079a5b3d8c
captions fetcher architecture. 1. ManifestlessCaptionsMetadata Other captions fetchers must first fetch a manifest (HLS or manifest) to discover captions tracks. This process does not exist for manifestless. All we need to do is scan the FormatStream's for the right itag, so this is an all-static class. 2. ManifestlessSubtitleWindowProvider Once a captions track is selected, a subtitles provider is instantiated. This is the main interface used by the player to retrieve captions according to playback position. This class stores fetched captions in a tree index by time for efficient lookups. Background captions fetches are used to populate the tree. 3. ManifestlessCaptionsFetch Captions are fetched one segment at a time. One instance of this object is required per fetch. It performs a blocking fetch on call(), and is intended to be submitted to a background-thread executor. 4. ManifestlessCaptionsFetch.CaptionSegment This is the result of the caption fetch. These values are used to populate the captions tree. Manifestlessness The initial request is always a headm request. There is a separate tree of every segment indexed by start time. This tree is used to improve manifestless sequence number calculation. Once we have data for the current timestamp, we walk forward through the tree to find the next unfetched sequence number, and fetch that. ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=177385094
ExoPlayer library
The ExoPlayer library is split into multiple modules. See ExoPlayer's top level README for more information about the available library modules and how to use them.