[mythtv] EIT active scanner

[Janne Grunau]

On Tuesday 13 June 2006 20:11, Yeasah Pell wrote:
> Some providers aggregate EIT for multiple transports onto a single
> transport, so that only one out of a bunch of multiplexes will have
> EIT data on it (but it will apply to the whole group of them)

Each transport should have at least now/next data. But your're right 
it's rather pointless to tune to each multiplex if we can get the same 
data from another multiplex. The only problem I see is to know if it's 
indeed the same data.

> Currently the active EIT scanner assumes that any multiplex with a
> channel that uses EIT will have EIT available, which can result in a
> lot of useless tuning activity (and potentially more rotor activity
> than is needed)

The tuning activity is IMHO not really a problem. Rotor movement is. But 
I'm pretty sure that there are no unnecassry rotor movement since we 
scan the multiplexes grouped by source. 

> Does adding a field to the dtv_multiplex table that indicates the
> presence of EIT seem like a good idea? This way we could watch for
> EIT at scan time, and populate this field accordingly, and the active
> scanner could use this information to determine that there's no point
> in scanning a particular multiplex (since it isn't going to find any
> EIT there)

One field isn't enough. The new eitscanner I'm currently working on 
collects statistics of the data on each multiplex. I'm not sure if it's 
necessary to save the statistics in the database.

Janne

ps: Your solution will lead to more rotor movements if you don't change 
EITTransportTimeout accordingly