Overscanning on HDTV via DVI with Mac Mini

[bck3]

I have a really important question and would SO grateful to anyone who can help:

I have a Mac Mini and an HDTV, a Panasonic 47 inch projection screen. I have it hooked to the HDTV through the DVI connection, but I am experiencing significant overscan - all edges are off the screen by a considerable degree. This is may be some limitation of my television. I have been searching the web for solutions, and on the mac, it seems there exist a couple applications which allow for the creation of "custom resolutions" - two of which are "SwitchResX" and "DisplayConfigX."

I am not sure how to configure an application like this. Any time I tried a custom resolution either the problem remained or the screen went black! I could not revert back, and everytime I restarted the Mac Mini would go back to the poorly chosen resolution and make my HDTV go black. I was able to hook it to a Dell monitor but when I hooked it back to the HDTV it was again black. I had to reinstall my OS just to get it back to default - even resetting the PRAM hadn't worked! Also worth noting, my television does not have settings to shrink the screen or anything like that.

Does ANYONE have any way of helping me with this significant OVERSCAN? I would reward anyone who can provide a practical step by step solution. There are many individuals out there experiencing similar problems and who cannot enjoy their Mac Mini in a way they originally anticipated being possible.

Kind regards,
Bradford

[sooke]

Well, I'm not familiar with those apps, but is there a zoom mode on your TV specifically for connection to a PC? You might want to check. My Samsung RPTV has a zoom mode for the DVI input for exactly this purpose. It scales the picure down a little so that the whole desktop can be seen on-screen.

Sooke

[coldengray]

sorry, just realized I didn't answer your question

[TWinbrook46636]

What is the model number of your Panasonic? Could this be a common occurance with CRT based HDTV displays?

[jsb_hburg]

Originally posted by bck3
I have a really important question and would SO grateful to anyone who can help:

I have a Mac Mini and an HDTV, a Panasonic 47 inch projection screen. I have it hooked to the HDTV through the DVI connection, but I am experiencing significant overscan - all edges are off the screen by a considerable degree. This is may be some limitation of my television. I have been searching the web for solutions, and on the mac, it seems there exist a couple applications which allow for the creation of "custom resolutions" - two of which are "SwitchResX" and "DisplayConfigX."

I am not sure how to configure an application like this. Any time I tried a custom resolution either the problem remained or the screen went black! I could not revert back, and everytime I restarted the Mac Mini would go back to the poorly chosen resolution and make my HDTV go black. I was able to hook it to a Dell monitor but when I hooked it back to the HDTV it was again black. I had to reinstall my OS just to get it back to default - even resetting the PRAM hadn't worked! Also worth noting, my television does not have settings to shrink the screen or anything like that.

Does ANYONE have any way of helping me with this significant OVERSCAN? I would reward anyone who can provide a practical step by step solution. There are many individuals out there experiencing similar problems and who cannot enjoy their Mac Mini in a way they originally anticipated being possible.

Kind regards,
Bradford

When I had a Mits CRT RPTV, I had to keep a computer monitor nearby which is much more forgiving when setting up custom resolutions. Have you tried the current RPTV forum here or the archived RPTV forum here and search for your model number and service menu to adjust for overscan?

Out of curiosity, do you have aspect control over DVI on your set? On my DLP, I have an aspect button that allows me to change the screen from normal to expand to panorama, etc? Have you checked this out on your set?

On my Samsung DLP with my Wintel, I achieved 1:1 pixel mapping at 1248x702 but I had to change the aspect from Wide(TV) to Normal. I have a Wide(PC) aspect which reduces the overscan but without 1:1 pixel mapping. Please see if aspect change is an option for your set.

Are you using SwitchResX?

[rcliff]

One piece of advice that may help a lot when doing this...

If you have a second computer anywhere on your LAN, you can use VNC or Timbuktu to remote control the Mac Mini. You should then be able to try various custom resolution settings until you're happy with the results without fear of losing control due to lack of video.

[jgeorge]

Bradford,

I'm in the same boat as you. I've hooked my Mac Mini to my Toshiba 57HDX82 and the overscan is horrible. The Mac Mini is the first device that I've been able to connect to my Toshiba via DVI and get a usable display. 720p XBox games have the same issue. After I had my tv for awhile, I had a tech come out to calibrate it. Unfortunately, when we corrected the overscan the geometry was too distorted.

