What is Metadata
Simply put, it is data about data. For example, a piece of paper contains data for 10 lines. Of these, five lines are in bold and five lines are normal. Again, total number of capital letters is twenty. So here is how a metadata for this paper will look like: Total lines: 10 Bold: 5
Capital letters: 20
Now if the above data is pasted on top of the paper, it will be a metadata of the paper. Simple.
In this case, the information that composes an FLV file is the data, and the metadata is information about that video. The length of the video (duration), the number of frames per second that the video displays (frame rate), and the number of kilobytes of data transferred per second when the video plays (video and audio data rates, where applicable) are all examples of video metadata. Additionally, the codec used to encode the video is also available.
Importance of FLV Metadata
Most FLV players read the metadata first to know the duration of the video file. After that it initializes or synchronizes the video file with its timeline or seekbar. If there is no metadata the seekbar will not progress with the video. Secondly, for more intelligent FLV players that serve the video or rather buffer the video dynamically, depending on the user’s internet speed, the FLV players read the FLV video bitrate from the FLV metadata and then sets the buffer accordingly.