Yamaha Corp (.mmf)

.mmf file signature | application/vnd.smaf

Mobile Application Format (MMF), also known as SMAF, is a multimedia file format developed by Yamaha Corporation. It was used for storing synthetic music, ringtones, and simple multimedia content on mobile phones and other handheld devices. The format is largely legacy today, and files are generally low risk, though support may be limited in modern software and some content may not play correctly.

Safe

Magic Bytes

Offset 0


              4D 4D 4D 44 00 00

Sources: Gary Kessler

Extension

.mmf

MIME Type

application/vnd.smaf

Byte Offset

Risk Level

Safe

Validation Code

How to validate .mmf files in Python

Python

def is_mmf(file_path: str) -> bool:
    """Check if file is a valid MMF by magic bytes."""
    signature = bytes([0x4D, 0x4D, 0x4D, 0x44, 0x00, 0x00])
    with open(file_path, "rb") as f:
        return f.read(6) == signature

How to validate .mmf files in Node.js

Node.js

function isMMF(buffer: Buffer): boolean {
  const signature = Buffer.from([0x4D, 0x4D, 0x4D, 0x44, 0x00, 0x00]);
  return buffer.subarray(0, 6).equals(signature);
}

How to validate .mmf files in Go

func IsMMF(data []byte) bool {
    signature := []byte{0x4D, 0x4D, 0x4D, 0x44, 0x00, 0x00}
    if len(data) < 6 {
        return false
    }
    return bytes.Equal(data[:6], signature)
}

API Endpoint

GET /api/v1/mmf


              curl https://filesignature.org/api/v1/mmf

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .mmf file?

A .mmf file is a Yamaha Corp file. Mobile Application Format (MMF), also known as SMAF, is a multimedia file format developed by Yamaha Corporation. It was used for storing synthetic music, ringtones, and simple multimedia content on mobile phones and other handheld devices. The format is largely legacy today, and files are generally low risk, though support may be limited in modern software and some content may not play correctly.

What are the magic bytes for .mmf files?

The magic bytes for Yamaha Corp files are 4D 4D 4D 44 00 00 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .mmf file?

To validate a .mmf file, read the first bytes of the file and compare them against the known magic bytes (4D 4D 4D 44 00 00) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .mmf files?

The primary MIME type for .mmf files is application/vnd.smaf.

Is it safe to open .mmf files?

Yamaha Corp (.mmf) files are generally safe to open. They are classified as low risk because they primarily contain data rather than executable code. However, always ensure files come from a trusted source.