Defined in File v4l2_video_capture.hpp
class V4L2VideoCaptureOp : public holoscan::Operator
Operator class to get the video stream from V4L2.
Inputs a video stream from a V4L2 node, including USB cameras and HDMI IN.
Input stream is on host. If no pixel format is specified in the yaml configuration file, the pixel format will be automatically selected. However, only
YUYVare then supported. If a pixel format is specified in the yaml file, then this format will be used. However, note that the operator then expects that this format can be encoded as RGBA32. If not, the behaviour is undefined.
Output stream is on host. Always RGBA32 at this time.
holoscan::ops::FormatConverterOpto move data from the host to a GPU device.
- HOLOSCAN_OPERATOR_FORWARD_ARGS (V4L2VideoCaptureOp) V4L2VideoCaptureOp()=default
virtual void setup(OperatorSpec &spec) override
Define the operator specification.
spec – The reference to the operator specification.
- virtual void start() override
Implement the startup logic of the operator.
This method is called multiple times over the lifecycle of the operator according to the order defined in the lifecycle, and used for heavy initialization tasks such as allocating memory resources.
- virtual void initialize() override
Initialize the operator.
This function is called when the fragment is initialized by Executor::initialize_fragment().
virtual void compute(InputContext &op_input, OutputContext &op_output, ExecutionContext &context) override
Implement the compute method.
This method is called by the runtime multiple times. The runtime calls this method until the operator is stopped.
op_input – The input context of the operator.
op_output – The output context of the operator.
context – The execution context of the operator.
- virtual void stop() override
Implement the shutdown logic of the operator.
This method is called multiple times over the lifecycle of the operator according to the order defined in the lifecycle, and used for heavy deinitialization tasks such as deallocation of all resources previously assigned in start.