[mythtv] Channel list in Program Guide

[Klaas de Waal]

On Sun, 14 Jul 2019 at 03:11, David Engel <david at istwok.net> wrote:
>
> On Sat, Jul 13, 2019 at 10:56:31PM +0200, Klaas de Waal wrote:
> > The Program Guide displayed by mythfrontend shows all channels in the
> > database. This includes the channels from videosources that are not
> > connected to a capturecard and thus can never be tuned to or recorded
> > from.
> >
> > I think this is wrong; the Program Guide should only show channels
> > that can be used, so only channels from videosources that are
> > connected to a capturecard.
> >
> > This can be easily implemented by a fix in
> > ChannelUtil::LoadChannels(), file channelutil.cpp:2396, change "LEFT
> > JOIN capturecard..." with "RIGHT JOIN capturecard ..." .
>
> Why not plain, INNER JOIN instead?
>
Yes, INNER JOIN is better here. After some thinking I realized that channels
without a capture card are not good for presentation in the guide but that
capture cards without channels are even worse. Thanks.

> > For mythtv-setup and mythfrontend this works OK but would it break
> > anything else, e.g. the services API or so?
>
> I don't know.  It should certainly only be done for guide and related
> queries.  Queries dealing with recorded and oldrecorded most
> definitely need to referenced channels that might not still be
> connected to inputs.
>
As far as I can find in my logs ChannelUtil::LoadChannels() is used only
to generate the channel list for the Program Guide. Searching through the
source code does not show additional places where it is used.
As this fix also does not seem to break the services API (thanks Bill)
I will go forward with this.

Thanks,
Klaas.