Module internal

Descriptions

A module can be :

• a output module : like a camera, an output module generate data (no processing.)
• a input module: like tuio, it's an ending module: no data are generated in the tree after the module.
• a input/output module: like an image filter, the data is processed from input, and the result are send on the output.

A module have 2 way to communicate with it :

• properties : every parameters you want configurable by the user. you can even do read-only property for information.
• inputs / outputs : that's the data you can have / generate.

The idea is to make each module independent, without knowing each-others. That's why you must not use a function from another module.

Threading

Our architecture permit to thread or not a module. Your processing will be always done in update() method. This method is called if notifyUpdate() have been asked.

Example of processing in non-threaded mode :

1. poll() called by pipeline
2. poll() check if update must be called (new data available on input)
3. yes, so update() is called

Example of processing in threaded mode :

1. poll() called by pipeline
2. poll() check if update must be called
3. yes, so notify thread to call update()
4. thread receive the notify message
5. thread call update()

NEVER call update() yourself.

Module methods

Properties

A module will always have default properties as :

• id(str) : the module id (uniq in the whole instance of Movid)
• use_thread(bool) : indicate if the module must be run in threaded mode or not

Methods :

• property(id) : return a moProperty().
• getProperties() : return the list of all properties

Inputs / Outputs

Methods :

• getInputCount() / getOutputCount() : retreive how much input/output are supported by module
• getInputInfos(idx) / getOutputInfox(idx) : retreive information about a specific input/output
• getInput(idx) / getOutput(idx) : get a specific input/output data stream

Run the module

Methods :

• start() : start the module. must be not called twice, without a stop()
• stop() : stop the module. must be not called without a start()
• isStarted() : return true if the module is started.
• poll() : used to poll module internal.
• update() : called to update / process input data
• lock() : lock data of the module
• unlock() : unlock data of the module

Informations

Methods :

• getName() : return the name of the module
• getDescription() : return a whole description of the module
• getAuthor() : return the author that make the module (native = from Movid Core)
• describe() : dump on console all module informations

Errors

Methods :

• haveError() : return true if the module is in an error state
• getLastError() : return the last error, and reset the error state

Controls

Methods :

• notifyUpdate() : notify the module to run update() as soon as possible
• notifyData() : notify the module that new data is available on one input