video - VLC + Windows 7 = Pixelated playback?

24
2013-08
  • fish

    I'm running a freshly installed Windows 7 Professional (not RC or beta, and not illegal stuff). I installed my usual software, and I was surprised to see that VLC video playback is pixelated when resizing the video. I tried the video output, and one of them seemed to work OK (maybe direct X output), but that disabled aero, which is ugly. I have an nvidia Geforce 8500GT with 512MB RAM on it. Can you guys help me out? Vlc is a must :)


    I tried all of the video output modes, and none of them worked. Reinstalling neither. Any ideas?

  • Answers
  • fish

    I have found a forum topic on VideoLAN forums. This is a well-known bug, and the devs say it is a bug in the drivers, not in VLC. Smelling some arrogance there, I might switch to GOM Player.

  • Bundy

    I switched from VLC to the MPC bundle ( CCCP ) much better in my opinion I'll never use VLC again

  • Imran

    Using OpenGL Video Output from Preferences->Video solved the problem for me. All other options were giving me pixelated output. It doesn't disable Aero (I'm using Radeon HD4670 with 9.6 Catalyst drivers)

  • Charlie Salts

    I've had a similar problem with VLC, except I was using Windows XP. My solution was to reinstall VLC - I think there was a config file that got buggered. Maybe this will work for you as well.

  • Synetech

    The problem isn’t VLC, or even the drivers; it’s Windows, or to be more specific, Aero.

    In Windows XP, the hardware-accelerated overlay surface of the video-card was not used by Windows, and thus was free for programs to use to write data directly to the video card’s output. (Have you ever tried to get a screencap of a video and gotten a black rectangle when you pasted it? That was because you captured the overlay surface, not the actual video.)

    In Windows 7, the Aero interface occupies the overlay surface to do its extensive fancy looking graphics and transparencies without slowing the system to a crawl. As a result, other programs cannot use the overlay (most video-cards only have one), and so videos have to resort to using software-rendering (eg using the CPU instead of GPU) to display the video instead. (Presumably, switching the screen into a full-screen mode, an app can use the overlay, though Alt-Tabbing to the desktop would then cause problems or at the least a delay as the video-card’s drivers are switch. Of course this is just theory, I have no actual evidence of programs using hardware-acceleration while Aero is running.)

    As you discovered, the software-rendered display looks fairly different from the accelerated display. You also figured out that you can use the Direct-X output module to use acceleration, but that requires disabling Aero. Imran mentioned using OpenGL, but that is also a software-rendered module.

    So here’s the scenario when viewing videos in Windows 7. You have a two basic choices:

    1. Disable Aero and use either a Windows Basic or Windows classic theme, but gain hardware-accelerated video.
    2. Keep Aero and use OpenGL (or other) output modules in your video player to render them in software. If you pick the default one, it will not look as good, but if you pick one that looks better (eg blending, smoothing, etc.) it will use more CPU.

  • Related Question

    Winamp has slow /skipping video playback on Windows 7
  • Roy Rico

    I have Windows 7 x64 (7600 90-day trial version) and Winamp 5.6 installed. When I play a video in Windows Media Player, the video plays smooth, however when I play a video in winamp, the video is mostly ok when played back at the original size (but not completely), but if I play it back in fullscreen, the playback gets really slow. The video's audio track plays just fine.

    I have a DELL XPS 420 computer (8GB of RAM) with a Nvidia GeForce 8800 CTS 512 video card. I've updated to the latest drivers. I have the default Windows 7 codecs, and the CCCP codec pack which used to be all I needed under Windows XP to play all types of videos. Are the codecs needed for Windows Y the same? What's going on?

    UPDATE:

    As suggested, I turned off Aero and winamp ran just fine again. So I just have to wait for winamp to be rewritten to work with the way Vista/Windows 7 runs?

    UPDATE 2:

    Winamp has updated their player, and it works great with Windows 7 now.


  • Related Answers
  • ted_j

    It's not necessarily the codecs, could be the implementation of how Winamp displays video frames. If it's using old-school 2D pixel updates than moving from a small output window to a large full screen window dramatically increases the number of pixels being written.

    Similarly, are you going "full screen" or "maximized window"? These are two discrete concepts, the latter probably means that too many pixels are being written.

    If you set VLC to not use the Direct3D display mechanics the performance for it goes to poo also. Checking to see what options Winamp has here would be appropriate.

    If the video plays okay in Windows Media Player than it's probably not the codecs, as IIRC WMP and WinAmp use the same codecs at runtime ( VLC has them built in ).