Patent ID: 8514928
Filing Date: 2013-08-20
Classification: H04L

Abstract:
1. A method for estimating the viewer perceived quality of a packet video stream comprising the steps of: a) detecting that a sequence of packets within said packet video stream form part of the same video frame and determining the length of said sequence as a first value (“nbytes”); b) determining the number of packets missing from said video frame as a second value (“npackets_lost”); c) classifying said sequence of packets as an I-frame or P-frame or B-frame; e) determining a decoder dependant factor (“FLC”); f) determining the effect of each missing packet within said video frame and calculating the resulting estimated percentage (“P”) of the decoded content of said frame that will be impaired; g) if said frame is a B-frame or P-frame dependent upon a preceding reference I-frame or P-frame, then retrieving from storage a propagated frame quality from said preceding reference frame; h) determining a frame quality score from the values of nbytes, npackets_lost, FLC, P and propagated frame quality; i) if said frame is an I-frame or P-frame then storing said frame quality score as a propagated frame quality value; j) determining a frame rate from measurement of the number of video frames per second; k) determining a frame rate factor from said frame rate; and l) calculating a Mean Opinion Score from least two of said frame quality scores and said frame rate factor.