command line - VLC to put 2 videos together, output video has glitchy playback and seeking

24
2013-08
  • A.M.

    I am trying to put two videos together (one after the other) using VLC. I did manage to get an output video with both original videos concatenated(That was hard enough to figure out!), but the output video has playback (at least in VLC) that is seriously wonky.

    I can tell that both videos are there, but:

    • there are long pauses in the video (though it looks like eventually all video is shown),
    • the audio also cuts in and out (and it looks like not all audio is played), and
    • when the video is not showing, the time seek bar is stuck, and sometimes it is stuck even when there is video playing.

    (How can so much go wrong with such a simple operation? I could understand it maybe messing up playback of just the second video, but the output file is very broken.)

    This is what I did:

    1. Place copies of the original videos in the same folder as vlc.exe
    2. Run the Command Prompt with "Run as administrator"
    3. Run this:

      vlc out-3.ogv out-4.ogv --sout=#gather:standard{access=file,mux=ogg,dst="D:\concat.ogv"} --sout-keep

    How can I get a more usable output file?

    (From looking at many different websites, it looked to me like concatenating two videos is not possible from within the actual VLC GUI, and can only be done from the command line, but I would be happy with an answer for either, of course!

    I would also be happy with some way of just fixing the video I already have.)

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    video - VLC + Windows 7 = Pixelated playback?
  • 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?


    • Related 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.