Kastor – Free Audio Extractor is an application that allows users to convert or extract video files to common audio files. It supports a wide range of audio and video formats including AVI, ASF, AAC, MP3, WMV, MP4, and MOV among others. Not only does this program give users the ability to convert entire videos, but parts of it as well. Furthermore, it can also perform conversions between audio formats. It has a simple user interface that features three main areas: the top part contains actions buttons, the middle part contains the file list, and the bottom part shows the actual sound file being extracted or converted.
The menu at the top enables users to perform various actions such as add files and save files in specific audio file formats. It also allows users to configure settings such as audio bit rate, frequency, quality, and audio channel, as well as view all saved files. The file list includes columns for the start and end of the extraction/conversion, file information, and the progress of the activity. The bottom part includes a visual timeline where the user can actually select the parts of a video file to be converted or extracted to audio format.