Opus Recommended Settings - Revision history

MrZeus: /* Mono or Stereo */

2026-09-16T10:37:22Z

Mono or Stereo

← Older revision		Revision as of 10:37, 16 September 2026
Line 65:		Line 65:
	== Mono or Stereo ==		== Mono or Stereo ==
	Opus tends to start '''downmixing stereo inputs to mono''' from roughly '''19 Kb/s and lower'''.		Opus tends to start '''downmixing stereo inputs to mono''' from roughly '''19 Kb/s and lower'''.
	You can check the details in the '''[https://github.com/xiph/opus/blob/main/src/opus_encoder.c#~~L149~~ opus_encoder.c]''' source file.		You can check the details in the '''[https://github.com/xiph/opus/blob/main/src/opus_encoder.c#L175 opus_encoder.c]''' source file.

	You can force downmixing at any bitrate by using the following command-line parameters:		You can force downmixing at any bitrate by using the following command-line parameters:

MrZeus: point to main, not old master branch

2026-09-16T10:36:28Z

point to main, not old master branch

← Older revision		Revision as of 10:36, 16 September 2026
Line 65:		Line 65:
	== Mono or Stereo ==		== Mono or Stereo ==
	Opus tends to start '''downmixing stereo inputs to mono''' from roughly '''19 Kb/s and lower'''.		Opus tends to start '''downmixing stereo inputs to mono''' from roughly '''19 Kb/s and lower'''.
	You can check the details in the '''[https://github.com/xiph/opus/blob/~~master~~/src/opus_encoder.c#L149 opus_encoder.c]''' source file.		You can check the details in the '''[https://github.com/xiph/opus/blob/main/src/opus_encoder.c#L149 opus_encoder.c]''' source file.

	You can force downmixing at any bitrate by using the following command-line parameters:		You can force downmixing at any bitrate by using the following command-line parameters:

MrZeus: /* Bandwidth Transition Thresholds */

2026-09-16T10:34:31Z

Bandwidth Transition Thresholds

← Older revision		Revision as of 10:34, 16 September 2026
Line 91:		Line 91:
	\|-		\|-
	\|style="text-align:right;"\|NarrowBand (3 - 4000)		\|style="text-align:right;"\|NarrowBand (3 - 4000)
	\|9		\|6
	\|15		\|6
	\|?		\|6
	\|?		\|6
	\|-		\|-
	\|style="text-align:right;"\|MediumBand (3 - 6000)		\|style="text-align:right;"\|MediumBand (3 - 6000)
	\|9		\|9
	\|~~18-22~~		\|9
	\|?		\|9
	\|?		\|9
	\|-		\|-
	\|style="text-align:right;"\|WideBand (3 - 8000)		\|style="text-align:right;"\|WideBand (3 - 8000)
	\|~~13.5~~		\|10
	\|~~22-28~~		\|10
	\|?		\|10
	\|?		\|10
	\|-		\|-
	\|style="text-align:right;"\|SuperWideBand (3-12000)		\|style="text-align:right;"\|SuperWideBand (3-12000)
	\|14		\|14
	\|~~28-32~~		\|12
	\|?		\|14
	\|?		\|12
	\|-		\|-
	\|style="text-align:right;"\|FullBand (3-20000)		\|style="text-align:right;"\|FullBand (3-20000)
	\|16		\|16
	\|~~32-64~~		\|14
	\|~~32-64~~		\|16
	\|~~64-128~~		\|14
	\|}		\|}

	The details of Opus' bandpass thresholds can be found in the '''[https://github.com/xiph/opus/blob/~~master~~/src/opus_encoder.c#L151 opus_encoder.c]''' source file.		The details of Opus' bandpass thresholds can be found in the '''[https://github.com/xiph/opus/blob/main/src/opus_encoder.c#L151 opus_encoder.c]''' source file.

	The '''[http://wiki.hydrogenaud.io/index.php?title=Opus HydrogenAudio]''' wiki also has some great information on Opus and its usage.		The '''[http://wiki.hydrogenaud.io/index.php?title=Opus HydrogenAudio]''' wiki also has some great information on Opus and its usage.