I've tried VNC and it helps, but I soon as I start to run a video or dvd the vnc client crashes.

Joe

[bck3]

Thank you all for replying to my original post - the more information people in my situation have about this problem the better!

Allow me to clarify a few things:

My Rear Projection CRT-based 47" HDTV television is the Panasonic PT-47WX53, which I understand is a very popular model. It has now been replaced in the last year by newer LCD based rear projections most likely.

There is no option in the settings menus to "shrink" or "shift" the picture for a given video input. There is an aspect button on the remote, which allows you, more or less, to change between "Full / 4:3 / and Zoom" for any given video input, including the Digital DVI connection. I have tried each of these, and none of them are satisfactory. Only the 4:3 setting will shrink the image sufficiently so I can see the left and right edges; the top and bottom remain off the screen. I know that have to create or tweak an existing resolution on the computer-side that will be compatible with the screen.

The BIGGEST problem right now is that I'm trying to alter numbers in the program I am using, "DisplayConfigX," but do not know precisely what I'm doing. It is the same concept as SwitchResX - however with SwitchResX when I would create a faulty resolution and the screen would go black, I couldn't figure out how to revert back. DisplayConfigX just allows the creation of custom resolutions, allows one to "install" them to the system, and all the resolutions appear in the Displays control panel, where it is much easier to revert back in the case of a TV blackout.

The reason I think I'm getting so many blackouts is because I do not know precisely what my TV can accept.

First, here is all the information DisplayConfigX requires from the user:

- It wants the following information so it is tailored specifically to my television:
- Range of Refresh Rate (in Hz)
- Range of Horizontal frequency (in KHz)
- Pixel Frequency (in MHz)
- Native Resolution (i.e. something like 1024:768)
- Default Refresh rate (in Hz)

(Ok, first of all, I don't know any of this information, none of it is found in my TV menus nor in my TV instructions)

- When you are creating custom resolutions (or display timings) as they are called, it asks for the following:

- Horizontal Active (in pixels)
- Horizontal Front porch (in pixels)
- Horizontal Sync (in pixels)
- Horizontal Back porch (in pixels)

- Vertical Active (in pixels)
- Vertical Front porch (in pixels)
- Vertical Sync (in pixels)
- Vertical Back porch (in pixels)

- Pixel Frequency (in MHz)
- Horizontal (in KHz)
- Refresh rate (in Hz)

That's everything - by inputting correct figures in these fields, you are supposed to have yielded a new custom resolution that you can then import into your display control panel and upon a restart make active. Of course, any that I ever create result in a black screen on the TV (as if it didn't like the refresh rate or horizontal frequency I chose).

Then, I happened upon this information, reported by another user in another forum regarding what I believe is the same TV I have:

_________________________
RE: GeForce 5200 & Panasonic PT-47WX53
Thanks for looking at this. Here is the info on the monitor.

Monitor
Windows description......... Plug and Play Monitor
Manufacturer description.... PANASONIC-PT
Manufacturer................ Panasonic
————————————————————————————
Plug and Play ID............ MEI3400
Serial number............... 82000000
————————————————————————————
Manufacture date............ 2003, ISO week 30
EDID revision............... 1.3
Display type and signal..... Digital
Sync input support.......... (n/a)
Screen size................. (n/a)
Power management............ Not supported

Color characteristics
Display gamma............... 2.20
Red chromaticity............ Rx 0.649 - Ry 0.336
Green chromaticity.......... Gx 0.290 - Gy 0.594
Blue chromaticity........... Bx 0.140 - By 0.064
White point (default)....... Wx 0.277 - Wy 0.282

Timing characteristics
VESA GTF support............ Not supported
Horizontal scan range....... 15-34kHz
Vertical scan range......... 59-61Hz
Video bandwidth............. 80MHz
Timing recommendation #1.... 1920x1080 at 30Hz
Modeline................ "1920x1080" 74.250 1920 2008 2052 2200 1080 1084 1094 1124 interlace +hsync +vsync
Timing recommendation #2.... 720x480 at 60Hz
Modeline................ "720x480" 27.000 720 736 798 858 480 489 495 525 -hsync -vsync

Standard timings supported
720 x 480 at 60Hz - Panasonic
1920 x 1080 at 30Hz - Panasonic

