| rdfs:comment
| - Abbreviation for the Axis & Allies 1984 edition.
- The acronym AAC may refer to:
* Advanced Audio Coding
* Aeronautical administrative communications
- AAC（Advanced Audio Coding），中文稱為「高級音頻編碼」，出现于1997年，最初是基于MPEG-2的音频编码技术。由Fraunhofer IIS、Dolby Laboratories （杜比实验室）、Apple（苹果公司）、AT&T（美国电话电报公司）、Sony（索尼）等公司共同开发，目的是取代MP3格式。2000年，MPEG-4标准出台，AAC重新整合了其特性，加入了SBR技术和PS技术，为区别于传统的MPEG-2 AAC，故含有SBR或PS特性的AAC又称为MPEG-4 AAC。
- AAC has been standardized by ISO and IEC, as part of the MPEG-2 and MPEG-4 specifications. The MPEG-2 standard contains several audio coding methods, including the MP3 coding scheme. AAC is able to include 48 full-bandwidth (up to 96 kHz) audio channels in one stream plus 16 low frequency effects (LFE, limited to 120 Hz) channels, up to 16 "coupling" or dialog channels, and up to 16 data streams. The quality for stereo is satisfactory to modest requirements at 96 kbit/s in joint stereo mode; however, hi-fi transparency demands data rates of at least 128 kbit/s (VBR). The MPEG-2 audio tests showed that AAC meets the requirements referred to as "transparent" for the ITU at 128 kbit/s for stereo, and 320 kbit/s for 5.1 audio.
- Advanced Audio Coding, shortened to AAC, is a codec developed by several high-calibre audio companies — among them Dolby, Fraunhofer, AT&T, Sony, and Nokia — to act as a progressive improvement over the MP3 format. It was formally declared an international standard in 1997 by the Moving Pictures Experts Group. The format further enables a degree of controlled distribution, since FairPlay Digital Rights Management terms are applied to AAC-encoded files at the point of purchase.
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| abstract
| - Advanced Audio Coding, shortened to AAC, is a codec developed by several high-calibre audio companies — among them Dolby, Fraunhofer, AT&T, Sony, and Nokia — to act as a progressive improvement over the MP3 format. It was formally declared an international standard in 1997 by the Moving Pictures Experts Group. It is a lossy format, meaning that some sound quality is lost in compression from native source to the resulting file. The order of loss is less than that of MP3, especially at the higher bitrates that more and more audio sources, such as Compact Discs, were able to produce, and as streaming audio technology improved. AAC gained most of its prominence from Apple when the company announced that the format would be centerpiece to its iPod product line and iTunes music service. The format further enables a degree of controlled distribution, since FairPlay Digital Rights Management terms are applied to AAC-encoded files at the point of purchase.
- Abbreviation for the Axis & Allies 1984 edition.
- The acronym AAC may refer to:
* Advanced Audio Coding
* Aeronautical administrative communications
- AAC（Advanced Audio Coding），中文稱為「高級音頻編碼」，出现于1997年，最初是基于MPEG-2的音频编码技术。由Fraunhofer IIS、Dolby Laboratories （杜比实验室）、Apple（苹果公司）、AT&T（美国电话电报公司）、Sony（索尼）等公司共同开发，目的是取代MP3格式。2000年，MPEG-4标准出台，AAC重新整合了其特性，加入了SBR技术和PS技术，为区别于传统的MPEG-2 AAC，故含有SBR或PS特性的AAC又称为MPEG-4 AAC。
- AAC has been standardized by ISO and IEC, as part of the MPEG-2 and MPEG-4 specifications. The MPEG-2 standard contains several audio coding methods, including the MP3 coding scheme. AAC is able to include 48 full-bandwidth (up to 96 kHz) audio channels in one stream plus 16 low frequency effects (LFE, limited to 120 Hz) channels, up to 16 "coupling" or dialog channels, and up to 16 data streams. The quality for stereo is satisfactory to modest requirements at 96 kbit/s in joint stereo mode; however, hi-fi transparency demands data rates of at least 128 kbit/s (VBR). The MPEG-2 audio tests showed that AAC meets the requirements referred to as "transparent" for the ITU at 128 kbit/s for stereo, and 320 kbit/s for 5.1 audio. AAC is also the default or standard audio format for: Apple's iPhone, iPod, iPad, iTunes, Nintendo DSi, DivX Plus Web Player, Sony's PlayStation 3 and is supported by Sony's PlayStation Portable, latest generation of Sony Walkman, phones from Sony Ericsson, the latest S40 and S60 models from Nokia, Android based phones, Nintendo's Wii (with the Photo Channel 1.1 update installed for Wii consoles purchased before late 2007), and the MPEG-4 video standard. The file extension is .aac.
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