On December 4, 2009, On2 Technologies announced the availability of its On2 VP8 SDK for DirectShow software. The software development kit enables developers to create applications for VP8 within the Microsoft DirectShow multimedia framework included in Microsoft Windows. In addition to functions for encoding and decoding VP6 for Flash and VP8 video streams, the SDK contains DirectShow filters for combining video with audio streams in MP4 multimedia file containers as well as video resizing, deinterlacing, and editing. The SDK brings On2's advanced Flash video format to a popular Windows multimedia framework. With the release of the VP8 SDK for DirectShow, the family of SDKs for On2's next-generation VP8 video format has grown to four. In addition to the DirectShow SDK, On2 has already released low-level VP8 codec SDKs for Windows, Linux and Mac OS.