Abstract: There are provided a plurality of methods for detecting a scene change in a streamed video, the streamed video comprising a series of pictures. An example method comprises calculating, for a plurality of positions, a difference between the costs of coding macro-blocks at the same position in successive pictures. The method further comprises identifying a new scene when the sum of the differences for a plurality of positions meets a threshold criterion. There is further provided a method of determining the perceptual impact of a packet loss on a streamed video the method comprising: identifying a packet loss; and determining if the lost packet contained information relating to a picture at the start of a new scene, wherein a new scene is detected using one of the methods disclosed herein.

Abstract: There are provided a plurality of methods for detecting a scene change in a streamed video, the streamed video comprising a series of pictures. An example method comprises calculating, for a plurality of positions, a difference between the costs of coding macro-blocks at the same position in successive pictures. The method further comprises identifying a new scene when the sum of the differences for a plurality of positions meets a threshold criterion. There is further provided a method of determining the perceptual impact of a packet loss on a streamed video the method comprising: identifying a packet loss; and determining if the lost packet contained information relating to a picture at the start of a new scene, wherein a new scene is detected using one of the methods disclosed herein.

Abstract: There is provided an apparatus for detecting a quality defect in a video sequence, the apparatus comprising: a receiver arranged to receive a video bitstream representing a video sequence; and a defect module arranged to determine a measure of quantization parameter for each picture of the video sequence, the defect module further arranged to identify a quality defect when an abrupt change in the measure of quantization parameter occurs.

Abstract: There are provided a plurality of methods for detecting a scene change in a streamed video, the streamed video comprising a series of pictures. An example method comprises calculating, for a plurality of positions, a difference between the costs of coding macro-blocks at the same position in successive pictures. The method further comprises identifying a new scene when the sum of the differences for a plurality of positions meets a threshold criterion. There is further provided a method of determining the perceptual impact of a packet loss on a streamed video the method comprising: identifying a packet loss; and determining if the lost packet contained information relating to a picture at the start of a new scene, wherein a new scene is detected using one of the methods disclosed herein.

Abstract: There is provided an apparatus for detecting a quality defect in a video sequence, the apparatus comprising: a receiver arranged to receive a video bitstream representing a video sequence; and a defect module arranged to determine a measure of quantization parameter for each picture of the video sequence, the defect module further arranged to identify a quality defect when an abrupt change in the measure of quantization parameter occurs.

Abstract: There is provided an apparatus for detecting a quality defect in a video sequence, the apparatus comprising: a receiver arranged to receive a video bitstream representing a video sequence; and a defect module arranged to determine a measure of quantization parameter for each picture of the video sequence, the defect module further arranged to identify a quality defect when an abrupt change in the measure of quantization parameter occurs.

Abstract: A method for measuring quality of packetized audio and video transmission over a transmission chain includes: providing one or more measurement detectors along the transmission chain; detecting, by the one or more measurement detectors, loss of bit stream packets at one or more measurement points; determining the unique identifier for each detected lost packet; sending, by the one or more measurement detectors, a list of lost packet identifiers to a central monitoring system; constructing, by the central monitoring system, a simulated stream for each measurement point based on a stored error-free stream and the received lost packet identifiers; and evaluating the simulated stream for deriving a quality score for each measurement point.

Abstract: A method for estimating the perception quality of a digital video signal includes: (1a) extracting information of the video bit stream, which is captured prior to decoding; (1b) getting estimation(s) for one or more impairment factors IF using, for each of the estimations, an impact function adapted for the respective impairment factor; and (1c) estimating the perceived quality of the digital video signal using the estimation(s) obtained in step (1b).

Abstract: A method for estimating the type of the GoP structure of a plurality of video frames in a video stream by estimating their frame types includes: capturing frame sizes in bytes of every video frame subsequent to an initial I-frame to obtain an array of frame sizes by exploiting features of a transport layer carrying the video stream; converting, after a number of frames, the array of frame sizes into an array of zeros and ones; matching the binarized array of frame sizes to a number of predefined short basic binary patterns, said predefined binary patterns depicting all GoP structures to be considered; converting the result of said matching to form a single score value; and determining the particular pattern of the number of predefined patterns of binaries having the best score value, according to a predefined metric.

Abstract: A method for assessing the quality of a transmitted video signal sequence at the receiver side includes the steps of: capturing the received input video bit stream prior to decoding and supplying it to a video bit stream analyzer; extracting, during a measurement time window, one or more features from the captured packet headers by the bit stream analyzer, without analyzing or decoding the packet payload; computing from the one or more features, a single parameter, xwpSEQ, representing an estimate of the spatio-temporal extent of the signal degradation due to packet-loss; supplying the determined parameter to a quality estimation module; and calculating, by the quality estimation module, a quality measure due to packet loss (Qtrans) based on the single parameter representing the estimate of the spatio-temporal extent of the signal degradation, xwpSEQ, due to packet-loss and based on video resolution information and employed video codec.

