x200 Video Playback Issues - Blacks and dark colors break up and show very bad digital artifacts

I am aware of the poor viewing angles, but that is not really my problem. I can live with a sub-standard viewing angle but I am not so sure I can live with this problem. The fact that it seems okay for you, and everybody except mgruenas and myself tells me the technician at EasyServ may have been inaccurate. I find it hard to believe that a new LCD, video card, and/or system board or an exchange for a different x200 would not fix the problem, although that is what he said. I am still waiting for someone from Lenovo (Dan Conti apparently) to contact me in regards to the CMT complaint that EasyServe generated.

 

I spoke with Dan Conti (located at the Memphis repair facility) today and he said he would generate this CMT number for me, and that someone from complaints should contact me tomorrow. Basically they are saying because the display quality did not live up to my expectations, and that it could not be repaired, that the CMT number would be generated. I am not yet sure what resolution I will work out with Lenovo, but I will post back as soon as I have more information.

 

I got an email from April Perkins (Lenovo Exuctive Complaints) about 2 hours ago. She is going to have my x200 shipped from the Memphis EasyServe facility to the Morrisville, NC location (I believe this is the IBM/Lenovo Headquarters and R&D facility in Research Triangle Park, NC). They are going to examine the problem more thoroughly and come up with a solution.

 

Let us know what happens and get all the names and numbers/extensions for the poeple just in case others need to get a hold of one of them to avoid having to go thru someone who doesn't know about the issue..

 

I will index everything and everyone as soon as I have the issue resolved.

In the meantime, this link to the IBM/Lenovo employee directory, might come in handy. It would actually be wise to add it to the Thinkpad Sticky (link it below the tabook). I used this directory to find Dan Conti's number after Easy Serve gave me his name, because things were moving a bit slowly.

 

Any news, Jon? Did you get your x200 back?

 

if u let ur laptop run under de maximum performance mode, this problem will not happen. i have de same phenomenon, and i believe it is de video driver's problem, wait for de new release. my driver ver is 7.15.10.1502.

 

I am still waiting for a reply from Lenovo Headquarters (Morisville, NC). I was checking my email and waiting by my phone all day, but no response as yet.

 

I just got word from April Perkin's this afternoon. She said that the tech verified my problem and I had one of two options "We can replace the LCD to see if that will fix the problem or we can return the machine and you can work with sales to make a new purchase".

I elected to have the LCD replaced, because I believe that will be a faster solution, I am satisfied with the other parts of my x200, and would rather not go through the effort of rebuilding my triple-boot OS if I can avoid it. I will post the results of this fix (better, worse, or same with new screen; I hope it is much better).

 

Bad News!! The replaced my LCD and I still have problems.

Apparently all of the x200 have defective screens. Quote "There is a larger issue here and it's with all of the X200 screens, not just your's. There is only one screen type avaialbe for the X200s [sp] where other models usually have two or three options. The X200s and X200T are not displaying these problems the way the X200 is."

They have offered to either send me my x200 back and let me think about it, or issue me a credit so that I can order a fresh computer. I am going to try and see if I can get the LED screen from the x200s put into my x200 (this will probably cause me to drop the webcam and WWAN upgradeability, and put on a resolution that I consider a bit too large for a 12.1", but I want this problem fixed by any means necessary). By the time I got an email from them they were already closed, so I probably won't hear anything else until Monday. Hopefully this is something I can get resolved on my x200, or I will have to weigh my options for weight/price/performance etc. between my broken x200 and a switch to an x200s or x200t that does not exhibit this problem.

In the meantime, I would recommend against the x200 regular for anyone that puts any importance on video playback. The weight, performance, battery life, build quality, etc. are all amazing, but the screen is seriously lacking and at the moment, there seems to be no known fix to the problem (including swapping out panels).

 

****. Bear in mind that the x200s has no webcam. And the x300/1 doesn't support large hard drives. I may have to ask for a refund. Jon: thanks so much for your work.

 

You can't say d a m n!?

 

I'm right there with you. !!Expletive Deleted!!

The x200t is actually looking pretty good to me right now. It apparently has an IPS LED screen and should provide very good colors and viewing angles. It also includes a webcam, all the ports of the x200, and a WWAN option. The obvious downsides are price (a shade more than the x200s), marginally slower processor, marginally heaver (about 3 ounces more than the x200, 12 ounces more than the x200s [all with max capacity batteries]), and battery life that is not quite as good as the x200s because it's only 8 cells. However, if they can't fix mine, the tablet is probably where I'm going to go, and I doubt I'll use the pen more than one or two times.

