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OGM (.ogm)

.ogm file signature | video/x-ogm

OGM (Ogg Media) is a multimedia container format derived from the Ogg bitstream structure, originally developed by Tobias Waldvogel and later maintained within the open-source multimedia community. It was used to package video, audio, and subtitles for playback on desktop media players, ripping tools, and video encoding workflows, especially when Matroska support was limited. OGM is now considered a legacy format, and malformed files from untrusted sources can still affect vulnerable media players.

Safe

Magic Bytes

Offset 0
4F 67 67 53 00 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 76 69 64 65 6F

Sources: Apache Tika

Extension

.ogm

MIME Type

video/x-ogm

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .ogm files in Python

Python 
def is_ogm(file_path: str) -> bool:
    """Check if file is a valid OGM by magic bytes."""
    signature = bytes([0x4F, 0x67, 0x67, 0x53, 0x00, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x76, 0x69, 0x64, 0x65, 0x6F])
    with open(file_path, "rb") as f:
        return f.read(33) == signature

How to validate .ogm files in Node.js

Node.js 
function isOGM(buffer: Buffer): boolean {
  const signature = Buffer.from([0x4F, 0x67, 0x67, 0x53, 0x00, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x76, 0x69, 0x64, 0x65, 0x6F]);
  return buffer.subarray(0, 33).equals(signature);
}

How to validate .ogm files in Go

Go 
func IsOGM(data []byte) bool {
    signature := []byte{0x4F, 0x67, 0x67, 0x53, 0x00, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x2E, 0x76, 0x69, 0x64, 0x65, 0x6F}
    if len(data) < 33 {
        return false
    }
    return bytes.Equal(data[:33], signature)
}

API Endpoint

GET /api/v1/ogm
curl https://filesignature.org/api/v1/ogm

See the full API documentation for all endpoints and parameters.

Related Formats

.drc .oga .ogg .ogv .ogx .opus

Frequently Asked Questions

What is a .ogm file?

A .ogm file is identified by the magic bytes 4F 67 67 53 00 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 76 69 64 65 6F at byte offset 0. OGM (Ogg Media) is a multimedia container format derived from the Ogg bitstream structure, originally developed by Tobias Waldvogel and later maintained within the open-source multimedia community. It was used to package video, audio, and subtitles for playback on desktop media players, ripping tools, and video encoding workflows, especially when Matroska support was limited. OGM is now considered a legacy format, and malformed files from untrusted sources can still affect vulnerable media players.

What are the magic bytes for .ogm files?

The magic bytes for OGM files are 4F 67 67 53 00 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 76 69 64 65 6F at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .ogm file?

To validate a .ogm file, read the first bytes of the file and compare them against the known magic bytes (4F 67 67 53 00 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 76 69 64 65 6F) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .ogm files?

The primary MIME type for .ogm files is video/x-ogm.

Is it safe to open .ogm files?

OGM (.ogm) 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.