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, by a processor, reference features that are characteristic of content in the received video stream;
calculating, by the processor, reduced reference features from the located reference features;
receiving, by the processor, reduced reference features of a transmitted video stream, the transmitted video stream corresponding to the received video stream;
calculating, by the processor, a received trajectory of the reduced reference features from the received video stream;
calculating, by the processor, a transmitted trajectory of the reduced reference features from the transmitted video stream; and
calculating, by the processor, 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 from the received video stream and the transmitted video stream comprise locations of the reference features.
4 . The method of claim 1 , wherein the reduced reference features from the received video stream and the transmitted video stream comprise a location of rectangular areas surrounding the reference features.
5 . The method of claim 1 , wherein the reduced reference features from the received video stream 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 from the received video stream 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 transmitted video stream.
8 . The method of claim 1 , further comprising:
receiving, by the processor, a frame of the transmitted video stream to the telecommunications endpoint, once per second, via a reliable channel; and
calculating, by the processor, reduced reference features from the frame.
9 . The method of claim 1 , wherein the received video stream originates from a remotely-located camera accessible via a communication path.
10 . The method of claim 1 , further comprising:
detecting, by the processor, 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 processor coupled to the computer-readable storage medium, the processor, when executing the executable instructions:
locates reference features that are characteristic of content in the received video stream;
calculates reduced reference features from the located reference features;
receives reduced reference features of a transmitted video stream, the transmitted video stream corresponding to the received video stream;
calculates a distance between the reduced reference features in the received video stream and the reduced reference features of the transmitted video stream;
calculates a received trajectory of the reduced reference features from the received video stream;
calculates a transmitted trajectory of the reduced reference features from the transmitted video stream; and
calculates 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 from the received video stream and the transmitted video stream comprise a location of rectangular areas surrounding the reference features.
14 . The system of claim 11 , wherein the reduced reference features from the received video stream 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 from the received video stream 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 transmitted video stream.
17 . The system of claim 11 , wherein the received video stream originates from a remotely-located camera accessible via a communication path.
18 . The system of claim 11 , wherein the processor, when executing the executable instructions:
detects an absence of reference features from the received video stream.