Re: [RFCv1] add DTMB support for DVB API

[Antti Palosaari <crope@iki.fi>]

On 12/23/2011 12:55 PM, Mauro Carvalho Chehab wrote:
> On 22-12-2011 19:30, Antti Palosaari wrote:
>> Rename DMB-TH to DTMB.
>
> Patrick seems to believe that CTTB is a better name. In any case,
> whatever name we pick, I think that the DocBook specs (and
> maybe a comment at the header file) should point all the known
> ways to call this standard. So, I'm fine with any choice.

I am not going to change it for CTTB unless there is no some document 
given says it is more correct than DTMB. I have looked very many papers 
over there and DTMB is absolutely more common as far as I gave seen.

>> Add few new values for existing parameters.
>>
>> Add two new parameters, interleaving and carrier.
>> DTMB supports interleavers: 240 and 720.
>> DTMB supports carriers: 1 and 3780.
>
> The API change looks sane to my eyes. I have just a couple
> comments below.

I think I will add carrier modes to enum fe_transmit_mode... I will send 
new propose soon.

>> @@ -169,8 +170,11 @@ typedef enum fe_modulation {
>>       APSK_16,
>>       APSK_32,
>>       DQPSK,
>> +    QAM_4_NR,
>
> While the NR is generally associated with the modulation,
> this is a channel code, and not part of the modulation itself
> (btw, the DVBv3 API calls it as "constellation").
>
> Ok, it is easier to add it here, but maybe it would be safer
> to add a separate field for channel coding that would be used
> to enable or disable the Nordstrom-Robinson code.
>
> This is currently used only with QAM-4, but nothing prevents this
> parity code to be added to other types of modulation.
>
>>   } fe_modulation_t;
>>
>> +#define QAM_4 QPSK
>
> IMHO, this is overkill, but I'm ok with that.

Anyone else have comment about that?

regards
Antti
-- 
http://palosaari.fi/