Even though Opus is now standardized by the IETF, this Opus implementation will keep improving in the future.
Of course, all future versions will still be fully compliant with the Opus IETF specification.
See the development page for the latest development information.
Opus-tools provides command-line utilities to encode, inspect, and decode .opus files.
Opusfile provides application developers with a high-level API for decoding and seeking in .opus files. DLLs for the
required libraries libogg 1.3.2, libopus 1.1.1 and openssl, are also included in the binary package.
This Opus 1.2.1 minor release fixes a relatively rare
issue where the 1.2 encoder would wrongly assume a signal to be bandlimited to 12 kHz and not encode frequencies
between 12 and 20 kHz. This only happens on a few clips, but it is good to update to avoid a potential
loss of quality.
There are no other changes compared to 1.2. Please report any problems.
In this release the Opus decoder opusdec has been converted to use the
opusfile library, and the Opus encoder opusenc has been converted to use
the libopusenc library. These libraries make it easy to robustly read
and write Ogg Opus audio files, and enable some new features. Both
libraries are available on the
opusdec enhancements include:
Read directly from http or https sources
New option --force-stereo will force stereo output
Improved support for chained input files with differing sample rate or
A summary is displayed for METADATA_BLOCK_PICTURE tags rather than
displaying the base64-encoded data
opusenc enhancements include:
Delayed decision support allows the encoder to look ahead up to two
seconds in order to improve encoding decisions
The options --music and --speech can be used to tune low bitrate audio
for music or speech, overriding automatic detection
The option --no-phase-inv disables the use of phase inversion for
intensity stereo, which can be useful for streams that are likely to
be downmixed to mono after decoding
New --tracknumber shortcut for setting tracknumber metadata
The opusinfo utility can display the demixing matrix from Ogg Opus
files using ambisonics channel mapping family 3
The experimental opusrtp tool supports new options to specify RTP
payload type, Ogg Opus output file, original sample rate, and number
of channels, and supports improved transmit timing, arbitrary
network devices, and IPv6
The Visual Studio 2015 project builds opusenc support for FLAC input
The old Visual Studio 2010 project has been removed