System and method to estimate end-to-end video frame delays
System and method to calculate video frame delay in a video stream received by a telecommunications endpoint, the method including: locating reference features characteristic of content in the received video stream; calculating, by use of a processor, reduced reference features from the located reference features; receiving reduced reference features of a transmitted video stream, the transmitted video stream corresponding to the received video stream; calculating, by use of a processor, a received trajectory of the reduced reference features from the received video stream; calculating, by use of a processor, a transmitted trajectory of the reduced reference features from the transmitted video stream; and calculating, by use of a processor, video frame delay as a time shift between the received trajectory and the transmitted trajectory.
1. A method to calculate video frame delay in a video stream received by a telecommunications endpoint, the method comprising:
locating reference features that are characteristic of content in the received video stream;
calculating, by use of a processor, reduced reference features from the located reference features;
receiving reduced reference features of a transmitted video stream, the transmitted video stream corresponding to the received video stream;
calculating, by use of a processor, a received trajectory of the reduced reference features from the received video stream;
calculating, by use of a processor, a transmitted trajectory of the reduced reference features from the transmitted video stream; and
calculating, by use of a processor, video frame delay as a time shift between the received trajectory and the transmitted trajectory.
2. The method of claim 1 , wherein the reference features that are characteristic of content comprise faces.
3. The method of claim 1 , wherein the reduced reference features comprise locations of the reference features.
4. The method of claim 1 , wherein the reduced reference features comprise a location of rectangular areas surrounding the reference features.
5. The method of claim 1 , wherein the reduced reference features are calculated at less than a full frame rate of the received video stream.
6. The method of claim 1 , wherein the reduced reference features are calculated at no more than five frames per second.
7. The method of claim 1 , wherein the reduced reference features of the transmitted video stream are received via a communication channel that is separate from a communication channel used to transport the video stream.
8. The method of claim 1 , further comprising:
receiving a frame of the transmitted video stream to the telecommunications endpoint, once per second, via a reliable channel; and
calculating reduced reference features from the frame.
9. The method of claim 1 , wherein the video stream originates from a remotely-located camera accessible via a communication path.
10. The method of claim 1 , further comprising:
detecting an absence of reference features from the received video stream.
11. A system to calculate video frame delay in a video stream received by a telecommunications endpoint, the system comprising:
a computer-readable storage medium, storing executable instructions; and
a plurality of processors coupled to the computer-readable storage medium, the processors, when executing the executable instructions:
locate reference features that are characteristic of content in the received video stream;
calculate reduced reference features from the located reference features;
receive reduced reference features of a transmitted video stream, the transmitted video stream corresponding to the received video stream;
calculate a distance between the reduced reference features in the received video stream and the reduced reference features of the transmitted video stream;
calculate a received trajectory of the reduced reference features from the received video stream;
calculate a transmitted trajectory of the reduced reference features from the transmitted video stream; and
calculate video frame delay as a time shift between the received trajectory and the transmitted trajectory.
12. The system of claim 11 , wherein the reference features that are characteristic of content comprise faces.
13. The system of claim 11 , wherein the reduced reference features comprise a location of rectangular areas surrounding the reference features.
14. The system of claim 11 , wherein the reduced reference features are calculated at less than a full frame rate of the received video stream.
15. The system of claim 11 , wherein the reduced reference features are calculated at no more than five frames per second.
16. The system of claim 11 , wherein the reduced reference features of the transmitted video stream are received via a communication channel that is separate from a communication channel used to transport the video stream.
17. The system of claim 11 , wherein the video stream originates from a remotely-located camera accessible via a communication path.
18. The system of claim 11 , wherein the processors, when executing the executable instructions:
detect an absence of reference features from the received video stream.