How to insert missing channel?

[LookyC]

SageTV's channel scan apparently misses a channel in my Comcast digital lineup, TBS. I reviewed all channels available under the adapter manually, to make sure it wasn't just misidentified and really just there under an incorrect channel. No dice.

To make sure it wasn't an issue of weak signal and for independent confirmation, I went through the steps to search through my my digital channels, by tuning in each one with azap and then attempting to view it with mplayer:

# http://www.linuxtv.org/wiki/index.php/Zap
# http://linuxtv.org/wiki/index.php/Dvbscan

# Scan for channels and save output:

w_scan -fa -A2 -X -c us | tee ~/dvbscan.txt

# Copy dvbscan.txt to ~/.azap/channels.conf

mkdir ~/.azap
cp ~/dvbscan.txt ~/.azap/channels.conf

# Look at channels.conf and pick out a channel to tune in

# Tune in a channel
azap -r WEIU-DT

# Run mplayer to watch TV
mplayer -ao sdl /dev/dvb/adapter0/dvr0

"Good" channels showed up in channels.conf like this:

WEIU-DT:711000000:QAM_256:2176:2177:1

"Stray" channels show up like this. Here is what is really TBS:

service_id 35:555000000:QAM_256:2048:2049:35

You read about Comcast disobeying spec and not tagging channels with their station ID sometimes. I hand-edited that entry so I could reference it with the "TBS" moniker:

TBS:555000000:QAM_256:2048:2049:35

Compare that line to azap's output, and the entry fields come into focus.

$ azap -r TBS
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
tuning to 555000000 Hz
video pid 0x0800, audio pid 0x0801
status 00 | signal 0000 | snr 0000 | ber 00000000 | unc 00000000 | 
status 1f | signal 0156 | snr 0156 | ber 000018c5 | unc 000018c5 | FE_HAS_LOCK
status 1f | signal 015a | snr 015a | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal 015a | snr 015a | ber 00000000 | unc 00000000 | FE_HAS_LOCK

So my missing TBS station is at 555MHz, the video PID is 0x0800 (decimal 2048), and the audio PID is 0x0801 (2049). And signal strength is the same as it is for all my strongest stations.

So my question is, is there a clean or dirty way to program this channel into SageTV? I'm running SageTV 7.0.15 Linux OEM.

[LookyC]

Figured this out. Searching on the nitty-gritty from before, I found it had indeed been dealt with before (kambo / SageTV - "Not Bad with QAM, but a few missing channels").

This is what worked for me:

(1) (The "dirty" part): added a new channel mapping to the bottom of /opt/sagetv/server/adapter0-QAM.frq:

CH:39 major:0 minor:17 prog:35 phy:79 frq:555000000 mod:11 inv:0 #:TBS

This line was cobbled out of two parts. First, from before, the line from channels.conf:

TBS:555000000:QAM_256:2048:2049:35

Second, the channel information from http://www.silicondust.com/support/channels/ :
(search through the different area line-ups with the drop-down box)

qam256   79-35   17   TBS   704x480p   4:3

Third, comparing other working channels, I was able to map the values into the fields. Some items are conspicuous by their absence, no video/audio PID's for example.

I did a reboot, but I don't know if you have to actually do anything to get the new line read.

(2) (The "clean" part):
Using the channel editor, I mapped one of the not-working TBS channels to
"79-0-17" (phy-major-minor).

Hey let's see what's on TBS tonight...