3GA is a 3GPP audio file created in 1998. It was created by the 3rd Generation Partnership Project. It is used mainly on mobile devices in order to record, play and transmit audio data. 3GPP (3rd Generation Partnership Project) is a consortium that develops specifications for mobile telephony. The format resembles 3GP files, however, it includes only audio data. In most cases, 3GA files are used by mobile phones in order to record and transmit audio data. For example, this is how audio is recorded in Samsung Galaxy phones. The .3GA file extension can be changed to .3GP, which is widespread. Everything is supported by many programs. The 3GA format uses an adaptive coding audio codec with variable speed (AMR, AMR-NB, GSM-AMR). The development of this codec was done in order to compress encoded speech signals using adaptive modulation. In 1999, the 3GPP consortium adopted the Adaptive Variable Rate Coding (AMR) standard. Currently, it is used by GSM and UMTS communication systems. It is this format for speech recording that has found wide application on mobile devices. We note at the same time that it is not possible to play such files very often on certain devices.
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.