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  1. Hello everybody

    I just want to play at a very slow speed an MPEG-2 or MPEG-4 movie and see what kind of frame is the current one:
    • "I" for Intra (independently encoded) frames
    • "P" for predicted (by motion compensation) frames
    • "B" for Bidirectional Interpolated frames

    Or, if such a player doesn't exist, is there a way to re-encode the movie "marking visually" each frame where the mark is a letter "printed" on the picture.

    Thank you very much!
    Falco2000, video newbie.
    Let's everyone help each other.
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  2. Banned
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    Oct 2004
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    New York, US
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    With mpg, open the file directly in VirtualDub and look at the status bar in the bottom of the window. You will see something like this:

    Frame 0 (0:00:00.000) [I]
    Frame 1 (0:00:00.042) [B]
    Frame 2 (0:00:00.083) [B]
    Frame 3 (0:00:00.125) [P]
    Last edited by sanlyn; 23rd Mar 2014 at 11:47.
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  3. Member
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    United States
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    It is not free, but VideoReDo has an option to display I,P,B. You can play the video or frame step the video one frame at a time. VideoReDo is intended to be an editor, but it has a play feature. Version 4 works with both MPEG-2 and H.264. You can try the trial version to see if it works for you.

    A free option would be AviDemux 2.6. It supports both MPEG-2 and H.264. You view the I,P,B at the bottom, like VirtualDub suggested above.
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  4. If you use ffdshow as your decoder it can stamp the frame type (and a lot of other stuff if you want) on each frame as the movie is playing. See it's OSD filters:

    Click image for larger version

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  5. Thank you for your fast answers. I already had installed VirtualDub on my pc so I used that.

    Thank you all very much
    Falco2000, video newbie.
    Let's everyone help each other.
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  6. Thank you to you too Jagabo.

    By the way, just for curiosity, (I hope I'm not talking nonsense), is there a way to see the real visual information of each NON FULL frame (full is type "i" if I understood correctly, so I'm talking about the "b" and "p" frames)?

    I mean, if some frames are only pieces of variations relative to full frames, is there a way to see those partial frames? They will surely look ugly, but I'm curious...

    Or non full frames are just information for the decoder like "move these group of pixels there" so that there isn't any real visual piece of information?
    Falco2000, video newbie.
    Let's everyone help each other.
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  7. Originally Posted by falco2000 View Post
    if some frames are only pieces of variations relative to full frames, is there a way to see those partial frames? They will surely look ugly, but I'm curious...

    Or non full frames are just information for the decoder like "move these group of pixels there" so that there isn't any real visual piece of information?
    It's a combination of motion vectors ("move these group of pixels there") and new blocks of data.

    ffdshow does have the ability to show motion vectors:

    Click image for larger version

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ID:	14121
    Last edited by jagabo; 3rd Oct 2012 at 11:55.
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