If, like me, you love to splice little clips of show dialogue and the like into your songs, here's how to extract the center audio track (which rarely has background music) from any MKV (Matroska video) files you may have downloaded or torrented; note that these need to be iTunes rips. It's also how you get close-to-acappellas for the show songs.
Note that this is for OS X or Linux only, if you're on Windows you can probably find a GUI utility to do it for you. And you'll need simple knowledge of how to use the command line (on the Mac it's called Terminal.app).
Go into a folder ("cd /path/to/folder") that contains your MKV files. Create a file that's called "centerchannel.sh" (no quotes). In the command line type "chmod +x centerchannel.sh" to make it an executable. Then open it up and paste in the following:
- Code: Select all
#!/bin/bash
mkdir -p audio/ac3
mkdir -p audio/wav
mkdir -p audio/center
for mkv in *.mkv; do
ac3=audio/ac3/${mkv}.ac3
wav=audio/wav/${mkv}.wav
center=audio/center/${mkv}.wav
if [[ ! -e ${ac3} ]]; then mkvextract tracks ${mkv} 2:${ac3}; fi
if [[ ! -e ${wav} ]]; then ffmpeg -i ${ac3} ${wav}; fi
if [[ ! -e ${center} ]]; then ffmpeg -i ${wav} -map_channel 0.0.2 ${center}; fi
done
If you then type "./centerchannel.sh" it will convert all the MKV files into WAV files in the audio/center folder that contain just the center channel! Then remix away!
