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USB-IF Publishes Audio Over USB Type-C Specifications (anandtech.com)
An anonymous reader quotes a report from AnandTech: The USB Implementers Forum this week published the USB Audio Device Class 3.0 (direct download) specification, which standardizes audio over USB Type-C interface. The new spec enables hardware makers to eliminate traditional 3.5mm mini-jacks from their devices and use USB-C ports to connect headsets and other audio equipment. Makers of peripherals can also build their audio solutions, which use USB-C instead of traditional analog connectors. Developers of the standard hope that elimination of mini-jacks will help to make devices slimmer, smarter and less power hungry. As reported, the USB Audio Device Class 3.0 specification supports both analog and digital audio. Analog audio is easy to implement and it does not impact data transfers and other functionality of USB-C cables since it uses the two secondary bus (SBU) pins. The USB ADC 3.0 defines minimum interoperability across analog and digital devices in order to avoid confusion of end-users because of incompatibility. In fact, all ADC 3.0-compliant hosts should support the so-called headset adapter devices, which allow to connect analog headsets to USB-C. However, digital audio is one of the primary reasons why companies like Intel wanted to develop the USB-C audio tech on the first place, hence, expect them to promote it. According to the USB ADC 3.0 standard, digital USB-C headphones will feature special multi-function processing units (MPUs), which will, to a large degree, define the feature set and quality of headsets. The MPUs will handle host and sink synchronization (this is a key challenge for digital USB audio), digital-to-analog conversion, low-latency active noise cancellation, acoustic echo canceling, equalization, microphone automatic gain control, volume control and others. Such chips will also contain programmable amplifiers and pre-amplifiers, which are currently located inside devices. Besides, USB ADC 3.0-compatible MPUs will also support USB Audio Type-III and Type-IV formats (the latest compressed formats), but will retain compatibility with formats supported by ADC 1.0 and 2.0. Finally, among the mandated things set to be supported by USB-C Audio devices are new Power Domains (allows devices to put certain domains in sleep mode when not in use) as well as BADD (basic audio device definition) 3.0 features for saving power and simplified discovery and management of various audio equipment (each type of devices has its own BADD profile).
Innovative my ass. Nokia and Sony Ericsson were combining everything in the same port years before: Pop-Port, FastPort.
And guess what it sucked and having a separate 3.5mm audio jack was considered a huge improvement.
Back then it was considered to be a way to force people to buy their accessories and a cash grab. Now Apple calls it "courage". Hah.
No mention of vorbis, flac, alac or opus. Great, isn't it?
PCM_IEC60958
AC-3
MPEG-1_Layer1
MPEG-1_Layer2/3 or MPEG-2_NOEXT
MPEG-2_EXT
MPEG-2_AAC_ADTS
MPEG-2_Layer1_LS
MPEG-2_Layer2/3_LS
DTS-I
DTS-II
DTS-III
ATRAC
ATRAC2/3
WMA
E-AC-3
MAT
DTS-IV
MPEG-4_HE_AAC
MPEG-4_HE_AAC_V2
MPEG-4_AAC_LC
DRA
MPEG-4_HE_AAC_SURROUND
MPEG-4_AAC_LC_SURROUND
MPEG-H_3D_AUDIO
AC4
MPEG-4_AAC_ELD