Opus - Revision history

Logan589XP: Added release notes for libopus 1.6 and updated stable release number to 1.6.1.

2026-01-15T23:14:08Z

Added release notes for libopus 1.6 and updated stable release number to 1.6.1.

← Older revision		Revision as of 23:14, 15 January 2026
Line 5:		Line 5:
	\| caption = Opus Interactive Audio Codec		\| caption = Opus Interactive Audio Codec
	\| maintainer = [http://xiph.org/ Xiph.Org Foundation]		\| maintainer = [http://xiph.org/ Xiph.Org Foundation]
	\| stable_release = 1.5.2		\| stable_release = 1.6.1
	\| operating_system = Windows, Mac OS/X, Linux/BSD		\| operating_system = Windows, Mac OS/X, Linux/BSD
	\| use = Encoder/Decoder		\| use = Encoder/Decoder
Line 375:		Line 375:
	* Improved x86 (AVX2) and Arm (Neon) optimizations		* Improved x86 (AVX2) and Arm (Neon) optimizations
	* Support for 4th and 5th order ambisonics		* Support for 4th and 5th order ambisonics

			==== libopus v1.6 ====
			Released on December 15th, 2025. This version contains:

			* A new wideband-to-fullband bandwidth extension (BWE) module
			* Support for 96 kHz audio with Opus HD
			* Significant improvement to Deep Redundancy (DRED)
			* A new 24-bit encoder/decoder API
			* Fixed-point improvements

	=== Other implementations ===		=== Other implementations ===

Logan589XP: Updated stable release number to 1.5.2.

2024-04-24T05:26:01Z

Updated stable release number to 1.5.2.

← Older revision		Revision as of 05:26, 24 April 2024
Line 5:		Line 5:
	\| caption = Opus Interactive Audio Codec		\| caption = Opus Interactive Audio Codec
	\| maintainer = [http://xiph.org/ Xiph.Org Foundation]		\| maintainer = [http://xiph.org/ Xiph.Org Foundation]
	\| stable_release = 1.5.1		\| stable_release = 1.5.2
	\| operating_system = Windows, Mac OS/X, Linux/BSD		\| operating_system = Windows, Mac OS/X, Linux/BSD
	\| use = Encoder/Decoder		\| use = Encoder/Decoder

Logan589XP: Added release notes for libopus 1.5.1 and updated stable release number to 1.5.1.

2024-03-09T05:11:56Z

Added release notes for libopus 1.5.1 and updated stable release number to 1.5.1.

← Older revision		Revision as of 05:11, 9 March 2024
Line 5:		Line 5:
	\| caption = Opus Interactive Audio Codec		\| caption = Opus Interactive Audio Codec
	\| maintainer = [http://xiph.org/ Xiph.Org Foundation]		\| maintainer = [http://xiph.org/ Xiph.Org Foundation]
	\| stable_release = 1.4		\| stable_release = 1.5.1
	\| operating_system = Windows, Mac OS/X, Linux/BSD		\| operating_system = Windows, Mac OS/X, Linux/BSD
	\| use = Encoder/Decoder		\| use = Encoder/Decoder
Line 366:		Line 366:
	* Improved tuning and various fixes to DTX		* Improved tuning and various fixes to DTX
	* Added Meson support, improved CMake support In addition to the improvements above, this release includes many minor bug fixes.		* Added Meson support, improved CMake support In addition to the improvements above, this release includes many minor bug fixes.

			==== libopus v1.5.1 ====
			Released on March 4th, 2024. This version contains:

			* Significant improvement to packet loss robustness using Deep Redundancy (DRED)
			* Improved packet loss concealment through Deep PLC
			* Low-bitrate speech quality enhancement down to 6 kb/s wideband
			* Improved x86 (AVX2) and Arm (Neon) optimizations
			* Support for 4th and 5th order ambisonics

	=== Other implementations ===		=== Other implementations ===

Artoria2e5: /* "Equivalent bitrate" */

2023-08-12T09:09:12Z

"Equivalent bitrate"

← Older revision		Revision as of 09:09, 12 August 2023
Line 273:		Line 273:

	* CBR requires 8% more bitrate for the same quality.		* CBR requires 8% more bitrate for the same quality.
	* Frame overhead is fixed and modelled as <code>(40channels+20)(frame_rate - 50);</code> for any frame_rate larger than 50. (frame_rate is the number of frames per second, so <code>1000/frame_size_ms</code>). There's no modelling for larger-than-standard frames.		* Frame overhead is fixed and modelled as <code>(40channels+20)(frame_rate - 50)</code> for any frame_rate larger than 50. (frame_rate is the number of frames per second, so <code>1000/frame_size_ms</code>). There's no modelling for reduction in overhead from larger-than-standard frames: you'd imagine the expression runs in the opposite direction as well.
	* Complexity turning results in up to 30% more bitrate requirement.		* Complexity turning results in up to 30% more bitrate requirement.

