M4A
MPEG-4 Audio
An audio container format using AAC or ALAC codecs, the default format for Apple Music and iTunes purchases.
Technisches Detail
Understanding m4a requires knowledge of file structure — how headers, metadata, and payload data are organized within the binary layout. Most file formats begin with a magic number (signature bytes) that identifies the format independently of the file extension: PDF starts with %PDF-, PNG with \x89PNG, ZIP with PK. MIME type detection combines magic number inspection with file extension matching. Format specifications define the exact byte layout, enabling tools to parse, validate, and convert files correctly.
Beispiel
```javascript
// M4A: file format detection
const header = new Uint8Array(await file.slice(0, 4).arrayBuffer());
const signature = Array.from(header).map(b => b.toString(16)).join(' ');
// PDF: '25 50 44 46' (%PDF)
// PNG: '89 50 4e 47' (.PNG)
// ZIP: '50 4b 03 04' (PK..)
```
Verwandte Formate
Verwandte Tools
F
Format Identifier
M
MIME Type Lookup
B
Base64 Encoder / Decoder
U
URL Encoder / Decoder
H
HTML Entity Encoder / Decoder
M
Markdown to HTML Converter
Y
YAML ↔ JSON Converter
L
Line Ending Converter
D
Data URI Generator
H
Hex Dump Viewer
U
Unicode Escape Converter
F
File Size Converter
C
Character Set Analyzer
F
Format Comparison Guide
C
Conversion Guide