hejops / mp3-decoder

Experimental MP3 decoder

mp3-decoder

Building an mp3 decoder in Python. For learning/teaching purposes only.

Descriptions

• ISO/IEC 11172-3

• Lagerstrom_MP3_Thesis | PDF

• MP3 File Format Specification

• Mp3-Standard-Tutorial

• The AudioFile: Understanding MP3 compression | Ars Technica

• lets-build-mp3-decoder.html

• mp3_theory.pdf

Implementations

• minimp3 (C)
• pdmp3 (C)
• mp3vis (TypeScript)

Example mp3 files

• free test data

Frame header

• MPEG Audio Frame Header - CodeProject

Bits	Item	Example
11	Sync	FFF
2	MPEG Version
2	MPEG Layer
1	Protection
4	Bitrate
2	Samp. freq.
1	Padding
1	Private
2	Mode
2	Mode extension
1	Copyright
1	Original media
2	Emphasis

Bit reservoir

• MP3 Sync Words