AAC（高级音频编码）
AAC 是一种有损音频编解码器，在相同比特率下提供比 MP3 更好的音质。它是 Apple Music、YouTube 和大多数流媒体服务的默认音频格式。AAC 支持多声道音频，是 MPEG-4 标准的一部分。
MIME 类型
audio/aac
类型
二进制
压缩
有损
优点
- + Better audio quality than MP3 at equivalent bitrates
- + Native support in Apple, Android, YouTube, and streaming platforms
- + Supports multichannel surround sound (up to 48 channels)
- + HE-AAC profiles enable high-quality low-bitrate streaming
缺点
- − Lossy compression still discards audio data permanently
- − Licensing fees apply for AAC encoder distribution
- − Some open-source tools have limited AAC encoding support
何时使用 .AAC
当需要在较低比特率下获得比 MP3 更好的音质时，将 AAC 用于音频流、播客和移动端分发。
技术细节
AAC 使用改进的 DCT 以及增强的心理声学模型、时域噪声整形 (TNS) 和预测工具。配置文件包括 AAC-LC（低复杂度）、HE-AAC（用于流媒体的高效版）和 xHE-AAC。
历史
AAC 由 Dolby、Fraunhofer、Sony、Nokia 和 AT&T 等组成的联盟在 1990 年代中期开发。它于 1997 年标准化为 ISO/IEC 13818-7 (MPEG-2 Part 7)，并在 MPEG-4 (ISO/IEC 14496-3) 中得到改进。
从 .AAC 转换
转换为 .AAC
相关格式
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