[linux-dvb] Q2: dvb api 3 - FE_ATSC

Rainer.scherg Rainer.Scherg at t-online.de
Mon Aug 22 22:38:28 CEST 2005


Patrick Boettcher schrieb:
> On Mon, 22 Aug 2005, Rainer.scherg wrote:

>> typedef enum fe_type {
>>     FE_QPSK,
>>     FE_QAM,
>>     FE_OFDM,
>>     FE_ATSC
[...]
> 
>> ATSC supports several modulations...
>> Shouldn't there be the modulation named  (e.g. VSB)?
>  
> No, because an ATSC demodulator is capable of decoding VSB and QAM signals.

OK, but querying  GET_INFO from frontend.
I cannot decide directly whether to use
    struct dvb_frontend_parameters {
		struct dvb_qam_parameters  qam;
		struct dvb_vsb_parameters  vsb;

In this case I have to crosscheck capabilities,
(which would make fe_type obsolete, because I
always could check for capabilities only).

Reason for my question is: best method of displaying
frontend information in dvbsnoop (-s feinfo)...




>> if you are having a frontend supporting more than one modulation?
>> (e.g. DVB-CT  -->   FE_QAM|FE_OFDM )
> 
> 
> DVB-T is much too different to DVB-C. When this will happen, you'll 
> probably make two different frontend-dev-nodes with separate parts in 
> the one driver.

good argument.

rainer




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