High Definition Compatible Digital

<h2 id="technical-overview">Technical overview</h2>
HDCD encodes the equivalent of 20 bits worth of data in a <a href="/facts/16-bit_sample/xxck7aLN">16-bit</a> digital audio signal by using custom <a href="/facts/Dither/fCBytTzz">dithering</a>, <a href="/facts/Audio_filter/NoWkx8fo">audio filters</a>, and some reversible amplitude and gain encoding:

<ul><li>Peak Extend, which is a reversible soft limiter;</li>
<li>Low Level Range Extend, which is a reversible gain on low-level signals.</li></ul>
There is thus a benefit at the expense of a very minor increase in noise.<a class="footnote-ref" id="fnref:6" href="#fn:6">6</a>
The claim that the encoding process is compatible with ordinary CD players (without audible distortion) is disputed: not being able to decode the peak soft limiting, a normal CD player will output distorted peaks.<a class="footnote-ref" id="fnref:7" href="#fn:7">7</a>

<h2 id="history">History</h2>
HDCD technology was developed between 1986 and 1991 by "Prof." Keith O. Johnson and Michael "Pflash" Pflaumer of <a href="/facts/Pacific_Microsonics/k6xxSATq">Pacific Microsonics</a> Inc. It was made publicly available as HDCD-enabled audio CDs (often identifiable by the HDCD logo printed on the back cover) in 1995.
Between 1996 and 1999 Pacific Microsonics VP of OEM Sales, Steve Fields, made over 20 trips to Japan, visiting <a href="/facts/Sanyo/kk7BSfKF">Sanyo</a>, <a href="/facts/Burr-Brown_Corporation/V0oHK93j">Burr-Brown Japan</a> and major audio companies, with the intent of licensing the HDCD technology. In 1998, Burr-Brown (now part of <a href="/facts/Texas_Instruments/88NUhuHF">Texas Instruments</a>) and Sanyo Electronics of Japan introduced low-cost <a href="/facts/Digital-to-analog_converter/5loEvAeb">digital-to-analog converters</a> with HDCD decoding included, allowing HDCD to be used in CD and DVD players in the $100 range. HDCD algorithms were included in DVD chips from many <a href="/facts/Integrated_circuit/fjn6vg7C">IC</a> makers including <a href="/facts/Motorola/ztqczx68">Motorola</a> and <a href="/facts/C-Cube/2pLwpXBI">C-Cube</a>, allowing HDCD to be offered by mass-market DVD player makers such as <a href="/facts/Panasonic/TqkBQmgj">Panasonic</a> and <a href="/facts/Toshiba/QHRaw8Tr">Toshiba</a>.
In 2000, Pacific Microsonics folded and Microsoft acquired the company and all of its intellectual property.<a class="footnote-ref" id="fnref:8" href="#fn:8">8</a><a class="footnote-ref" id="fnref:9" href="#fn:9">9</a> Microsoft discontinued the official HDCD website in 2005.
In January 2007, there were roughly the same number of titles available on <a href="/facts/Super_Audio_CD/f4a7Gu0V">SACD</a> as on HDCD-encoded CDs.

<h2 id="hardware-players">Hardware players</h2>
A number of manufacturers offer players with HDCD capability. Some Panasonic DVD players and the <a href="/facts/OPPO_Digital/3fQDhlVe">Oppo</a> line of players all feature HDCD decoding.<a class="footnote-ref" id="fnref:10" href="#fn:10">10</a><a class="footnote-ref" id="fnref:11" href="#fn:11">11</a> Several <a href="/facts/Yamaha_Corporation/VaulfF9U">Yamaha</a> Blu-ray players<a class="footnote-ref" id="fnref:12" href="#fn:12">12</a><a class="footnote-ref" id="fnref:13" href="#fn:13">13</a> as well as Emotiva CD players<a class="footnote-ref" id="fnref:14" href="#fn:14">14</a> decode HDCD.

