[mythtv-users] How does myth use info in channel table to tune QAM channels?

[Brian Walter]

Michael Thome wrote:
> Which database fields does myth use to tune QAM channels?  How do these 
> rules interact with zap2it lineups?
>
> Background:  I've got an HDHR connected to cable to get the unencrypted 
> QAM256 channels.  I can scan for 'em, watch 'em, etc, but:
> 1. Most of the program streams dont have PID/ATSC information associated 
> with them, and those that do don't quite match zap2it's keys.
> 2. none of the streams are in the same place as OTA.
> 3. The set of unencrypted channels contains all the OTA channels plus a 
> few of the (local) cable channels - the cable company's published lineup 
> does *not* include all the OTA channels, so none of the zap2it lineups 
> covers everything.
>
> Example: here is an extract of what the channel table looks like after a 
> successful scan:
>
> mysql> SELECT 
> chanid,channum,freqid,callsign,xmltvid,tvformat,mplexid,serviceid,atsc_major_chan,atsc_minor_chan 
> FROM `channel` WHERE `sourceid` = '5';
> | chanid | channum | freqid | callsign     | xmltvid | tvformat | 
> mplexid | serviceid | atsc_major_chan | atsc_minor_chan |
> |   5041 | 4.1     | 87     | WBZ-DT       |         | ATSC     |     
> 132 |         2 |               4 |               1 |
> |   5740 | 74#0    | 74     | UNKNOWN74#0  |         | Default  |     
> 120 |        65 |               0 |               0 |
>
> for 5041, channum is reasonable, but we couldn't match zap2it because 
> 87.2 isn't 4.1 and WBZ-DT isn't WBZDT.  I assume that I can insert the 
> right xmltvid (20431) and I'll get lineups, but is it safe to change the 
> callsign to match (or is it totally ignored by tuning and schedule)?
>
> for 5740, by watching the stream I can see it is WENH (xmlid 11418).  I 
> assume I can add the xmltvid and scheduling will work, but I'd also like 
> to fix the channum for the on-screen schedule (74#0 isn't mnemonic) - 
> can I change channum to "11"?  callsign to "WENH"? What is mplexid? Why 
> is tvformat entered as "Default" and not "ATSC"?  Shouldn't it be ATSC 
> with atsc_major/minor_chan set to something useful?  As an aside, how'd 
> we get from 74.65 (what an hdhomerun_config scan reports) to 74#0?
>
> Obviously, I actually have tried fooling around with these fields - I 
> usually end up with broken channels, though:  for instance in the second 
> case above, changing channum=11, callsign=WENH, xmltvid=11418 leads to 
> nice looking schedule information attached to an un-tunable channel: I 
> would have thought that freqid=74, serviceid=65 and sourceid=an hdhr 
> source was plenty to tune successfully.
>
> Thanks!
> _______________________________________________
>   

Looks like your in New England too :)

I have the same cable setup (comcast - Southern NH).  After scanning, I 
changed two fields (via mythweb) - the xmltvid and the frequency - in 
the sample you have above I believe BZ is 804 (from zap2it).  Use the 
'channel number' from zap2it for the freqid in the table.

After that, everything worked great.

Depending on the rest of your tuner options (I have a pvr500 for 
standard cable) the 74#0 type of channels are digital broadcast of 
analog (no hd stuff).  I found them to be 'noisy' and not very reliable 
and ended up deleting them.

Brian