[libdvbpsi-devel] Can the EIT decoder decode successfully when the TS packet is not continued?

[Jean-Paul Saman]

On Thu, Aug 15, 2013 at 11:49 AM, watch_the_rain <watch_the_rain at 163.com>wrote:

> Thanks for your answer.My boss have changed a data packet to test.
> But a software my company used to test the TS stream can parse out all the
> events from the discontinuous packets,why can't the libdvbpsi do this?
>

There is too little information to give an answer to this question.

I'll try anyway to give some pointers:
- TS stream could be in violation of the standard and your tool just
happens to match that.
- libdvbpsi 1.1.0 EIT parser could have a bug
- libdvbpsi 0.1.6 EIT parser could falsely detect mangled content making
you believe it detected more events

If you lose ~33 % percent of your stream, then you have a big problem. Fix
that first, then look at the EIT content.

Kind regards,

Jean-Paul Saman.


> 在 2013-08-15 14:57:37，"Jean-Paul Saman" <jpsaman at videolan.org> 写道：
>
> HI,
>
>
> On Thu, Aug 15, 2013 at 5:22 AM, watch_the_rain <watch_the_rain at 163.com>wrote:
>
>> Today I found that the the progam did not find the event schedule
>> information in the EIT table when I decode a new TS stream, but It works
>> well with the old stream. (The verison of the library I used was v 0.1.6.)
>> Then I tryed with the latest version(v1.1.0), the result iwas a little
>> better,14 events in the event schedule table were found.
>> The debug error infromation was printf like this:
>>      TS discontinuity (received 6, expected 5) for PID 18
>>      TS discontinuity (received 0, expected 15) for PID 18
>>      TS discontinuity (received 0, expected 15) for PID 18
>>      ............
>> So I printed the continuity counter number in the ts paket I before
>> pushed to the EIT decoder,It showed text below (just a small fraction):
>>      continuity_counter:0
>>      continuity_counter:1
>>      continuity_counter:2
>>      continuity_counter:4
>>      libdvbpsi error (PSI decoder): TS discontinuity (received 4,
>> expected 3) for PID 18
>>      continuity_counter:5
>>      libdvbpsi debug (EIT decoder): Table version 11, i_table_id 80,
>> i_extension     1, section   0 up to 248, current 1
>>      continuity_counter:6
>>      continuity_counter:9
>>      libdvbpsi error (PSI decoder): TS discontinuity (received 9,
>> expected 7) for PID 18
>>     continuity_counter:11
>>     libdvbpsi error (PSI decoder): TS discontinuity (received 11,
>> expected 10) for PID 18
>>     continuity_counter:12
>>     libdvbpsi debug (EIT decoder): Table version 11, i_table_id 80,
>> i_extension     3, section   8 up to 248, current 1
>>     continuity_counter:13
>>     continuity_counter:14
>>     continuity_counter:0
>>     libdvbpsi error (PSI decoder): TS discontinuity (received 0, expected
>> 15) for PID 18
>>     .........
>> A “continuity_counter:  xx” means pushing a packet to EIT decoder once.
>> There were an average of one error message every 6 packets. The packets
>> missed were lost in the transport.
>> Is the high frequency of discontinuity that made the decoder failed? And
>> I think that the packet loss is too hight in the ts transport, but the superior
>> don't think so. What do you think?
>> I'm sorry my English was not good, there must be some error in the email.
>> Please help me, thanks very much!
>>
>>
> In the example log above you lost 5 packets out of 15, which is one third
> !!!
>
> You have massive loss of packets and thus you miss information form the
> EIT tables.
>
> First fix the reason for the packet loss, then test the EIT again.
>
>
>>
>>
>>
>>
>> _______________________________________________
>> libdvbpsi-devel mailing list
>> libdvbpsi-devel at videolan.org
>> https://mailman.videolan.org/listinfo/libdvbpsi-devel
>>
>>
> Kind regards,
>
> Jean-Paul Saman
>
>
>
>
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