There are only a handful of options to choose from in that "Map DVB by Location" section that come preloaded with tvheadend. The good news is that you can add custom. The bad news is that its a little involved to do so.
First, for you need to drop into the command line and have hdhomerun perform a scan on one of its three tuners. Since they are all hooked up to the same cablecard it really makes no difference which tuner you scan. Anyway.. to do this in linux:
To get your hdhomerun device id
$>hdhomerun_config discover
This will output something like "hdhomerun device 1234AA56 found at 192.168.1.xxx". The 1234AA56 is your device id.
To get do a scan:
$>hdhomerun_config <deviceid> scan 0 scan.txt
Where <deviceid> is your device id from above "0" is the tuner you want to scan (choose whichever 0, 1, or 2) and scan.txt is the file that it will write out with all the gory info.
After a few minutes you will have a file that will look like:
SCANNING: 861000000 (us-irc:135, us-cable:135)
LOCK: none (ss=69 snq=0 seq=0)
SCANNING: 859750000 (us-hrc:135)
LOCK: none (ss=70 snq=0 seq=0)
SCANNING: 855000000 (us-irc:134, us-cable:134)
LOCK: none (ss=78 snq=0 seq=0)
SCANNING: 853750000 (us-hrc:134)
LOCK: qam256 (ss=71 snq=81 seq=100)
TSID: 0x81B8
PROGRAM 1: 449 TEAM 10 (encrypted)
PROGRAM 3: 440 TEAM 01 (encrypted)
PROGRAM 5: 441 TEAM 02 (encrypted)
PROGRAM 7: 442 TEAM 03 (encrypted)
PROGRAM 9: 443 TEAM 04 (encrypted)
PROGRAM 11: 444 TEAM 05 (encrypted)
PROGRAM 13: 445 TEAM 06 (encrypted)
PROGRAM 15: 446 TEAM 07 (encrypted)
PROGRAM 17: 447 TEAM 08 (encrypted)
PROGRAM 19: 448 TEAM 09 (encrypted)
The frequency is listed after "SCANNING: " and is a 9 digit number. You will want to build a file that contains all of the frequencies for which a PROGRAM is found. For reference sake the frequency/program combination is essentially a Channel as most of us would recognize. Comcast is nice enough to give both the Channel Number and Channel name for each frequency/program
The file you need to build will look like:
A 873750000 qam256
A 879750000 qam256
... and on and on until you get all your frequencies
Don't worry about the "A" and "qam256" just stick them in this file as they are needed.
Now... move this file to /usr/local/share/tvheadend/data/dvb-scan/atsc and name it something like us-IL-Chicago. Restart tvheadend, and you will now have your custom frequency list show up in the "map DVB by location" button.
After you scan is complete you are still going to have to manually add your Channel names in the "Services" tab BEFORE you "Map DVB services to Channel" otherwise only the services with names will make it over to your channels tab. This can be tedious, but you can rely on your scan.txt file and the "Multiplex" and the URL in the "Play" column within the services tab to determine which service line is which channel. The trick with the URL in the "Play" column is to recognize that the last 4 characters of the URL is the "PROGRAM" from the scan.txt... but in hexidecimal. So you will need to convert from hex to decimal which you can do with any number of online converters.
