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27 Section 4: Video Service The name of this service is VS or Video Service. A Video Service serves a client a requested
area of interest AOI from a collection of WAMI data and delivers it as a video stream or file of a known format. Italso provides metadata about the same AOIas part of the video stream. The
video stream delivered is in a standard and known format. At least one video stream must be supported. At least one video stream must be MISB compliant to follow the MISP.
To find out collections are being served by a service, or to get information about a collection, use a Collection Service or CS. See Collection Service Specifications version 1.0.2 for more.
28 VS data model
28.1 Client Resources, Bandwidth, and Latency
The number of fielded sensors is constantly growing. For surveillance and defense applications, a web server may be required to field a large number of collections. Each collection may have
thousands to hundreds of thousands of frames. To request for N-number of AOIs from WAMI frames, you would require N requests. The networks may be high bandwidth, but with high
latency. They may not be high bandwidth either.
The interface shall provide a way to receive as much data as possible in a single request as well as allow the client to receive data in smaller chunks in parallel. The clients may not have enough
computing resources such as memory to handle a large request and therefore may also need requests that ask for small areas of interest as maps.
For low or high bandwidth networks and reasonably low latency, and for clients with limited resources, the basic method to follow could be to:
1. Divide requests for maps into reasonable sizes – in terms of width and height. 2. Send those requests out in parallel
3. Exploit the received data
For high bandwidth, high latency connections and for thick clients: 1. Know in advance how many frames of AOIs AOIs you wish to request.
2. If the AOI is the same, use GetMapVideo 3. If the AOI may change across frames, generate a track and use GetPathMapVideo
4. If you desire to display metadata, include the request for metadata. 5. Send a single GetMapVideoGetPathMapVideo request and receive a video stream with
optionally embedded metadata.
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28.2 When to use a Video Service and an Image Service
From a given set of collections of WAMI frames, for specific areas of interest over specific time windows, if you want:
1. Still images and optional metadata to play as a flip book, use an image service 2. Just the metadata about those still images, use an image service
3.
Streaming video with optional embedded metadata, use a video service
28.3 Path