<h2 id="software-players">Software players</h2>
<h3>Windows Media Player</h3>
Since version 9 of Microsoft's <a href="/facts/Windows_Media_Player/k6xxSATq">Windows Media Player</a> (WMP), HDCD enabled CDs can be played on personal computers fitted with a 24-bit <a href="/facts/Sound_card/bxlF4YBa">sound card</a>.<a class="footnote-ref" id="fnref:15" href="#fn:15">15</a><a class="footnote-ref" id="fnref:16" href="#fn:16">16</a>
With some HDCD discs and some DVD players using WMP, the first track may not be recognized as HDCD, but all subsequent tracks are. This is because HDCD has a control signal, and if the signal is not detected by WMP at the beginning of the song, the HDCD decoder is not activated.

<h3>Other software</h3>
In 2007, a member of the <a href="/facts/Doom9/HCImqLdj">Doom9 forum</a> authored a Windows <a href="/facts/Command-line_interface/R9JpGmXQ">CLI</a> utility, hdcd.exe,<a class="footnote-ref" id="fnref:17" href="#fn:17">17</a>[unreliable source?] to extract and decode the HDCD data in 16-bit <a href="/facts/WAV/ptUfKleW">WAV</a> files <a href="/facts/CD_ripper/kCTAbNj2">ripped</a> from HDCD discs. This utility writes <a href="/facts/24-bit_audio/24ccTeTT">24-bit</a> <a href="/facts/WAV/ptUfKleW">WAV</a> output files with four bits of padding per sample. The author of the utility decided not to make the source code publicly available as the HDCD technology is patented.<a class="footnote-ref" id="fnref:18" href="#fn:18">18</a>
Illustrate's dBpoweramp Music Converter, a Windows <a href="/facts/Graphical_user_interface/wBlQFWDP">GUI</a> program, has an HDCD <a href="/facts/Digital_signal_processing/PEG7azr8">DSP</a> effect that acts as a front-end to the utility listed above.<a class="footnote-ref" id="fnref:19" href="#fn:19">19</a>
A plugin is available for <a href="/facts/Foobar2000/Pby5dtdw">foobar2000</a> that will decode HDCD data in any 16-bit <a href="/facts/Pulse-code_modulation/5gdfjtH3">PCM</a> passed through it, resulting in a 20-bit PCM stream.<a class="footnote-ref" id="fnref:20" href="#fn:20">20</a>
<a href="/facts/FFmpeg/85yf3kHI">FFmpeg</a>'s <a href="/facts/Libavfilter/85yf3kHI">libavfilter</a> includes an HDCD filter as of FFmpeg 3.1 (June 2016) that will convert 16-bit PCM with HDCD data to 20-bit PCM.<a class="footnote-ref" id="fnref:21" href="#fn:21">21</a>
An open-source HDCD decoder library exists as libhdcd.<a class="footnote-ref" id="fnref:22" href="#fn:22">22</a>

<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/DualDisc/IUmfce1j">DualDisc</a></li>
<li><a href="/facts/DVD-Audio/X5I65Vxd">DVD-Audio</a></li>
<li><a href="/facts/Extended_Resolution_Compact_Disc/s0KSoIzM">Extended Resolution Compact Disc</a> (XRCD)</li>
<li><a href="/facts/Super_Audio_CD/f4a7Gu0V">Super Audio CD</a> (SACD)</li>
<li><a href="/facts/Super_Bit_Mapping/V2RlWbuD">Super Bit Mapping</a> (SBM)</li></ul>

