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A home theater PC (HTPC) or media center computer is a convergence device that combines some or all the capabilities of a personal computer with a software application that supports video, photo, audio playback, and sometimes video recording functionality. Although computers with some of these capabilities were available from the late 1980s, the "Home Theater PC" term first appeared in mainstream press in 1996. In recent years, other types of consumer electronics, including gaming systems and dedicated media devices have crossed over to manage video and music content. The term "media center" also refers to specialized application software designed to run on standard personal computers. An HTPC and other convergence devices integrate components of a home theater into a unit co-located with a home entertainment system. An HTPC system typically has a remote control and the software interface normally has a 10-foot user interface design so that it can be comfortably viewed at typical television viewing distances. An HTPC can be purchased pre-configured with the required hardware and software needed to add video programming or music to the PC. Enthusiasts can also piece together a system out of discrete components as part of a software-based HTPC.〔 Since 2007 Digital media player and Smart TV software has been incorporated into consumer electronics through software or hardware changes including gaming systems, Blu-ray Disc players, networked media players, televisions, and set-top boxes. The increased availability of specialized devices, coupled with paid and free digital online content, now offer alternatives to multipurpose (and more costly) personal computers. == History == The HTPC as a concept is the product of several technology innovations including high-powered home computers, digital media, and the shift from standard resolution CRT to high definition monitors, projectors, and large screen televisions. Integrating televisions and personal computers dates back to the late 1980s with tuner cards that could be added to Commodore Amiga PCs via the Video Toaster. This adaptation would allow a small video window to appear on the screen with broadcast or cable content. Apple Computer also developed the Macintosh TV in late 1993 that included a tuner card built into an Macintosh LC 520 chassis but quickly withdrew from the market with only 10,000 units shipped.〔(【引用サイトリンク】title=Macintosh 500 Series )〕 In 1996 Gateway Computer unveiled the ''Destination'' computer that included a tuner card and video card. The unit cost $4,000 and mostly integrated television viewing and computer functions on one color monitor.〔 The Destination was called a "PC-TV Combo" but by December the term "Home-theater PC" appeared in mainstream media: "The home theater PC will be a combination entertainment and information appliance". By 2000, DVD players had become relatively ubiquitous and consumers were seeking ways to improve the picture. The value of using a computer instead of stand alone DVD player drove more usage of the PC as a home media device. In particular, the desire for progressive scanning DVD players (480p instead of 480i) with better video fidelity led some consumers to consider their computers instead of very expensive DVD players. As DVD players dropped in price, so did PCs and their related video processing and storage capabilities. In 2000, DVD decryption software using the DeCSS algorithm let DVD owners consolidate their DVD video libraries on hard-drives.〔In a 2007 landmark ruling, a U.S. court found this practice legal in specific applications where the CSS encryption is transferred to the copy on the hard drive in spite of the Digital Millennium Copyright Act. 〕 Innovations like TiVo and ReplayTV allowed viewers to store and timeshift broadcast content using specialty designed computers. ReplayTV for instance ran on a VxWorks platform. Incorporating these capabilities into PCs was well within the ability of a computer hobbyist who was willing to build and program these systems. Key benefits of these DIY projects included lower cost and more features. Advancements in hardware identified another weak link: the absence of media management software to make it easy to display and control the video from a distance.〔 By 2002, major software developments also facilitated media management, hardware integration, and content presentation. MythTV provided a free and open source solution using Linux. The concept was to combine a digital tuner with digital video recording, program guides, and computer capabilities with a 10-foot user interface. XBMC was another free and open software project started with re-purposing the Xbox as a home theater PC but has since been ported to Windows and Macintosh operating systems in various forms including Boxee and Plex. Mainstream commercial software packages included Microsoft's XP Media Center Edition (2002) that was bundled with Windows XP and Apple's Front Row (2005) software bundled with Mac OS X. By early 2006, commercial examples of this integration included the Mac mini which had the Apple Remote, 5.1 digital audio, and an updated Front Row interface that would play shared media. Because of these features and the Mini's small form factor, consumers began using the Mini as a Mac-based home theater PC. As digital cable and satellite became the norm, HTPC software became more dependent on external decoder boxes, and the subscription costs that came with them. For instance, MythTV is capable of capturing unencrypted HDTV streams, such as those broadcast over the air or on cable using a QAM tuner. However, most U.S. cable and satellite set-top boxes provide only encrypted HD streams for "non-basic" content, which can be decoded only by OpenCable-approved hardware or software. In September 2009, OEM restrictions were officially lifted for cableCARD devices, opening up the possibility for HTPC integration. The advent of the fully digital HDTV displays helped to complete the value and ease of use of a HTPC system. Digital projectors, plasma and LCD displays often came pre-configured to accept computer video outputs including VGA, DVI and Component Video. Furthermore, both the computers and the displays could include video scalers to better conform the image to the screen format and resolutions. Likewise, computers also included HDMI ports that carry both audio and video signals to home video displays or AV Receivers. The simplified integration of computer and home theater displays has allowed for fully digital content distribution over the internet. For instance, by 2007 Netflix "watch instantly" subscribers could view streaming content using their HTPCs with a browser or with plug-ins with applications like Plex and XBMC. Similar plug-ins are also available for Hulu, YouTube, and broadcasters like NBC, CBS and PBS. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Home theater PC」の詳細全文を読む スポンサード リンク
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