[MPEG2-SYSTEMS]PCR Discontinuity Issues

[thatsmohitag]

Hi,

I have a doubt regarding discontinuity indicator in the case of pcr packets, mentioned in section 2.4.3.5- discontinuity_indicator of H.222.0

What I interpret from the Standard is:

<valid_pcr, discontinuity_indicator = 0>
<valid_pcr, discontinuity_indicator = 0>
<invalid_pcr, discontinuity_indicator = 1> //do not use this value
<valid_pcr, discontinuity_indicator = 1> //use this value
<valid_pcr, discontinuity_indicator = 0>
.
.
.


The standard also mentions that there can be more than two packets with discontinuity indicator =1.
But the question in this case is that how does one differentiate which packet contains the valid pcr value???


Thanks
Mohit Agarwal

[neuron2]

The discontinuity_indicator can signal either PCR discontinuities or continuity_counter discontinuities. In either case, the presence of a signalled discontinuity does not mean that any transport packets are invalid, it just means that the parser should expect to see the discontinuity. It is only when a discontinuity is present that is not signalled that there is a problem.

[thatsmohitag]

:thanks:

I meant that pcr value to be invalid,Not the TS Packet.

Neverthelesss I have come out with new interpretation
Please see whether its correct

<pcr_flag=0> <di=1>
<pcr_flag=0> <di=1>
:
:
<pcr_flag=1> <di=1>//new system time base

When pcr flag and di=1 are both one then only a new time base starts???

[neuron2]

That is my understanding, yes.