At this point it appears that Dolby has managed to worm its way into the new ATSC 3 broadcast TV standard as well in the form of something called AC-4.
Dolby started as a tape hiss reduction system that actually was useful. Since that time it has more and more become just a way to extract license fees from companies making electronics that involve audio.
For the TV standard they could of just used the open Opus codec, but since the people who are creating the standards are the ones getting the licensing revenue there is no real incentive to do something like that. These "industry standards" have become a kind of a scam.
So no, Dolby is not all that interested in licensing software implementations of their codecs for random programs. That is simply not where the big money is and it isn't really their business.
So, I am thinking this post deserves a better title.
The patent status of MP2 seems to be hard to determine.
DTS seems to be still patented.
HDMI supersedes S/PDIF so comprehensively that the S/PDIF standard will likely never be substantially revised. There's no compelling reason to invest in the R&D.
IIRC, toslink 1.0 (circa ‘82 or ‘83) had a limit of 2 or 3 mbps while modern toslink is well over 100mbps (constrained more by distance than speed).
Layer 2 is not considered software, although it can be performed by software in systems where such a concept makes sense. However, in AES3, this does not make sense, and has always been handled in devices via a chip that merely turns AES3 into I2S to be fed to either a DAC or another interface chip (ex: conversion between AES PHYs is often done by just bridging the receiver of one type to the transmitter of another type semi-blindly via I2S).
Also, the AES3 protocol is incredibly simple. It only has a very limited set of flags (very limited in today's sense, more than enough for what was intended in 1985, see https://en.wikipedia.org/wiki/AES3#Channel_status_word ), and was never actually meant to do anything but stereo audio at conventional rates. Doing encoded bitstreams across it is largely a hack, and is limited to the base versions of Dolby and DTS.
Using >3mbit over Toslink is not done involving an AES3-purposed PHY, but instead with other unrelated protocols, such as Digital ADAT. Distance on typical Toslink is already constrained to about 30 feet.
I have seen other people quote this mythical 100mbit number, but no one has ever been able to cite such a use in the real world: no standard I have ever seen that uses Toslink as a PHY has supported such a transmission rate: ADAT maxes out at around 12mbit, and MADI does not use Toslink at all.
Also, in further irony, in use, I have found unbalanced AES3 (such as via RCA or BNC) to be more reliable than Toslink; and virtually all of professional AES3 usage is done by 3 pin XLR because of how unreliable Toslink is...
Although a lot of professionals have moved on from AES3 entirely, and use MADI or Dante, or don't use digital transmission pipes inside of their studio at all and run it entirely on a single PC.
I think I’m going to do some more research on that 100mbps number. Perhaps they meant Bd/s?
16 * 44,100 * 2 = 1,411,200
HDMI can carry uncompressed 7.1 channel audio - will a Mac send that? If it does, does any playback software support that?
Aura: delayed 4 years by "Reasonable and Non-Discriminatory” licensing
edit: Thank you both folks who replied. I posted this comment, emailed the mods, then saw your replies. :-)