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  1. Using Audacity, how does one slowdown audio from Pal to Ntsc (25fps>23.976) without changing the pitch?
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  2. Always Watching guns1inger's Avatar
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    Change Temp
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  3. No, thats not the answer...
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  4. That's what it says:
    Change Tempo... Without changing pitch
    Are the developers lying about what it does?

    http://manual.audacityteam.org/index.php?title=Effect_Menu

    And are you sure the pitch doesn't need changing?
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  5. Always Watching guns1inger's Avatar
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    Typo - Change Tempo is the effect that changes the length of a clip without altering the pitch. It does this by speeding it up or slowing it down accordingly. You just need to know by how much. In your case, speed it up by 4%
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  6. Always Watching guns1inger's Avatar
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    Originally Posted by manono
    That's what it says:
    Change Tempo... Without changing pitch
    Are the developers lieing about what it does?

    http://manual.audacityteam.org/index.php?title=Effect_Menu

    And are you sure the pitch doesn't need changing?
    I suspect the OP is hoping for an effect that lets him type in the framerates, rather than requiring that he do the math himself.
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  7. I use eac3to change audio to 23.976 from 25. But I notice a difference in PITCH between the two, cause it is now moving at a different speed.

    I thought I could just get the frequency from the original audio and "Change the new audo to the same pitch, but the freq changes dependent on where the starting point is in the sound.
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  8. Always Watching guns1inger's Avatar
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    Audacity has a Change Pitch filter as well, for changing pitch without changing tempo.
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  9. Yes, yes yes, audacity has these features as everyone keeps posting.
    Obviously you just go to effects and there all listed there, i can see that.
    The question is;
    Sure you can change the pitch but how do you know what to change the pitch to, from the original audio source?
    When you slow down audio from pal to ntsc, your going to change its pitch...
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  10. Always Watching guns1inger's Avatar
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    If you use the Change Tempo filter in audacity then it will not change the pitch. That is the whole point. No need to worry about the pitch change because there isn't one

    if you use a process that does change the pitch then you will have to work out the difference by ear, or use a better process in the first place.

    Your first question was : How do I change the speed of a clip in audacity without changing the pitch.

    That was answered - Change Temp does this.

    You then start talking about using a different program to do your speed change.

    How about you start again by clearly stating what process you are using, and where you are getting stuck.

    So far you have made sense at all.
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  11. So the answer is by ear? There isn't a way to calculate pitch difference when changing to standard pal to ntsc?

    Originally Posted by guns1inger
    Your first question was : How do I change the speed of a clip in audacity without changing the pitch.
    That was answered - Change Temp does this.
    No It was;
    Using Audacity, how does one slowdown audio from Pal to Ntsc (25fps>23.976) without changing the pitch?
    By telling me "change tempo" that doesn't show me how to change audio from pal to ntsc by using "TEMPO"
    So what your telling me is audacity doesn't do this type of conversion;
    [/quote]

    Originally Posted by guns1inger
    You then start talking about using a different program to do your speed change.
    Obviously then I must use another program that does change pal to ntsc(25fps>23.976) which I mentioned EAC3TO
    that does this, but there is a pitch change.
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  12. Always Watching guns1inger's Avatar
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    Originally Posted by guns1inger
    Typo - Change Tempo is the effect that changes the length of a clip without altering the pitch. It does this by speeding it up or slowing it down accordingly. You just need to know by how much. In your case, speed it up by 4%
    What more do you need to know ?

    It is simple maths - work out the percentage change in speed of your framerates, and use this to change the tempo/speed/running time of the audio track.

    The other thing to consider is if the pitch change is in fact just correcting a pitch change made when the video was sped up to 25 fps in the first place. This varies from movie to movie.
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  13. The answers above are correct. I've done it.

    Using Change Tempo you'll need to use a value of -4.096% when going from 25fps to 23.976fps without a change to the pitch.
    Use Change Speed (same value of -4.096% I believe) to change from 25fps to 23.976fps and let Audacity change the pitch automatically (voices will be slightly lower/deeper).
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  14. Thanks guns1inger & gonzalimator

    gonzalimator made it much clearer on how to use the 4% change(more accurate -4.096%) by;
    Tempo can change pal to ntsc w/o pitch change
    speed will do same w/ pitch change

    So im assuming
    Pitch + 4.096% will correct audio that was ALREADY changed from 25>23.976 that needed pitch correction(Audacity was not used, but a program like Eac3to, correct?
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  15. Yes, I think that's true. A pitch change of -4.096% should get the pitch back to normal if it sounded too high from a conversion of film to pal without preserving the original pitch. Also, if you ever need to go in the other direction (for whatever reason) I summarized what I did. I wanted to write it down because the percentage is not the same and I thought that if I was wrong, someone could correct me.

    The way I solved it (and I'm sure others may not have arrived at their solutions by the same logic...) was by looking at the difference between 25fps and 23.976fps and determining what percentage that difference represented.

    25 - 23.976 = 1.024 the difference.
    1.024 / 25 = 0.04096 (I divided by 25 because the source video was 25fps)

    In the above example the percentage the difference represented was 4.096% If I wanted to go from 23.976 to 25 I would do this:

    1.024 / 23.976 = 0.042709376042709376042709376 (it keeps repeating)

    Therefore, to change from 23.976 to 25fps the percentage is 4.271% It's not the same so watch out!!

    gonzalimator
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  16. That is absolutely correct!

    23.976-25=1.024x100=102.4/23.976=4.2709376 or 4.271%

    I will be using aduacity from now on to convert my audio from Pal to Ntsc.
    I tried this and their was no noticeable sound/pitch difference, so it works.

    BTW, how do you convert 44100khz to 48000khz using audacity?
    Thanks~
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  17. Always Watching guns1inger's Avatar
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    Unfortunately I naively thought you might actually pull your finger out and do a little thinking and little research for yourself, then use a calculator to do the math. I understand that it would take almost 5 minutes of your busy schedule to this, so I am not completely surprised your were unable to find the time.
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  18. ** backs away slowly**
    Happy to be here.
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  19. Never mind, found it, just change the freq in the left corner and it will save it to that setting. NO there is no MATH to do! Lol
    Good thing I had my calculator and my finger ready to do this! (there is no effect/change frequency)
    BTW 4% is incorrect and the video would be out of sync, there is a difference(Accurate numbers make a correct answer)
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    But how do you go from Pal to Ntsc (25fps>23.976) without changing the pitch OR duration?

    (And guns1inger if you are still around, no need to write one of your rude and unhelpful replies)
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  21. Originally Posted by branch View Post
    But how do you go from Pal to Ntsc (25fps>23.976) without changing the pitch OR duration?
    And not change the duration either? You do nothing. Exactly what do you want to change if neither the pitch nor the length?

    And unless you come up with a question that actually makes some sense, you'll get some rude replies whether gunslinger's here or not.
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  22. Member AlanHK's Avatar
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    Originally Posted by branch View Post
    But how do you go from Pal to Ntsc (25fps>23.976) without changing the pitch OR duration?
    If you're doing this you're going to drop some video frames and keep the audio unchanged.
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