[linux-dvb] Re: TDA10045H Patch

[Holger Waechtler <holger@convergence.de>]

James Conner wrote:
> I added the following line to the dev-kernel/build-2.4/insmod.sh script 
> where appropriate...
>
> insmod ./tda10045h.o 
> tda10045h_firmware=/usr/lib/DVB/driver/frontends/tda10045h.mc
Basically you can write your own module loader script, for your setup
you only need to load the DVB core, the budget driver and tda10045h.o...


> next bit to worry about is dvbtune... I'm on the Crystal Palace 
> transmitter, so I got my frequencies from 
If you use tzap (DVB/apps/szap/tzap.c in the DVB/ tree, just type make
in this directory and then create an appropriate channels.conf file for
crystal palace - example in this directory - ) you get some more verbose
output that's easier to interpret for debugging purposes. Example
parameter set below.

When this works fine you can create your own updated channel list using
the scan utility in DVB/apps/scan/.

If your local transmitter is not yet in the initial channel list just
tune manually using tzap or dvbtune and then type 'scan -c' in a second
console as soon you that your tuning application achieved a stable lock.
If you get a meaningfull NIT on this channel add it as initial
transponder to initial.h, rebuild scan and execute it without the '-c'
argument and you get (hopefully) the complete channel list. Please
prepare a diff and post your patch on the LinuxDVB mailinglist when scan
does not works out of the box.


> http://www.itc.org.uk/uk_television_sector/reception_advice/digital_trans_guide/show_transmitter.asp?siteID=66 
> and used the frequency=1000000*((UHF_Channel*8)+306) to get my frequency 
> in megahertz...
For UK transmissions you have to add an offset of +-166666Hz to most
transponders, more detailed information on Dave Chapmans dvbtune pages
(http://www.linuxstb.org/dvb-t/index.shtml) and the UK transmitter
frequency list (follow the link on Dave's website).

A while ago someone posted this parameter set for scan (see initial.h
for more), I have no idea if these parameters are still up-to-date,
check the providers website for more information:

/**
  *  Crystal Palace, (BBC1, ...)
  */
{
         .type = FE_OFDM,
         .param = {
                .frequency = 505833333,
                .inversion = INVERSION_AUTO,
                { ofdm:
                         {
                                 .bandwidth = BANDWIDTH_8_MHZ,
                                 .code_rate_HP = FEC_3_4,
                                 .code_rate_LP = FEC_NONE,
                                 .constellation = QAM_16,
                                 .transmission_mode = TRANSMISSION_MODE_2K,
                                 .guard_interval = GUARD_INTERVAL_1_32,
                                 .hierarchy_information = HIERARCHY_NONE
                         }
                 }
         }
},


> build2.4/# dvbtune -f 506000000 -i
> tuning DVB-T to 506000000
> .....wait here forever.....
For DVB-T you usually need to pass some more tuning informations,
usually at laest bandwidth, often FEC and QAM mode. Which one you need
exactly depends on the actual frontend on your card. Some can determine
more parameters on their own, some less. But all tune faster if you
provide the complete parameter set, autoprobing always takes some time.


> So... I did an strace.. just to see what's going on...
>
> We seem to be getting stuck here....
>
> write(2, "tuning DVB-T to 506000000\n", 26tuning DVB-T to 506000000
> ) = 26
> ioctl(4, 0x40046f47, 0xbffffae4)        = 0
> poll([{fd=4, events=POLLIN}], 1, 10000) = 0
> ioctl(4, 0x40046f47, 0xbffffae4)        = 0
> poll([{fd=4, events=POLLIN}], 1, 10000) = 0
> ioctl(4, 0x40046f47, 0xbffffae4)        = 0
> poll([{fd=4, events=POLLIN}], 1, 10000) = 0
> ioctl(4, 0x40046f47, 0xbffffae4)        = 0
I suppose that's the poll() or select() call waiting for frontend status
events, nothing to worry. If you pass a correct parameter set for tuning
this poll() call should return as soon you get a frontend lock.

good luck,

Holger




--
Info:
To unsubscribe send a mail to ecartis@linuxtv.org with "unsubscribe linux-dvb" as subject.