MrZeus: /* Bandwidth Transition Thresholds */

2026-09-15T21:07:14Z

Bandwidth Transition Thresholds

← Older revision		Revision as of 21:07, 15 September 2026
Line 91:		Line 91:
	\|-		\|-
	\|style="text-align:right;"\|NarrowBand (3 - 4000)		\|style="text-align:right;"\|NarrowBand (3 - 4000)
	\|12		\|9
	\|15		\|15
	\|?		\|?
Line 97:		Line 97:
	\|-		\|-
	\|style="text-align:right;"\|MediumBand (3 - 6000)		\|style="text-align:right;"\|MediumBand (3 - 6000)
	\|15		\|9
	\|18-22		\|18-22
	\|?		\|?
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	\|-		\|-
	\|style="text-align:right;"\|WideBand (3 - 8000)		\|style="text-align:right;"\|WideBand (3 - 8000)
	\|~~16-20~~		\|13.5
	\|22-28		\|22-28
	\|?		\|?
Line 109:		Line 109:
	\|-		\|-
	\|style="text-align:right;"\|SuperWideBand (3-12000)		\|style="text-align:right;"\|SuperWideBand (3-12000)
	\|~~24-28~~		\|14
	\|28-32		\|28-32
	\|?		\|?
Line 115:		Line 115:
	\|-		\|-
	\|style="text-align:right;"\|FullBand (3-20000)		\|style="text-align:right;"\|FullBand (3-20000)
	\|~~28-40~~		\|16
	\|32-64		\|32-64
	\|32-64		\|32-64
Line 121:		Line 121:
	\|}		\|}

	The details of Opus' bandpass thresholds can be found in the '''[https://github.com/xiph/opus/blob/master/src/opus_encoder.c#~~L121~~ opus_encoder.c]''' source file.		The details of Opus' bandpass thresholds can be found in the '''[https://github.com/xiph/opus/blob/master/src/opus_encoder.c#L151 opus_encoder.c]''' source file.

	The '''[http://wiki.hydrogenaud.io/index.php?title=Opus HydrogenAudio]''' wiki also has some great information on Opus and its usage.		The '''[http://wiki.hydrogenaud.io/index.php?title=Opus HydrogenAudio]''' wiki also has some great information on Opus and its usage.

MarkH: fix broken demo3 link

2024-11-25T15:10:24Z

fix broken demo3 link

← Older revision		Revision as of 15:10, 25 November 2024
Line 49:		Line 49:
	\|6 (5.1 surround)		\|6 (5.1 surround)
	\|128 - 256		\|128 - 256
	\|rowspan="2"\|For surround sound, Opus uses '''[https://xiph.org/~xiphmont/demo/opus/demo3.shtml surround-sound bitrate allocation]'''.		\|rowspan="2"\|For surround sound, Opus uses '''[https://people.xiph.org/~xiphmont/demo/opus/demo3.shtml surround-sound bitrate allocation]'''.
	\|-		\|-
	\|8 (7.1 surround)		\|8 (7.1 surround)

MrZeus: /* Mono or Stereo */ tweak mono/stereo threshhold according to current source code

2018-12-14T13:15:23Z

Mono or Stereo: tweak mono/stereo threshhold according to current source code

← Older revision		Revision as of 13:15, 14 December 2018
Line 64:		Line 64:

	== Mono or Stereo ==		== Mono or Stereo ==
	Opus tends to start '''downmixing stereo inputs to mono''' from roughly '''24 Kb/s and lower'''.		Opus tends to start '''downmixing stereo inputs to mono''' from roughly '''19 Kb/s and lower'''.
	You can check the details in the '''[https://github.com/xiph/opus/blob/master/src/opus_encoder.c#~~L148~~ opus_encoder.c]''' source file.		You can check the details in the '''[https://github.com/xiph/opus/blob/master/src/opus_encoder.c#L149 opus_encoder.c]''' source file.

