Page 1 of 2

Collecting QAM data to supplement listing information - scan

PostPosted: Fri Nov 11, 2011 9:01 am
by rkulagow
I've created a perl scanner which leverages the information we can obtain from a HDHR-CC device to create an accurate call sign to QAM mapping. This will help end the issue of not knowing which QAM frequencies have what content on them (without watching each channel to figure it out).

Tribune's systems (the source of the data for Schedules Direct) are not programmed to support QAM because the cable companies don't want to distribute QAM data, so Tribune isn't going to do the R&D to support QAM if there's no "market" for it. Since the cable companies are the ones that would need to request the requirement, (and they're not), Tribune isn’t going to implement something which won’t be used, and which the cable companies won’t supply data for in the first place. We've asked Tribune, and for whatever reason, the cable companies seem to consider QAM tuning information as proprietary.

When the scan is complete the result will be a {headend}.qam.conf file. If you have a HDHR-CC and at least one HDHR-atsc then the script will use the HDHR-atsc device to create .mpg files which you can watch with mplayer or vlc if you'd like to confirm what the scanner found and that the QAM information obtained from the -CC is valid. If you don't have an ATSC HDHR, you can still help, but the script won't create the MPG files.

After running the scan, please send the .conf file to

Schedules Direct will manage the collection of QAM files and make them available to other users in the same headend, allowing those of you that don't have a HDHR-CC to still have accurate lineups based on the scans of subscribers that do.

So, if you're reasonably proficient on the Linux command line, and have a HDHR-CC, please go to

and download

The source code should be pretty self-documenting. It works on my Ubuntu 11.10 system.

Please let me know if you have any questions, and thanks for helping the Schedules Direct community.

Re: Collecting QAM data to supplement listing information -

PostPosted: Fri Jan 06, 2012 11:34 am
by rkulagow
Channels that can be decrypted by the cable card should be in the lineup anyway, and a cable card tuner doesn't need to tune by QAM freq and program - it tunes via "channel" number.

I had a version of the scanner which did the auth=subscribed, but it resulted in channels that couldn't be used without a cable card, and that's what we're trying to accomplish.

Can you run hdhomerun_config {yourDCRdevicenumber} get /sys/debug

and paste the results please?

Re: Collecting QAM data to supplement listing information -

PostPosted: Sat Feb 04, 2012 5:55 pm
by rkulagow
jpasher wrote:If I tweak the script to include channels where auth=subscribed and not capture an MPEG or streaminfo, it will generate a QAM mapping file, but I'm wondering if that is actually the data that is desired. Should I just run it that way and send the file along, or will that be meaningless? I guess my question is what is the ultimate goal of the output for the script, since the info won't be needed for MythTV to work (for me personally)?

The issue is that because you have a HDHR Prime, all the channels are valid for you, because your MCard authorizes you to view those channels. So you're able to get QAM tuning data of course. For someone without a HDHR Prime (who is in your headend), that data isn't going to be useful, because they won't be able to tune without a MCard. Using "subscribed" as the authtype without using a second non-Prime device to confirm that the resulting QAM data is usable without an MCard means that you're probably going to get valid QAM data for all 1000 channels in your lineup.

That's why you need to confirm the data with a second device.

And unless something has changed, you need different firmware on the Prime to make it a "standard" HDHR.