User manual OPTICOM CB01 SPECIFICATION DATA

[. . . ] Lab users can choose between the PEXQ software suite and the PEVQ analyzer hardware. PEVQ evaluates the quality of multimedia (QCIF, CIF, VGA), SD and HD video formats based on perceptual measurement, reliably, objectively and fast. PEVQ is based on the earlier PVQM technology developed by KPN Research and new developments of OPTICOM. Video Quality Testing Data Quality Testing OPTICOM Product Line: Voice Quality Testing PSQM ITU-T P. 861 CB01 ITU-T P. 862 3SQM ITU-T P. 563 ECHO Audio Quality Testing PEAQ ITU-T BS. 1387 Video Quality Testing PEVQ Network Quality Testing VQmon Principle PEVQ is a full reference, intrusive measurement algorithm for video quality. [. . . ] Its basic structure is shown in the figure below. Reference Signal Key Features: · Accurate, reliable and fast objective analysis of perceived video quality · Full reference based endto-end quality analysis Temporal indicators time Impaired Signal Temporal and spatial alignment Perceptual difference (Y, Cr, Cb) Distortion indicator integration PEVQ Score Y Cr Cb Distortion classification } Indicators for cause analysis · Outputs MOS score that correlates well with subjective MOS · Additional KPIs for detailed analysis · Measurement of multimedia (QCIF, CIF, VGA), SD and HD video quality time The algorithm can be divided up into four separate blocks. The first block ­ pre-processing stage ­ is responsible for the spatial and temporal alignment of the reference and the impaired signal. This process ensures that only corresponding frames are compared to each other. The second block calculates the perceptual difference of the aligned signals. Perceptual means that only those differences are taken into account which are actually perceived by a human viewer. Furthermore the activity of the motion in the reference signal provides another indicator representing the temporal information. This indicator is important as it takes into account that in frame series with low activity the perception of details is much higher than in frame series with quick motion. The third block in the figure classifies the previously calculated indicators and detects certain types of distortions. Delay The min, max and mean delay of each frame of the test signal related to the reference signal, as well as delay vs. PSNR To allow for a coarse analysis of distortions in different domains the PSNR is provided for the Y, Cb and Cr components separately. Jerkiness describes the smoothness of a video playback which is often impaired by down-sampling, coding processes and perturbed transmissions. Blur is a distortion characterized by reduced sharpness of contour edges and spatial detail. Blockiness is often the result of a low bit rate coding that uses a block matching algorithm for the motion estimation and a coarse quantization for the image blocks. Frame Skips and Freezes are temporal artefacts occurring in video transmissions caused by e. g. Effective Frame Rate Down-sampling of a video signal on a frame by frame basis often results in loss of information which often leads to the degradation of the video signal. [. . . ] Frame Skips and Freezes are temporal artefacts occurring in video transmissions caused by e. g. Effective Frame Rate Down-sampling of a video signal on a frame by frame basis often results in loss of information which often leads to the degradation of the video signal. The effective frame rate is an indicator quantifying the severeness of such a process. [. . . ]