Convert AAC to OGG

A proprietary format with lossy compression, which have been created as an alternative for MP3 with a higher quality of coding. Overtones out of human perception are being removed. AAC is two times less than MP3, which means 1/10 of CD digital data.

The format has being widely used since 1997 as the seventh release of MPEG-2 family. As it is supplied by hardware players, the format is highly demanded by music fans. It has been widely spread in Apple production and is being used by default in iTunes.

The format conception is similar to MP3, but it is more advanced. Being able to execute larger compression, it is represented as a separate segment of MPEG-4 standard which is used for creation of compact audio files. AAC is highly efficient with variable and continuous bitrate, with sampling frequency of 8-96 KHz.

The current version complies with the standard of ISO/IEC 14496-3. Compression is performed on the basis of auditory masking effect that provides with data reduction with no deterioration for sound quality.

The format is available without any restrictions. It was created in 2002 by programmers of The Xiphophorus Company (xiph.org foundation) as an open source software project and given its name after a character from Terry Pratchett’s “Small Gods”. The format is intended for multimedia playing and editing; sampling frequency is 6-192 kHz. It was designed for live streaming with an option to store some tracks with their own tags within the same file. When the file is opened in a player, all tracks show, which gives the appearance of music being opened from different files.

Originally, it was used for the entirety of OGG-using files, but for the recent ten years, it has being associated mainly with files of OGG Vorbis. The function set is the same as one of AC3 and AAC codecs, which leave the popular MP3 behind. The spread of OGG is restricted a bit due to the fact that it is not supplied by Apple products.

At its core, the extension is a container for several streams of audio, video and metadata. It generates the sound of a medium or high level within the range of 16-128 kbps/channel and exceeds MP3 by sound quality. In order to reduce the file size, the program deletes a certain amount of data, and therefore, the compression is irreversible. The format is best suited for storage of musical tracks, but it can be used as well for voice recording.