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
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.
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 video streams from the plurality of video streams that were transmitted over the shared link on the network;
identifying the intra-frames that are generated substantially simultaneously in the identified number of the video streams; and
time-offsetting the identified.
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;
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,
the video server being operative for:
identifying the video streams from the plurality of video streams transmitted over the shared link on the network;
identifying the intra-frames that are generated substantially simultaneously in the identified number of the video streams;
time-offsetting the identified intra-frames.
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.