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Seeking through videos in VLC = Blocks everywhere!

Gotcha ForceGotcha Force Registered User regular
edited September 2007 in Help / Advice Forum
So im using VLC because it can handle a lot and is fast, but lets say i seek to any point of a video (15 minutes in or something), VLC seems to barf on itself because immediately i am met with a bunch of blocks of picture everywhere/HUGE macroblocking and really ugly video artifacts. It takes about 3-5 seconds to go away and sucks. What is the cause of this?

I would just use windows media player or MPC or whatever, but all of those reset the volume whenever i seek, so if i have it at halfway down, then suddenly the video is blasting if i go to the middle of a tvshow or whatnot (this also happens with music).

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    OrganichuOrganichu poops peesRegistered User, Moderator mod
    edited September 2007
    I can't help except to tell you this isn't a freak issue. I've been wondering about this, too, as it happens to me.

    Organichu on
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    iTunesIsEviliTunesIsEvil Cornfield? Cornfield.Registered User regular
    edited September 2007
    Disclaimer: I'm not really *positive* this is what's happening, but from my understanding of VLC, video encoding, video decoding, and video display it's what I've come up with. :)

    It kinda depends on the video and what it was encoded with/as. VLC has problems decoding some formats as they primarily rely on their internal implementation of specific codecs that they've had to reverse-engineer. Basically what you're seeing is VLC going "trying to play, trying to play, oh shit we're skipping around, try to catch up, try to catch up, buffer, buffer, ok trying to play again..." etc. It's kinda sending bad data to the video buffer because it's busy trying to catch up with where you're going.
    I would just use windows media player or MPC or whatever, but all of those reset the volume whenever i seek, so if i have it at halfway down, then suddenly the video is blasting if i go to the middle of a tvshow or whatnot (this also happens with music).
    And as a side-note I have never had MPC do this to me. I wonder if it's something specific that you're watching... I use MPC to play almost everything and have had it playing almost every format I can think of without seeing that kind of issue...

    iTunesIsEvil on
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    blincolnblincoln Registered User regular
    edited September 2007
    It might be a function of the codec and/or encoding options too. If there is only a keyframe e.g. every 120 frames, it can take (in that case) up to four seconds before the playback hits a keyframe that will redraw the whole screen instead of just the difference between the last and current frames. I used to see that a lot with MPEG 2 videos. I assume that some players will grab the previous keyframe every time you seek to avoid the problem, which is maybe why you don't see it in MPC.

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    EchoEcho ski-bap ba-dapModerator mod
    edited September 2007
    It takes about 3-5 seconds to go away and sucks. What is the cause of this?

    Keyframes.

    A keyframe is where the movie stores the entire image. Then it'll just store what changes between frames, until it hits a new keyframe.

    So when you forward through the movie and hit something between keyframes VLC will just show the data in that frame and what changes until it hits a keyframe and gets fresh image data to work from.

    Echo on
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    LewishamLewisham Registered User regular
    edited September 2007
    Echo is exactly right. Thread over.

    Lewisham on
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    Prof. AwesomeProf. Awesome Registered User regular
    edited September 2007
    So im using VLC because it can handle a lot and is fast, but lets say i seek to any point of a video (15 minutes in or something), VLC seems to barf on itself because immediately i am met with a bunch of blocks of picture everywhere/HUGE macroblocking and really ugly video artifacts. It takes about 3-5 seconds to go away and sucks. What is the cause of this?

    I would just use windows media player or MPC or whatever, but all of those reset the volume whenever i seek, so if i have it at halfway down, then suddenly the video is blasting if i go to the middle of a tvshow or whatnot (this also happens with music).
    I switched to media player classic with CCCP from VLC and I don't have any of these problems.

    Prof. Awesome on
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    EggyToastEggyToast Jersey CityRegistered User regular
    edited September 2007
    Echo's answer is also why VLC is so speedy. Other players will put a slight delay into the video when you click to seek, as it looks for keyframes around where you are and interpolates in order to determine everything it needs for the video at the spot you're at. VLC doesn't -- it just starts playing.

    It's something you could look to fix on videos you create yourself. It's not worth it to fix on videos you download.

    I've never had a player reset the volume while seeking, though. Windows Media Player (not sure about classic, I use the latest version just in a classic skin) retains its volume settings even between files.

    EggyToast on
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    Gotcha ForceGotcha Force Registered User regular
    edited September 2007
    Windows media player and MPC didnt used to reset the volume on my old comp, but it does on my new computer. VLC and winamp somehow make it so the volume doesnt reset.

    Also does anyone know a good interface for VLC, and how to make it permanent? The interface for VLC is just ATROCIOUS, and i want something more like every other media player out there (good volume control, a seek bar that doesnt have invisible preset locations all over the place.. ugh)

    Gotcha Force on
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