 

I just finished dealing with Lenovo executive complaints. They are going to refund me for the x200 because I was dissatisfied with the screen and it could not be repaired (only a single manufacturer, and all have the same problem). I am going to get myself an x200 tablet to replace it.

At its core, the tablet is very similar to the x200. It has the same port selection, add in cards, a comparable (albeit marginally slower clocked and lower TDP) processor, identical keyboard, and feature set. It also has a comparable weight and battery life to the x200 (although admittedly worse than the x200s). The tablet also maintains the full suite of options of the x200, including the camera and WWAN.

The main difference, and to me key selling point, is that the x200 tablet looks like it has a marvelous screen. There are 3 options available, all WXGA (125 DPI), two LED, and one multi-touch. I opted for the frameless LED with active digitizer because it looks to be the best screen of the bunch. It is LED backlit, 285 nits, ultra wide viewing angle, IPS technology, 500:1 contrast, has an outdoor viewable matte finish, and has a WACOM active digitizer built in. This screen is also frameless (blends smoothly into the background), and I think this fixes the one aesthetic failing of the x200 (the giant bezel around the screen). The x200t is more expensive than the x200, but I think if you are really concerned about screen quality (and it appears that I am), then I think it is your best option.

Hopefully, Lenovo will get some secondary sources and/or LED screens for the x200 regular in the future to fix this problem. It should be noted for all others that read this thread. The x200 screen is actually very good for web browsing, document editing, and other office work,and some people seem to be satisfied with it for video playback, although for me (and mgruenglas) it was lacking in this last category.

 

I would have loved to get the tablet version, but I couldn't justify the cost.

I hope you enjoy your new tablet. I'm so envious.

 

PARTIAL SOLUTION/WORKAROUND

Having also run into the same ugly dithering / banding / stripe patterns in the dark areas of videos and photos, I've come up with a partial solution of sorts. The TFT panel in the ThinkPad X200 sadly does appear to be the cheap TN type with 6 bits per color, using extremely poor static dithering patterns for dark colors (luma values 0 to 7-10 out of 255). I've experimented with a bunch of things for a while, and decided to forego using the lower luma range for video playback altogether. That is, I wrote a simplistic video filter to scale luma (brightness) levels from the full range 0-255 to the "safe" range 7-255. Recall that luma value 0 maps to pure black, and luma value 255 maps to pure white. The workaround calculates new brightness level for each pixel via a simple formula:

new_luma_level = (old_luma_level * (new_luma_range_width / old_luma_range_width)) + new_black_level

This does not downright lose the information in the bottom range of luma, rather it scales it up. Dark gray (luma level 7) becomes the new black Size of new dynamic brightness range is 97.2% of the old range, so some visual information is lost at display time, but oh well. I've found the luma cutoff of 7 to be the "sweet spot" for preserving as much dynamic brightness range as possible, while avoiding nasty dithering patterns, but you can play with it. New black is obviously lighter/brighter than the old one, but TFT displays aren't famous for good black levels to begin with. In any case I felt all these to be reasonable tradeoffs.

I did try other software approaches (forcing TV luma range of 16-235, custom dithering, noise/smoothing/sharpening, gamma adjustments), but scaling luma to range 7-255 yielded the best results visually. My background in video processing is very casual, perhaps someone can come up with a better solution. Working on individual color channels could be promising.

I've implemented (actually, quickly hacked this as an HLSL shader for MPC-HC (Media Player Classic - Homecinema). Should also work in KMPlayer ( http://kmplayer.en.softonic.com/), but I haven't tested.

Instructions for Getting the Workaround to Work with MPC-HC

1. Download MPC-HC from http://mpc-hc.sourceforge.net/, extract and configure it according to website instructions.
   
   
2. Search for a file named d3dx9_*.dll under your windows or program files folders, copy it to the same directory as mplayerc.exe (directory to which you extracted MPC-HC in step (1)). If you have a 64-bit edition of Vista or XP, copy the right file (one matching the 32- or 64-bit edition of MPC-HC you downloaded). If you can't find the file, you may need to download and install the latest DirectX End-User Runtime (http://www.microsoft.com/downloads/results.aspx?pocId=&freetext=directx&DisplayLang=en).
   
