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HD-3000 card: can't view live tv, CAN record HDTV - RESOLVED
http://forum.linhes.org/viewtopic.php?f=15&t=9829
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Author:  neutron68 [ Fri Apr 28, 2006 8:22 am ]
Post subject:  HD-3000 card: can't view live tv, CAN record HDTV - RESOLVED

(System specs in signature line.)

I've got the HD-3000 card configured with the DVB driver and it scans/maps local channels from inside Mythtv. I can schedule a recording of an HDTV program and it records to disk ok. I can playback the HDTV program ok too. I have XvMC turned on for playback. CPU usage is at 53% during playback.

I am not able to use any of the command line utilities like dtvsignal or dtvscan from a shell window. They return back zero signal strength - which must be wrong since programs are recorded when scheduled in Mythtv.
I believe the HD-3000 is mapped to /dev/dvb/adapter0/frontend0 because this the the device that responds to the dtvsignal command.

I am not able to watch live tv with the setup. When you click on WATCH TV, you get a black screen and a few seconds later you get an info box telling you the channel you are tuned to and the program on the channel. Most of the time I can't change channels to another channel. All I can do is hit ESC and get back to the Mythtv menu.

Anyone know of the cause and fix for this live tv issue?

Author:  RacerX [ Fri Apr 28, 2006 10:00 am ]
Post subject: 

Hello

The first thing I would do is check the log

/var/log/mythtv/mythbackend.log

and see what happens when you enter live TV

also from the shell run the command

FEMON

and see if your signal is locking

Author:  Liv2Cod [ Fri Apr 28, 2006 6:26 pm ]
Post subject: 

I'm pretty sure that dtvscan and dtvsignal are only useful when you are NOT using the dvb drivers with the HD-3000 (i.e. they only with with ivtv drivers).

Your symptoms sound like your "default" channel is set to one that isn't providing a signal. That's always been sort of toxic to Myth. It likes to tune only to channels that have valid ATSC signals.

Try running the mythbackend-setup program and choosing a default channel that has a good strong signal. Then see if you can get Live TV.

Author:  neutron68 [ Fri Apr 28, 2006 8:53 pm ]
Post subject:  signal strength 96% - still no image

I just tried WATCH TV again using the highest gain and altitude UHF antenna I have. The signal strength reads out 96%, yet still no image??

When I run 'femon' I get signal strengths in the F998 range, snr in the FC3F range and every line says FE_HAS_LOCK.
I would guess that femon is looking at my default channel?

(How do I copy lines from a shell window to a web browser window??)

The mythbackend.log file shows it's trying to change to live tv:
"TVREC(1): Changing from None to WatchingLiveTV"
"DVB#0 DVB SI Table Parser Started"

and then gives up within 10 seconds saying :
"Finished recording Auschwitz: Inside the Nazi State": channel 1021

See any clues?

Eric

Author:  RacerX [ Fri Apr 28, 2006 10:17 pm ]
Post subject: 

Ok

It appears that your getting the signal fine. I would agree with Liv2Cod that your default channel is not set to a valid channel

Run mythtv-setup

Go to Input Connections Section

Tip ** You must chose a default channel and this a a big deal because it likes to default to Channel 3 which does not exist when you have an Antenna. It also returns to 3 when the backends crashes I think. If you leave it on 3 it will not work. Morever you have to pick a channel that you are gettting the strongest signal from. I knew to try ABC or PBS first.

Tip ** The syntax of the channels would be 7-1 is channel 71 always take out the punctuation....This will save you many many black screens in when you try to start live tv.

Author:  neutron68 [ Sat Apr 29, 2006 11:41 am ]
Post subject:  tried many channels as my default - still no live tv

I'll gladly provide any info I can. I'm not sure how to copy the contents of a shell window to an e-mail. Cut and paste doesn't seem to work (like windows? CTRL-C to cut? CNTRL-P to paste?)

I tried many of the scanned channels as the default channel and none allowed live tv to deliver video and audio when the WATCH TV option is selected.

