[linux-dvb] [PATCH] tda1004x driver has code to support HIERARCHY_AUTO, but does not set FE_CAN_HIERARCHY_AUTO

Patrick Boettcher patrick.boettcher at desy.de
Wed Sep 19 10:20:13 CEST 2007


Hi,

On Tue, 18 Sep 2007, Wolfgang Wegner wrote:
> On Tue, Sep 18, 2007 at 11:35:31PM +0200, Patrick Boettcher wrote:
> > 
> > I don't understand your conclusion.
> 
> sorry, probably my wording was all wrong.
> 
> > Try this doc 
> > http://www.dvb.org/(RoxenUserID=cc5cd761bc596bbccaf4820a0a017e74)/technology/fact_sheets/WP01_DVB-T%20Hierarchical.pdf
> > 
> > It describes the constellation and the possibilities.
> 
> Thank you for the link!
> In fact it shows my thinking was wrong, the wording clearly states "two
> completely different services".
> >From my digital transmission classes I remembered it was planned to
> deliver an SD stream in the HP channel and just the additional data
> for HD decoding in the LP stream, such that for HD decoding both streams
> would have to be used. Probably that is simply not possible to realize
> on the encoding side, because it would be more bandwidth efficient.

Oh, have a look at ISDB-T and you will be surprised. In this case the 
demod has 3 viterbi decoders and 3 fec-engines and (has to/can) combine 
the output all streams into one TS.

Patrick.

--
  Mail: patrick.boettcher at desy.de
  WWW:  http://www.wi-bw.tfh-wildau.de/~pboettch/



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