The file extension OGA is a rather rarely used extension for audio files in Vorbis (also OGG Vorbis) format. Most files in the OGG Vorbis format, regardless of the type of data with the file extension ogg provided. Any software that can handle ogg files should also be able to handle OGA files. If an OGA file is not displayed in the file selection window, changing the extension in ogg can help.
The OGG container format is a free, free-to-use format developed by Xiph.Org. The entire project, which wants to offer a free alternative to licensed formats such as aac, mp3 or h264, includes several compression methods for audio and video data. The container supports various compression methods for audio and video streams, subtitles, chapters and metadata.
Since 2007 Xiph.Org recommends using the extension ogg only for OGG Vorbis files.
The lossy compression method Vorbis was wrapped as a free alternative to MP3. Vorbis provides more efficient compression. It supports up to 255 channels in different arrangements. Uninterrupted playback, replay gain, variable bitrates and metadata are also supported.
OGG Vorbis is not as common as MP3, but the support on hardware and software side is steadily increasing. So more and more games use the OGG Vorbis format and many MP3 players can also play OGG Vorbis.
Xiph.Org provides a codec for Microsoft Windows, Apple Mac OSX and Linux that can be integrated into the operating system, so that almost every player supports this format.