[linux-dvb] [PATCH] 8PSK/BPSK DVB-S/S2 support

Alan Nisota alannisota at gmail.com
Sat Feb 18 16:08:59 CET 2006


This is a trivial patch which adds capabilities for 8PSK (QPSK_8) and
BPSK (QPSK_B) modes to frontend .h
The change does not affect the size of the dvb_frontend_parameters, so
it is backwards compatible with all software (for cards that don't
utilize the 'modulation' value.

I am not sure what to do about mixing software that does not support
8PSK modulation with hardware that does.  In this case, there is the
small chance that a program does not initialize the
dvb_frontend_parameters, structure and that the value in the
'modulation' variable equals QPSK_8 or QPSK_B in which case any card
looking for these will be switched to the wrong mode.

Perhaps an additional 'union' is necessary to prevent that, however,
these cards obey  qpsk commands as well, and software I've looked at
seems to assume a card uses only one of the available modes
(qpsk/qam/vsb/ofdm) so it would mean a lot more coding to applications
to treat 8PSK/BPSK as different from QPSK.

Additionally, there is now only room for 8 additional capabilities in
the fe_caps enum.
I am open to other suggestions.

This patch only includes the changes needed for frontend.h.  As the
last of three patches, I'll include one which uses these changes to
support 8psk/bpsk on the genpix board, but I'd prefer to get feedback
that the implementation I used here s the right strategy

Signed off by: Alan Nisota <alannisota at gmail.com>
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