I went through the channel list editor to see how the channels were classified. All the digital tv channels were classified as ATSC and all the NTSC channels were classified as default. I changed all the NTSC channels to NTSC - just to be sure nothing was going off into an unknown state. Doing that didn't help any.

Observations:
If I have a known-ATSC channel as the default, I get the black screen with a info box telling the channel and program and it never leaves the screen and does not allow me to change channels. ESC is the only out.

If I have a know-NTSC channel as the default, I get the black screen with a info box telling the channel and program and within 5 seconds the info box fades away and allows me to change channels. If I then change the channel to a known-ATSC channel, I get the info box over the black screen and it does not allow me to change channels again. ESC is the only out.

I just opened an xterm window and typed mythfrontend, then tried to WATCH TV, it gave me the black screen, as before so I hit ESC to get out and left Mythtv. The shell window has line after line of:
"AFD Error: Unknown decoding error [mpegvideo_xvmc @ 0xb7372620]get_buffer() failed (1 1073741824 2 (nil))

I then opened up a Bash shell window and typed mythfrontend, then tried to WATCH TV, it gave me the black screen as before so I hit ESC to get out and left Mythtv. The shell window has different info in it:

"TV: Attempting to change fro None to WatchingLiveTV
VideoOutputXv Error: Unable to create XvMC Context, status(11): BadAlloc
VideoOutputXv Error: Could not open XvMC port"

I've got the tv ouput set to use Standard XvMC. Should it be something else, like VIA XvMC. This motherboard doesn't have an VIA video chips. The only VIA chip on the board is for IEEE-1394.

Eric

Author:  RacerX [ Sat Apr 29, 2006 1:09 pm ]
Post subject: 

Well

R5B7 is a little different from previous versions, it records everything that you watch regradlesss of wether or not you set it to record.

I would think the thing to do it stick with ATSC. Uninstall (clear the card in mythsetup,) then reconfigure it

Under General change the Setting from NTSC to ATSC
Under Capture Card set up a DVB card, use defaults
Setup a Video Source for Antenna
Under Input Connections choose the source Antenna that just created
Under the channel scan you can tell it to get rid of punctuation.
Now run scanning for channels
Go back to Input Connections and make sure your default channel is set correctly.

Run mythfilldatabase

Reboot the system

Keep your fingers crossed and give it a try

Author:  neutron68 [ Sat Apr 29, 2006 4:01 pm ]
Post subject:  some live tv works - still not working 100%

1. in the tv playback settings section of mythtv, if I change the mpeg setting to standard (rather than XvMC), it allows live tv to operate

2. live tv only seems to operate with the channel and sub-channels of the default channel entered in mythtv-setup

Eric

Author:  RacerX [ Sat Apr 29, 2006 8:09 pm ]
Post subject: 

Am I correct that the reason that live TV was not working was because your using onboard video and it does not work properly at the moment with Xvmc?

Lots of posts regrading A8N-VM seems like a work in progress..

Author:  neutron68 [ Sat Apr 29, 2006 8:22 pm ]
Post subject:  correct, XvMC with nvidia driver 8178 prevented live tv

Thanks for your help thus far! It got me looking and experimenting.

RacerX wrote:
Am I correct that the reason that live TV was not working was because your using onboard video and it does not work properly at the moment with Xvmc?


Yes, I believe XvMC (in combination with nvidia driver 1.0-8178) was the problem with live tv giving a black screen.
With the mpeg2 decoder set to standard rather than XvMC, live video is possible.

I just updated the nvidia drivers to version 1.0-8756 and live tv works with the mpeg2 decoder set to XvMC or Standard. So it looks like the nvidia driver was most of the problem before.

The last major live tv problem to solve is being restricted to the DTV channel (and it's sub-channels) that is set as the default start channel in the mythtv-setup windows. That problem baffels me as it seems more like a Myth problem than a driver issue. Thoughts??

posted 5-22-06

It turned out that my KnoppMyth install was corrupted by the use of the apt-get command.
I did a reinstall of R5B7 from scratch and all the channel changing problems were gone.

BEWARE OF APT-GET until the souces.list file is fixed.

Good luck,
Eric


Eric

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