	You can force downmixing at any bitrate by using the following command-line parameters:		You can force downmixing at any bitrate by using the following command-line parameters:

Jmspeex at 18:34, 30 May 2017

2017-05-30T18:34:01Z

← Older revision		Revision as of 18:34, 30 May 2017
Line 132:		Line 132:
	For real-time applications, sending fewer packets per second reduces the overall bitrate, since it reduces the overhead from '''[https://en.wikipedia.org/wiki/IPv6_packet#Fixed_header IP]''', '''[https://en.wikipedia.org/wiki/User_Datagram_Protocol#Packet_structure UDP]''', and '''[https://en.wikipedia.org/wiki/Real-time_Transport_Protocol#Packet_header RTP headers]'''.		For real-time applications, sending fewer packets per second reduces the overall bitrate, since it reduces the overhead from '''[https://en.wikipedia.org/wiki/IPv6_packet#Fixed_header IP]''', '''[https://en.wikipedia.org/wiki/User_Datagram_Protocol#Packet_structure UDP]''', and '''[https://en.wikipedia.org/wiki/Real-time_Transport_Protocol#Packet_header RTP headers]'''.
	However, it increases latency and sensitivity to packet losses, as losing one packet constitutes a loss of a bigger chunk of audio.		However, it increases latency and sensitivity to packet losses, as losing one packet constitutes a loss of a bigger chunk of audio.
	~~Increasing the frame duration also slightly improves coding efficiency~~, ~~but the gain becomes small for~~ frame sizes above 20~~ ~~ms.		Unless operating at very low bitrates over RTP, there is no reason to use frame sizes above 20 ms, as those will have slightly lower quality for music encoding.

	For these reasons, the default 20 ms frames are a good choice for most applications.		For these reasons, the default 20 ms frames are a good choice for most applications.

MrZeus: /* Bandwidth Transition Thresholds */ stop hiding bandwidth ranges under attr tags

2016-12-14T14:37:17Z

Bandwidth Transition Thresholds: stop hiding bandwidth ranges under attr tags

← Older revision		Revision as of 14:37, 14 December 2016
Line 78:		Line 78:

	{\| class="wikitable" style="text-align:center"		{\| class="wikitable" style="text-align:center"
	\|-		\|-
	\|~~rowspan~~="2"\|(~~bitrates in ~~Kb/s)		!rowspan="3"\|Bandpass Range (Hz)
			!colspan="4"\|Rough Bitrate Required (Kb/s)
			\|-
	!colspan="2"\|Mono		!colspan="2"\|Mono
	!colspan="2"\|Stereo		!colspan="2"\|Stereo
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	!Music		!Music
	\|-		\|-
	~~!<abbr title~~="(3-~~4000~~ Hz)~~">NarrowBand</abbr>~~		\|style="text-align:right;"\|NarrowBand (3 - 4000)
	\|12		\|12
	\|15		\|15
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	\|?		\|?
	\|-		\|-
	~~!<abbr title~~="(3-~~6000~~ Hz)~~">MediumBand</abbr>~~		\|style="text-align:right;"\|MediumBand (3 - 6000)
	\|15		\|15
	\|18-22		\|18-22
Line 100:		Line 102:
	\|?		\|?
	\|-		\|-
	~~!<abbr title~~="(3-~~8000~~ Hz)~~">WideBand</abbr>~~		\|style="text-align:right;"\|WideBand (3 - 8000)
	\|16-20		\|16-20
	\|22-28		\|22-28
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	\|?		\|?
	\|-		\|-
	~~!<abbr title~~="(3-12000~~ Hz~~)~~">SuperWideBand</abbr>~~		\|style="text-align:right;"\|SuperWideBand (3-12000)
	\|24-28		\|24-28
	\|28-32		\|28-32
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	\|?		\|?
	\|-		\|-
	~~!<abbr title~~="(3-20000~~ Hz~~)~~">FullBand</abbr>~~		\|style="text-align:right;"\|FullBand (3-20000)
	\|28-40		\|28-40
	\|32-64		\|32-64

MrZeus: /* Recommended Bitrates */ slight reformatting, adding nbsp's for number ranges

2016-11-09T12:35:07Z

Recommended Bitrates: slight reformatting, adding nbsp's for number ranges

← Older revision		Revision as of 12:35, 9 November 2016
Line 4:		Line 4:
	The settings in the table below are meant to '''start you off''' with a decent tradeoff between '''good quality''' and '''small file size''' (or '''bitrate usage''', if you're streaming).		The settings in the table below are meant to '''start you off''' with a decent tradeoff between '''good quality''' and '''small file size''' (or '''bitrate usage''', if you're streaming).

