[vdr] VDR -> S2API: 2 questions

Manu Abraham abraham.manu at gmail.com
Sat Nov 22 18:00:18 CET 2008


Alex Betis wrote:
> On Sat, Nov 22, 2008 at 6:35 PM, Klaus Schmidinger <
> Klaus.Schmidinger at cadsoft.de> wrote:
> 
>> On 22.11.2008 17:25, Georg Acher wrote:
>>> On Sat, Nov 22, 2008 at 06:21:51PM +0200, Alex Betis wrote:
>>>> On Sat, Nov 22, 2008 at 5:14 PM, Klaus Schmidinger <
>>>> Klaus.Schmidinger at cadsoft.de> wrote:
>>>>
>>>>> Maybe I'm totally missing something here, but I can't figure out how
>>>>> an application using the S2API driver can tell whether a DVB device is
>>>>> DVB-S or DVB-S2. Can somebody please point me in the right direction
>> here?
>>>> I run into the same question when made changes in scan-s2 application.
>>>> The question I want to ask is why do you really need it?


In a DVB-S2 demodulator, according to ETSI specifications, and according
to the manufacturers, there are 2 demodulators, A DVB-S demodulator and
a DVB-S2 demodulator. So with 2 demodulators, you have 2 distinct paths.

With these 2 distinct paths, you need a flag, aka a delivery system
notation, to select the path as well as a "holder" to hold common
delivery system specifics. This is the whole difference between
multiproto and S2API.

S2API depends on a flat concept where it assumes a single demodulator,
ie the concept of a delivery system doesn't exist there.

Expect more fun when there are newer delivery systems which are going to
define backward compatibility stuff, ie when vendors do start to
implement backward compatible stuff in hardware, similar to DVB-S2

It is just a matter of time, till the more advanced features are
implemented practically by more broadcasters, rather than the few
experimental ones.

I guess, there is more to come.....

Regards,
Manu



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