OPUS is an audio file that is encoded using the Ogg Opus format (lossy coding). It was created for online audio streaming, that is, in order to transmit sound through a global network. The format is being developed by the Internet Engineering Task Force (IETF) and Xiph.Org communities. Applies SILK codecs when used in Skype and CELT (from Xiph.Org), provides support for variable bitrate. Most often, the OPUS codec is used for video conferencing, game chats, VoIP telephony. OPUS is a free audio codec that has international standard status (IETF RFC 6716). Its main advantages are a low coding delay (from 2.5 to 60 ms) and its significant speed, an increased degree of compression of audio data with high-quality sound, as well as support for multi-channel audio (within 255 channels). In 2011, J. Skeglund of Google conducted two series of tests, during which OPUS coding and decoding were compared, taking into account the assessments of experts and ordinary listeners. Studies have shown that OPUS provides stereo music with the same quality as MP3 and better quality than G.719 64 kbps. OPUS offers great streaming capabilities with dynamic tweaking and very low latency. This is always high sound quality and excellent data compression. Full support for OPUS is provided by Mozilla applications. He is the key Skype audio codec.
AIF (AIFF) is an audio file format. Under the name Audio Interchange File Format (AIFF), it was developed in 1988 by Apple Computer Corporation. At the same time, the IFF format from the developer Electronic Arts has become the base. This format is commonly used on Apple Macintosh PCs. An AIFF file is an uncompressed CD-quality audio that is very similar to the .WAV format. Since there is no compression in AIFF, the file takes up more space compared to compressed counterparts: 1 minute of standard stereo audio usually takes about 10 MB. AIFF is a format that has found application in professional audio and video applications, because compared to such a popular format as mp3, the sound does not lose quality in it. The extension for a standard file of this format is .AIFF or .AIF. AIFF is mainly used in working with sound professionals who need to preserve high-quality sound bites, sound tracks. Most types of musical equipment support the loading of sound clips in AIFF format. AIFF audio files are usually large. They occupy approximately 10 MB per minute of sound. AIFF audio files have good support among universal players and multimedia software.