager for identifying digital video content to be provided;

a video server, responsive to said session manager, for providing said digital video content, said video content being further characterized by a plurality of video segments;

a multiplexer for selecting and combining video segments into one or more multi-channel multiplexes;

a modulator for modulating said multi-channel multiplexes onto a plurality of discrete channels for transmission over a distribution network;

at least one client connected to said distribution network for receiving and displaying video segments transmitted on at least one of said plurality of discrete channels;

means for said client to request a transition from a current video segment to a new video segment at any point in the current video segment;

means within said video server for defining a start point of said new video segment in response to said client request and inserting a start point identifier in the new video segment indicative of said start point; and

means within said multiplexer and responsive to said start point identifier for effecting a smooth transition to the new video segment synchronized to said start point of the new video segment.

21. A video multiplexer system according to claim 8, further characterized by:

buffering means within said multiplexer for maintaining a predetermined buffer level of video segment information;

means within said multiplexer for discarding buffered video segment data from said current video segment after effecting the transition to the new video segment; and

means within said video server for providing data from said new video segment at a rate sufficient after said transition to restore buffering of said new video segment data within said multiplexer to said predetermined level.

9. A video multiplexer system characterized by:

a session manager for identifying digital video content to be provided;

a video server, responsive to said session manager, for providing said digital video content, said video content being further characterized by a plurality of video segments;

a multiplexer for selecting and combining video segments into one or more multi-channel multiplexes;

a modulator for modulating said multi-channel multiplexes onto a plurality of discrete channels for transmission over a distribution network;

at least one client connected to said distribution network for receiving and displaying video segments transmitted on at least one of said plurality of discrete channels;

means for said client to request a transition from a current video segment to a new video segment at any point in the current video segment;

means within said video server for defining a start point of said new video segment in response to said client request and inserting a start point identifier in the new video segment indicative of said start point; and

means within said multiplexer and responsive to said start point identifier for effecting a smooth transition to the new video segment synchronized to said start point of the new video segment;

buffering means within said multiplexer for maintaining a predetermined buffer level of video segment information;

means within said multiplexer for discarding buffered video segment data from said current video segment after effecting the transition to the new video segment; and

means within said video server for providing data from said new video segment at a rate sufficient after said transition to restore buffering of said new video segment data within said multiplexer to said predetermined level.

10. A video multiplexer system according to claim 9, wherein:

said video server provides data from said new video segment at a rate faster than required for real-time display of said new video segment for a fixed period of time after said transition.

11. A video multiplexer system according to claim 9, wherein:

said video server provides data from said new video segment at rate faster than required for real-time display of said new video segment until it determines that an amount of video data in excess of real-time display requirements corresponding to said predetermined buffer level has been transmitted.

12. A video multiplexer system according to claim 9, further characterized by:

flow control means between said multiplexer and said video server for maintaining said predetermined buffer level at said multiplexer.

13. A video multiplexer system according to claim 12, wherein:

said flow control means exists as a part of data communications mechanisms, within a headend network.

14. A method of providing low-latency transitions between video segments in a video multiplexer system, characterized by:

providing a session manager for identifying digital video content to be provided;

providing a video server, responsive to said session manager, for providing said digital video content, said video content being further characterized by a plurality of video segments;

providing a multiplexer for selecting and combining video segments into one or more multi-channel multiplexes;

providing a modulator for modulating said multi-channel multiplexes onto a plurality of discrete channels for transmission over a distribution network;

providing at least one client connected to said distribution network for receiving and displaying video segments transmitted on at least one of said plurality of discrete channels;

making a request by said client for a transition from a current video segment to a new video segment at any point in the current video segment;

providing a new video segment in response to said client request;

defining a start point within said new video segment in response to said client request;

inserting a start point identifier in the new video segment indicative of said start point; and

causing a smooth transition of said client to said new video segment synchronously with said start point of the new video segment in response to said start point identifier.

15. A method according to claim 14, further characterized by:

defining at least two virtual channels within a discrete channel received by said client;

causing resynchronization of said client synchronously with said transition by providing video segment data to the client on one of the two virtual channels prior to the transition and on the other of the two virtual channels after the transition thereby causing the client to switch virtual channels at the time of the transition.

16. A method according to claim 14, further characterized by:

defining a desired buffer level for video segment information;

discarding buffered video segment data from said current video segment after effecting the transition to the new video segment; and

providing data from said new video segment at a rate sufficient after said transition to restore buffering of said new video segment data to said desired level.

17. A method according to claim 16, further characterized by:

providing data from said new video segment at a rate faster than required for real-time display of said new video segment for a fixed period of time after said transition.

18. A method according to claim 16, further characterized by:

providing data from said new video segment at rate faster than required for real-time display of said new video segment until it determines that an amount of new video segment data in excess of real-time display data requirements corresponding to said desired buffer level has been transmitted.

19. A method according to claim 16, further characterized by:

providing flow control means between said multiplexer and said video server for maintaining said desired buffer level at said multiplexer.