[mythtv] DVB support - Status update

Andy Davidoff dert at pobox.com
Thu May 1 02:49:25 EDT 2003

One way we could represent all tuning is with the addition of a value
to the channel table that indicates the location of extended attributes.
To get the complete attributes for channel 666, /all/ code could simply

  $extend = select extended from channel where chanid = 666
  select * from channel left join channel_$extend using (chanid)
          where chanid = 666

channel_$extend would evaluate to channel_dvb, which would hold extra
attributes in one (or more) records for each channel.  Iterating over
all tuning formats with extended attributes for each would be similar:

  foreach $format in select distinct extended from channel
          select * from channel left join channel_$format using (chanid)

This would not impact the existing code at all, but it would give you
room to structure DVB's extra attributes without breaking the standard.

If I were you (and I was following this suggestion ;-), I would
populate channel_dvb with one record per each DVB channel defined in
the channel table.  You could use multiple records, but this would
only make sense (to me) if you had a high degree of variability in
the number of extra attributes used per each channel, or a fairly
arbitrary structure to the data (key-value string pairs, for example).

Thanks for your lengthy description; hope this gives you some ideas...

PS. We could handle multiple streams on a single channel with "slave"
    capture cards that are untunable; they'd be tuned as a side-effect
    of the tuning of their "master" (the real capture card) and could
    only thereafter capture a/v.  Does this sound like an ugly hack?

On May 01, at 01:18, Ben Bucksch encoded a 3.8K recording:
> DVB tuning itself is not *all* that complicated.

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