Patent expiration for E-AC3 (Dolby Digital Plus)? [Archive]

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kurkosdr

21st September 2022, 21:15

E-AC3 (aka Dolby Digital Plus) is used exclusively for some terrestrial television broadcasts in Europe. For example:
https://www.digitalbitrate.com/dtv.php?mux=MUXA&liste=1&live=3&lang=en
https://www.digitalbitrate.com/dtv.php?mux=R1,IDF&liste=1&live=1&lang=en

This got me thinking:

- Is there a patent list (and anticipated expiration date) for decoding E-AC3?

I've tried Googling around and there is no information on the subject. All I can find is people talking about the expiration of AC3 patents and a ETSI patent declaration from 2004 (which, considering how old it is, I am not sure it covers E-AC3).

In fact, even pinpointing a "release date" for E-AC3 has also been impossible for me. Even Wikipedia doesn't have that information. Best I can find is that E-AC3 was a mandatory format for HD-DVD, and since the first HD-DVD player was released on 31st March 2006 (and has a "Dolby Digital Plus" badge), this gives us a "worst case" date of 31st March 2006 when it comes to prior art.

Does anyone have any information on the topic?

PS: The DigitalBitrate website can tell the difference between AC3 and E-AC3 (example of AC3 identified here (https://www.digitalbitrate.com/dtv.php?mux=CH30&liste=1&live=16&lang=en)), so the examples above are not a case of a misidentified stream. You really need an E-AC3 decoder to watch terrestrial TV in some EU countries...

hajj_3

25th September 2022, 09:56

FranceBB

25th September 2022, 23:57

SeeMoreDigital

26th September 2022, 09:06

AFAIK 2026 at the very best for E-AC3 and by then AC4 will probably be widespread anyway and we're gonna be in the same situation we're now (i.e with AC3 patent expired and E-AC3 patent still in place and the codec being widespread)...EAC3 got a much needed boost with media streaming services, especially those that offer Atmos. But some audio streaming services are now offering MPEG-H :eek:

hajj_3

26th September 2022, 09:42

AFAIK 2026 at the very best for E-AC3 and by then AC4 will probably be widespread anyway and we're gonna be in the same situation we're now (i.e with AC3 patent expired and E-AC3 patent still in place and the codec being widespread)...

I doubt it. AC4 has been out for 8yrs, still little adoption, no support in ffmpeg even though it is used by atsc 3.0. E-AC3 is widely used by streaming services, lots of tv's, amplifiers and set top boxes support it. AC3 is used by dvd's and european tv broadcasts and E-AC3 is commonly available on blurays as a part of dolby truehd and many tv broadcasts.

kurkosdr

28th September 2022, 17:24

https://hydrogenaud.io/index.php?topic=122053.0

This patent list includes patents for TrueHD, a newer format, so it is a worst case scenario but not a definite patent list for E-AC3. That's why I also asked here, this forum is frequented by people knowledgeable in this kind of stuff.

kurkosdr

28th September 2022, 17:35

I doubt it. AC4 has been out for 8yrs, still little adoption, no support in ffmpeg even though it is used by atsc 3.0. E-AC3 is widely used by streaming services, lots of tv's, amplifiers and set top boxes support it. AC3 is used by dvd's and european tv broadcasts and E-AC3 is commonly available on blurays as a part of dolby truehd and many tv broadcasts.

The powers that be in ETSI and ATSC made AC4 and MPEG-H 3D Audio mandatory for UHD receivers (yes, both, despite both serving the same purpose, because why enable rent-seeking for one special interest group when you can do it for two)? And it's already being used in UHD terrestrial broadcasts in some EU countries (see here (https://www.digitalbitrate.com/dtv.php?mux=HEVC&liste=1&live=1&lang=en) and here (https://www.digitalbitrate.com/dtv.php?live=13&mux=MUX6&liste=1&lang=en)).

So it will be adopted no matter what.

Balling

2nd October 2022, 23:18

>support in ffmpeg even though it is used by atsc 3.0.

Anyone who needs it, has ffmpeg with it.

