OpusExtensions - Revision history

MarkH: RFC 7845

2016-05-01T04:12:43Z

RFC 7845

← Older revision		Revision as of 04:12, 1 May 2016
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	== List of reserved invalid Opus TOC sequences ==		== List of reserved invalid Opus TOC sequences ==

	* `Op` is used as a prefix for metadata headers in .opus files. [https://tools.ietf.org/html/~~draft-ietf-codec-oggopus~~ RFC 7845]		* `Op` is used as a prefix for metadata headers in .opus files. [https://tools.ietf.org/html/rfc7845 RFC 7845]
	* '0x3FF' in the first 11 bits marks an `opus_control_header` in MPEG-TS. [[OpusTS]]		* '0x3FF' in the first 11 bits marks an `opus_control_header` in MPEG-TS. [[OpusTS]]

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	* 0x4F07...0x4F40		* 0x4F07...0x4F40
	* 0x4F47...0x4F6F		* 0x4F47...0x4F6F
	* 0x4F70 ("Op"): ID and Comment headers in .opus files [https://tools.ietf.org/html/~~draft-ietf-codec-oggopus~~ RFC 7845]		* 0x4F70 ("Op"): ID and Comment headers in .opus files [https://tools.ietf.org/html/rfc7845 RFC 7845]
	* 0x4F71...0x4F80		* 0x4F71...0x4F80
	* 0x4F87...0x4FC0		* 0x4F87...0x4FC0

Derf: Fix off-by-one in start of each range (thanks to Mark Harris for the report)

2016-04-19T21:49:51Z

Fix off-by-one in start of each range (thanks to Mark Harris for the report)

Show changes

Rillian: merge sections

2016-04-19T21:20:31Z

merge sections

← Older revision		Revision as of 21:20, 19 April 2016
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	* `Op` is used as a prefix for metadata headers in .opus files. [https://tools.ietf.org/html/draft-ietf-codec-oggopus RFC 7845]		* `Op` is used as a prefix for metadata headers in .opus files. [https://tools.ietf.org/html/draft-ietf-codec-oggopus RFC 7845]
	* '0x3FF' in the first 11 bits marks an `opus_control_header` in MPEG-TS. [[OpusTS]]		* '0x3FF' in the first 11 bits marks an `opus_control_header` in MPEG-TS. [[OpusTS]]

	~~== Constructing invalid TOC sequences ==~~

	~~The only restriction that doesn't depend on the number of bytes~~
	~~in the packet is [R5], which is, "Code 3 packets contain at least~~
	~~one frame, but no more than 120 ms of audio total."~~

	== Space of all invalid Opus TOC sequences ==		== Space of all invalid Opus TOC sequences ==
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	* 0xE3F0...0xE3FF		* 0xE3F0...0xE3FF

			The only restriction that doesn't depend on the number of bytes
			in the packet is [R5], which is, "Code 3 packets contain at least
			one frame, but no more than 120 ms of audio total."
	* 0xE700		* 0xE700
	* 0xE730...0xE740		* 0xE730...0xE740

Derf: Add list of all invalid TOC sequences (both assigned and unassigned)

2016-04-19T21:06:01Z

Add list of all invalid TOC sequences (both assigned and unassigned)

Show changes

Rillian: Derf's braindump from IRC

2016-04-19T20:50:08Z

Derf's braindump from IRC

← Older revision		Revision as of 20:50, 19 April 2016
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	* `Op` is used as a prefix for metadata headers in .opus files. [https://tools.ietf.org/html/draft-ietf-codec-oggopus RFC 7845]		* `Op` is used as a prefix for metadata headers in .opus files. [https://tools.ietf.org/html/draft-ietf-codec-oggopus RFC 7845]
	* '0x3FF' in the first 11 bits marks an `opus_access_unit` in mpeg-ts. [[OpusTS]]		* '0x3FF' in the first 11 bits marks an `opus_access_unit` in mpeg-ts. [[OpusTS]]

			== Constructing invalid sequences ==

			The only restriction that doesn't depend on the number of bytes
			in the packet is [R5], which is, "Code 3 packets contain at least
			one frame, but no more than 120 ms of audio total."

Rillian: opus_audio_descriptor isn't a PES packet, and starts with a valid TOC, so it doesn't belong on this list.

2016-04-19T20:47:12Z

opus_audio_descriptor isn't a PES packet, and starts with a valid TOC, so it doesn't belong on this list.

