[mythtv-users] cannot "remap" channels in channel table for HDHomeRun Prime

Ronald Frazier ron at ronfrazier.net
Tue Nov 29 14:40:14 UTC 2011

On Tue, Nov 29, 2011 at 8:29 AM, Khanh Tran <khanh at khanh.net> wrote:
> I've been "remapping" my channels with the clear QAM HDHomeRun, much
> like most cable companies do now.  For example, I remap channel 7 to
> be 707 (the HD version).  This way, it's easier to get to the HD
> versions of the channels.  I copy over the freqid, mplexid,
> atsc_major_chan, etc, but when I do this with the HDHomeRun Prime,
> MythTV still tells the Prime to tune the "regular" SD channel 7.
> What else am I missing?

I don't actually own an Prime, but I don't believe you can do this.
The Prime uses virtual channel tuning when a cablecard is installed.
This means it expects to tune the channel number directly without
using other parameters.

In the database there are several fields for each channel. Channum is
the field that myth uses for what it thinks the channel is. Then there
are other fields like freqid, serviceid, mplexid, atsc_major_chan,
atsc_minor_chan, etc. With your regular HDHR, it doesn't actually use
the channum for tuning. Instead it uses the mplexid (and the
associated values in the dtv_multiplex table) to tune the multiplex,
and then the serviceid to select the program within that multiplex.
This means the channum that myth uses for display and the fields that
are used for tuning have no overlap, so you can change them

Looking at the code for tuning on the Prime (at least in 0.24), myth
uses the channum not only for display, but also for virtual channel
tuning. Thus you cannot change one independent of the other.

Ron Frazier

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