FranceBB

3rd October 2022, 21:08

>support in ffmpeg even though it is used by atsc 3.0.

Anyone who needs it, has ffmpeg with it.

You mean decoding? Does it mean VLC and MPV support it too out of the box (and if not, why)?

Balling

4th October 2022, 01:47

You mean decoding? Does it mean VLC and MPV support it too out of the box (and if not, why)?

Only decoding. richarddpl has patches. What do you mean out of the box? Both use ffmpeg. If you compile with those patches...

FranceBB

8th October 2022, 17:11

What do you mean out of the box? Both use ffmpeg. If you compile with those patches...

I meant compiled without patches.
For me out of the box means "as it is" so basically with the "patches merged to master".
Anyway, since those have not been merged, is there a reason?

Balling

10th October 2022, 15:30

I meant compiled without patches.
For me out of the box means "as it is" so basically with the "patches merged to master".
Anyway, since those have not been merged, is there a reason?

Some filters are not perfect per authors's, richardpl's that is, opinion.

hajj_3

22nd July 2025, 09:34

This blog post from Mainconcept confirms that Dolby E-AC3 patents expire in early 2026 (i assume the patent US7,516,064 which expires on 30th Jan 2026): https://blog.mainconcept.com/dolby-digital-audio-in-ffmpeg

j7n

29th July 2025, 11:51

Does Elon Musk's superior librempeg fork have an AC-4 decoder? So far I have only seen AC-4 immersive stereo (2 channel) in the wild. No software encoders for AC-4 surround. These new codecs only exist to feed big corporations. Not just Dolby, but also DTS and Fraunhofer with MPEG-H. I too believe that AC-4 will get pushed more strongly once E-AC-3 patents expire.

clsid

29th July 2025, 12:04

Yes, it does.

Latest MPC-HC version supports AC4 decoding.

hajj_3

30th January 2026, 18:37

I think the last patent has now expired: US7516064, this expired today.

kurkosdr

31st January 2026, 00:25

:mad:I think the last patent has now expired: US7516064, this expired today.
Let's see if the Fedora people add E-AC3 support like they added AC3 when the patents expired (if it's cleared for use by Fedora, it can be assumed to be patent-free in the US). I asked years ago (https://x.com/kurkosdr/status/1486360676356575236), but they didn't get back to me. I PM'ed the person, and they replied that they'll try to take a look, but clearing codecs is a lot of work, so no promises.

I understand I am just one Twitter account among the many, but E-AC3 support is important regardless. My suspicion is that Americans don't care much about E-AC3, because no broadcast service in the US uses it (and streaming services will happily serve you AC3 or AAC if you don't have an E-AC3 decoder installed). So, I wouldn't be surprised if they view E-AC3 5.1 as that weird codec used in European broadcasts and hence unimportant to Americans (and for the E-AC3+JOC used by streaming services, they can either ignore it or bitstream it to a soundbar/receiver).

Does Elon Musk's superior librempeg fork have an AC-4 decoder? So far I have only seen AC-4 immersive stereo (2 channel) in the wild. No software encoders for AC-4 surround. These new codecs only exist to feed big corporations. Not just Dolby, but also DTS and Fraunhofer with MPEG-H. I too believe that AC-4 will get pushed more strongly once E-AC-3 patents expire.
Let's look at the bright side. In Europe, none of the two codecs ended up being mandatory (thus making my pessimistic prediction in this thread false). Every HEVC broadcast in Europe uses a stereo E-AC3 compatibility stream along with AC4, so if you want basic stereo playback, you can ignore the AC4 steam entirely and play the E-AC3. And MPEG-H 3D Audio is nowhere to be seen. Don't know how things are in the US regarding AC4.

Don't get me wrong, I still hate it how the powers that be greenlit two standards (AC4 and MPEG-H 3D Audio), both of them incompatible with AC3 and E-AC3 (which means the backwards compatibility concern doesn't apply), but at least neither became truly mandatory. TVs will feature AC4 and maybe even MPEG-H 3D Audio for future-proofing purposes, but you don't need to have it. Good.

If only E-AC3 became available everywhere like AC3 did when the patents expired...