Markers and Indexes

There are several differences between markers and indexes. Markers can be applied to any media type (usually audio or video) and are added to the file by the content author. Typically, a marker indicates the beginning of a particularly interesting section of the media file that a client might want to seek to. For example, if the presenter at a conference changed, then a client could seek to the next speaker. Markers can include some textural information, indicating why this point is of interest.

Indexes only apply to video files, and do not contain any additional information. Indexes are created by this SDK, not the content author, and provide a time-based method for seeking, based on the index frames produced by the video codec. If the indexing process is not completed, then only the markers available within the media file can be used for seeking. If the indexing process has been completed, then both markers and indexes can be used to seek through the file.