[linux-dvb] question about definition of section in PSI of Transport stream

[linux-dvb] question about definition of section in PSI of Transport stream

[loody]

Dear all:
I am reading iso13818-1 right now.
But I cannot figure out what the section mean in PSI.

In PAT, there is a N loop tell us how many programs in this TS and the
corresponding pid of PMT.
Is section equivalent to program?
Suppose there is 10 loop in PAT, and there will be 10 sections, right?

thanks for your help,
miloody

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Re: [linux-dvb] question about definition of section in PSI of Transport stream

[Nico Sabbi]

On Thursday 24 July 2008 11:46:48 loody wrote:
> Dear all:
> I am reading iso13818-1 right now.
> But I cannot figure out what the section mean in PSI.
>
> In PAT, there is a N loop tell us how many programs in this TS and
> the corresponding pid of PMT.
> Is section equivalent to program?

each item identifies a program and a pid

> Suppose there is 10 loop in PAT, and there will be 10 sections,
> right?

no, the section is only needed to split overly long PATs and / or PMTs
in smaller pieces

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Re: [linux-dvb] question about definition of section in PSI of Transport stream

[loody]

Hi:
thanks for your explanation.
BTW, I find all my Ts only have one section, section_number and
last_section_number are both 0.

Would you please tell me where I can get multi-sections TS for tracing?

appreciate your help,
miloody


2008/7/24 Nico Sabbi <Nicola.Sabbi@poste.it>:
> On Thursday 24 July 2008 11:46:48 loody wrote:
>> Dear all:
>> I am reading iso13818-1 right now.
>> But I cannot figure out what the section mean in PSI.
>>
>> In PAT, there is a N loop tell us how many programs in this TS and
>> the corresponding pid of PMT.
>> Is section equivalent to program?
>
> each item identifies a program and a pid
>
>> Suppose there is 10 loop in PAT, and there will be 10 sections,
>> right?
>
> no, the section is only needed to split overly long PATs and / or PMTs
> in smaller pieces
>
> _______________________________________________
> linux-dvb mailing list
> linux-dvb@linuxtv.org
> http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
>

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Re: [linux-dvb] question about definition of section in PSI of Transport stream

[Nico Sabbi]

On Friday 25 July 2008 11:12:53 you wrote:
> Hi:
> thanks for your explanation.
> BTW, I find all my Ts only have one section, section_number and
> last_section_number are both 0.

yes, there's only one section

>
> Would you please tell me where I can get multi-sections TS for
> tracing?
>
> appreciate your help,
> miloody

Please,  don't top-post.
Some satellite transponder with many programs surely has multi-section
PMTs, but I never found any

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Re: [linux-dvb] question about definition of section in PSI of Transport stream

[Andreas Regel]

Nico Sabbi wrote:
> On Friday 25 July 2008 11:12:53 you wrote:
>> Hi:
>> thanks for your explanation.
>> BTW, I find all my Ts only have one section, section_number and
>> last_section_number are both 0.
> 
> yes, there's only one section
> 
>> Would you please tell me where I can get multi-sections TS for
>> tracing?
>>
>> appreciate your help,
>> miloody
> 
> Please,  don't top-post.
> Some satellite transponder with many programs surely has multi-section
> PMTs, but I never found any

PMTs are always just one section. PATs could have more than one but that 
would normally need more than 250 programmes on one TS, so it's not that 
easy to find a TS with multi section PATs. Other tables, like NIT or SDT 
often are bigger than 1024 bytes and split over several sections.

Regards
Andreas

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Re: [linux-dvb] question about definition of section in PSI of Transport stream

[Nico Sabbi]

Il giorno ven, 25/07/2008 alle 15.13 +0200, Andreas Regel ha scritto:
> Nico Sabbi wrote:
> > On Friday 25 July 2008 11:12:53 you wrote:
> >> Hi:
> >> thanks for your explanation.
> >> BTW, I find all my Ts only have one section, section_number and
> >> last_section_number are both 0.
> > 
> > yes, there's only one section
> > 
> >> Would you please tell me where I can get multi-sections TS for
> >> tracing?
> >>
> >> appreciate your help,
> >> miloody
> > 
> > Please,  don't top-post.
> > Some satellite transponder with many programs surely has multi-section
> > PMTs, but I never found any
> 
> PMTs are always just one section. PATs could have more than one but that 
> would normally need more than 250 programmes on one TS, so it's not that 
> easy to find a TS with multi section PATs. Other tables, like NIT or SDT 
> often are bigger than 1024 bytes and split over several sections.
> 
> Regards
> Andreas
> 

yes, but in theory even PMTs can be sectioned


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Re: [linux-dvb] question about definition of section in PSI of Transport stream

