Freeware Advanced AudioOpen-Source AAC Codecs

ISO-Free LGPL v2.1+ AAC Encoder (FAAC) & GPL v2+ Decoder (FAAD2)

GitHub Organization

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FAAC / FAAD2AAC-LC & HE-AACLGPL v2.1+ / GPL v2+

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FAAC 2.0+ Architecture

Written in C11/C99. Free of legacy ISO reference code. LGPL v2.1+ licensed.

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Profiles & Rate Control

AAC-LC and HE-AAC v1 (SBR). Supports VBR (-q), ABR (-b), and CBR (--cbr) with bit reservoir modeling.

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Encoding Speed

Lightweight, low-overhead C implementation with 3–5x throughput headroom over standard encoders.

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FAAD2 Decoder

Standalone GPL v2+ decoder for MPEG-2/4 AAC, HE-AAC v1/v2 (SBR+PS), and multi-channel streams up to 7.1.

Under Development

The official Freeware Advanced Audio website and documentation portal are currently under active development. Comprehensive documentation, API references, and interactive tools will be added here soon.

Ecosystem Users & Integrations

FAAC and FAAD2 are integrated into major open-source media frameworks, audio converters, and embedded systems worldwide:

fre:ac: Popular cross-platform audio converter and CD ripper directly bundling FAAC and FAAD2 binaries.
Thingino: Embedded Linux IP camera firmware utilizing FAAC for real-time, low-overhead AAC stream encoding.
Audiobook Boss: Open-source audiobook processing suite integrating FAAC for M4A encoding and packaging.
GStreamer: Official GStreamer plugins (gst-plugins-bad) providing faac and faad elements for multimedia pipelines.
VLC Media Player: Includes FAAD2 decoder support in its modular codec plugin architecture.