Please update opus-tools to 0.2. It has some desirable improvements.
https://www.opus-codec.org/release/dev/2018/09/18/opus-tools-0_2.html
opus-tools 0.2 - Sep 18, 2018
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 Downloads page.
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 channel count
* 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
Additionally:
* 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
* Numerous bug fixes are also included