cmaf streaming

As streaming video over the internet became widespread, many different media containers and formats were introduced, became popular, and eventually became less widely used. As a streaming video service provider, this evolution of formats and standards (along with the variable combination of formats supported by different device types) meant that media often had to be stored multiple times in multiple formats and then encrypted multiple times as well, if a wide variety of end devices was to be supported. 

To address this proliferation of formats, various key industry players collaborated to develop the Common Media Application Format (CMAF). Work started as early as 2014 and the first version was published as an international standard by MPEG in January 2018. 

CMAF’s purpose is to act as a common media container for HTTP delivered adaptive bitrate video. It takes the fragmented ISOBMFF (MP4) format (as used by DASH and more lately by HLS) and adds additional restrictions to facilitate interoperability and arrive at a common media segment format for streaming for both HLS and DASH protocols. This should have quickly addressed the unnecessary proliferation of storage and processing that has characterised many streaming solutions to date. Unfortunately, it took a long time to agree on a common encryption format which resulted in a need for duplicated segments in the CDN. It is only lately that one can make encrypted media segments that work for both HLS and DASH.