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  1. Member
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    How do I find out the exact duration of a portion of a DVD so I know the file I rip matches it perfectly?

    Using DVD Decryptor, it tells me a video is 42:30.12, but when I rip a VOB and load it into VirtualDub, it says the length of the video is 43.32.850. Worse, the audio is 42:32.553. I don't know why. KMPlayer also says the video is 42:30, not 42:32. What am I supposed to believe? When VirtualDub is "parsing" does it change the length? I always assumed I could trust DVD Decryptor to give me a perfect duplicate. Now I don't know.

    GSpot says the file is 41:38.287! That's completely different!
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  2. Mod Neophyte Super Moderator redwudz's Avatar
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    Different programs read file lengths differently. VOBs are fairly complex, with chapters, subtitles, possible multiple languages, and formatting information. The second problem is video files need to be cut on keyframes (I frames), otherwise many editors will just revert to the nearest keyframe. That can cause inaccurate reading of lengths. Though you are unlikely to find them in a VOB or MPEG, variable rate video or audio will also cause problems reading the duration of a file.

    I usually extract the MPEG out of the VOB and just use that. That should also give you a more accurate reading of the length.
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  3. Member
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    How do I do that?
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  4. Member yoda313's Avatar
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    vob2mpg should do the trick.
    Donatello - The Shredder? Michelangelo - Maybe all that hardware is for making coleslaw?
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  5. Make a D2V project file using DGIndex and use it in an AviSynth script together with DGDecode. Open that in VDub(Mod) and get the length. It's the only sure way, as far as I know.
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    Too complicated for my skills. I can't deal with AviSynth.
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  7. Member
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    Okay, I watched the DVD in Windows Media Player (shudder to think), and it does say 42:30. So I guess for whatever reason, DVD Decryptor's estimate was wrong (and KMPlayer is pretty wonky with the timecode anyway).

    But the audio being shorter is still a problem. Should I select "change so video and audio durations match" in VirtualDub? I mean, is the audio the more accurate length, or is the video the more accurate length? Should I change the video or should I change the audio? I think I should change the audio, but I'm not sure of the best way to do that. It's only a fraction of a second off.
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  8. Member
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    Media Player Classic Home Cinema is the only free media video player listed here that gives me accurate results. Although it only displays in seconds, you can right-arrow and count the frame #'s. It's been good enough, even for finding end credits point to reduce bitrate. But, you have to use the first .IFO "VIDEO_TS.IFO" and then navigate to the title you want [.VOB's and "VTS_01_0.IFO" etc are not accurate]. StaxRip has a nice, seemingly accurate, preview. I'd like to try Elisa media center, but it keeps crashing, or maybe there are some other encoder tools that will easily give frame # or milliseconds in preview.
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