[linux-dvb] DVB-S2 API vs. HVR4000: When?

frankio kaboom at tiscalinet.it
Wed Nov 7 21:27:13 CET 2007


Manu Abraham wrote:
> Francesco Schiavarelli wrote:
>   
>> Johannes Stezenbach wrote:
>>     
>>> On Sat, Nov 03, 2007, Manu Abraham wrote:
>>>       
>>>> If you see H.2 and H.3, the difference is between CCM and VCM
>>>> (Note: that both are cases of multiple "TS's")
>>>>
>>>> H.2 (CCM) is applicable for DVB-T muxes. Here there is a HP/LP stream
>>>> selection in some fashion combined with the merger/slicer where
>>>> stream id is used. 
>>>>         
>>> What makes you think there is HP/LP involved? All H.2 says
>>> is that two DVB-T streams are transmitted using one
>>> DVB-S2 transponder to a DVB-T transmitter. The DVB-T transmitter
>>> could then transmit them on two different frequencies in
>>> non-hierarchical mode.
>>>
>>> (Indeed H.2 says "two DTT MUXes at 24 Mbit/s each" indicating
>>> they are not hierarchical because you can't get that
>>> bitrate in DVB-T hierarchical mode. But even if it were DVB-T
>>> hierarchical mode it has nothing to do with DVB-S2 backwards
>>> compatible mode hierarchical modulation.)
>>>
>>>       
>> I agree with you, Johannes.
>> There is no evidence of hierarchical modulation, nevertheless the two
>> streams I was looking at had the same channel protection that is no
>> HP/LP, and I was told it was DVB-S2 CCM.
>>
>> When the transponder will be up again I'll be able to do more tests.
>>     
>
> Yeah, looks more like that, will have a patch soon to do some tests for it.
> STM's comments confirm that.
>
> Manu
>
>   
Now the beam is up on 13.0E 11373 H 27500 8PSK 2/3
It is made up of 2 DTT muxes (no HP/LP)
ISI1   16QAM 1/2 1/4    9.953 Mbps
ISI2   64QAM 5/6 1/4    24.882 Mbps

Unfortunately I don't  know how long it will last, so let the tests 
begin! :-)
I'll wait for the patch.

thanks,
Francesco




More information about the linux-dvb mailing list