Knowledge Base for All

The technique to minimize the human voice and remain the music voice of a mp3, we can use Audacity ( audacity.sourceforge.net ). 1. Click the "down" triangle to open the menu. 2. "Split Stereo track" 3. "Mono" both track 4. Select and invert one of the track ("Effect" -> "Invert") 5. Save the MP3 Step is shown in the below picture: [ mp3 去人聲 audacity ]

Copy Virtual Box image file Use VBoxManage clonevdi There are a few steps involved in order to make a copy of a VirtualBox .vdi disk file. #1. Shut down all virtual machine and start Virtual Box main program #2. Release the .vdi file – File > Virtual Media Manager > Select the virtual machine disk to be copied > Click “Release” #3. Open command prompt (go to C:\Program Files\Sun\VirtualBox) VBoxManage clonevdi c:\myvirtualdisk\Original.vdi c:\myvirtualdisk\NewCopy.vdi #4. Add the new virtual disk image – File > Virtual Media Manager > Add #5. Re-attach original virtual disk image to its VM Reference: http://www.kernelhardware.org/make-a-copy-of-virtualbox-vdi/