[mythtv-users] ATSC channels scan and play but will not lock.

Yashka Oreza yashka at gmail.com
Sun Aug 26 00:24:24 UTC 2007

I just moved my pcHDTV 5500 tuner card from my old mythbox into my new amd64
system running 64-bit ubuntu feisty and Myth-.20-2. It's set up as a DVB
device and seems to work superficially.

The channels scan and are detected by myth ok. I know that there is
excellent signal strength.

TV even records fine if I set up a recording

Live TV is a huge mess.

1. Nothing tunes when livetv is launched
2. Channel tuning is instantaneous but the screen goes black after 5-10
3. There is no signal strength or lock-on info displayed in the OSD - I have
no idea why.
4. !00% of the time, even when the channel I just selected comes in
perfectly clear, I get the "You should have a lock by now" popup after
whatever threshold I had set it to passes.

I know it's not exclusively a frontend problem - I have the same behavior on
a remote frontend that I had previously used with the old beckend without

Link to pertinent backend log: http://rafb.net/p/0ncls733.html

In addition, I can only get 5-10 seconds of video during LiveTV before the
front-end changes channels, seemingly at random, to one of the channels I
had tuned to previously. It's almost as if there's a lag of one change
before the system reacts. But this dosen't always happen. Somethimes it will
be playing fine and then just go black.

This is the single weirdest problem I've ever experienced with myth. I
should add that it happened both with .20.2 and previously with a SVN trunk
compile from several days ago.

I tried scanning with dvbtools and got a usable channels.conf - azap reports
a lock just fine when I try to test it. I cannot figure out how to tune the
channels with mplayer or any other player, though.

Myth refuses to import the channels.conf I generated with a "failed to parse
channels.conf" error.

I noticed that the multiplex frequencies in the database were slightly (but
not much) different from the ones in my channels.conf, so I changed them to
match. This had no effect in either direction. If I try hard enough,
changing channels repeatedly, I can see a few seconds of smooth video for
every channel before it freaks out. However, I never get a lock on anything.
Recall that azap reports a lock.

Anyone got any ideas of what could be causing something like this?
View this message in context: http://www.nabble.com/ATSC-channels-scan-and-play-but-will-not-lock.-tf4329618s15552.html#a12330978
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