[linux-dvb] DVB-T devices supporting hierarchical mode?

Mauro Borghi mauro.borghi at TILAB.COM
Wed Feb 15 17:48:41 CET 2006

Patrick Boettcher wrote:

> On Wed, 15 Feb 2006, Johannes Stezenbach wrote:
>> On Wed, Feb 15, 2006, Patrick Boettcher wrote:
>>> On Wed, 15 Feb 2006, Manu Abraham wrote:
>>>> Patrick Boettcher wrote:
>>>>> Afaik: by default in a non-hierarchical transmission the alpha is 
>>>>> always
>>>>> 1 (that is where it clashes with HIERARCHY_NONE, I remember once 
>>>>> having
>>>>> difficulties with that).
>>>> 300 744 states that alpha=000 is non hierarchial.
>>> It refers to the TPS, doesn't it?
>> I only have the tda10046 data sheet at hand. Non-hierarchical
>> and alpha=1 are distinct register settings, and the HP/LP selector
>> is a seperate bit. IIRC the same is true for MT352.
>> Do DibCom data sheets disagree?
> No.
> Select_HP is a bit and Alpha is another one.
> So, what does the HIERARCHY_1, _2 and _4 in linux-dvb mean?

I think the only sensible answer is _1, _2, _4 is the ALPHA value (with 
_NONE meaning zero).

Looking at the interface of a professional decoder (from Tandberg), the 
ALPHA value is automatically detected (like an _AUTO in linux-dvb), 
while stream selection has three states: OFF, HIGH, LOW - and is user 
For what I understand, selecting OFF has the same effect of selecting HIGH.

 From all this thread of mails... it seems that stream selection is at 
present not possible with current API and drivers. Is it?


More information about the linux-dvb mailing list