Alpine HDS-990 HDS-990 Owners Manual - Page 29

What is MP3? MP3, whose official name is "MPEG Audio Layer 3", is a compression standard specified by MPEG, a joint executive body under ISO (International Organization for Standardization) and IEC. MP3 files contain compressed audio data. MP3 encoding can compress audio data at an extremely high ratio, reducing the size of music files to one-tenth of the original size. At the same time, the sound quality remains close to the level of CD. The MP3 format achieves such a high compression rate by removing sounds that cannot be heard by the human ear or that are masked by other sounds. What is WMA? WMA or "Windows Media™ Audio" is compressed audio data. WMA is similar to MP3 audio data. What is AAC? AAC is the abbreviation of "Advanced Audio Coding", which is a basic audio compression format adopted by MPEG2 or MPEG4. What is M4A? M4A is the file extension of the MPEG-4 audio standard, and M4A files contain compressed audio data. What is WAV? WAV is a sound file format developed by Microsoft. It conforms to the RIFF (Resource Interchange File Format) file specification. It is used to save audio information resources on the Windows platform and is widely supported by the Windows platform and its applications. It also supports a variety of compression algorithms such as MSADPCM, CCITT A LAW, and supports multiple audio numbers, sampling frequencies and channels. The standard formatted WAV file is the same as the CD format. It also has a sampling frequency of 44.1kHz and a 16-bit quantized number. The quality of sound files is almost the same as that of CD! It is the closest to lossless music format, so the file size is relatively large. What is FLAC? FLAC Chinese can be interpreted as lossless audio compression coding. FLAC is a 26 EN well-known set of free audio compression coding, which is characterized by lossless compression. Unlike other lossy compression codes such as MP3 and AAC, it will not destroy any original audio information. What is APE? APE is one of the popular lossless compression formats for digital music. Unlike lossy compression formats such as MP3, which irreversibly delete data (insensitive to human hearing) to reduce the size of the source file, lossless compression formats such as APE use a more refined recording method to reduce the volume. The source file is the same, thus ensuring the integrity of the file. What is DSD? The DSD music format is a format of lossless music. Because its encoding method is different from the ordinary encoding method, it is a digital encoding, so it has become a niche and special music format. How to create MP3/WMA/AAC/M4A/WAV/FLAC/APE/DSD files Audio data is compressed using software with MP3/WMA/AAC/M4A/WAV/FLAC/APE/DSD codec. About creating MP3/WMA/AAC/ For detailed information about /M4A/WAV /FLAC/APE/DSD files, please refer to the software user manual. MP3/WMA/AAC/M4 A/WAV/FLAC/APE/DSD files that can be pl ayed by this unit have the following file extensions. MP3："mp3" WMA："wma" AAC："m4a" M4A："m4a" WAV："wav" FLAC："flac" APE："ape" DSD："dsf"or"dff" Files without extension cannot be played. It does not support WMA Lossless, WMA Professional, protected files, or original AAC files (with ".aac" as the extension). There are many different versions of the AAC format. Confirm that the software used conforms to the above acceptable format.