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  1. Member
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    I have a DVD (VOB) file that was recorded at 15 FPS but for whatever reason it was provided at 29.97 FPS so it is too fast. I am trying to convert both the audio and video back to ~15 FPS. Using MPEG Streamclip, I exported out using "Demux to M2V and AC3". Converted the M2V to AVI at 14.985 FPS no problem. I have never worked with audio so I'm not sure how to convert the audio to match. First, am I going about it the right way? If so, how do you slow down the audio to match?

    Also, is there a quicker option to convert the audio and video without having to demux since I want them to be the same speed? I understand why you would want to demux if you wanted to do one or the other but since I want the same audio and video just at a different frame rate I would think there would be an easier way. Any feedback would be greatly appreciated. Thanks.
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  2. aBigMeanie aedipuss's Avatar
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    audio doesn't have an fps just time length and bits per sec. as long as the time of the video doesn't change the audio should be fine.

    i can't think of an authoring program that would allow 15fps as dvd input though. must be some other problem. did you check the extracted mpeg in gspot?
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    aedipuss-

    I knew audio was not measured in fps which is why I was not sure how to handle audio. I screw around with video all the time but have never had to change the speed of video with audio and don't know much at all about audio.

    What I was provided on DVD is clearly running fast as I can tell by looking at the timer on the video. Hell... I just checked the times and the original video ran approximately 4 minutes. The new video runs at 27 minutes but the timing on the video clock is correct. I will try gspot and see what it says, if anything.
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    Correction. The length of the original video is 13 minutes, 45 seconds.

    Also, if you change the video's frame rate, won't the video be decreased or increased in length?
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  5. Always Watching guns1inger's Avatar
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    What do you want at the end of this ?

    15 fps is not a legal framerate for DVD, so what you really need to do is revert to the 15 fps framerate to get the speed correct, then duplicate every frame to get back to DVD legal. If you do this, you won't have to alter the audio at all.

    Although better quality can be obtained from more complex methods, you might want to have a look at http://compression.ru/video/frame_rate_conversion/index_en_msu.html to get your framerate back to 29.97 fps.
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    Sorry for the confusion. I received the file in DVD format. I just want it in a useable computer format whether that be AVI, MPEG, WMV, MOV, etc. The 15 FPS is fine since it is now playing in real time at least according to the clock displayed on the video. I just am clueless when it comes to converting the audio to match the speed of the video.

    What I have attempted to do was open the AC3 file in Nero WaveEditor and under Tools there is an option called "Time Correction." I bumped it to 200% and it seems to play at the correct speed as the length is now the same as the video. However, the audio is of horrible quality.

    I have posted a 10 second clip of the audio after using the time correction tool. Any ideas how this can be fixed or is there a better way? I really appreciate the feedback and help!

    Click here to listen to crappy audio
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  7. aBigMeanie aedipuss's Avatar
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    if the dvd played ok, then use dvdshrink to reauthor it to movie only with 1 audio track to a new folder on your h.d. delete everything but the vobs. use vob2mpeg and convert it to mpg-2. it should play fine on the computer.
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    You could try using DGPulldown on it to bring the 15fps to 29.97fps. I've done that with 25fps progressive DivX PAL content to convert to NTSC dvd's. It does not throw the audio out of sync or pitch this way. Got the idea from the Holy Grail Guide to converting PAL to NTSC (something like that).

    Or run it through FAVC to see if that can convert it to a more playback friendly version for you. I think it may do a similar process. Good luck.

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    The original DVD I was provided plays but it was encoded at 29.97 FPS (which for a DVD is correct). However, the original video must have been shot at 15 FPS because the time that is reflected in the video is running too fast. I took the VOB file that was the actual video and copied it to my hard drive. I then separated the video and audio and changed the frame rate of the video to 15 FPS and compared it with a stop watch and the video is now running real time according to the time reflected on the video.

    I am now trying to modify the audio file to match.

    I don't understand the recommendation of using DVDshrink & VOB2MPEG. I am trying to change the audio to match my video. I have tried converting the entire movie to MPEG and used other tools to change the frame rate which worked but the audio was off (which was expected).

    I have successfully converted my video to a playable format on my computer at the right speed but it has no audio. I simply want my audio to now match.

    Thanks for the continued assistance.
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    Originally Posted by RickA
    You could try using DGPulldown on it to bring the 15fps to 29.97fps. I've done that with 25fps progressive DivX PAL content to convert to NTSC dvd's. It does not throw the audio out of sync or pitch this way. Got the idea from the Holy Grail Guide to converting PAL to NTSC (something like that).

    Or run it through FAVC to see if that can convert it to a more playback friendly version for you. I think it may do a similar process. Good luck.

    Cheers,
    Rick
    Thanks for the recommendation Rick. I am actually trying to do the opposite. Convert the video and audio from 29.97 FPS to 15 FPS.
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    My apologies then deltaromeo - I missunderstood. I thought you had an iffy 29.97 copy of a 15fps video. Managed to get back to a properly working 15fps and were looking to head back to a properly working 29.97 again.

    I thought you had said you managed to get the video to 15fps and it played fine. Then were able to time correct the audio with Nero. Just figured you were going to use those to get back to a dvd spec of 29.97 fps.
    Sounds like you are working in territory I have not ventured yet. There are some pretty smart people on these forums so hopefully they can help you better then my attempt.

    Would FAVC or FilmMachine not let you 'reverse engineer' the vid for you?

    Good luck,
    Rick
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    Originally Posted by RickA
    My apologies then deltaromeo - I missunderstood. I thought you had an iffy 29.97 copy of a 15fps video. Managed to get back to a properly working 15fps and were looking to head back to a properly working 29.97 again.

    I thought you had said you managed to get the video to 15fps and it played fine. Then were able to time correct the audio with Nero. Just figured you were going to use those to get back to a dvd spec of 29.97 fps.
    Sounds like you are working in territory I have not ventured yet. There are some pretty smart people on these forums so hopefully they can help you better then my attempt.

    Would FAVC or FilmMachine not let you 'reverse engineer' the vid for you?

    Good luck,
    Rick
    Rick-

    Thanks for the assistance. I did manage to get the video converted to 15 FPS. I also attempted the audio with Nero but the quality is bad. I'm sure there is some filter to run on it but I tried everything available inside Nero.

    I will try the recommended tools you pointed to. Thanks again.
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