How to Convert MP4 or MKV File to MP3 or M4A File

Motivation:

You have downloaded some MP4 or MKV video files.

You want to extract audio parts so that you could copy them to your iPhone to listen to them while turning off the display of your phone.

Procedure:

  • Download this portable application to your Windows.
  • Unzip the files to a location.
  • Open Mp4ToMp3_64.exe.
  • Click on the Add files button to add MP4 or MKV files to the application.
  • If you want to extract the original audio (for example the M4A format) then select Try extract original audio stream option below the Audio section on the right panel.
  • Click the Convert button.
  • Copy the MP3 or M4A files to your phone.

This procedure can be used for extracting audio from M4B (Apple audiobook file format) file to M4A or MP3 file too.

 

How to Install a Clean iOS

Motivation:

You want to sell or give away your iPhone. You want to ensure that the new owner will not access any of your data.

You may also need to give your iPhone to a technician to fix the broken display of your iPhone. You want to ensure that the technician cannot access any of your data.

You may also have so many buggy applications on your iPhone and want to increase stability and performance of your iOS.

Procedure:

  • Import your Photos to a MacBook.
  • Create a backup of data. It is best to let your iPhone synchronize everything with iCloud, including Photos and Contacts.
  • Turn off Find My iPhone.
  • Plug your iPhone to a MacBook.
  • Open Finder. Click on your iPhone on the left panel.
  • Click Restore iPhone… button.
  • Click Backup button.
  • Click Restore and Update button. Click Next button. Click Agree button.
  • Follow the instructions to install a clean iOS to your iPhone.

Post Installation Configuration:

  • Setup your iPhone.
  • Activate your iPhone.
  • Setup Face ID.
  • Restore your Apps & Data from iCloud backup.
  • Synchronize music to your iPhone.
  • Go to Settings > Generals > Software Update > Automatic Updates. Turn off Automatic Updates.
  • Go to Settings > Generals > Display & Brightness > Text Size. Drag the slider to the right to increase text size.
  • Go to Settings > Messages. Enable iMessage.