Editing Advanced Audio Coding (section)

==Licensing and patents==
No licenses or payments are required for a user to stream or distribute audio in AAC format.<ref>{{cite web | url = https://www.via-corp.com/licensing/aac/aac-faqs/ | title = AAC Licensing FAQ Q5 | publisher = Via Licensing | access-date=2020-01-15 }}</ref> This reason alone might have made AAC a more attractive format to distribute audio than its predecessor MP3, particularly for streaming audio (such as Internet radio) depending on the use case.

However, a patent license is required for all manufacturers or developers of AAC "end-user" [[codecs]].<ref>{{cite web| url = https://www.via-corp.com/licensing/aac/license-fees/ | title = AAC License Fees | publisher = Via Licensing |access-date=2020-01-15 }}</ref> The terms (as disclosed to SEC) uses per-unit pricing. In the case of software, each computer running the software is to be considered a separate "unit".<ref name="license-ag">{{cite web |author1=Via Licensing Corporation |title=AAC PATENT LICENSE AGREEMENT |url=https://www.sec.gov/Archives/edgar/data/1649009/000121390020023370/ea125930ex10-9_siyatamobile.htm |website=www.sec.gov |access-date=21 April 2023 |date=June 5, 2018}}</ref>

It used to be common for [[free and open source software]] implementations such as [[FFmpeg]] and [[FAAC]] to only distribute in [[source code]] form so as to not "otherwise supply" an AAC codec. However, FFmpeg has since become more lenient on patent matters: the "gyan.dev" builds recommended by the official site now contain its AAC codec, with the FFmpeg legal page stating that patent law conformance is the user's responsibility.<ref>{{cite web |title=FFmpeg License and Legal Considerations |url=https://ffmpeg.org/legal.html |website=ffmpeg.org}}</ref> (See below under Products that support AAC, Software.) The [[Fedora Project]], a community backed by [[Red Hat]], has imported the "Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android" to its repositories on September 25, 2018,<ref>{{cite web |title=Commit - rpms/fdk-aac-free - b27d53fbad872ea0ec103653fddaec83238132d9 - src.fedoraproject.org |url=https://src.fedoraproject.org/rpms/fdk-aac-free/c/b27d53fbad872ea0ec103653fddaec83238132d9?branch=rawhide |website=src.fedoraproject.org}}</ref> and has enabled FFmpeg's native AAC encoder and decoder for its ffmpeg-free package on January 31, 2023.<ref>{{cite web |title=Commit - rpms/ffmpeg - 45f894ec0e43a37775393c159021a4ac60170a55 - src.fedoraproject.org |url=https://src.fedoraproject.org/rpms/ffmpeg/c/45f894ec0e43a37775393c159021a4ac60170a55?branch=rawhide |website=src.fedoraproject.org}}</ref>

The AAC patent holders include [[Bell Labs]], [[Dolby]], [[ETRI]], [[Fraunhofer Society|Fraunhofer]], [[JVC Kenwood]], [[LG Electronics]], [[Microsoft]], [[NEC]], [[Nippon Telegraph and Telephone|NTT]] (and its subsidiary [[NTT Docomo]]), [[Panasonic]], [[Philips]], and [[Sony Corporation]].<ref name="aac-licensors"/><ref name="businesswire"/> Based on the list of patents from the SEC terms, the last baseline AAC patent expires in 2028, and the last patent for all AAC extensions mentioned expires in 2031.<ref>{{cite web |title=List of AAC related patents |url=https://hydrogenaud.io/index.php/topic,121109.0.html |website=hydrogenaud.io}}</ref>