[linux-dvb] Re: [PATCH] dvb_bt8xx: sub_device

[Markus Germeier <mager@tzi.de>]

Johannes Stezenbach <js@convergence.de> writes:

> You're joker. You have a DVB-T frontend and set DVB-C
> tuning paramters...

I never claimed, that I understood what I was doing there. ;-)

> I guess u.qam.modulation = 9 will actually set
> u.ofdm.code_rate_LP = FEC_AUTO.

Rereading the gdb outputs it appears that you are correct:

tzap (working):
388             if (ioctl(fe_fd, FE_SET_FRONTEND, frontend) < 0) {
(gdb) print *frontend
$1 = {frequency = 562000000, inversion = INVERSION_AUTO, u = {qpsk = {symbol_rate = 0, fec_inner = FEC_1_2}, qam = {symbol_rate = 0, fec_inner = FEC_1_2, 
      modulation = 9}, ofdm = {bandwidth = BANDWIDTH_8_MHZ, code_rate_HP = FEC_1_2, code_rate_LP = FEC_AUTO, constellation = QAM_16, 
      transmission_mode = TRANSMISSION_MODE_8K, guard_interval = GUARD_INTERVAL_1_32, hierarchy_information = HIERARCHY_NONE}}}

dvbstream 0.5 (not working)
223       if (ioctl(fd_frontend,FE_SET_FRONTEND,feparams) < 0) {
(gdb) print *feparams
$1 = {frequency = 562000000, inversion = INVERSION_OFF, u = {qpsk = {symbol_rate = 0, fec_inner = FEC_1_2}, qam = {symbol_rate = 0, fec_inner = FEC_1_2, 
      modulation = QPSK}, ofdm = {bandwidth = BANDWIDTH_8_MHZ, code_rate_HP = FEC_1_2, code_rate_LP = FEC_NONE, constellation = QAM_16, 
      transmission_mode = TRANSMISSION_MODE_8K, guard_interval = GUARD_INTERVAL_1_32, hierarchy_information = HIERARCHY_NONE}}}

feparams->u.ofdm.code_rate_LP = FEC_AUTO;

so this seems to be more sane. ;-)

Changing the LP_CODERATE_DEFAULT to FEC_AUTO is probably a good thing
to do(tm).

Regards
        Markus

-- 
Markus Germeier
mager@tzi.de