<h2 id="external-links">External links</h2>
<ul><li><a href="https://web.archive.org/web/20050622080528/http://www.hdcd.com/">Microsoft's now discontinued HDCD official website</a> at the <a href="/facts/Wayback_Machine/nmQ3a6JC">Wayback Machine</a> (archived 2005-06-22)</li>
<li><a href="https://web.archive.org/web/20041204171913/http://www.hdcd.com/about/whatisHDCD.html">Microsoft's now discontinued HDCD official FAQ</a> at the <a href="/facts/Wayback_Machine/nmQ3a6JC">Wayback Machine</a> (archived 2004-12-04)</li>
<li><a href="https://web.archive.org/web/20150402044617/http://www.goodwinshighend.com/hdcd.htm">"HDCD - An Overview"</a>. Goodwin's High End. Archived from <a href="http://www.goodwinshighend.com/hdcd.htm">the original</a> on 2015-04-02.</li>
<li><a href="http://wiki.hydrogenaud.io/index.php?title=High_Definition_Compatible_Digital">High Definition Compatible Digital</a> at HydrogenAudio wiki</li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1">"Home Technology eMagazine - Classic Home Toys Installment #19 The Final CD Format: HDCD". HomeToys. 30 November 2008. Archived from the original on 21 June 2015. Retrieved 5 August 2012. <a href="https://web.archive.org/web/20150621233156/http://www.hometoys.com/article/2008/11/classic-home-toys-installment-19-the-final-cd-format-hdcd/1106/" target="_blank">https://web.archive.org/web/20150621233156/http://www.hometoys.com/article/2008/11/classic-home-toys-installment-19-the-final-cd-format-hdcd/1106/</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">"HDCD (High Definition Compatible Digital) from Pacific Microsonics". TimeForDVD.com. 23 February 2002. Retrieved 5 August 2012. <a href="http://www.timefordvd.com/ref/HDCD.shtml" target="_blank">http://www.timefordvd.com/ref/HDCD.shtml</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">"Home Technology eMagazine - Classic Home Toys Installment #19 The Final CD Format: HDCD". HomeToys. 30 November 2008. Archived from the original on 21 June 2015. Retrieved 5 August 2012. <a href="https://web.archive.org/web/20150621233156/http://www.hometoys.com/article/2008/11/classic-home-toys-installment-19-the-final-cd-format-hdcd/1106/" target="_blank">https://web.archive.org/web/20150621233156/http://www.hometoys.com/article/2008/11/classic-home-toys-installment-19-the-final-cd-format-hdcd/1106/</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">List of HDCD-encoded compact discs (with technical details) at HydrogenAudio wiki <a href="http://wiki.hydrogenaud.io/index.php?title=List_of_HDCD-encoded_Compact_Discs" target="_blank">http://wiki.hydrogenaud.io/index.php?title=List_of_HDCD-encoded_Compact_Discs</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
<li id="fn:5">List of known HDCD compact discs (names only) at Head-Fi.org <a href="http://www.head-fi.org/t/65414/hdcd-list" target="_blank">http://www.head-fi.org/t/65414/hdcd-list</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></li>
<li id="fn:6">Johnson, Keith O.; Pflaumer, Michael W. (1996-11-01). "Compatible Resolution Enhancement in Digital Audio Systems". Audio Engineering Society. Retrieved 2022-12-07. <a href="https://www.aes.org/e-lib/browse.cfm?elib=7387" target="_blank">https://www.aes.org/e-lib/browse.cfm?elib=7387</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></li>
<li id="fn:7">"The HDCD Enigma". Audiomisc.co.uk. Retrieved 2022-12-07. <a href="https://www.audiomisc.co.uk/HFN/HDCD/Enigma.html" target="_blank">https://www.audiomisc.co.uk/HFN/HDCD/Enigma.html</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
<li id="fn:8">US 5479168, Johnson, Keith O. & Pflaumer, Michael W., "Compatible signal encode/decode system", published 1995-12-26, assigned to Pacific Microsonics Inc.
 <a href="https://worldwide.espacenet.com/textdoc?DB=EPODOC&IDX=US5479168" target="_blank">https://worldwide.espacenet.com/textdoc?DB=EPODOC&IDX=US5479168</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></li>
<li id="fn:9">US 5872531, Johnson, Keith O. & Pflaumer, Michael W., "Signal encode/decode system", published 1999-02-16, assigned to Pacific Microsonics Inc.
 <a href="https://worldwide.espacenet.com/textdoc?DB=EPODOC&IDX=US5872531" target="_blank">https://worldwide.espacenet.com/textdoc?DB=EPODOC&IDX=US5872531</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></li>
