hi patrick, On Wednesday 22 February 2006 21:39, Patrick Boettcher wrote: > I am not a signal expert, not at all, but wouldn't it be better to rename > QPSK_8 to 8PSK and QPSK_B to BPSK? (and accordingly FE_CAN_..) > (see http://en.wikipedia.org/wiki/8PSK) imho it is not allowed by c/c++ naming conventions to start a var with a number instead of a char. we do only have _one_ enumeration value left. that's why i thought to use that as a flag for signalling for the newer types (eg. dvb-s2) that there is more information in backported api v4 stuff like enum dvb_fe_code_rate caps_fec; /*!< supported fecs */ enum dvb_fe_modulation caps_modulation; /*!< supported modulations */ enum dvb_fe_common_cap caps_common; /*!< supported common capabilities */ enum dvb_fe_other_cap caps_other; /*!< supported other capabilities*/ have a look within the api v4 repository within frontend.h > > http://en.wikipedia.org/wiki/DVB-S2 also mentions higher PSK-modulations. ETSI Standard 300468 has reserved 2 bits to define modulation. AUTO, QPSK, 8PSK & 16-Quam ( which is marked as not available for dvb-s2 ) > > As this is a good chance we might also consider adding the additional > DVB-H parameter (taking the additional TPS-values into account)? i do not know anything in detail from dvb-h until now. but of course, if there are details available already we should integrate it within another patch. _BUT_ see above for the enumeration (CAN... ) problem we do actually have. > What about the problems discussed last week about the hierarchy-parameter > and the selection of LP and HP streams (+ ALPHA value) for DVB-T/H? i didn't follow that discussion, will try to read up. > IIRC, during the discussion in November someone also mentioned, that > DVB-S2 also support hierarchical transmissions... yes, ETSI TR 102 376 v1.0.1 page 26 gives us more information about that topic. backwards compatibility for dvb-s: a) LP/HP constellation is to perform layered modulation (not available - would cause new satellites to be launched) b) having DVB-S/DVB-S2 mixed up within a 8PSK modulation, this is an option, but i actually do not know a dvb-s2 frontend is implemented to have dvb-s2 modulations, but output would be dvb-s data (means how to select the HP stream) maybe some other people on the list have more specific knowledge? regards marcel
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