Sinks

Sinks abstract the concept of receiving data to produce new data or perform a specifc action such as publishing or storing it in a database.

Design guidelines for sinks

It is recommeded that sinks perform a single specific task and complex actions are achieved by interaction of several sinks specified at configuration time rather than a monolithic approach.

API reference

This module contains the Built-in sinks.

class videoanalytics.pipeline.sinks.ImageWriter(name, context, output_path)

Writes the current frame to a image using OpenCV image write.

This component READS the following entries in the global context:

Variable name	Description
IMG_FILENAME	Filename for the output image file. Note: this name is generated by ImageSequenceReader.
INPUT_WIDTH	Input video width in pixels.
INPUT_HEIGHT	Input video height in pixels.
FRAME	Numpy array representing the frame.

Parameters

• name (str) – the component unique name.

• context (dict) – The global context.

• output_path (str) – path to store images.

process()

This method is called for each active component in the pipeline.

setup()

This method is called after all components from the pipeline are instanced.

shutdown()

This method is called after the process finished.

class videoanalytics.pipeline.sinks.VariableCSVWriter(name, context, filename, variables_to_write)

Stores variables in a CSV.

This component READS the entries matching the variable names specified in configurations, example “VARIABLE_1”, etc.:

Variable name	Description
VARIABLE_1	Variable updated by some component.
VARIABLE_2	Variable updated by some component.
…	…
VARIABLE_N	Variable updated by some component.

Parameters

• name (str) – the component unique name.

• context (dict) – The global context.

• filename (str) – CSV filename.

• variables_to_write (list) – List of variables to write.

process()

This method is called for each active component in the pipeline.

setup()

This method is called after all components from the pipeline are instanced.

shutdown()

This method is called after the process finished.

class videoanalytics.pipeline.sinks.VideoWriter(name, context, filename, output_format='XVID', fps=None, width=None, height=None)

Writes video to a file using OpenCV writer.

This component READS the following entries in the global context:

Variable name	Description
INPUT_FPS	Input video FPS.
INPUT_WIDTH	Input video width in pixels.
INPUT_HEIGHT	Input video height in pixels.
FRAME	Numpy array representing the frame.

Parameters

• name (str) – the component unique name.

• context (dict) – The global context.

• filename (str) – output video filename.

• output_format (str) – output format (default to XVID). Any format supported by OpenCV VideoWriter_fourcc.

process()

This method is called for each active component in the pipeline.

setup()

This method is called after all components from the pipeline are instanced.

shutdown()

This method is called after the process finished.