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

Francesco Schiavarelli kaboom at tiscalinet.it
Tue Nov 6 18:23:41 CET 2007


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.

Francesco




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