← Older revision		Revision as of 20:47, 19 April 2016
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	* `Op` is used as a prefix for metadata headers in .opus files. [https://tools.ietf.org/html/draft-ietf-codec-oggopus RFC 7845]		* `Op` is used as a prefix for metadata headers in .opus files. [https://tools.ietf.org/html/draft-ietf-codec-oggopus RFC 7845]
	* '0x3FF' in the first 11 bits marks an `opus_access_unit` in mpeg-ts. [[OpusTS]]		* '0x3FF' in the first 11 bits marks an `opus_access_unit` in mpeg-ts. [[OpusTS]]
	* '0x7F` is the tag for the `opus_audio_descriptor` in mpeg-ts. [[OpusTS]]

Rillian at 20:32, 19 April 2016

2016-04-19T20:32:46Z

← Older revision		Revision as of 20:32, 19 April 2016
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	== List of invalid Opus audio data sequences ==		== List of invalid Opus audio data sequences ==

	* `Og` is used as a prefix for metadata headers in .opus files. [https://tools.ietf.org/html/draft-ietf-codec-oggopus RFC 7845]		* `Op` is used as a prefix for metadata headers in .opus files. [https://tools.ietf.org/html/draft-ietf-codec-oggopus RFC 7845]
	* '0x3FF' in the first 11 bits marks an `opus_access_unit` in mpeg-ts. [[OpusTS]]		* '0x3FF' in the first 11 bits marks an `opus_access_unit` in mpeg-ts. [[OpusTS]]
	* '0x7F` is the tag for the `opus_audio_descriptor` in mpeg-ts. [[OpusTS]]		* '0x7F` is the tag for the `opus_audio_descriptor` in mpeg-ts. [[OpusTS]]

Rillian: fix references

2016-04-19T20:20:38Z

fix references

← Older revision		Revision as of 20:20, 19 April 2016
Line 5:		Line 5:
	== List of invalid Opus audio data sequences ==		== List of invalid Opus audio data sequences ==

	* `Og` is used as a prefix for metadata headers in .opus files. [[https://tools.ietf.org/html/draft-ietf-codec-oggopus RFC 7845]]		* `Og` is used as a prefix for metadata headers in .opus files. [https://tools.ietf.org/html/draft-ietf-codec-oggopus RFC 7845]
	* '0x3FF' in the first 11 bits marks an `opus_access_unit` in mpeg-ts. [[OpusTS]		* '0x3FF' in the first 11 bits marks an `opus_access_unit` in mpeg-ts. [[OpusTS]]
	* '0x7F` is the tag for the `opus_audio_descriptor` in mpeg-ts. [[OpusTS]]		* '0x7F` is the tag for the `opus_audio_descriptor` in mpeg-ts. [[OpusTS]]

Rillian: Update mpeg-ts

2016-04-19T20:19:51Z

Update mpeg-ts

← Older revision		Revision as of 20:19, 19 April 2016
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	* `Og` is used as a prefix for metadata headers in .opus files. [[https://tools.ietf.org/html/draft-ietf-codec-oggopus RFC 7845]]		* `Og` is used as a prefix for metadata headers in .opus files. [[https://tools.ietf.org/html/draft-ietf-codec-oggopus RFC 7845]]
	* '??` ~~an 11~~-~~bit sequence (not yet defined)~~ is ~~used to distinguish~~ `~~opus_control_header~~` ~~packets~~ in ~~MPEG~~-TS. [[OpusTS]]		* '0x3FF' in the first 11 bits marks an `opus_access_unit` in mpeg-ts. [[OpusTS]
			* '0x7F` is the tag for the `opus_audio_descriptor` in mpeg-ts. [[OpusTS]]

Rillian: Start a page to track invalid TOC sequences used for extensions.

2016-04-19T19:51:37Z

Start a page to track invalid TOC sequences used for extensions.

New page

Opus audio data packets begin with a "table of contents" (TOC) sequence which defines the frame duration, audio bandwidth and coding mode of the packet, as well as describing how individual frames are packed into the data packet. [[https://tools.ietf.org/html/rfc6716#section-3.1 RFC 6716 Section 3.1]]. Other types of data packets are used with Opus in various containers are designed to start with a sequence which is not a valid TOC. This simplifies sorting such data for muxing implementations and ensures they will be rejected by the decoder if they are accidentally passed as Opus audio data.

Below is a list of such alternate sequences, to avoid duplication.

== List of invalid Opus audio data sequences ==

* `Og` is used as a prefix for metadata headers in .opus files. [[https://tools.ietf.org/html/draft-ietf-codec-oggopus RFC 7845]]
* '??` an 11-bit sequence (not yet defined) is used to distinguish `opus_control_header` packets in MPEG-TS. [[OpusTS]]