[Andreas Regel]

Nico Sabbi schrieb:
> Il giorno ven, 25/07/2008 alle 15.13 +0200, Andreas Regel ha scritto:
>> Nico Sabbi wrote:
>>> On Friday 25 July 2008 11:12:53 you wrote:
>>>> Hi:
>>>> thanks for your explanation.
>>>> BTW, I find all my Ts only have one section, section_number and
>>>> last_section_number are both 0.
>>> yes, there's only one section
>>>
>>>> Would you please tell me where I can get multi-sections TS for
>>>> tracing?
>>>>
>>>> appreciate your help,
>>>> miloody
>>> Please,  don't top-post.
>>> Some satellite transponder with many programs surely has multi-section
>>> PMTs, but I never found any
>> PMTs are always just one section. PATs could have more than one but that 
>> would normally need more than 250 programmes on one TS, so it's not that 
>> easy to find a TS with multi section PATs. Other tables, like NIT or SDT 
>> often are bigger than 1024 bytes and split over several sections.
>>
>> Regards
>> Andreas
>>
> 
> yes, but in theory even PMTs can be sectioned

In theory yes, but that would be against MPEG standard.

Andreas

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[linux-dvb] RE : question about definition of section in PSI of Transport stream

[Thierry Lelegard]

> Nico Sabbi wrote:
>
> yes, but in theory even PMTs can be sectioned

No, this is forbidden by ISO 13818-1:

2.4.4.9 Semantic definition of fields in Transport Stream program map section
[...]
section_number - The value of this 8-bit field shall be 0x00.
last_section_number - The value of this 8-bit field shall be 0x00.

-Thierry


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Re: [linux-dvb] question about definition of section in PSI of Transport stream

[Andreas Oberritter]

Andreas Regel wrote:
> PMTs are always just one section. PATs could have more than one but that 
> would normally need more than 250 programmes on one TS, so it's not that 
> easy to find a TS with multi section PATs. Other tables, like NIT or SDT 
> often are bigger than 1024 bytes and split over several sections.

IIRC there were some radio channels called "Les Radios" sharing one PMT
PID with the same service id on Astra 19.2E some years ago. I think
they're now called Canalsat Radios. Maybe they still have PMTs with
multiple sections. See http://www.satindex.de/paytv/cs-france/ .

Regards,
Andreas

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[linux-dvb] Re : question about definition of section in PSI of Transport stream

[manu]

Le 25.07.2008 05:12:53, loody a écrit :
> Hi:
> thanks for your explanation.
> BTW, I find all my Ts only have one section, section_number and
> last_section_number are both 0.
> 
> Would you please tell me where I can get multi-sections TS for
> tracing?
> 
> appreciate your help,
> miloody
> 
> 
> 2008/7/24 Nico Sabbi <Nicola.Sabbi@poste.it>:
> > On Thursday 24 July 2008 11:46:48 loody wrote:
> >> Dear all:
> >> I am reading iso13818-1 right now.
> >> But I cannot figure out what the section mean in PSI.
> >>
> >> In PAT, there is a N loop tell us how many programs in this TS and
> >> the corresponding pid of PMT.
> >> Is section equivalent to program?
> >
> > each item identifies a program and a pid
> >
> >> Suppose there is 10 loop in PAT, and there will be 10 sections,
> >> right?
> >
> > no, the section is only needed to split overly long PATs and / or
> PMTs
> > in smaller pieces
> >
> > _______________________________________________
> > linux-dvb mailing list
> > linux-dvb@linuxtv.org
> > http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
> >

Other tables like EIT are split over several sections (pid is 0x12 
IIRC)
Bye
Manu


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