The OPUS file format stores data in the OPUS format. Converting to FLV produces a video file that packages Sorenson Spark or VP6 video in Adobe's Flash container, now largely obsolete following the end of Flash Player support. This wraps the audio track in a video container, which some platforms require for upload. Metadata such as creation date and embedded colour profiles is preserved where the target format supports it. This makes FLV the practical choice when the destination system requires it or when the original format is not supported by the target application. 1converter runs this conversion on the server: your file is uploaded encrypted over HTTPS, converted using trusted open-source libraries, and the output is held for 24 hours before automatic deletion.