High Definition Compatible Digital - Revision history

Porcuswiki: Wayback Machine link

2024-08-31T04:30:57Z

Wayback Machine link

← Older revision		Revision as of 04:30, 31 August 2024
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	keep the code detect timers in the decoder active and to update the decoder if one starts playing a		keep the code detect timers in the decoder active and to update the decoder if one starts playing a
	selection in the middle of a continuous recording.		selection in the middle of a continuous recording.
	:— "extract from the AES paper presented by Keith Johnson" [https://hydrogenaud.io/index.php/topic,79427.msg900371.html#msg900371] paper:[~~http~~://www.goodwinshighend.com/music/hdcd/aes_paper.pdf]		:— "extract from the AES paper presented by Keith Johnson" [https://hydrogenaud.io/index.php/topic,79427.msg900371.html#msg900371] paper:[https://web.archive.org/web/20150520174117/https://www.goodwinshighend.com/music/hdcd/aes_paper.pdf]

	===Regarding the Low-level Gain Adjustment feature===		===Regarding the Low-level Gain Adjustment feature===
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	==External links==		==External links==
	* [~~http~~://www.goodwinshighend.com/music/hdcd/aes_paper.pdf Compatible Resolution Enhancement in Digital Audio Systems], a paper presented to AES Convention 1996 by Keith Johnson		* [https://web.archive.org/web/20150520174117/https://www.goodwinshighend.com/music/hdcd/aes_paper.pdf Compatible Resolution Enhancement in Digital Audio Systems], a paper presented to AES Convention 1996 by Keith Johnson
	* {{ha\|https://hydrogenaud.io/index.php/topic,79427.msg737725.html#msg737725\|Charles Hansen describes HDCD}}		* {{ha\|https://hydrogenaud.io/index.php/topic,79427.msg737725.html#msg737725\|Charles Hansen describes HDCD}}

D235j: added Ed Meitner patent

2020-10-23T17:40:56Z

added Ed Meitner patent

← Older revision		Revision as of 17:40, 23 October 2020
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	[T]he PM Model One and Model Two professional units, which were combination A/D and D/A converters) that had two different playback (reconstruction) filters for HDCD. While the PM A/D used two different anti-aliasing filters while performing A/D conversion (depending on the level of high-frequency content), they were precluded from using two different playback filters as Ed Meitner had already patented that idea for Museatex (now out of business).		[T]he PM Model One and Model Two professional units, which were combination A/D and D/A converters) that had two different playback (reconstruction) filters for HDCD. While the PM A/D used two different anti-aliasing filters while performing A/D conversion (depending on the level of high-frequency content), they were precluded from using two different playback filters as Ed Meitner had already patented that idea for Museatex (now out of business).
	:— CHansen [http://www.head-fi.org/t/65414/hdcd-list/570#post_12725140]		:— CHansen [http://www.head-fi.org/t/65414/hdcd-list/570#post_12725140]
			:— US Patent Number 5,388,221: [https://patents.google.com/patent/US5388221A]

	===HA Forum posts of interest===		===HA Forum posts of interest===

73.145.58.240: /* HDCD never caught on */

2020-08-24T20:05:02Z

HDCD never caught on

← Older revision		Revision as of 20:05, 24 August 2020
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	</pre>		</pre>

	== HDCD ~~was (mostly) a scam~~ ==		== HDCD never caught on ==

	For casual readers, here is what you need to know about the existence of HDCD.		For casual readers, here is what you need to know about the existence of HDCD.

98.161.19.41: /* Audio players */

2020-01-01T17:06:27Z

Audio players

← Older revision		Revision as of 17:06, 1 January 2020
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	* [[dBpoweramp]] will decode HDCD to 24-bit PCM (uses the hdcd.exe tool for processing)		* [[dBpoweramp]] will decode HDCD to 24-bit PCM (uses the hdcd.exe tool for processing)
	* [[CUETools]]		* [[CUETools]]
			* [https://www.jriver.com/index.html JRiver Media Center]

	=== hdcd.exe ===		=== hdcd.exe ===

Beardgoggles: /* Links */ Added "See also" section.

2019-07-14T14:42:16Z

Links: Added "See also" section.

