[mythtv-users] Interpreting capturecard for HDHomeRun

[David Engel]

On Sun, Mar 15, 2020 at 01:38:05PM -0700, Ross Boylan wrote:
> Along the way to writing a program to update channels for the repack, I've
> run into the issue of figuring out the relation between entries in the
> capturecard table and spots on my HDHomeRun tuner.  Highlights:
> select cardid, parentid, videodevice, cardtype from capturecard;
>  +--------+----------+-------------+-----------+
> | cardid | parentid | videodevice | cardtype  |
> +--------+----------+-------------+-----------+
> |      1 |        0 | 10424297    | HDHOMERUN |
> |      2 |        1 | 10424297    | HDHOMERUN |
> |      3 |        0 | 10424297    | HDHOMERUN |
> |      4 |        3 | 10424297    | HDHOMERUN |
> +--------+----------+-------------+-----------+
> 
> My HDHR device has 2 tuners, know at /tuner0 and /tuner1 when using
> hdhomerun_config.
> I created double entries for capture cards so that I could record, e.g.,
> 4.1 and 4.2 at the same time.
> These "extra" entries appear to be identified by having a non-zero parentid.
> 
> I am looking for a mapping from cardid to /tuner0 or /tuner1.

There is no such mapping.  MythTV uses libhdhomerun to dynamically
allocate a tuner, which can be any free tuner, when needed.  MythTV
input 1 might use HDHR tuner0 one time and HDHR tuner1 the next time.

> One could construct a rule that would give such a mapping but a) the rule
> is rather ad hoc and b) it would conclude that cardids 1 and 2 are tuner0.
> But perhaps sometimes they are tuner0 and sometimes 1.
> 
> Any suggestions on how to proceed?
> 
> Background: I want to find a free tuner on which I can do a channelscan
> with hdhomerun_config.

In my experience, which is only with HDHomeRun Primes and 2+-year old
firmware, scans done by the HDHR always use all tuners whether they
are already in use or not.  Maybe they've fixed that with recent
firmware.  I don't know.

David
-- 
David Engel
david at istwok.net