[mythtv] SI/PSIP Parser

[Taylor Jacob]

> Some general thoughts on this, from the ATSC side of the house...  I
> hate to see duplicated effort here -- Daniel's parser classes are pretty
> far along -- but if it means we share code between DVB and ATSC, I'm all
> for it.

I have seen some of Daniels patches at least as of 2 months ago and he should be able to
move ATSC code into my "super" class with ease.. All of my ATSC stuff has just been
proof of concept nothing worth using..

> 1. Setup improvements.  zap2it provides us with nearly everything we
> need to eliminate the setup step where the user edits the database to
> fill in the freqid field for the ATSC stations.  I've actually got code
> in my local tree that gets the fccchannelnumber and channelminor from
> zap2it, propogates them through the temporary tables, and stuffs them in
> the freqid field.  The only flaw is that channelminor and program number
> are not always the same.  Channelminor is mentioned in TVCT (part of
> PSIP); program number in PMT.  And there's nothing to keep a station
> from changing the program number on a whim; channelminor is more
> permanent (world-visible).  I then thought "well why not just cache the
> PIDs in the database and skip program number entirely" and didn't
> proceed any further.  Which brings me to...

On my set top ATSC box I have to re-scan from time to time because they are always
changing what minor channels exist and what not, so I suspect there may be a need for some
sort of Auto-PID code instead of caching PIDs in the DB (Which I don't like the idea of caching
PIDs since it takes almsot no time to get and parse the PAT and PMT).

> 2. PID caching.  There's absolutely no reason why DVB and ATSC can't
> share PID caching code and database structures.  Should include the
> capability of recording alternate audio streams too.

See above.  I have a nice PMT QObject that you can check if its a TV service, get the languages,
etc that there will be NO changes required for ATSC to use.  It also can handle the PMT
descriptors for saying 'hey this service has moved', etc..

> Also, if you need ATSC PSIP data for testing, it's pretty easy to grab
> just the PSIP PIDs from a stream.  They end up being pretty small files
> that way, too.

Well I need to get my PCHdtv card installed and working to get more than the 1 stream I have now.