APPARATUS FOR AND METHOD OF IDENTIFYING VIDEO STREAMS TRANSMITTED OVER A SHARED NETWORK LINK, AND FOR IDENTIFYING AND TIME-OFFSETTING INTRA-FRAMES GENERATED SUBSTANTIALLY SIMULTANEOUSLY IN SUCH STREAMS

• US 20150085132A1
• Filed: 09/24/2013
• Published: 03/26/2015
• Est. Priority Date: 09/24/2013
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: BEKIARES, TYRONE D., TINE, STEVEN D., SCHMIDT, HINRICH A.
• Granted Patent: US 9,544,534 B2
• Time in Patent Office: Days
• US Class Current: 348/159
• CPC Class Codes: H04N 7/0806 the signals being two or more video signals H04N7/0803, H04N7/081 take precedence
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

Multiple cameras are operatively connected over a shared link to a video server on a video network. The cameras are operated to capture a plurality of video streams. Each video stream has intra-frames and predictive frames that are sequentially generated timewise apart. A number of the video streams that transmit over the shared link on the network is identified. A number of intra-frames that are generated substantially simultaneously in the identified video streams is also identified. The identified intra-frames in the video streams are offset in time to minimize video artifacts from being present in the video streams being transmitted over the shared link.

Claims

1. A method of operating a video network, comprising:

operatively connecting a plurality of cameras over a shared link to a video server on the network;

operating each camera to capture a corresponding plurality of video streams, each video stream having intra-frames and predictive frames that are sequentially generated timewise apart;

identifying a number of the video streams transmitted over the shared link on the network, and identifying a number of the intra-frames that are generated substantially simultaneously in the identified number of the video streams; and

time-offsetting the identified number of the intra-frames to minimize video artifacts from being present in the video streams being transmitted over the shared link.

2. The method of claim 1, and configuring the shared link as a wireless link.

3. The method of claim 1, wherein the identifying is performed by analyzing candidate ones of the video streams, and by determining which of the candidate video streams generate their respective intra-frames within an allowable time offset relative to one another.

4. The method of claim 3, wherein the analyzing is performed by correlating peaks above a predetermined threshold in one of jitter and packet loss rate of the candidate video streams with occurrences of the intra-frames of the candidate video streams.

5. The method of claim 4, wherein the identifying is performed by analyzing other ones of the video streams when the peaks are uncorrelated with the occurrences of the intra-frames.

6. The method of claim 1, wherein the time-offsetting is performed by adjusting when the video streams begin to stream by operating each camera at different times.

7. The method of claim 1, wherein the identifying is performed by analyzing all of the video streams.

8. The method of claim 1, wherein the time-offsetting is performed by adjusting respective intra-frame periods of the video streams.

9. The method of claim 1, wherein the time-offsetting is performed by adjusting when each identified intra-frame is generated.

10. An apparatus for operating a video network, comprising:

a plurality of cameras operatively connected together over a shared link on the network; and

a video server on the network for operating each camera to capture a corresponding plurality of video streams, each video stream having intra-frames and predictive frames that are sequentially generated timewise apart, and

the video server being operative for identifying a number of the video streams transmitted over the shared link on the network, for identifying a number of the intra-frames that are generated substantially simultaneously in the identified number of the video streams, and for time-offsetting the identified number of the intra-frames to minimize video artifacts from being present in the video streams being transmitted over the shared link.

11. The apparatus of claim 10, wherein the shared link is a wireless link.

12. The apparatus of claim 10, wherein the video server is operative for analyzing candidate ones of the video streams, and for determining which of the candidate video streams generate their respective intra-frames within an allowable time offset relative to one another.

13. The apparatus of claim 12, wherein the video server is operative for correlating peaks above a predetermined threshold in one of jitter and packet loss rate of the candidate video streams with occurrences of the intra-frames of the candidate video streams.

14. The apparatus of claim 13, wherein the video server is operative for analyzing other ones of the video streams when the peaks are uncorrelated with the occurrences of the intra-frames.

15. The apparatus of claim 10, wherein the video server is operative for adjusting when the video streams begin to stream by operating each camera at different times.

16. The apparatus of claim 10, wherein the video server is operative for adjusting respective intra-frame periods of the video streams.

17. The apparatus of claim 10, wherein the video server is operative for adjusting when each identified intra-frame is generated.

18. The apparatus of claim 10, wherein the video server includes a network video recorder.

19. The apparatus of claim 18, wherein the video server further includes a monitoring agent.

20. The apparatus of claim 10, wherein each camera is a stand-alone device that does not communicate directly with any of the other cameras.