View unanswered posts    View active topics

All times are UTC - 6 hours





Post new topic Reply to topic  [ 6 posts ] 
Print view Previous topic   Next topic  
Author Message
Search for:
PostPosted: Sat Feb 26, 2005 8:07 pm 
Offline
Joined: Fri May 21, 2004 11:55 pm
Posts: 1206
Location: Silicon Valley, CA
I have the oddest problem. After upgrading my box from R4 to R5A10 (0.17 Myth) I can record all channels perfectly but one. Channel 11.1, the NBC affiliate in my area, will fail to record every time with the dreaded "no signal level" error. This is with either my HD-2000 or HD-3000 tuner cards. I can tune in the signal using "dtvsignal" and it comes in perfectly. It's just that Myth can't tune it.

I'm really out of ideas as to how to even debug this problem. I look at the channel table and it seems perfectly fine. The frequency is 12-1 as it should be. The other entries all look similar, and they work fine. Only NBC fails to record. Before I loaded 0.17 it recorded fine.

I left a message on myth-users but no responses yet.

I'm stumped.

_________________
Do you code to live, or live to code?
Search LinHES forum through Google


Top
 Profile  
 
 Post subject:
PostPosted: Sat Feb 26, 2005 11:19 pm 
Offline
Joined: Mon May 10, 2004 8:08 pm
Posts: 1891
Location: Adelaide, Australia
Those are dvb cards right? To receive a channel you need to have specify the correct ids for the video and audio for it to demux them from the digital stream (each tuned frequency is capable of carrying multiple channels). Tuning the card only involves receiving the full stream, so it is possible for it to report that it is tuning correctly (i.e good snr/unc) but not receive any actual video/audio. Some stations change the ids that they are using to broadcast video and audio in different timeslots (a real pain). If you tuned the channels at one time and then tried to record at another, the channels may not be on the stream anymore.

Can you receive the video using tzap -r "channel name" (with an appropriate channels.conf) and mplayer /dev/dvb/adapter0/dvr0 in another window?


Top
 Profile  
 
 Post subject:
PostPosted: Sun Feb 27, 2005 12:49 am 
Offline
Joined: Mon Oct 06, 2003 10:38 am
Posts: 4978
Location: Nashville, TN
nah the hd3000's use a modified bttv driver at this point, although I hear they are thinking of going dvb, and someone has actually written a dvb driver for the 3000, but it is not the one that comes with knoppmyth.

_________________
Have a question search the forum and have a look at the KnoppMythWiki.

Xsecrets


Top
 Profile  
 
 Post subject:
PostPosted: Sun Feb 27, 2005 4:36 pm 
Offline
Joined: Mon May 10, 2004 8:08 pm
Posts: 1891
Location: Adelaide, Australia
Do they pick up terrestrial digital tv signals though? I assumed they did because iof the HD part of the card name, but operhaps that is just a marketing ploy). Because if they do the essence of what I said should still apply (just not sure how it is handled with the modified bttv driver).


Top
 Profile  
 
 Post subject:
PostPosted: Sun Feb 27, 2005 4:39 pm 
Offline
Joined: Mon Oct 06, 2003 10:38 am
Posts: 4978
Location: Nashville, TN
yes they do pick up OTA ATSC signals.

_________________
Have a question search the forum and have a look at the KnoppMythWiki.

Xsecrets


Top
 Profile  
 
 Post subject:
PostPosted: Sun Feb 27, 2005 4:43 pm 
Offline
Joined: Fri May 21, 2004 11:55 pm
Posts: 1206
Location: Silicon Valley, CA
Well, I found the problem... :oops:

Further testing with dtvsignal showed that the signal on channel 12 was "spotty" -- it would suddenly drop to zero and come right back on. Antenna position did not matter. I have an amplifier on the antenna, which I replaced with a different model. It helped the signal on channel 12 immensely (although some of the upper channels were actually reduced a bit).

It only goes to show you the wisdom of a saying we have at work... Whenever you think you've solved a problem, look deeper and you'll find another!

_________________
Do you code to live, or live to code?
Search LinHES forum through Google


Top
 Profile  
 

Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 


All times are UTC - 6 hours




Who is online

Users browsing this forum: No registered users and 25 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group

Theme Created By ceyhansuyu