← Older revision		Revision as of 14:42, 14 July 2019
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	* [https://hydrogenaud.io/index.php/topic,30999.msg778685.html#msg778685 Gumboot - 12 December, 2011, 12:21:01 PM], re: nearly stateless		* [https://hydrogenaud.io/index.php/topic,30999.msg778685.html#msg778685 Gumboot - 12 December, 2011, 12:21:01 PM], re: nearly stateless

	==~~Links~~==		==See also==
			* [[foobar2000:HDCD decoder (foo_hdcd)\|HDCD decoder (foo_hdcd)]], a foobar2000 component

			==External links==
	* [http://www.goodwinshighend.com/music/hdcd/aes_paper.pdf Compatible Resolution Enhancement in Digital Audio Systems], a paper presented to AES Convention 1996 by Keith Johnson		* [http://www.goodwinshighend.com/music/hdcd/aes_paper.pdf Compatible Resolution Enhancement in Digital Audio Systems], a paper presented to AES Convention 1996 by Keith Johnson
	* [https://hydrogenaud.io/index.php/topic,79427.msg737725.html#msg737725 ~~CHansen~~ describes HDCD~~] at HA forum~~		* {{ha\|https://hydrogenaud.io/index.php/topic,79427.msg737725.html#msg737725\|Charles Hansen describes HDCD}}

Bp: /* Audio Formats */ add some info about what formats may contain HDCD packets

2016-09-12T20:47:29Z

Audio Formats: add some info about what formats may contain HDCD packets

← Older revision		Revision as of 20:47, 12 September 2016
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	* See a full technical examination by Jim Lesurf: [http://www.audiomisc.co.uk/HFN/HDCD/Enigma.html Page 1] [http://www.audiomisc.co.uk/HFN/HDCD/Examined.html Page 2]		* See a full technical examination by Jim Lesurf: [http://www.audiomisc.co.uk/HFN/HDCD/Enigma.html Page 1] [http://www.audiomisc.co.uk/HFN/HDCD/Examined.html Page 2]

			== Audio Formats ==
			The Model Two supported all CD-Audio and DVD-Audio formats. Sample rates of 44100, 88200, 176400, 48000, 96000, or 192000 Hz, and bit depths of 16, 20, or 24 bits. HDCD packets may appear in any PCM that passed through a Model Two.

	== Decoding software ==		== Decoding software ==

Bp: /* Analyze mode */

2016-08-27T06:30:28Z

Analyze mode

← Older revision		Revision as of 06:30, 27 August 2016
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	! Track		! Track
	! Option setting		! Option setting
			! hdcd-detect option
	! Description		! Description
	\|-		\|-
	\| 1 \|\| analyze_mode=off \|\| HDCD decoded		\| 1 \|\| analyze_mode=off \|\| -z off \|\| HDCD decoded
	\|-		\|-
	\| 2 \|\| analyze_mode=lle \|\| LLE gain adjust levels in each sample		\| 2 \|\| analyze_mode=lle \|\| -z lle \|\| LLE gain adjust levels in each sample
	\|-		\|-
	\| 3 \|\| analyze_mode=pe \|\| Samples where PE occurs		\| 3 \|\| analyze_mode=pe \|\| -z pe \|\| Samples where PE occurs
	\|-		\|-
	\| 4 \|\| analyze_mode=pe:force_pe=true \|\| Original sample was in the -3dBFS range (should match above when PE is permanent, but maybe not when it isn't)		\| 4 \|\| analyze_mode=pe:force_pe=true \|\| -z pel \|\| Original sample was in the -3dBFS range (should match above when PE is permanent, but maybe not when it isn't)
	\|-		\|-
	\| 5 \|\| analyze_mode=tgm \|\| Samples where the target_gain was ignored because it didn't match in both channels		\| 5 \|\| analyze_mode=tgm \|\| -z tgm \|\| Samples where the target_gain was ignored because it didn't match in both channels
	\|-		\|-
	\| Not shown \|\| analyze_mode=cdt \|\| Samples where HDCD decoding was active (whole track in this case)		\| Not shown \|\| analyze_mode=cdt \|\| -z cdt \|\| Samples where HDCD decoding was active (whole track in this case)
	\|-		\|-
	\| Not shown \|\| analyze_mode=lle:process_stereo=false \|\| Similar to tgm, but shows the level at each sample in each channel		\| Not shown \|\| analyze_mode=lle:process_stereo=false \|\| -z ltgm \|\| Similar to tgm, but shows the level at each sample in each channel
	\|}		\|}

