Packet-based video network indicating video signal synchronization and methodology thereof

• US 8,050,252 B2
• Filed: 03/30/2005
• Issued: 11/01/2011
• Est. Priority Date: 03/31/2004
• Status: Active Grant

• Current Assignee: Sony Europe (Amsterdam) BV (Sony Group Corp.)
• Original Assignee: Sony United Kingdom Limited (Sony Group Corp.)
• Inventors: Saunders, Nicholas Ian, Compton, Matthew
• Primary Examiner(s): Ryman; Daniel J
• Assistant Examiner(s): OH, ANDREW CHUNG SUK
• Application Number:
  US11/093,525
• Publication Number:
  US 20050220194A1
• Time in Patent Office: 2,407 Days
• Field of Search: 370/503
• US Class Current: 370/352
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04N 21/242 Synchronization processes, e.g. processing of PCR [Program Clock References] arrangements for synchronising broadcast or distribution via plural systems in broadcast distribution systems H04H20/18
• CPC Class Codes: H04N 21/6437 Real-time Transport Protocol [RTP]
• CPC Class Codes: H04N 5/268 Signal distribution or switching

Abstract

A video data network device arranged to receive a video signal and an associated synchronisation signal and to launch video data packets representing the video signal onto a packet-based data network comprises means for detecting whether the video signal is synchronised with the synchronisation signal; and means for launching data onto the network indicating whether the video signal is synchronised with the synchronisation signal.

Claims

1. A video data network source device, comprising:

a detector configured to receive a video signal, a reference clock synchronization signal related to a source timing of said video signal, and a frame synchronization signal related to the source timing of said video signal, and to provide a synchronization output indicating whether said video signal is synchronized to said reference clock synchronization signal and said frame synchronization signal;

a packetizer configured to generate video data packets, each video data packet representing at least a portion of the video signal;

a multiplexer configured to multiplex said video data packets, timing data indicating a frequency and a phase of said reference clock synchronization signal and said frame synchronization signal, and synchronization data based on said synchronization output to produce network data packets, said synchronization data indicating whether said video signal is not synchronized to said reference clock synchronization signal and said frame synchronization signal; and

a launcher configured to launch said network data packets onto a packet-based data network.

2. The video data network source device according to claim 1, wherein

said synchronization data comprises a data flag of one or more bits within at least a subset of said video data packets.

3. The video data network source device according to claim 2, wherein

said data flag is within a packet header of the at least a subset of said video data packets.

4. The video data network source device according to claim 3, wherein

said video data packets are BT.656 data packets.

5. The video data network source device according to claim 4, wherein

said data flag is carried within a packet header of said BT.656 packets.

6. The video data network source device according to claim 1, wherein

said video data packets are Real Time Protocol (RTP) data packets.

7. A video data network device, comprising:

a network interface configured to receive network data packets including video data packets each representing at least a portion of a video signal, timing data indicating a frequency and a phase of a reference clock synchronization signal related to a source timing of said video signal and a frame synchronization signal related to the source timing of said video signal, and synchronization data, said synchronization data indicating whether said video signal is not synchronized to said reference clock synchronization signal and said frame synchronization signal;

logic configured to synchronize a local reference clock synchronization signal and a local frame synchronization signal in accordance with said timing data;

logic configured to output said video signal in accordance to said local reference clock synchronization signal and said local frame synchronization signal; and

logic configured to generate a visible indicator associated with said video signal based on said synchronization data, said visible indicator indicating when the video signal is not synchronized to said reference clock synchronization signal and said frame synchronization signal.

8. The video data network device according to claim 7, wherein

said visible indicator comprises a visible modification of said video signal.

9. The video data network device according to claim 8, wherein

said visible indicator comprises a modification of the appearance of at least some pixels represented by said video signal.

10. The video data network device according to claim 9, wherein

said visible indicator comprises a readable message superposed on at least a portion of images represented by said video signal.

11. The video data network device according to claim 8, wherein

said visible indicator comprises a modification of a phase of said video signal with respect to at least one of said local reference clock synchronization signal and said local frame synchronization signal.

12. The video data network device according to claim 11, wherein

said visible indicator comprises a modification of said phase of said video signal so as to simulate a frame roll.

