Johannes Stezenbach wrote:
No, I renamed _NONE to _UNKNOWN. For FE_SET_PARAMS one would
use _AUTO, _UNKNOWN should be an error. But FE_GET_PARAMS
may return _UNKNOWN if a parameter's value isn't known.
_RESERVEDs were removed.
Ok, i couldn't initially make out due to the whole lot of changes of
deprecating the older IOCTL's
I don't really care whether it is RESERVED or UNKNOWN.
- moved modcod to dvb_frontend.h -- I'm relatively convinced
there's no use for this in the API
(dvbs2_params takes mod + fec instead)
TR 102 376 v 1.1.1 page 41 IP Unicast Services
6 Interactive applications
[snip]
Under the said opinions, i can think of 2 ways
(Option #1)
Move modcod to the dvb_frontend , since it is of no use in the API as
Johannes said. The bad sides of it are
(a) we will need dvbs_modcod_encoder convenience function as well
(b) apps still use a different strategy than what is specified in the specs
(Option #2)
Leave modcod as it is, and be happy. It is according to the standards
and no additional convenience functions are needed.
I personally vote for Option #2.
ACM is not for broadcast use, but for two-way
communication, where the receiver can send commands back to
the transmitter to control the modulation.
Yes, It is meant for IP Unicast services and others, not for broadcast.
Well, you seem to be saying that i did not understand anything at all in
the S2 specifications. Well as i look, the way the discussion is going,
people who don't have DVB-S2 seem to be pushing it out with whatever
might they have. :-/
The way I read the standard, the ACM return channel
could be a telephone line or DSL/internet to the playout center.
The demod hw would handle ACM receiption automatically, and an
application would monitor signal quality and send commands back
to the transmitter to change modulation and fec until it gets
max throughput at good quality.
Well, as i said, from the specs, again 6.1 has a nice picture how it is
done too .. I did _not_ say that the demod is having DVB-RCS capabilities.
In any case, whatever mode is used the specs _says_ MODCOD is used. IMHO
MODCOD is necessary, eliminating modulation + coderate.
Thus I believe even with ACM there is no need for modcod
in the API. Maybe decode_dvbs2_modcod() in dvb_frontend
isn't needed, either.
:-/
Manu
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