HydrogenAudio

Lossy Audio Compression => AAC => AAC - General => Topic started by: OLPP on 2021-06-06 06:27:30

Title: List of AAC related patents
Post by: OLPP on 2021-06-06 06:27:30
Hello. I found a copy of AAC patent licensing agreement (https://www.sec.gov/Archives/edgar/data/0001649009/000121390020023370/ea125930ex10-9_siyatamobile.htm) and created a list of patents which are related to AAC from it. The license mentions that these patents are related to AAC-LC, HE-AAC, HE-AAC v2, AAC-LD, AAC-LD v2, Error resilient AAC Scalable, Error resilient AAC-ELD, and xHE-AAC.

Hopefully this can help estimate the time when all the AAC profiles become patent free.
Title: Re: List of AAC related patents
Post by: OLPP on 2021-06-06 08:37:29
I updated all the estimated expiration dates of US patents. Those dates are all from the search results of Google Patents.
Title: Re: List of AAC related patents
Post by: OLPP on 2021-06-11 07:57:49
I should also note that this list is made from the licensing agreement from June 2018. Other companies joining the patent pool since then (https://www.globenewswire.com/en/news-release/2020/05/19/2035654/0/en/Samsung-Joins-Via-Licensing-s-Advanced-Audio-Coding-Patent-Pool.html) makes the list above incomplete. It would probably still be useful for estimating the expiration dates of patents for old AAC profiles like HE-AAC (v2) and AAC-LC.
Title: Re: List of AAC related patents
Post by: IgorC on 2021-06-11 15:01:59
Patents related to what? Encoding, decoding or what? What is goal for this study?

Patents for decoding MP3 and LC-AAC have been already expired.  
Title: Re: List of AAC related patents
Post by: OLPP on 2021-06-11 16:20:28
Patents related to what? Encoding, decoding or what? What is goal for this study?

Patents for decoding MP3 and LC-AAC have been already expired.  
The goal (more like a dream at this point) is to find out the time when each AAC profile (HE-AAC, HE-AAC v2, etc.) becomes completely patent free. Patents for encoding and decoding would naturally be included. At least from my search, there was no news articles about it. There were some articles about MPEG-2 Video and MPEG-4 Visual (Not AVC), but nothing about AAC.

So I made the list as a starting point. Unfortunately, scanning through hundreds of patents and accurately connecting them to each profile while calculating the expiration dates isn't something I can do with ease. That's the reason why I uploaded the list. Maybe someone else who has both the technical and legal knowledge and potential interest about patent free codecs can use it as a base for further investigation.

And, yes. I'm aware that MP3 became patent free four years ago. I wrote "MP3(?)" at that list on purpose in order to conjure up any kind of response. People love to correct others on the Internet, you know. :) I wonder if that patent is related to SBR. I don't know enough about the specifics of the HE-AAC decoding process to assess that.

By the way, are you sure MPEG-4 AAC LC is patent free? I know that Fedora included the LC part of the FDK codec, but I don't know exactly how much of that codec is actually included in it. (Only the MPEG-2 part? Or the entire MPEG-4 part?)
Title: Re: List of AAC related patents
Post by: Replica9000 on 2021-06-11 17:50:05

By the way, are you sure MPEG-4 AAC LC is patent free? I know that Fedora included the LC part of the FDK codec, but I don't know exactly how much of that codec is actually included in it. (Only the MPEG-2 part? Or the entire MPEG-4 part?)

This is what fdkaac will encode on my Debian machine. 
 2: MPEG-4 AAC LC (default)
5: MPEG-4 HE-AAC (SBR)
29: MPEG-4 HE-AAC v2 (SBR+PS)
23: MPEG-4 AAC LD
39: MPEG-4 AAC ELD
Title: Re: List of AAC related patents
Post by: OLPP on 2021-06-12 02:36:07
Patents for decoding MP3 and LC-AAC have been already expired.  

This is what fdkaac will encode on my Debian machine. 
 2: MPEG-4 AAC LC (default)
5: MPEG-4 HE-AAC (SBR)
29: MPEG-4 HE-AAC v2 (SBR+PS)
23: MPEG-4 AAC LD
39: MPEG-4 AAC ELD
I was talking about fdk-aac-free (https://koji.fedoraproject.org/koji/buildinfo?buildID=1676751). In that version, all the other profiles except AAC LC is stripped from the FDK encoder in order to prevent patent disputes. I checked its source code and found PNS in it. That would mean that Redhat considers MPEG-4 AAC LC to be patent free, which is good news.
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