EXFO EXpert IPTV Test Tools (FTB-1 / 2 Pro) - Manual (Page 49)

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A.1.1.2 Impact of Packet Loss on Specific Video Codecs
As shown in Figure 2-3, a simple non-robust video stream can be severely degraded with even
low levels of packet loss due to the error propagation effects described above. Peak Signal-to-
Noise Ratio (PSNR) is an objective measurement of video service quality comparing the
maximum power of the video signal to the power of corrupting noise affecting the signal.
Generally, a PSNR of under 20dB is regarded as unwatchable, and this level is reached for
MPEG video with a loss rate under 1 percent.
Figure 2-3.
Estimated PSNR
for Three
Common Codecs