Raw EDID (1)
00: 00 FF FF FF FF FF FF 00 34 A9 00 34 00 00 00 82
10: 1E 0D 01 03 80 00 00 78 0A 44 E1 A6 56 4A 98 23
20: 10 47 48 00 00 00 01 01 01 01 01 01 01 01 01 01
30: 01 01 01 01 01 01 01 1D 80 18 71 1C 16 20 58 2C
40: 25 00 10 09 00 00 00 9E 8C 0A D0 8A 20 E0 2D 10
50: 10 3E 96 00 10 09 00 00 00 18 00 00 00 FC 00 50
60: 41 4E 41 53 4F 4E 49 43 2D 50 54 56 00 00 00 FD
70: 00 3B 3D 0F 22 08 00 0A 20 20 20 20 20 20 01 1A

Display adapter
Adapter description......... NVIDIA GeForce FX 5200
Adapter device ID........... 0x032210DE
Display settings............ 640x480, 8bpp

_______________________

It appears as if this user's graphics card, an NVIDIA GeForce FX 5200, is clearly different than the Mac Mini's ATI Radeon 9200, but does this provide any information about my television's settings?

What I need is to make sense of what values to input in order to yield an acceptable set of values compatible with my Panasonic HDTV...

I welcome anyone with that level of expertise to chime in on this forum to share your knowledge for us 'dummies.' Again, I know there are many experiencing similar problems with overscan, but I'm sure we can solve it!

Regards,
Bradford

[bck3]

One correction:

DisplayConfigX asks for all the horizontal values of active, front porch, sync, and back porch (which are all in pixels). Also, it needs the vertical values of active, front porch, sync, and back porch (but they are all measured in 'lines', not pixels).

Brad

[rcliff]

Have a look in this thread. It may help you understand the timings better

http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=206854

[Sport73]

My settings in DisplayConfigX on my Hitachi 50VS810:

Create a new Timing.

Horizontal settings:
Active: 1184
Front Porch: 112
Sync: 112
Back Porch: 208

Vertical Settings:
Active: 685
Front Porch: 10
Sync: 3
Back Porch: 35

Refresh Rate set to 60.015.

[jdryyz]

[QUOTE=bck3]I have a really important question and would SO grateful to anyone who can help:

I have a Mac Mini and an HDTV, a Panasonic 47 inch projection screen. I have it hooked to the HDTV through the DVI connection, but I am experiencing significant overscan - all edges are off the screen by a considerable degree. This is may be some limitation of my television. I have been searching the web for solutions, and on the mac, it seems there exist a couple applications which allow for the creation of "custom resolutions" - two of which are "SwitchResX" and "DisplayConfigX."

I am not sure how to configure an application like this. Any time I tried a custom resolution either the problem remained or the screen went black! I could not revert back, and everytime I restarted the Mac Mini would go back to the poorly chosen resolution and make my HDTV go black. I was able to hook it to a Dell monitor but when I hooked it back to the HDTV it was again black. I had to reinstall my OS just to get it back to default - even resetting the PRAM hadn't worked! Also worth noting, my television does not have settings to shrink the screen or anything like that.

Does ANYONE have any way of helping me with this significant OVERSCAN? I would reward anyone who can provide a practical step by step solution. There are many individuals out there experiencing similar problems and who cannot enjoy their Mac Mini in a way they originally anticipated being possible.

Kind regards,
Bradford[/QUOTE]


Bradford,

There is a setting in the Mac OS X Displays preferences ("Options" button) where you can turn off the Overscan. I had the same problem as you with my Sony KDP-57WS655 connected via DVI-HDMI cable. When overscan is disabled, it had the side-effect of creating a small border around the entire image, but for the purposes of testing, it looks fine.

Unfortunately, I am only able to output 1280 x 720 resolution. The funny part is, 1920 x 1080 (interlaced) appears as an available resolution in the Displays preferences, but all I get is a black screen when I select it. I suspect this may be due the Mini actually outputting a progressive signal instead of interlaced. I know my Sony can't handle 1080p.

Is anyone else out there using a similar setup to my own? It would be neat to use DisplayConfigX to get someting higher than 720p out of the mini but I'm leary of playing with the settings.

I do not intend to keep my 2nd gen Mac Mini hooked up in this manner very long because it actually lives in another location, but from I've seen today, a next generation Mac Mini will be here soon. I know its only a matter of time before DVR capability arrives (Front Row 3.0?).

Jeff