MP2 is an extension of compressed MPEG Layer II audio files. This type of file is still the standard format for digital television and radio. However, most users prefer the MP3 format. The MP2 file is compatible with most portable audio players. We emphasize that for certain devices it is necessary to convert MP2 files to MP3 format. Note that MP2 files are not identical to MPEG-2 video files. Typically, an MPEG-2 video file is used as an MPG extension. In some cases, MP2 files are called musicam files, which cannot be considered correct. In the 80s of the last century, specialists developed many versions of MP files. It was then that the developers of the International Standardization Organization Moving Picture Experts Group (MPEG) were engaged in new standards for digital encoding of audio and video data. Part of the initial release of the MP1 files were 3 separate layers of the audio file. In the 90s, they developed the MP2 format. To this day, this format is used for digital television and radio broadcasting. Due to its broad support for MPEG-1, MP2 files can be played, saved, converted and edited by a multitude of multimedia players and audio editors on a wide variety of platforms and operating systems.
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.