Avoiding Screen Burn (1 Viewer)

[CyberSimian]

Yes, it's time for this year's thread about avoiding screen burn. But first, the preliminaries: it is usually claimed that LCD screens do not suffer from screen burn. Not so!

In 2006 I purchased a Toshiba LCD TV with fluorescent illumination. I used it for three years with a Humax PVR connected via SCART; this had some overscan, so there were no black strips around the edges of the picture. Then in 2009 I started using Windows Media Center, connected initially via VGA, and later via DVI. The best fit that I could get (whilst avoiding overscan) left a one-centimeter black strip on all four edges of the picture. About a year later, I discovered how to scale the Windows desktop so that it fitted the screen exactly without overscan. But by then it was too late -- the black strips around the edges of the picture had permanently imprinted themselves onto the screen, with the result that the former boundaries between picture and black strip are now visible when there are areas of plain tone near the edges (such as plain blue sky).

I also use a character-based file-manager on the HTPC. This file manager has quite saturated colours, and if left on the screen for a peroid of time (15-30 minutes), it leaves a ghost image when that window is closed. This ghost image remains visible for several hours (but thankfully does fade eventually).

Recently I purchased a new TV -- a Sony LCD with LED illumination. So the question of screen burn has captured my attention again. The Sony has a very useful "Picture off" function, that simply turns off the LEDs, whilst leaving everything else operating normally. This is ideal for listening to DVB-T radio broadcasts, or listening to music sourced from the HTPC. The problem is that it takes 13 button presses on the remote control to use this function! So, it is not really a practical solution (it needs to be a simple toggle accessed directly from a button on the remote control).

Now we come to MP. I tried enabling MP's "Screen Saver" function, selecting the "blank screen" option with a 30-second timeout. Does it work? Well, yes and no! It actually behaves in two different ways according to what is displayed on the screen:

(1) If I pause high definition live TV, or a recording of HD TV, when the screen-saver activates, the screen blanks and the LEDs turn off.

(2) If I pause standard definition live TV, or a recording of SD TV, when the screen-saver activates, the screen blanks but the LEDs do NOT turn off. This is also the case for the MP panels that do not have video, and the MP panels that play the radio (both paused and not paused).

(3) If the MP panel has a video thumbnail, the screen blanks even when the video is playing, but behaves as (1) or (2) according to whether the video in the thumbnail is HD or SD.

I used the Sony's "Info" display to see what it thought it was displaying, and it showed "1080p" in all cases (video running, video paused, HD, SD).

So it seems as though MP's Screen Saver does something different when displaying HD, compared to displaying SD. Needless to say, I would prefer the LEDs to turn off when the screen is blanked, and hence I would like MP to use the HD action in all situations. Questions:

(a) Is there any explanation for this difference in screen-saver behaviour between HD and SD?
(b) Is there any chance that MP could be altered to use the HD method in all cases?

Thank you.

-- from CyberSimian in the UK

 

[Edalex]

Some new TVs have API to control them from network. Maybe you could check if yours too and code some stuff to emulate those 13 buttons

 

[CyberSimian]

I tried enabling MP's "Screen Saver" function, selecting the "blank screen" option with a 30-second timeout. Does it work? Well, yes and no! It actually behaves in two different ways according to what is displayed on the screen:
(1) If I pause high definition live TV, or a recording of HD TV, when the screen-saver activates, the screen blanks and the LEDs turn off.
(2) If I pause standard definition live TV, or a recording of SD TV, when the screen-saver activates, the screen blanks but the LEDs do NOT turn off. This is also the case for the MP panels that do not have video, and the MP panels that play the radio (both paused and not paused).

I have now discovered what causes this difference in behaviour when MP's screen saver operates, so I thought that I would describe it here for anyone else who has a similar problem.

The difference in behaviour is caused by the Sony TV's "smart" processing. The Sony has the usual settings for controlling the backlight, contrast, brightness, colour, hue, colour temperature, sharpness, noise reduction, MPEG noise reduction, dot noise reduction, reality creation, smooth gradation, motion flow, film mode, plus (of course) the additional advanced settings.

The Sony also supports "scene modes", which are pre-sets for different combinations of the above settings. The scene modes are: General, Cinema, Sports, Music, Animation, Photo, Game, and Graphics. There is also an "Auto" setting that causes the Sony to examine the video stream and select the scene mode that it thinks is most appropriate. This is the problem. My HTPC is set to send 1080p video to the Sony, and this is what happens:

(1) When the video is HD (live TV or recorded TV), "Auto" causes the Sony to select the General scene mode, which results in the LEDs switching off when the MP screen saver operates.

