context: There are also open compression formats like Opus and Vorbis that are available free of charge and without any known patent restrictions. Some of the newer audio compression formats, such as AAC, WMA Pro and Vorbis, are free of some limitations inherent to the MP3 format that cannot be overcome by any MP3 encoder.
question: ఓపస్ మరియు వోర్బిస్ ఏ విధమైన సంపీడన ఫార్మాట్ యొక్క రెండు వివరణలు?
answers: open