AAC
Advanced Audio Coding
A lossy audio codec designed as the successor to MP3, offering better quality at similar bitrates.
技术细节
Understanding aac 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.
示例
```javascript
// AAC: 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..)
```
相关格式
相关工具
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