[mythtv-users] Blinking lines in LiveTV/Recorded Video

[Clark Lee]

Another observation:

The boarder lines of the OSD, are also blanking - Thus I think it is not the incoming signal or encoding problem, but a playback/display problem somehow.
Horizontal lines are blinking while vertical lines are not affected. Is it strange?



________________________________
From: Clark Lee <clarkchen900 at yahoo.com.cn>
To: Discussion about mythtv <mythtv-users at mythtv.org>
Sent: Sunday, September 13, 2009 1:36:21 PM
Subject: Re: [mythtv-users] Blinking lines in LiveTV/Recorded Video


Thanks, Jeff. However, I guess I didn't describe the case clearly so you misunderstood it.

The blinking lines are not at the top and bottom position of the screen, I guess this is the overscan area that you were refering to.
I am using an external digital cable STB to demodulate digital cable signal, and the STB output composite video signal to my capture card in PAL format. So there should not be any data embedded in the signal in this case.

The blinking lines actually happen to any lines on screen; actually I can notice that some fonts in the screan are also blinking. The lines are easier to notice especially when it is a light color on the black background. I would say, the whole screen is 'blanking' somehow with a low frequency.

TvTime will show well with no issue. Thus I am kind of confused. It is related to 'de-interleaving'? I am not sure whether my STB output interleaved signal or prograssive signal... anyone have idea how to tell that?

Thanks,

Clark



________________________________
From: Jeff <junk_inbox at verizon.net>
To: Discussion about mythtv <mythtv-users at mythtv.org>
Sent: Sunday, September 13, 2009 6:51:02 AM
Subject: Re: [mythtv-users] Blinking lines in LiveTV/Recorded Video


On Sat, Sep 12, 2009 at 6:07 AM, Clark Lee <clarkchen900 at yahoo.com.cn> wrote:

>I am using an external STB for composite video and audio input for TV signal. The signal is PAL-DK of China
>>The LiveTV/Record profile are using default settings as RTjpeg, quality 170, etc.
>
>>The video has some annoying problem, as the all the horizantal lines, especiall white lines with black/dark background, seems blinking with a few Hz frequency.
>
>>This problem doesn't exist if I use TvTime to view the signal from the same STB box and capture card. I would say, TvTime's video quality is far better than LiveTV in MythTV. I know that Mythtv is always encoding the incoming signal first and than play it back. However, do I must bear the blinking lines?
>
>>Is this a problem of the RTjpeg encoding or my setup issue?
>
>>I have tried MPEG4 with default soft encoding - turned to be an even worse solution. Is this true?
>
>>Thanks very much,
>
>>Clark
>
It's not the encoding, it's that Myth shows you more of the 'overscan' area.  What you're seeing is data embedded in the signal - in the US it's used for Closed Captioning (subtitles), in your country it may be the same, or for some other data.

But it's a simple fix - setup your system for 2% overscan in myth.
     Utilities/Setup -> Setup -> Tv Settings -> Playback -> Page 2
          Vertical Scaling: 2
          Horizontal Scaling: 2
     Then select "Next" to go through the remaining screens until you get to "Finish" to save the settings.

That should take care of that issue. 

J-e-f-f-A


      
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mythtv.org/pipermail/mythtv-users/attachments/20090912/68151b01/attachment.htm>