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  1. I have a video and audio file both showing up as 2:18:12. The audio/video is in sync for what it seems to my eyes and ears is in sync at the start. By the end of the mix the audio is ahead of the video by 500 ms.

    I tried to do different stretching and delay... but it makes everything worse.

    What is the best way to sync them.
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  2. aBigMeanie aedipuss's Avatar
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    make a new version of your own. fixing someone else's mistake on a sketchy video isn't worth the effort.
    --
    "a lot of people are better dead" - prisoner KSC2-303
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  3. The event is done and I have a video that starts out great ends like garbage. I can't tell my kids coaches to set up the game again and tell them to do and say everything exactly the same. I recorded it on a canon vixia.

    I was able to pull the video and audio from the file using iMovie. They are the same length. I am using vmktoolnix to try to get them to align.

    I don't want to split it up into a bunch of clips and then arrange everything to line the audio and video up.
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    Is this the video as it comes out of the camera or is the result of some conversion?

    Is there a glitch somewhere in the video at which it goes out, or does it gradually drift and get worse the further you go?
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  5. Originally Posted by tunerX View Post
    I was able to pull the video and audio from the file using iMovie. They are the same length. I am using vmktoolnix to try to get them to align.
    What format is the source video? Why do you want to convert it (goal)? Why did you use iMovie - is MKVToolNix not able to open the file directly?
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  6. I took the SD card out of my camera put it in my mac then imported the video into iMovie so I could cut it into clips and upload to vimeo. The source video is in an AVCHD container on the SD card. The video inside the AVCHD is .mts.

    If I play it on the camera it is out of sync too.

    I have never had this problem with the camera before. But this is the first time I have ever recorded something this long.

    It starts out in sync then gradually drifts towards the end of the movie.
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  7. Mod Neophyte Super Moderator redwudz's Avatar
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    Usually the 'easy' way is to use a audio editor like Audacity to change the audio length. Audacity does have a Mac version.
    Audacity may also show you if you have a dropout in the signal by examining the waveform.

    Gradual drift of sync is usually an error with a difference of the length of the audio or video,
    but can also be dropouts of signal with either, or a combination of both.

    I often record video events on a micro SD card of eight hours or more with no sync problems.

    And you might mention what camera you used for recording, just for general information.

    And welcome to our forums.
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  8. I went back to using mkvtoolnix and stretch. It took me a while to figure out what values to put in but I was able to stretch the video and made two copies one which was 250ms and one that is 500ms shorter and the audio is pretty much aligned at the spots I want to clip.

    Canon VIXIA HF R70.
    Last edited by tunerX; 9th Feb 2018 at 10:53.
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  9. Member
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    I'm having the same situation so I thought I may as well post in this thread.. For a long time I've been encoding bluray movies for a while and I usually don't get any problems. I use a combination of avisynth and MeGUI.

    I'm currently having an issue with Back To The Future 1 on bluray. Basically if I just mux the source audio and video together its fine, but as soon as I encode the audio it goes out of sync and it goes more and more out of sync as the movie goes on. I've tried things like FFAudioSource, NicDTSSource and LWLibavVideoSource. I've also tried all the "preferred decoder" options in MeGUI. None of these things worked.

    My guess would be it's because the "framerate" for the audio is incorrect. Perhaps it thinks its the PAL "framerate" rather than the NTSC. Any suggestions and if so how would I type it out in a script?
    Last edited by WAusJackBauer; 14th Feb 2018 at 03:52.
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  10. Mod Neophyte Super Moderator redwudz's Avatar
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    Have you checked it with MediaInfo? Maybe a variable framerate problem with the video?
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  11. Member
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    Originally Posted by redwudz View Post
    Have you checked it with MediaInfo? Maybe a variable framerate problem with the video?
    Yep just checked, 23.976 (24000/1001) FPS and constant
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  12. Member Bernix's Avatar
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    Can't be there duplicated frames when frames are dropped? So video has same duration as audio? Probably someone capture it (badly) and then encode at 24000/1001 constant framerate?
    So try open in some editor : Avidemux, Virtualdub and go frame by frame if there are not duplicates. Probably wrong idea but I would definitely try it.

    Edit: if at end just 500 ms there will be very few duplicates if any... it is 12 frames in whole video...
    Probably good to shift audio on start bit to at the end is just 250ms which is better than 500ms.

    Bernix
    Last edited by Bernix; 14th Feb 2018 at 07:37. Reason: EDIT and edit again
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  13. Member
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    Originally Posted by Bernix View Post
    Can't be there duplicated frames when frames are dropped? So video has same duration as audio? Probably someone capture it (badly) and then encode at 24000/1001 constant framerate?
    So try open in some editor : Avidemux, Virtualdub and go frame by frame if there are not duplicates. Probably wrong idea but I would definitely try it.

    Bernix
    This is ripped straight from the bluray disc, it hasn't been touched.

    I don't have those programs installed, are they pretty straight forward?
    Last edited by WAusJackBauer; 14th Feb 2018 at 07:41.
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  14. Member Bernix's Avatar
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    Avidemux is very simple, open it and if you have trouble with something ask. I suggest you shift audio by 250 ms in opposite way. Everything set to copy just shift autio.

    Bernix
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    Originally Posted by Bernix View Post
    Avidemux is very simple, open it and if you have trouble with something ask. I suggest you shift audio by 250 ms in opposite way. Everything set to copy just shift autio.

    Bernix
    Are you sure that will work seeing as the audio goes more and more out of sync as the movie goes on?

    EDIT: I have 64 bit windows but pretty much everything I install is the 32 bit version, which one do I install?

    EDIT 2: Installed the latest 32 bit version, says it can not find a demuxer for it. If it helps at all, when I ripped the audio in MeGUI it said the audio was DTS Core (otherwise known as DTS HD I think)
    Last edited by WAusJackBauer; 14th Feb 2018 at 21:15.
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