(2) When the video is SD upscaled by the HTPC to 1080p, "Auto" causes the Sony to select the Graphics scene mode, which results in the LEDs remaining powered on when the screen saver operates. This also happens when playing live or recorded radio, or displaying an MP panel. The Sony also selects Graphics scene mode when displaying the Windows desktop.

So the solution is not to use the "Auto" scene mode; instead select a specific scene mode. It is easy to experiment to identify the scene modes which result in the LEDs switching off when the screen saver operates.

-- from CyberSimian in the UK

 

[joecrow]

Hi

I too am concerned about screen burn but when the blank screen option is activated with my Philips TV it responds with a large white text box saying "Not Connected", it does not have a picture off function as far as I know. I regularly play Radio for long periods so would like some kind of screensaver or visualization. I have tried using the MP Photo Slideshow plugin but it does not seem to work with MP 1.12 (no response on the forum so no idea if it is supported) and I have not, to my surprise, had any sucess in finding visualisations for Radio Time.
Any alternatives anyone?

 

[ajs]

Any alternatives anyone?

Turn off display (not TV) on TV.

 

[CyberSimian]

I too am concerned about screen burn but when the blank screen option is activated with my Philips TV it responds with a large white text box saying "Not Connected"

My Humax PVR (a HDR-Fox T2) has built-in protection against screen burn -- if I pause live or recorded TV, after 60 seconds the picture changes to a large digital clock that drifts around the screen. Does your "Not Connected" box have a timeout, so that it displays only for a fixed period of time and then blanks (1-2 minutes, perhaps)?

I regularly play Radio for long periods so would like some kind of screensaver or visualization.

Before I settled on MP's blank screen saver, I also looked for a visualisation or slide-show facility in MP, but did not find one. I think that earlier releases of MP did have visualisation code, but it had to be removed as the owner of that code was no longer willing for it to be included in MP. I don't know whether it worked with DVB-T radio (it might have been only for digital music).

I also at one time used the Windows screen saver, which I set to a small timeout (one minute). The Windows screen saver is different from the MP screen saver. On MP screens that do not have video, the Windows screen saver will operate after the specified timeout, if there is no user input. User input closes the screen saver and returns to the MP panel. In this context, user input includes changing the MP volume using the remote control. In my current setup, I use a separate analogue audio amplifier, and the volume and mute controls on my universal remote control operate the audio amplifier, and do not operate MP. There are various Windows screen savers included in Windows. I like "Aurora", which is included in Vista, but not included in more-recent versions of Windows (but I copied it to a Win 7 installation, and it does work).

I also listen to radio broadcasts via DVB-T, but I did not want to switch on my TV just for the audio (even if the screen was protected by MP's blank screen saver). So I opted for a different solution. I happened to have an old DVB-T tuner box which I no longer used (a Humax F2-Fox T). It is not DVB-T2, and does not have an HDMI connection, so I would not use it for TV. But it is fine for listening to the DVB-T radio broadcasts, with the analogue audio output of the tuner box connected directly to my audio amplifier. The tuner box displays the channel number of the radio station, but I cannot see the EPG with the TV switched off! However, that is OK for me, as I mostly listen to only 2-3 different radio channels.

-- from CyberSimian in the UK

 

[joecrow]

I too am concerned about screen burn but when the blank screen option is activated with my Philips TV it responds with a large white text box saying "Not Connected"

My Humax PVR (a HDR-Fox T2) has built-in protection against screen burn -- if I pause live or recorded TV, after 60 seconds the picture changes to a large digital clock that drifts around the screen. Does your "Not Connected" box have a timeout, so that it displays only for a fixed period of time and then blanks (1-2 minutes, perhaps)?/QUOTE]

You would certainly think it would but I have never seen it move or go out and in other circumstances it has been present for a long while.

I regularly play Radio for long periods so would like some kind of screensaver or visualization.

I also at one time used the Windows screen saver, which I set to a small timeout (one minute). The Windows screen saver is different from the MP screen saver. On MP screens that do not have video, the Windows screen saver will operate after the specified timeout, if there is no user input. User input closes the screen saver and returns to the MP panel. In this context, user input includes changing the MP volume using the remote control. In my current setup, I use a separate analogue audio amplifier, and the volume and mute controls on my universal remote control operate the audio amplifier, and do not operate MP. There are various Windows screen savers included in Windows. I like "Aurora", which is included in Vista, but not included in more-recent versions of Windows (but I copied it to a Win 7 installation, and it does work).

-- from CyberSimian in the UK

That is a really good tip, I had not realised that the audio only sections in MP would trigger the Win. screensaver so many many thanks for that, I have tried it and it seems to work just fine

Thanks again
Joe