MPEG-1/2 file signature
Magic number at the start of the file
An MPEG-1 or MPEG-2 program stream (Video CD, DVD, broadcast) starts with the pack header 00 00 01 BA; a raw video sequence starts 00 00 01 B3.
What this magic number means
A magic number is a short, fixed run of bytes at a known position that tells a program what a file really is, no matter what the filename says. If a file starts with the bytes 00 00 01 BA, it is a MPEG-1/2 file.
What each byte of 00 00 01 BA means
Here is the signature byte by byte, the way a hex editor shows it: the position in the file, the value in hex and in decimal, and the character that value stands for in ASCII. Bytes with no printable character show a dot.
| Byte offset | Hex | Decimal | ASCII |
|---|---|---|---|
| 0 | 00 | 0 | . |
| 1 | 00 | 0 | . |
| 2 | 01 | 1 | . |
| 3 | BA | 186 | . |
Signature variants
MPEG-1/2 appears with more than one byte pattern. These all identify the same family:
| Hex signature | Offset | Note |
|---|---|---|
| 00 00 01 BA | 0 | program stream pack header |
| 00 00 01 B3 | 0 | video sequence header |
Formats that use the 00 00 01 BA signature
These file types in our database carry this signature:
How to check a file's signature
You can read the bytes of any file yourself. They are shown in hex, the same way this page lists them.
Linux & macOS
- xxd -l 16 example.mpg
- hexdump -C -n 16 example.mpg
- file example.mpg
Windows (PowerShell)
- Format-Hex -Path example.mpg -Count 16
Python
- open("example.mpg","rb").read(4).hex()
In your browser
- Drop the file into the WhatFileType identifier, which reads the signature without uploading it.
Frequently asked questions
What is the MPEG-1/2 file signature?
MPEG-1/2 files start with the hex bytes 00 00 01 BA. This magic number identifies the format regardless of the file's name or extension.
How do I check a file's magic number?
Open the file in a hex editor, or run a command such as xxd -l 16 example.mpg on Linux or macOS, or Format-Hex -Path example.mpg -Count 16 in Windows PowerShell, and read the first bytes.
Can a file fake the MPEG-1/2 signature?
Renaming a file does not change its bytes, so the extension can lie but the signature usually cannot. A genuine MPEG-1/2 file has these exact bytes; a file with the wrong bytes is not really MPEG-1/2, whatever its name says.
Related signatures
Sources
Reuse this signature
This entry is part of the WhatFileType file signature reference, published under a CC BY 4.0 licence with the full provenance for every entry, a copy-paste embed and a JSON export. Credit WhatFileType and the data is yours to republish.