13. A video data network, comprising:

at least one source device including

a detector configured to receive a video signal, a reference clock synchronization signal related to a source timing of said video signal, and a frame synchronization signal related to the source timing of said video signal, and to provide a synchronization output indicating whether said video signal is synchronized to said reference clock synchronization signal and said frame synchronization signal,

a packetizer configured to generate video data packets, each video data packet representing at least a portion of the video signal,

a multiplexer configured to multiplex said video data packets, timing data indicating a frequency and a phase of said reference clock synchronization signal and said frame synchronization signal, and synchronization data based on said synchronization output to produce network data packets, said synchronization data indicating whether said video signal is not synchronized to said reference clock synchronization signal and said frame synchronization signal; and

a launcher configured to launch said network data packets onto a packet-based data network; and

at least one destination device including

a network interface configured to receive said network data packets including said video data packets, said timing data indicating said frequency and said phase of said reference clock synchronization signal and said frame synchronization signal, and said synchronization data, said synchronization data indicating whether said video signal is not synchronized to said reference clock synchronization signal and said frame synchronization signal,

logic configured to synchronize a local reference clock synchronization signal and a local frame synchronization signal to said reference clock synchronization signal and said frame synchronization signal using said timing data,

logic configured to output said video signal in accordance to said local reference clock synchronization signal and said local frame synchronization signal,

logic configured to generate a visible indicator associated with said video signal based on said synchronization data, said visible indicator indicating when the video signal is not synchronized to the reference clock synchronization signal and the frame synchronization signal, and

a network connection providing data communication between the at least one source device and the at least one destination device.

14. A method of operation of a video data network source device, comprising:

receiving a video signal, a reference clock synchronization signal related to a source timing of said video signal, and a frame synchronization signal related to the source timing of said video signal;

providing a synchronization output indicating whether said video signal is synchronized to said reference clock synchronization signal and said frame synchronization signal;

generating video data packets, each video data packet representing at least a portion of the video signal;

multiplexing said video data packets, timing data indicating a frequency and a phase of said reference clock synchronization signal and said frame synchronization signal, and synchronization data based on said synchronization output to produce network data packets, said synchronization data indicating whether said video signal is not synchronized to said reference clock synchronization signal and said frame synchronization signal; and

launching said network data packets onto a packet-based data network.

15. A method of operation of a video data network device, comprising:

receiving network data packets including video data packets each representing at least a portion of a video signal, timing data indicating a frequency and a phase of a reference clock synchronization signal related to a source timing of said video signal and a frame synchronization signal related to the source timing of said video signal, and synchronization data, said synchronization data indicating whether said video signal is not synchronized to said reference clock synchronization signal and said frame synchronization signal;

synchronizing a local reference clock synchronization signal and a local frame synchronization signal to said reference clock synchronization signal and said frame synchronization signal using said timing data;

outputting said video signal in accordance to said local reference clock synchronization signal and said local frame synchronization signal; and

generating a visible indicator associated with said video signal based on said synchronization data, said visible indicator indicating when the video signal is not synchronized to said reference clock synchronization signal and said frame synchronization signal.

16. A non-transitory computer-readable storage medium storing computer-readable instructions thereon, the computer-readable instructions, when executed by a processor, cause the processor to perform steps, comprising:

receiving network data packets including video data packets each representing at least a portion of a video signal, timing data indicating a frequency and a phase of a reference clock synchronization signal related to a source timing of said video signal and a frame synchronization signal related to the source timing of said video signal, and synchronization data, said synchronization data indicating whether said video signal is not synchronized to said reference clock synchronization signal and said frame synchronization signal;

synchronizing a local reference clock synchronization signal and a local frame synchronization signal to said reference clock synchronization signal and said frame synchronization signal using said timing data;

outputting said video signal in accordance to said local reference clock synchronization signal and said local frame synchronization signal; and

generating a visible indicator associated with said video signal based on said synchronization data, said visible indicator indicating when the video signal is not synchronized to said reference clock synchronization signal and said frame synchronization signal.

17. A non-transitory computer-readable storage medium storing computer-readable instructions thereon, the computer-readable instructions, when executed by a processor, cause the processor to perform steps, comprising:

receiving a video signal, a reference clock synchronization signal related to a source timing of said video signal, and a frame synchronization signal related to the source timing of said video signal;

providing a synchronization output indicating whether said video signal is synchronized to said reference clock synchronization signal and said frame synchronization signal;

generating video data packets, each video data packet representing at least a portion of the video signal;

multiplexing said video data packets, timing data indicating a frequency and a phase of said reference clock synchronization signal and said frame synchronization signal, and synchronization data based on said synchronization output to produce network data packets, said synchronization data indicating whether said video signal is not synchronized to said reference clock synchronization signal and said frame synchronization signal; and

launching said network data packets onto a packet-based data network.