	You should test the suggested bitrate by actually '''listening''' to your encoded audio and then tweaking the bitrate:		You should test the suggested bitrate by actually '''listening''' to your encoded audio and then:
	* '''down''' if you think the quality is good, but the file size (or bitrate) is too big		* tweaking the bitrate '''down''' if you think the quality is good, but the file size (or bitrate) is too big,
	* '''up''' if you think the quality is bad, and you can afford having bigger files (or a larger streaming bitrate)		* tweaking the bitrate '''up''' if you think the quality is bad, and you can afford having bigger files (or a larger streaming bitrate).

	{\| class="wikitable" style="text-align:center"		{\| class="wikitable" style="text-align:center"
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	\|1 (mono)		\|1 (mono)
	\|Use '''[http://www.rowetel.com/?page_id=452 Codec 2]'''		\|Use '''[http://www.rowetel.com/?page_id=452 Codec 2]'''
	\|Opus only supports bitrates down to 6 Kb/s. Codec 2 handles ultra low bitrate speech ~~from~~ 0.7 to 3.2 Kb/s.		\|Opus only supports bitrates '''down to 6 Kb/s'''.<br>
			Codec 2 handles ultra low bitrate speech at '''0.7 - 3.2 Kb/s'''.
	\|-		\|-
	\|VoIP		\|VoIP
	\|1		\|1
	\|10-24		\|10 - 24
	\|10 Kb/s will deliver narrowband most of the time, 24 Kb/s should give fullband.<br>		\|10 Kb/s will deliver narrowband most of the time, 24 Kb/s should give fullband.<br>
	More details in '''[[Opus_Recommended_Settings#Bandwidth_Transition_Thresholds\|the relevant table]]''' further down this page.		More details in '''[[Opus_Recommended_Settings#Bandwidth_Transition_Thresholds\|the relevant table]]''' further down this page.
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	\|Music Streaming / Radio		\|Music Streaming / Radio
	\|2		\|2
	\|64-96		\|64 - 96
	\|Opus has better quality than MP3, AAC and [[Vorbis]] at these rates.<br>		\|Opus has better quality than MP3, AAC and [[Vorbis]] at these rates.<br>
	(listening test results: '''[http://listening-tests.hydrogenaud.io/igorc/results.html 64 Kb/s]''', '''[http://listening-test.coresv.net/results.htm 96 Kb/s]''')		(listening test results: '''[http://listening-tests.hydrogenaud.io/igorc/results.html 64 Kb/s]''', '''[http://listening-test.coresv.net/results.htm 96 Kb/s]''')
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	\|rowspan="3"\|Music Storage		\|rowspan="3"\|Music Storage
	\|2		\|2
	\|96-128		\|96 - 128
	\|Opus at 128 KB/s (VBR) is pretty much '''[https://en.wikipedia.org/wiki/Transparency_(data_compression) transparent]'''.		\|Opus at 128 KB/s (VBR) is pretty much '''[https://en.wikipedia.org/wiki/Transparency_(data_compression) transparent]'''.
	\|-		\|-
	\|6 (5.1 surround)		\|6 (5.1 surround)
	\|128-256		\|128 - 256
	\|rowspan="2"\|For surround sound, Opus uses '''[https://xiph.org/~xiphmont/demo/opus/demo3.shtml surround-sound bitrate allocation]'''.		\|rowspan="2"\|For surround sound, Opus uses '''[https://xiph.org/~xiphmont/demo/opus/demo3.shtml surround-sound bitrate allocation]'''.
	\|-		\|-
	\|8 (7.1 surround)		\|8 (7.1 surround)
	\|256-450		\|256 - 450
	\|-		\|-
	\|Music Archiving		\|Music Archiving
	\|1-8		\|1 - 8
	\|Use '''[[FLAC]]'''		\|Use '''[[FLAC]]'''
	\|If you are archiving audio, use a '''[https://en.wikipedia.org/wiki/Audio_file_format#Lossless_compressed_audio_format lossless audio format]''' to prevent '''[https://en.wikipedia.org/wiki/Generation_loss generation loss]'''.		\|If you are archiving audio, use a '''[https://en.wikipedia.org/wiki/Audio_file_format#Lossless_compressed_audio_format lossless audio format]''' to prevent '''[https://en.wikipedia.org/wiki/Generation_loss generation loss]'''.

