Changing the Tempo (not the pitch) of .f4v videos (in a Mac)

[zzz83]

I need to speed-up some .f4v video files. I want to change the "tempo" of the videos not changing the pitch of the audio. I have heard SonyVegas can do that but I own a Mac. Does anyone know any free options for doing this??
Thanks!

[redwudz]

Try the freeware Audacity audio editor. It can do that and accepts a fair number of audio formats. It does have a Mac version.

And I'm moving you to our Mac forum where you may get more answers.

And welcome to our forums.

[rumplestiltskin]

QuickTime Pro; open the video, the "command-K". In that dialog, drag the "playback speed" slider as you wish.

[zzz83]

Try the freeware Audacity audio editor. It can do that and accepts a fair number of audio formats. It does have a Mac version.

And I'm moving you to our Mac forum where you may get more answers.

And welcome to our forums.

I have tried Audacity and it seems to work nice with audio. However I need to edit both audio and video. Apparently Audacity cannot do that, can it?

Thanks!

[zzz83]

QuickTime Pro; open the video, the "command-K". In that dialog, drag the "playback speed" slider as you wish.

I have tried Quicktime Player (the free version) and seems to work. I was expecting a more accurate tool, though. With Quicktime Player the audio is unstable when sped-up over 1.5X (this doesn't happened with for example Audacity, but unfortunately I do need the video). The Pro version is much better than the free version?
Thanks a lot!!

[rumplestiltskin]

If you can do the speed-up in QT Player (not Pro) then the Pro "extras" won't do anything more substantial; save your money. I do wonder what would happen, though, if you dropped the video into iMovie, let's say, and played with it there. I suspect the audio would still be better extracted and altered in Audacity. So if you extracted and altered the audio then brought the video into iMovie and sped it up and then imported the audio into iMovie for the final export? Don't know how accurate you can be in iMovie with the speedup so maybe that's the first thing to do and then use Audacity to make the audio match the video? (I'm getting dizzy...)

[terryj]

Far simpler:

Using Audacity and Quicktime Pro

Extract the audio using QT Pro to a .WAV file.
Save as the video with the extracted audio now missing as "no sound.extension"
Open .wav file in Audacity. Set the speed to what you wish.
Export the audio to an AIFF 16bit file.

Open the new audio in QT Pro.
Open the Video in QT Pro.

in QT Pro, Select the audio ( cmd-a) and then copy ( cmd-c)
then select the Movie and the Edit-->Add to Movie.
Playback the movie and see if the audio is to your liking.

[zzz83]

Far simpler:

Using Audacity and Quicktime Pro

Extract the audio using QT Pro to a .WAV file.
Save as the video with the extracted audio now missing as "no sound.extension"
Open .wav file in Audacity. Set the speed to what you wish.
Export the audio to an AIFF 16bit file.

Open the new audio in QT Pro.
Open the Video in QT Pro.

in QT Pro, Select the audio ( cmd-a) and then copy ( cmd-c)
then select the Movie and the Edit-->Add to Movie.
Playback the movie and see if the audio is to your liking.

Thanks man. Question: Can I do this with the freeware version? (QT Player)

[terryj]

Your welcome. no.

[zzz83]

If you can do the speed-up in QT Player (not Pro) then the Pro "extras" won't do anything more substantial; save your money. I do wonder what would happen, though, if you dropped the video into iMovie, let's say, and played with it there. I suspect the audio would still be better extracted and altered in Audacity. So if you extracted and altered the audio then brought the video into iMovie and sped it up and then imported the audio into iMovie for the final export? Don't know how accurate you can be in iMovie with the speedup so maybe that's the first thing to do and then use Audacity to make the audio match the video? (I'm getting dizzy...)

Plus I have to convert the videos, since iMovie does not support .f4v files.

[terryj]

If you can do the speed-up in QT Player (not Pro) then the Pro "extras" won't do anything more substantial; save your money. I do wonder what would happen, though, if you dropped the video into iMovie, let's say, and played with it there. I suspect the audio would still be better extracted and altered in Audacity. So if you extracted and altered the audio then brought the video into iMovie and sped it up and then imported the audio into iMovie for the final export? Don't know how accurate you can be in iMovie with the speedup so maybe that's the first thing to do and then use Audacity to make the audio match the video? (I'm getting dizzy...)

Plus I have to convert the videos, since iMovie does not support .f4v files.

hence my last suggestion to simply do everything in QT pro.