If you have an MP4 video file that you want to convert into a multiple-track MIDI audio file, you cannot perform a direct conversion. Instead, you have to convert the MP4 video into an MP3 audio file with Media Convert, a free file-conversion Web site. Once you have an MP3 audio file, you can convert it to MIDI using intelliScore Ensemble, the only multi-instrument MP3-to-MIDI file converter in the world, according to its Web site.
Go to the Media Convert website (see Resources).
Select your MP4 file by clicking the "Browse" button in the "File" area. Under "Input format," select "MPEG-4 (.mp4)."
Select MP3 as the output format from the drop-down menu. Click the "OK" button to convert the MP4 to an MP3. The screens will refresh while the file converts. A download link for the new MP3 file will appear when the conversion is complete. Download the MP3 file to your computer.
Download intelliScore Ensemble and install it on your computer. It is free to download and free to use for a trial period. The 2009 purchase price after the free trial is $129.
Launch intelliScore Ensemble on your computer. A New Project Wizard will appear. Click "Obtain audio" to select the MP3 file. Click "Next" to move through the wizard and "Start" to begin the conversion. When the new MIDI file has been created, it will automatically open in your MIDI player or editor on your computer.