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CSPS streams_v0.2
The concept of streams is a the central point of CSPS library realizing the link between library modules. This pages gives a presentation of streams considered in the CSPS topology.
Streams are vectors of unidimensional array of the same length that are called stream components and that stores physical quantities or information related to time. Each stream have to carry a component that stores the timestamp related to the quantities stored in the other components.
Because CSPS library as to handle earth positioning, acceleration, velocity and other three dimensional quantities, the considered information are often three dimensional floating point vectors. The physical stream is a generic stream that contains three floating components and a synchronization component as illustrated on the following image :
The three x, y and z components of physical quantity carried by the stream are double precision floating point values. The synchronization component stores timestamp using unsigend 64-bits binary register.
Integer unitary streams are designed to carry single quantities that are time related. The component accompanying the synchronization component is able to store integer values such as timestamps, tags or information on measures :
It follows that both component are unsigned 64-bits binary registers. The data component can stores more than one information on the 64-bits for a given timestamp of the synchronization component.
Many quantities managed by CSPS library, such as information on camera attached frame, use more than one stream to store their data in order to keep defined stream types as low as possible.
In those cases, the synchronization component of each stream is identical because streams carry similiar informations defined on the same time discretization. Then, being module input or output streams, this component is imported or exported only once and those stream are said attached. In other words, attached streams share the same time discretization that is stored in their common synchronization component.