[mythtv-users] Fwd: Mythtv - black screen when trying to watch tv on computer

Michael T. Dean mtdean at thirdcontact.com
Sun Apr 1 18:00:09 UTC 2007


On 04/01/2007 10:15 AM, Douglas Ward wrote:
> I have set up a Mythtv box running Mandriva 2007 and using a Hauppage 
> PVR 350 capture card.
...
> In Mythtv I can connect to the backend database, run mythfilldatabase 
> and scan channels for Tuner 1.
Unrelated, but if you're a North American user you should /never/ scan 
for channels with analog cards.  Use "Fetch channels from listings 
source" to get your channels.  (If you're not a North American user, 
chances are there are better ways to define channels than using the 
analog scan (which leaves much to be desired).)

To clean up the mess scanning has probably made for you, use 
mythtv-setup's "Delete all video sources" button in the Video Sources 
section and then recreate your video source, input connections, and then 
use the "Fetch channels from listings source" button to create your 
channels.

> When I try to watch tv or record a program all I get is a black screen.

You've configured your system to use the PVR-350's hardware decoder.  
This can /only/ be used with the PVR-350's TV out, so it won't work with 
your system connected to a monitor.  So, just disable, "Use the 
PVR-350's TV out / MPEG decoder" and you'll be up and running.

There's no reason to worry about not being able to use the hardware 
decoder.  With today's processors (actually those from the last 4 years 
or more) an SDTV-resolution MPEG-2 recording is easy to decode in 
software, so really--due to its limitations (720x480 max resolution 
output using 50+-year old NTSC technology, no OpenGL, no 2-D 
acceleration, ...)--there is, IMHO, no good reason to use the PVR-350's 
TV out.  I used my PVR-350 as a PVR-250 (i.e. didn't use the decoder) 
for 3 years.

And, since my HDTV-upgrade, my 350, 250, and 2x150's are now just 
paperweights.  In this role, however, the hardware decoder has proven 
effective--it adds a bit of heft to the 350 making it capable of 
performing as a paperweight in winds 3-5mph higher than the maximum 
windspeed a 250 can handle.  The new 150's--with their "1 chip instead 
of 2 and everything miniaturized" design--are actually the least 
effective of my 4 PVR paperweights.  So, even though you spent a bit 
more to get that hardware decoder and you'll probably decide not to use 
it, don't worry because, eventually, you can get some use out of it.  :)

> When I pick something out of the channel guide it records but mythtv 
> says that it doesn't exist in the play back screens.  I can see the 
> video in the /home/recordings directory.  Very strange.

http://www.mythtv.org/wiki/index.php/Frequently_Asked_Questions#Q:_Why_aren.27t_my_new_recordings_showing_up_in_Watch_Recordings.3F

> Has anyone seen this kind of behavior before?

Only enough people that it made the FAQ list.  :)

Enjoy,
Mike


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