[mythtv-users] HDTV reception via Cable

R. G. Newbury newbury at mandamus.org
Thu Mar 23 22:50:33 UTC 2006


Christian Burger wrote:
> 
> -----Original Message-----
> ------------------------------
> 
> Message: 18
> Date: Wed, 22 Mar 2006 10:14:12 -0500
> From: "R. G. Newbury" <newbury at mandamus.org>
> Subject: Re: [mythtv-users] HDTV reception via Cable
> To: christian.burger at abtg.net, 	Discussion about mythtv
> 	<mythtv-users at mythtv.org>
> Message-ID: <442169C4.4040906 at mandamus.org>
> Content-Type: text/plain; charset=iso-8859-1; format=flowed
> 
> Christian Burger wrote:
> 
>>Can you manually tune your card with azap or mplayer?  I too am on Charter
>>but using an Aver TVHD A180.  Myth just won't tune the card no matter what
>>I've tried, but mplayer will tune it via channels.conf.  When you generate
>>your channels.conf you are just doing atscscan atsc/us-Cable-Standard >
>>channels.conf right?
> 
> 
> We will need more information to be able to diagnose the problem.
> 
> It sounds like you have followed a guide but obviously something has 
> gone wrong... This is the wiki page:
> 
> http://www.mythtv.org/wiki/index.php/Adding_QAM_Channels_For_HDTV_Tuner_Card
> s
> 
> Does "atscscan US-Cable-Standard-whatever-the-name-is-Frequencies" work?
> 
> It should give you a list of probably upwards of a couple of hundred 
> 'channels' on 8 to 10 different frequencies. If you don't get 
> anything/much from one frequency set, try the other Frequency files and 
> modulation methods Your cable co may use a different transmission 
> standard on the cable, possibly not QAM-256.
> 
> Don't be surprised at the number of 'hits' you get. These 'hits' include 
> all of the encrypted (Pay-per-view etc) channels and all of the music 
> channels. In the Toronto area, I get 27 unencrypted digital channels on 
> Rogers, out of a scan of 404! (The music channels are probably actually 
> usable, with some poking and prodding of myth).
> 
> If you cannot get this far, TARFUN....  And I would suspect that the 
> hardware is bad...
> 
> Geoff
> ---------------------------------
> 
> I get a usable channels.conf that I am able to tune using mplayer.
> So I am pretty confident the hardware works okay.  I think the problem is 
> my sourceid.  I tried the recommend azap -r STATION and dvbscan -c but it
> lists all my channels (services) when I run it.  I think I will go ahead and
> beat my head on the wall as it will probably help my progress :)

Your use of the word sourceid here tells me that you are confused. 
dvbscan is supposed to list everything it can find. You have to figure 
out what is useable from that.

Test sequence:
Does the card show up at /dev/dvb/adapter0/dvr0?  (If at /dev/video0 
then you are loading the wrong kernel module. Make yourself a dunce cap 
and wear it for 2 minutes in the bathroom with the lights out, as 
punishment for not reading this list properly!.

Run dvbscan to make a channels.conf. Copy the summary section into a 
file and store it a ~/.azap/channels.conf

If you can capture a channel stream using azap -r STATION to tune to the 
station, and 'cat /dev/dvr/adapter0/dvr0 > test.mpg' gives you something 
you can watch with mplayer  (as in mplayer test.mpg) then the hardware 
works.

Using  atscscan or qamscan which are floating around, or just the hard 
way, find out which channels are unencrypted and usable. Spend even more 
time figuring out which channels they actually are...There is no real 
way (without the use of a set top box diagnostic) to find out that 
[1032]:571000000:20:21:24 is really WNUT or whatever, on channel 108.

At labs.zap2it.com you set up (or should have) a channel lineup for your 
digital channels. You cannot really do that until you know which 
channels you can actually get, and want to get. I'll call that your 
'Charter Digital' lineup. You will probably have a Charter Analog lineup 
for channels below 72 (as numbered by Charter). The channel numbers 
above 72 mean absolutely nothing..they are just identifiers.

Once you have a lineup, make it one of your sources under mythtv-setup. 
I will presume you already have the analog lineup as the first entry. 
That means your Charter Digital lineup will be #2 and will therefore 
become sourceid=2. Mythfilldatabase will run (if you run mythtv-setup in 
a window you can move it and watch the underlying transaction going on).

Now associate your HD3000 card, 'TUNER' with Charter Digital. You can 
then see the channels listed in the channel editor section. Set the 
transmission type to ATSC. Exit mythtv-setup. Run mythfilldatabase 
(again) from the commandline. It will be quick.

Now, open the dtv_multiplex table in mysql. You will need to enter one 
row in the table for each frequency which is used for an active, usable 
channel in your channels.conf. The mplexid will be autoincremented as 
set as you do this. Therefore it is best to start with the lowest 
frequency and work up. When done, set the sourceid for all rows as 
sourceid=2 and the modulation as QAM_256 (or whatever Charter uses..).

Now open the channel table. Select each row by the callsign and check 
that it matches the channum and chanid you expect. The chanid should be 
2xxx where xxx is the Charter cable channel number. You will need to 
poke into each channel's row, the mplexid number for the frequency, set 
the sourceid (if not properly set) and set the serviceid equal to the 
last number (the pid) of the line in your channels.conf for that 
channel. The pid is the identifier of the digital stream on the 
frequency. You may also want to play with the icons, name etc.

That's it. It is not difficult, but it is particular.

Note that there is a quick way to look at the 'raw' streams (going from 
memory here):
Use azap -r STATION to tune, in one console.
Use mplayer -vid xx -aid yy in another console where vid,aid and pid are 
the last three numbers on the channels.conf line....If vid is 0, you may 
have an audio channel, but try one digit less than the audio id..

Geoff





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