<li id="fn:10">"Universal Network 3D Blu-ray Players - Buy Direct from the Manufacturer". OPPO Digital. Retrieved 2012-08-05. <a href="http://www.oppodigital.com" target="_blank">http://www.oppodigital.com</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></li>
<li id="fn:11">"Unofficial OPPO UDP-203 Frequently Asked Questions". AVSForum. Retrieved 2017-03-03. <a href="http://watershade.net/wmcclain/UDP-203-faq.html" target="_blank">http://watershade.net/wmcclain/UDP-203-faq.html</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></li>
<li id="fn:12">"Yamaha BD-A1060 Universal Blu-Ray Player Review". Secrets of Home Theater and High Fidelity. 2016-11-14. Retrieved 2017-03-04. <a href="http://hometheaterhifi.com/reviews/video-player/universal/yamaha-bd-a1060-universal-blu-ray-player-review/" target="_blank">http://hometheaterhifi.com/reviews/video-player/universal/yamaha-bd-a1060-universal-blu-ray-player-review/</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></li>
<li id="fn:13">"2 new Yamaha uni players - including one with balanced analog outputs". Steve Hoffman Music Forums. 2016-07-16. Retrieved 2017-03-04. <a href="http://forums.stevehoffman.tv/threads/2-new-yamaha-uni-players-including-one-with-balanced-analog-outputs.566747/" target="_blank">http://forums.stevehoffman.tv/threads/2-new-yamaha-uni-players-including-one-with-balanced-analog-outputs.566747/</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></li>
<li id="fn:14">"Emotiva ERC-3 Differential Reference CD Player/Digital Transport Review". Secrets of Home Theater and High Fidelity. 2014-09-02. Retrieved 2017-03-04. <a href="http://hometheaterhifi.com/reviews/audio-player/cd-players/emotiva-erc-3-differential-reference-cd-player-digital-transport-review/" target="_blank">http://hometheaterhifi.com/reviews/audio-player/cd-players/emotiva-erc-3-differential-reference-cd-player-digital-transport-review/</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></li>
<li id="fn:15">"Features of Windows Media Player 9 Series". Microsoft.com. Retrieved 2012-08-05. <a href="http://www.microsoft.com/windows/windowsmedia/player/9series/features.aspx" target="_blank">http://www.microsoft.com/windows/windowsmedia/player/9series/features.aspx</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></li>
<li id="fn:16">"Smart Jukebox Features". Microsoft.com. Retrieved 2012-08-05. <a href="http://www.microsoft.com/windows/windowsmedia/mp10/jukebox.aspx" target="_blank">http://www.microsoft.com/windows/windowsmedia/mp10/jukebox.aspx</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></li>
<li id="fn:17">utility <a href="http://forum.doom9.org/showthread.php?t=129136" target="_blank">http://forum.doom9.org/showthread.php?t=129136</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></li>
<li id="fn:18">"HDCD Software Decoder - Doom9's Forum". Forum.doom9.org. Retrieved 2012-08-05. <a href="http://forum.doom9.org/showthread.php?p=1044539#post1044539" target="_blank">http://forum.doom9.org/showthread.php?p=1044539#post1044539</a> <a href="#fnref:18" class="footnote-back-ref">↩</a></li>
<li id="fn:19">dBPoweramp's DSP Effects page [1]; dBpoweramp's local help file <a href="http://www.dbpoweramp.com/dbpoweramp-dsp.htm" target="_blank">http://www.dbpoweramp.com/dbpoweramp-dsp.htm</a> <a href="#fnref:19" class="footnote-back-ref">↩</a></li>
<li id="fn:20">"foobar2000 HDCD decoder component". Foobar2000.org. 2012-07-18. Retrieved 2012-08-05. <a href="http://www.foobar2000.org/components/view/foo_hdcd" target="_blank">http://www.foobar2000.org/components/view/foo_hdcd</a> <a href="#fnref:20" class="footnote-back-ref">↩</a></li>
<li id="fn:21">"June 27th, 2016, FFmpeg 3.1 "Laplace"". FFmpeg.org. Retrieved 2 July 2016. <a href="https://ffmpeg.org/index.html#pr3.1" target="_blank">https://ffmpeg.org/index.html#pr3.1</a> <a href="#fnref:21" class="footnote-back-ref">↩</a></li>
<li id="fn:22">"libhdcd - An HDCD decoder library". GitHub. Retrieved 21 August 2016. <a href="https://github.com/bp0/libhdcd" target="_blank">https://github.com/bp0/libhdcd</a> <a href="#fnref:22" class="footnote-back-ref">↩</a></li>
</ol>

High Definition Compatible Digital open-in-new

High Definition Compatible Digital