   
3. In MPC-HC go to View/Options menu. Under Playback/Output tab, set DirectShow Video to VMR9 (renderless), Surface to 3D surfaces (recommended), Resizer to one of Bicubic options. I find resizer Bibubic A=-0.75 (PS 2.0) to be the sweet spot. Uncheck box Direct3D Fullscreen (remove tearing), check boxes VMR9 mixer mode and Lock back-buffer.
   
   (login to a forum.notebookreview.com account to view images)
   
   
   I found that playing H.264 videos via DXVA decoder from PowerDVD 8 doesn't work if I set output to EVR Custom Pres. If you don't use this codec, you can set output to EVR Custom and configure it similarly to the above (or to your taste . EVR Custom may do even sharper stretching of video to full-screen than VMR9 renderless. Support for EVR is out-of-the-box in Vista, but may require jumping through some hoops on XP.
   
   
4. MPC-HC can also help with another problem of X200 - quiet speakers. In MPC-HC go to View/Options menu. Under Internal Filters/Audio Switcher tab, check boxes Enable built-in audio switcher..., Normalize, Regain Volume. Can also play with Boost slider.
   
   
5. In MPC-HC go to View/Shader Editor. In the long tab, whose drop-down lists the names of built-in shaders, type the name of new shader (i.e., X200 regular) and press Enter. In the tab to the right select ps_3_0. In the tab below select the contents, delete them, and copy and paste the following shader source code, then press Enter.
   
   
   Code:

   // Workaround for ugly dithering of dark colors on ThinkPad X200 laptop. Quick hack by zbarsky at cornell dot edu.
   sampler s0 : register(s0);
   
   // luma 0-255 => new_black-255
   #define new_black (7.0/255.0)
   #define multiplier (1.0 - new_black)
   
   float4 main(float2 tex : TEXCOORD0) : COLOR
   {
   	return((tex2D(s0,tex) * multiplier) + new_black);
   }
   

   In the bottom editor tab you should see the message D3DXCompileShader succeeded. Overall things should look like this:
   
   
   
   
6. During playback open Play/Shaders menu. Make sure there's a check against the name of your new shader. If you want, you can toggle the shader off to have the proper black levels during well-lit scenes in the movie, by Toggle Pixel Shader. Note: if there is a check against Toggle Pixel Shader, that means the shader is toggled off (disabled), and vice versa.

I've considered requesting the refund on my X200 and buying another portable laptop, but its other characteristics (CPU power, weight, battery life, price after Christmas and employee discounts are strong, and the aforementioned workaround for video playback made things livable.

Other Notes

Note that you want to apply this luma scaling filter at the very end of video postprocessing chain, after all deblocking/deringing, noising, stretching to full screen, sharpening, etc. It should occur right before feeding final pixels to display. Hence doing it as a shader. Besides, it's also better to let the GPU crunch it rather than loading the CPU. I suppose that the same thing could be done via a setting in one of ffdshow/FFmpeg filters, but I didn't bother.

This shader can also be combined with other shaders. For example, here's the 5x5 sharpening shader from KMPlayer combined with my shader, you can use it in step (5) of the instruction above.

The described approach may also be useful for video playback on other TFT panels with poor dithering of dark colors. If using this shader, you may need to adjust the new_black luma level from its present value of 7, and your graphics card should support Pixel Shaders version 2.0, at least.

This workaround shader is written in HLSL. I think in its present form it will only work on Windows and only in some media players, namely ones supporting custom HLSL shaders. Once I get around to installing Linux on my X200, I'll do something for Linux. The most straightforward thing to do would be to port this shader from HLSL to GLSL (prolly combined with one of the scaling vertex programs) and use it with mplayer, for example. One could also patch the Xorg videocard driver and enable/disable luma scaling at runtime via hotkeys, this would help with all X applications.

Even on Windows the described workaround will work only in applications which had this shader explicitly imported and enabled, i.e. MPC-HC or KMPlayer. It won't help in other apps, i.e. Windows Media Player or other media players, YouTube, Move Player, photo viewing/editing programs, etc. Well, you shouldn't be using TN panels for photo editing anyway ;-)

P.S.: Contact info is in the shader source code.

 

^^^ Holy s**t, that's hardcore! I just got my x200 a few days ago and haven't put it through any of its paces, but if I have a problem, I'll certainly look into this. Thanks for the effort!

 

Another way you might archive essentially the same thing would be to go into the GMA control panel and increase the brightness by 7. This does push the worst of the dithering away, but makes for a more washed out screen. You can of course toggle between 7 and 0 if you like and then use whatever media player you like, but dithering is inherent in this panel, if it is 6 bit as it seems then there is no real way around it.