Glossary

Playlist: This is a representation of an HLS or DASH manifest.

Media Playlist: This is a manifest that represents a single rendition or media stream of the source.

Master Playlist Controller: This acts as the main controller for the playback engine. It interacts with the SegmentLoaders, PlaylistLoaders, PlaybackWatcher, etc.

Playlist Loader: This will request the source and load the master manifest. It is also instructed by the ABR algorithm to load a media playlist or wraps a media playlist if it is provided as the source. There are more details about the playlist loader here.

DASH Playlist Loader: This will do as the PlaylistLoader does, but for DASH sources. It also handles DASH specific functionaltiy, such as refreshing the MPD according to the minimumRefreshPeriod and synchronizing to a server clock.

Segment Loader: This determines which segment should be loaded, requests it via the Media Segment Loader and passes the result to the Source Updater.

Media Segment Loader: This requests a given segment, decrypts the segment if necessary, and returns it to the Segment Loader.

Source Updater: This manages the browser's SourceBuffers. It appends decrypted segment bytes provided by the Segment Loader to the corresponding Source Buffer.

ABR(Adaptive Bitrate) Algorithm: This concept is described more in detail here. Our chosen ABR algorithm is referenced by selectPlaylist and is described more here.

Playback Watcher: This attemps to resolve common playback stalls caused by improper seeking, gaps in content and browser issues.

Sync Controller: This will attempt to create a mapping between the segment index and a display time on the player.