Video type parameters. The <video> element allows UA capability-based fallback with multiple alternative video resources designated by multiple <source> elements.
The UA is expected to pick the alternative it tries to play by comparing the information given in the type attribute against its knowledge about its own playback capabilities. The same information is also exposed to scripts via the canPlayType function. The main media type designates the container format.
In general, it does not say anything about codecs needed to decode the streams packaged in the container.
2D & 3D Animation. Visualizations. Design Helper.