Abstract: A method for assessing the quality of a transmitted video signal sequence at a receiver side includes: capturing the input video bit stream; extracting at least one feature or a set of features; determining the continuous probability of visibility for each packet loss event which occurred within a specific time interval; and employing the continuous probability of packet loss visibility as a weighting factor of the at least one feature or set of features extracted from the video bit stream to calculate an estimate of the overall quality, Q, of the transmitted video sequence.

Abstract: A method for temporally synchronizing an input bit stream of a video decoder with a processed video sequence decoded by an external video decoder includes the steps of: capturing the input bit stream and supplying it to a bit stream analyzer; parsing and analyzing the captured input bit stream by the bit stream analyzer; decoding the input bit stream and providing reconstructed images Nrec therefrom; storing the reconstructed images Nrec in a buffer; and comparing a processed video sequence received from the output side of the video decoder with each of the stored reconstructed images, to find a matching frame n* from the reconstructed images in the buffer.

Abstract: A method for assessing the quality of a video signal during encoding or compressing of the video signal includes: estimating the quality (Qcod) of the video signal using one or more parameters; and using at least one additional parameter to adjust the estimated video signal quality, wherein the at least one additional parameter includes the key-frame rate (kfr) of the video signal as a Group of Pictures (GOP)-length-related parameter. Adjustment of the estimated video signal quality is in accordance with the following equation: Qcod=(a1*kfr+a2)*exp(b*br)+c; where a1, a2, b, and c are coefficients and br is the bit-rate of the video signal.

Abstract: A method for estimating the perception quality of a digital video signal includes: (1a) extracting information of the video bit stream, which is captured prior to decoding; (1b) getting estimation(s) for one or more impairment factors IF using, for each of the estimations, an impact function adapted for the respective impairment factor; and (1c) estimating the perceived quality of the digital video signal using the estimation(s) obtained in step (1b).

Abstract: There are provided a plurality of methods for detecting a scene change in a streamed video, the streamed video comprising a series of pictures. An example method comprises calculating, for a plurality of positions, a difference between the costs of coding macro-blocks at the same position in successive pictures. The method further comprises identifying a new scene when the sum of the differences for a plurality of positions meets a threshold criterion. There is further provided a method of determining the perceptual impact of a packet loss on a streamed video the method comprising: identifying a packet loss; and determining if the lost packet contained information relating to a picture at the start of a new scene, wherein a new scene is detected using one of the methods disclosed herein.

Abstract: There is provided an apparatus for detecting a quality defect in a video sequence, the apparatus comprising: a receiver arranged to receive a video bitstream representing a video sequence; and a defect module arranged to determine a measure of quantization parameter for each picture of the video sequence, the defect module further arranged to identify a quality defect when an abrupt change in the measure of quantization parameter occurs.

Abstract: A method for assessing the quality of a transmitted video signal sequence at a receiver side includes: capturing the input video bit stream; extracting at least one feature or a set of features; determining the continuous probability of visibility for each packet loss event which occurred within a specific time interval; and employing the continuous probability of packet loss visibility as a weighting factor of the at least one feature or set of features extracted from the video bit stream to calculate an estimate of the overall quality, Q, of the transmitted video sequence.

Abstract: A method for assessing the quality of a transmitted video signal sequence at the receiver side includes the steps of: capturing the received input video bit stream prior to decoding and supplying it to a video bit stream analyzer; extracting, during a measurement time window, one or more features from the captured packet headers by the bit stream analyzer, without analyzing or decoding the packet payload; computing from the one or more features, a single parameter, xwpSEQ, representing an estimate of the spatio-temporal extent of the signal degradation due to packet-loss; supplying the determined parameter to a quality estimation module; and calculating, by the quality estimation module, a quality measure due to packet loss (Qtrans) based on the single parameter representing the estimate of the spatio-temporal extent of the signal degradation, xwpSEQ, due to packet-loss and based on video resolution information and employed video codec.

Abstract: A method for estimating the type of the GoP structure of a plurality of video frames in a video stream by estimating their frame types includes: capturing frame sizes in bytes of every video frame subsequent to an initial I-frame to obtain an array of frame sizes by exploiting features of a transport layer carrying the video stream; converting, after a number of frames, the array of frame sizes into an array of zeros and ones; matching the binarized array of frame sizes to a number of predefined short basic binary patterns, said predefined binary patterns depicting all GoP structures to be considered; converting the result of said matching to form a single score value; and determining the particular pattern of the number of predefined patterns of binaries having the best score value, according to a predefined metric.

Abstract: A method for assessing the quality of a video signal during encoding or compressing of the video signal includes: estimating the quality (Qcod) of the video signal using one or more parameters; and using at least one additional parameter to adjust the estimated video signal quality, wherein the at least one additional parameter includes the key-frame rate (kfr) of the video signal as a Group of Pictures (GOP)-length-related parameter. Adjustment of the estimated video signal quality is in accordance with the following equation: Qcod=(a1*kfr+a2)*exp(b*br)+c; where a1, a2, b, and c are coefficients and br is the bit-rate of the video signal.