IPTV Result Video (Page #4) -
displays the
Quality of Service (QOS)
results;
PCR Clock
- Presence of 27MHz Program Clock Reference
PCR Jitter
- PCR deviation in (ms)
MPEG Packet Loss
- continuity error (%)
Latency
- the time to complete a program change measured in milliseconds (ms)
Note:
Program Clock Reference (PCR)
MPEG TS normally contain a built-in timing packet known as the Program Clock Reference (PCR).
Recovering the 27 MHz clock at the decoder end of the transmission system is necessary to re-create the
video signal. The PCR values need to be correct at the signal origin and should not be distorted along the
transmission path to a point where decoding the compressed signal becomes problematic. Measuring the
interval between the arrival of PCR values, the accuracy of the expected values and also the jitter
accumulated on those PCR values transmitted is necessary to assure that streams can be decoded. PCR
jitter is a good indication of timing distortions due to poor encoding. Excessive PCR jitter results in visual
impairments such as frame freezes, color loss and pixelization. The amount of PCR jitter that is considered
excessive varies, and depends on various factors including STB buffer sizes and software architecture.
However, in today’s packetized video networks, PCR jitter should not exceed 10 ms. If PCR jitter is not
constant, then a momentary problem from inserting local programming may be the cause.
IPTV Result Video (Page #5) -
displays the
Transport
results;
MPEG Packet Loss
Packets expected
Pass Through - IPTV Results (6)
Pass Through - IPTV Results (MAP)
BX100A/V e-Manual D07-00-001 Rev E01
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