HDMI, VLC and WMP (and how Aero can ruin almost everything)

I have not had a TV in about 9 years, and for good reason (at least good reasons for me). Even when coming to the US and the possible exposure to hundreds of TV channels by getting Comcast or AT&T U-verse hooked up, the possibility did not sound that appealing to me. Knowing myself, I would just randomly watch shows just for the sake of it—and waste my time with watching too much TV. So I decided to just consume my daily dose of information through the internet, with the occasional video that I watch on my laptop screen.

Recently though, I started watching more and more video online, especially on services like Hulu, news videos through CNN video or catching one or the other hockey game through the means of online streaming. Doing all this and watching it on the 15 inch laptop screen is fine for a while, but I felt like it is time to upgrade. Especially if you have guests over and you wanna share the viewing experience. So I set a budget of around five hundred dollars and decided on a Panasonic Viera 42 inch plasma TV from BestBuy, equipped with two HDMI inputs so I would be able to hook up my Dell laptop (running Windows 7 Professional) to the TV to enjoy watching videos on the big screen. That is why, together with the TV, I also invested in a 12ft long HDMI cable by Rocketfish.

So far so good.

However, after hooking up the laptop to the TV, I noticed certain issues manifesting on the TV screen.

Window artifacts and flickering

First, when setting up the desktop in a way that it would extend to the TV screen, I noticed that when I dragged a window over to the TV, the window (e.g. windows explorer) would start to flicker. When moving the window further, certain artifacts would remain at the previous position of the window (see screenshot). That was not really that much of a big deal, as playing back windows through the browser, either through Netflix, Hulu or any other online source.

Flash/Browser playback OK, media players not

Despite the issues mentioned above, all the videos I watched through the browser were coming through great. No matter if I played them through Netflix, or watching a TV series episode on Hulu, the quality was always great, no flickering nothing. It got really bad however as soon as I started up VLC or Windows Media Player (WMP).

As soon as I would play back a video file (no matter which codec, I tried DivX as well as Xvid, as well as playing back a DVD) in VLC, no matter if on the laptop desktop or the TV screen, I would get flickering colored dots across the video image. If set to full screen, the dots would turn into thin black horizontal and vertical lines (maybe 200 to 300 pixels long), flickering across the video image.

I observed almost the exact same behavior with WMP, except that the image looked fine on the laptop screen, but as soon as I would play back the same video on the TV screen, I would see the flickering lines again. Obviously, this experience was suboptimal and defeated the purpose of having an HDTV.

Cable too long? Wrong codec? Outdated drivers?

I had a couple of ideas what the issue might be. While doing some lengthy research on Google, people were suggesting that the HDMI cable might be either too long or faulty, possibly related to a false HDCP handshake. Other people who had similar problems were able to fix things by uninstalling and reinstalling video codecs. A lot of other frustrated computer users on the other hand thought that outdated video drivers or BIOS might be the culprit. Based on that info I tried all of the following.

  • Uninstalling and re-installing VLC
  • Installing the Windows 7 Codec Pack, as it was recommended on one site I found
  • Changing the output resolution (the TV resolution was set to 1920 x 1080, at 60Hz and 32-bit of color depth)
  • Updating the driver of my nVidia GeForce graphics card
  • Updating the BIOS to the most recent revision

None of it helped. The last thing that I had wanted to try is switch out the HDMI cable for a different one and see if that does anything. But thankfully, I did not come to that.

After some more research and almost giving in to the fact that the cable must be the issue I found another site that was suggesting that Windows Aero is often the issue for many video playback problems on Windows 7. So I turned it off by selecting one of the Windows Basic themes…and bingo, that fixed the artifacts problem. I was now able to drag windows around without any lag, flickering or remaining artifacts on the TV screen. Only downside is that if you disable Aero, you don’t get the fancy effects like transparency on windows. One may or may not care about that (I know I don’t).

Still the flickering black lines when playing back video in a media player remained. A search on one of the VLC forums revealed a fix for that. One suggestion there was to change the video output mode of VLC from ‘Default’ to something else. And low and behold, when I selected ‘Windows GDI video output’, the flickering vanished and the video playback on the TV started working without any flaws.

While it is certainly satisfying being able to fix issues like that by myself, I wish that sometimes things would ‘just work’ without having to sift through tons of online forums to find hints to these problems…