Convert MP3 to OPUS

MP3 (formally MPEG-1 Audio Layer-3 or MPEG-2 Audio Layer-3) is a digital format for storage of audio files as well as for audio streaming. The format was designed by MPEG programmers. It is one of the most required codecs for digital coding. The format is widely used in various file-sharing sites for evaluation downloading.

Due to lossy compression in this audio format, it is possible to compress CD tracks up to 1/10 of their original size while maintaining high playback quality. Moreover, it can be encoded at higher or lower bit rates to adjust the resulting quality. Overtones, which cannot be perceived by a human ear, are removed. Complex algorithms allow for smaller size of tracks. As a result, one compact disk can contain several hundred songs. MP3 is compatible with all most popular operating systems and supported by the most of modern DVD-players and music systems.

Prior to MP3 introduction, MPEG-1 had been widely used. That format contained not only audio data, but images as well. MP3 breaks an audio file into parts of the same length. When the processing is over, each part is packed into its own frame. It involves the technology of spectral limit that requires a continuous input signal to provide the use of two adjacent frames.

When spectral deleting is over, the file is to be compressed with mathematic methods. If necessary, compression rate can be changed, even inside the same frame. Files of 128 kbit/s have 11-fold compression. Further reduction of the file size will lead to significant deterioration in sound quality.

The format has been created by IETF community for online broadcasting and is being used for lossy compression of audio data. It provides with excellent quality of sound and very good compression level due to the technology of dynamically adjusted streaming. Being a key audio codec of Skype, OPUS is based on the Skype message-transfer algorithms. As a container, they use .ogg extension.

The format uses CELT and SILK codecs, which allow easy change of bitrate within the range of 6-510 Kbit/s. That is why it has gained prevalence in video chats and video conferences, as well as IP translations.