File Types

MIDI is a communication protocol that lets electronic musical instruments talk to each other.

It stores music as a series of commands, not the actual sound notes.

Uses 8-bit serial transmission (asynchronous).

Each MIDI message has a sequence of bytes:

The first byte is called the status byte, telling the device what action to perform.

This byte also includes the MIDI channel number (there are 16 channels).

Examples of MIDI commands:

Note on/off: Indicates when a key is pressed or released.

Key pressure: Shows how hard a key is pressed (affects volume or loudness).

MIDI files typically need less memory compared to other audio files.

MP3 uses audio compression technology to shrink music and sound files.

Compression can reduce the original file size by about 90%.

It uses file compression algorithms based on Perceptual Music Shaping:

Removes sounds that humans cannot hear well.

Removes certain sounds without significantly affecting audio quality.

CDs are converted to MP3 using compression software.

MP3 is a lossy format: some original audio information is lost during compression.

MP4 is a multimedia file format that can store:

Music

Videos

Photos

Animations

Allows streaming videos without noticeable loss in quality.

Supports a variety of media types, not just sound.

JPEG is a popular image file format used to reduce photo file sizes.

Compression reduces the number of pixels per unit area (resolution).

When a photo is compressed to JPEG, the file size is reduced, sometimes by a factor of 5 to 15 times compared to raw bitmap images.

Used widely for digital photos, websites, and where storage space is limited.