Bp: /* libhdcd */ update

2016-08-26T09:02:51Z

libhdcd: update

← Older revision		Revision as of 09:02, 26 August 2016
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	It comes with a detection/decoder tool:		It comes with a detection/decoder tool:
	hdcd-detect ~~HDCD16~~.wav ~~OUT24~~.wav		hdcd-detect -o OUT24.wav HDCD16.wav
	If an output file is not specified, only HDCD detection information is printed.		If an output file is not specified, only HDCD detection information is printed.

Bp: /* Interesting Notes */

2016-08-26T04:13:21Z

Interesting Notes

← Older revision		Revision as of 04:13, 26 August 2016
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	[T]he PM Model One and Model Two professional units, which were combination A/D and D/A converters) that had two different playback (reconstruction) filters for HDCD. While the PM A/D used two different anti-aliasing filters while performing A/D conversion (depending on the level of high-frequency content), they were precluded from using two different playback filters as Ed Meitner had already patented that idea for Museatex (now out of business).		[T]he PM Model One and Model Two professional units, which were combination A/D and D/A converters) that had two different playback (reconstruction) filters for HDCD. While the PM A/D used two different anti-aliasing filters while performing A/D conversion (depending on the level of high-frequency content), they were precluded from using two different playback filters as Ed Meitner had already patented that idea for Museatex (now out of business).
	:— CHansen [http://www.head-fi.org/t/65414/hdcd-list/570#post_12725140]		:— CHansen [http://www.head-fi.org/t/65414/hdcd-list/570#post_12725140]

			===HA Forum posts of interest===
			* [https://hydrogenaud.io/index.php/topic,30999.msg513734.html#msg513734 Christopher Key - 31 August, 2007, 04:52:24 PM]
			* [https://hydrogenaud.io/index.php/topic,30999.msg778594.html#msg778594 Gumboot - 11 December, 2011, 05:41:43 PM], re: gain change ramp
			* [https://hydrogenaud.io/index.php/topic,30999.msg778685.html#msg778685 Gumboot - 12 December, 2011, 12:21:01 PM], re: nearly stateless

	==Links==		==Links==
	* [http://www.goodwinshighend.com/music/hdcd/aes_paper.pdf Compatible Resolution Enhancement in Digital Audio Systems], a paper presented to AES Convention 1996 by Keith Johnson		* [http://www.goodwinshighend.com/music/hdcd/aes_paper.pdf Compatible Resolution Enhancement in Digital Audio Systems], a paper presented to AES Convention 1996 by Keith Johnson
	* [https://hydrogenaud.io/index.php/topic,79427.msg737725.html#msg737725 CHansen describes HDCD] at HA forum		* [https://hydrogenaud.io/index.php/topic,79427.msg737725.html#msg737725 CHansen describes HDCD] at HA forum

Bp: /* Decoding software */ libhdcd tool usage

2016-08-21T23:20:59Z

Decoding software: libhdcd tool usage

← Older revision		Revision as of 23:20, 21 August 2016
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	=== libhdcd ===		=== libhdcd ===
	An open-source HDCD decoder library exists as [https://github.com/bp0/libhdcd libhdcd]. It is based on the foo_hdcd and ffmpeg/af_hdcd work by Christopher Key, Chris Moeller (kode54), Gumboot, Burt P. and others.		An open-source HDCD decoder library exists as [https://github.com/bp0/libhdcd libhdcd]. It is based on the foo_hdcd and ffmpeg/af_hdcd work by Christopher Key, Chris Moeller (kode54), Gumboot, Burt P. and others.

			It comes with a detection/decoder tool:
			hdcd-detect HDCD16.wav OUT24.wav
			If an output file is not specified, only HDCD detection information is printed.

	=== FFmpeg ===		=== FFmpeg ===