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Page history last edited by Luke 11 years ago

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To follow these instructions, you need, in order of appearance:

  • Quicktime Pro (like $30 but you can get it from the department)
  • Audacity (free, open source download)


1st Step – Extract audio track using Quicktime 7 Pro

Step 1.1 - Open movie file in Quicktime Pro

Step 1.2 - Press COMMAND+J to get movie properties window

Step 1.3 - Select the audio track & hit the “Extract” button near top left of window…audio track should pop up in its own quicktime player window

Step 1.4 - Save audio track somewhere you can find it.


2nd Step – Use Audacity to obscure names in audio track

Step 2.1 - Go to File menu, select Import (Or you can hit SHIFT+COMMAND+I to select your audio file) and Import the audio file from Step 1

Step 2.2 - Listen for name, Select the time during which name is pronounced, it play to make sure you selected it properly

Step 2.3 - Go to Generate menu and select what you want to replace the name with, e.g., silence, tone, or noise.  Play around to see which works best for your purposes. 

Step 2.4 - Repeat for all the names…

Step 2.5 - Export new audio file from Audacity.  Save as .mp3, .m4v or .WAV or something Quicktime Pro can handle.

(Here's a helpful VIDEO so you can see how to do your thing with Audacity)



3rd step – Import audio file back into Movie using Quicktime Pro

Step 3.1 - In QuickTime Player, choose File > Open File and select the audio file you want to import.


Step 3.2 - In the QuickTime Player window that opens, choose Edit > Select All to select the entire audio file, then choose Edit > Copy.

Step 3.3 - Open the movie to which you want to add the audio.

Step 3.4 - To add the audio to the whole movie, choose Edit > Add.

(Here's a website with more specific instructions if you need them)




HOW TO INSTALL and use Audacity:


1. To install Audacity, first download and install the FFMPEG libraries from here: http://manual.audacityteam.org/man/FAQ:Installation_and_Plug-Ins#1._Download

2. And then download and install the latest version of Audacity from here (beta, but I couldn't get the latest stable version to work with video, at least under Mac OS X Lion): http://audacity.sourceforge.net/download/beta_mac#recdown


With Audacity, you can import the audio track of a QuickTime or mp4 movie (by just opening the video file in Audacity), and edit it. You can play it back until you hear the name, then mark the section of the waveform during which the name is spoken, and generate a "bleep" tone instead of the actually spoken word. After you have replaced all the names with bleeps, you can export the audio track as a mp3 file, and replace the original audio track of the movie with the bleeped one in QuickTime Pro. If you have any questions about how to perform the particular steps, just let me know, and I can walk you through.


Thanks to Benedikt Herrer of UMaine for some helpful tips!

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