Artoria2e5: /* "Equivalent bitrate" */

2023-08-12T09:08:22Z

"Equivalent bitrate"

← Older revision		Revision as of 09:08, 12 August 2023
Line 273:		Line 273:

	* CBR requires 8% more bitrate for the same quality.		* CBR requires 8% more bitrate for the same quality.
	* Frame overhead is fixed and modelled as <code>(40channels+20)(frame_rate - 50);</code> for any frame_rate larger than 50. (frame_rate is the number of frames per second, so <code>1000/frame_size_ms</code>).		* Frame overhead is fixed and modelled as <code>(40channels+20)(frame_rate - 50);</code> for any frame_rate larger than 50. (frame_rate is the number of frames per second, so <code>1000/frame_size_ms</code>). There's no modelling for larger-than-standard frames.
	* Complexity turning results in up to 30% more bitrate requirement.		* Complexity turning results in up to 30% more bitrate requirement.

Artoria2e5: /* Lower latency versus quality/bitrate trade-off */

2023-08-12T09:07:54Z

Lower latency versus quality/bitrate trade-off

← Older revision		Revision as of 09:07, 12 August 2023
Line 268:		Line 268:

	N.B. This table is useful for interactive streaming only. For music storage & delayed playback or non-interactive streaming, latency reduction is not important and the default 20 ms frame size is preferable.		N.B. This table is useful for interactive streaming only. For music storage & delayed playback or non-interactive streaming, latency reduction is not important and the default 20 ms frame size is preferable.

			==== "Equivalent bitrate" ====
			Opus code includes a [https://github.com/xiph/opus/blob/9fc8fc4cf432640f284113ba502ee027268b0d9f/src/opus_encoder.c#L806 {{code\|compute_equiv_rate()}}] function. Given the bitrate, framesize, cbr decision, and complexity setting, it converts the bitrate to an standard config (VBR, 20 ms frame, complexity 10) equivalent to be used for bandwidth, layer, and stereo decisions. The interesting bits are:

			* CBR requires 8% more bitrate for the same quality.
			* Frame overhead is fixed and modelled as <code>(40channels+20)(frame_rate - 50);</code> for any frame_rate larger than 50. (frame_rate is the number of frames per second, so <code>1000/frame_size_ms</code>).
			* Complexity turning results in up to 30% more bitrate requirement.

			This layer of conversion is why Opus runs wideband speech at 9 kbps VBR and CVBR, but with CBR it takes 10 kbps (now we know it's exactly 9.75 kbps) to use WB.

	=== Channel count vs bitrate ===		=== Channel count vs bitrate ===

Artoria2e5: /* Music encoding quality */

2023-08-12T05:29:37Z

Music encoding quality

← Older revision		Revision as of 05:29, 12 August 2023
Line 124:		Line 124:
	!Use cases/notes/competitive codecs		!Use cases/notes/competitive codecs
	\|-		\|-
	!6 kbps		!4 kbps
	\|mono		\|mono
	\|6 kHz		\|6 kHz
Line 131:		Line 131:
	\| —		\| —
	\|-		\|-
	!8 kbps		!9 kbps
	\|mono		\|mono
	\|6 kHz		\|8 kHz
	\|SILK		\|SILK
	\|Poor, muffled but OK for bitrate		\|Poor, muffled but OK for bitrate

Artoria2e5: /* Other software */

2023-08-12T05:28:34Z

Other software

← Older revision		Revision as of 05:28, 12 August 2023
Line 451:		Line 451:
	* [http://www.xdlab.ru/en/ TagScanner]		* [http://www.xdlab.ru/en/ TagScanner]
	* [http://www.xmedia-recode.de/ XMedia Recode]		* [http://www.xmedia-recode.de/ XMedia Recode]
			* [[loudgain]]

	== References & Notes ==		== References & Notes ==

Artoria2e5: /* Channel count vs bitrate */

2023-08-12T05:26:08Z

Channel count vs bitrate

← Older revision		Revision as of 05:26, 12 August 2023
Line 269:		Line 269:
	N.B. This table is useful for interactive streaming only. For music storage & delayed playback or non-interactive streaming, latency reduction is not important and the default 20 ms frame size is preferable.		N.B. This table is useful for interactive streaming only. For music storage & delayed playback or non-interactive streaming, latency reduction is not important and the default 20 ms frame size is preferable.

	== Channel count vs bitrate ==		=== Channel count vs bitrate ===

	For surround sound bitrates, use [[Bitrate#Equivalent bitrate estimates for multichannel audio]].		For surround sound bitrates, use [[Bitrate#Equivalent bitrate estimates for multichannel audio]].

Artoria2e5: /* Indicative bitrate and quality */

2023-08-12T05:26:00Z

Indicative bitrate and quality

← Older revision		Revision as of 05:26, 12 August 2023
Line 268:		Line 268:

	N.B. This table is useful for interactive streaming only. For music storage & delayed playback or non-interactive streaming, latency reduction is not important and the default 20 ms frame size is preferable.		N.B. This table is useful for interactive streaming only. For music storage & delayed playback or non-interactive streaming, latency reduction is not important and the default 20 ms frame size is preferable.

			== Channel count vs bitrate ==

			For surround sound bitrates, use [[Bitrate#Equivalent bitrate estimates for multichannel audio]].

			For ambisonics, see [https://www.mdpi.com/2076-3417/10/9/3188 AMBIQUAL listening test], paper figures 11 and 12.

	== Implementations ==		== Implementations ==