Accessibility/Captioning Work Plan: Difference between revisions

There is both a container and a codec involved for each video format. For a given container, you need to have a defined (and supported by tools and other video players for network effects) mapping for muxing a giving captioning format into the container. So the video codec rules. The container depends on what's conventional for the video codec, and the choice of captioning format depends on what's conventional for the container. In theory, given a muxing rule, you can put any video codec and any captiong format in any container, but in practice, video codec tends to have a conventional native container, so the video codec dictates the container and then different containers have different conventional timed text formats and the timed text formats might not have muxing rules for non-native containers. Example: Ogg and MP4 are containers, whereas Theora and H.264 are codecs. Gstreamer and QuickTime are both timed media frameworks, which each can play various other container/codec combinations (?). Ogg, Theora and CMML are a natural match. MP4, H.264 and 3GPP TT are a natural match. While technically, you *could* define a way to put 3GPP TT inside Ogg, the disadvantage to doing this is blah.