MrZeus: /* Recommended Bitrates */ capitalisation, label listening test results with bitrate

2016-11-09T11:32:38Z

Recommended Bitrates: capitalisation, label listening test results with bitrate

← Older revision		Revision as of 11:32, 9 November 2016
Line 17:		Line 17:
	\|Low bandwidth HF/VHF digital radio		\|Low bandwidth HF/VHF digital radio
	\|1 (mono)		\|1 (mono)
	\|~~use~~ '''[http://www.rowetel.com/?page_id=452 Codec 2]'''		\|Use '''[http://www.rowetel.com/?page_id=452 Codec 2]'''
	\|Opus only supports bitrates down to 6 Kb/s. Codec 2 handles ultra low bitrate speech from 0.7 to 3.2 Kb/s.		\|Opus only supports bitrates down to 6 Kb/s. Codec 2 handles ultra low bitrate speech from 0.7 to 3.2 Kb/s.
	\|-		\|-
Line 23:		Line 23:
	\|1		\|1
	\|10-24		\|10-24
	\|10 Kb/s will deliver narrowband most of the time, 24 Kb/s should give fullband.<br>More details in '''[[Opus_Recommended_Settings#Bandwidth_Transition_Thresholds\|the relevant table]]''' further down this page.		\|10 Kb/s will deliver narrowband most of the time, 24 Kb/s should give fullband.<br>
			More details in '''[[Opus_Recommended_Settings#Bandwidth_Transition_Thresholds\|the relevant table]]''' further down this page.
	\|-		\|-
	\|rowspan="2"\|Audiobooks / Podcasts		\|rowspan="2"\|Audiobooks / Podcasts
	\|1		\|1
	\|24		\|24
	\|~~bitrates~~ from here on up tend to deliver fullband audio.		\|Bitrates from here on up tend to deliver fullband audio.
	\|-		\|-
	\|2 (stereo)		\|2 (stereo)
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	\|2		\|2
	\|64-96		\|64-96
	\|Opus has better quality than MP3, AAC and [[Vorbis]] at these rates.<br>(test results '''[http://listening-tests.hydrogenaud.io/igorc/results.html ~~here~~]''' ~~and~~ '''[http://listening-test.coresv.net/results.htm ~~here~~]''')		\|Opus has better quality than MP3, AAC and [[Vorbis]] at these rates.<br>
			(listening test results: '''[http://listening-tests.hydrogenaud.io/igorc/results.html 64 Kb/s]''', '''[http://listening-test.coresv.net/results.htm 96 Kb/s]''')
	\|-		\|-
	\|rowspan="3"\|Music Storage		\|rowspan="3"\|Music Storage
	\|2		\|2
	\|96-128		\|96-128
	\|Opus at 128 KB/s (VBR) is pretty much '''[https://en.wikipedia.org/wiki/Transparency_(data_compression) transparent]'''		\|Opus at 128 KB/s (VBR) is pretty much '''[https://en.wikipedia.org/wiki/Transparency_(data_compression) transparent]'''.
	\|-		\|-
	\|6 (5.1 surround)		\|6 (5.1 surround)
	\|128-256		\|128-256
	\|rowspan="2"\|~~for~~ surround sound, Opus uses '''[https://xiph.org/~xiphmont/demo/opus/demo3.shtml surround-sound bitrate allocation]'''		\|rowspan="2"\|For surround sound, Opus uses '''[https://xiph.org/~xiphmont/demo/opus/demo3.shtml surround-sound bitrate allocation]'''.
	\|-		\|-
	\|8 (7.1 surround)		\|8 (7.1 surround)
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	\|Music Archiving		\|Music Archiving
	\|1-8		\|1-8
	\|~~use~~ '''[[FLAC]]'''		\|Use '''[[FLAC]]'''
	\|if you are archiving audio, use a '''[https://en.wikipedia.org/wiki/Audio_file_format#Lossless_compressed_audio_format lossless audio format]''' to prevent '''[https://en.wikipedia.org/wiki/Generation_loss generation loss]'''		\|If you are archiving audio, use a '''[https://en.wikipedia.org/wiki/Audio_file_format#Lossless_compressed_audio_format lossless audio format]''' to prevent '''[https://en.wikipedia.org/wiki/Generation_loss generation loss]'''.
	\|}		\|}