Example Demo Custom Stream Type

Table of Contents

• Description
• Prebuilt Binaries
• Source Code
  • Common
  • Stream Types
  • Access
  • Generator
  • Plugin

Description

Shows how to create own stream meta types.

Prebuilt Binaries

• Demo Custom Stream Types Data Access
• Demo Custom Stream Types Data Generator

Source Code

./examples/demo_adtfplugins/demo_custom_stream_type/

Common

sensor_data.h

 
#pragma once
#include <adtffiltersdk/adtf_filtersdk.h>
 
// this is an example data structure for sensor data.
struct tSensorData
{
    double fDistance;
};
 
// this is a covenience method that creates a media description structure definition for tSensorData.
// A Media Description/DDL will be generated from this.
inline adtf::mediadescription::structure<tSensorData> get_sensor_data_type_definition()
{
    return adtf::mediadescription::structure<tSensorData>("tSensorData").
            Add("fDistance", &tSensorData::fDistance);
}

Stream Types

stream_type_custom_sensor.h

 
#pragma once
#include <adtffiltersdk/adtf_filtersdk.h>
 
#include "sensor_data.h"
 
// This is a stream meta type, that also defines an IsCompatible method.
// This way you can ensure that only stream types with matching Property values
// are accepted by Input Pins and Readers.
struct stream_meta_type_custom_sensor
{
    static constexpr const tChar* const MetaTypeName = "demo/custom_sensor";
 
    static constexpr const tChar* const SensorType = "sensor_type";
 
    static void SetProperties(const adtf::ucom::iobject_ptr<adtf::base::IProperties>& pProperties)
    {
        adtf::base::set_property(*pProperties.Get(), SensorType, "");
 
        // this will set the md_description, md_struct etc. properties based on the type definition.
        adtf::mediadescription::set_media_description_properties(*pProperties.Get(), get_sensor_data_type_definition());
    }
 
    static tResult IsCompatible(const adtf::streaming::IStreamType& oTypeToCheck,
                                const adtf::streaming::IStreamType& oTypeExpected)
    {
        auto strSourceSensorType = adtf::streaming::get_property<adtf::util::cString>(oTypeToCheck, SensorType);
        auto strDestSensorType = adtf::streaming::get_property<adtf::util::cString>(oTypeExpected, SensorType);
 
        if (strSourceSensorType != strDestSensorType)
        {
            RETURN_ERROR_DESC(ERR_FAILED,
                              "The required destination sensor type '%s' differs from the source sensor type '%s'",
                              strSourceSensorType.GetPtr(),
                              strDestSensorType.GetPtr());
        }
 
        RETURN_NOERROR;
    }
};
 
// and another helper class to create a stream type with the given property values.
struct stream_type_custom_sensor: public adtf::streaming::stream_type<stream_meta_type_custom_sensor>
{
    stream_type_custom_sensor() = default;
 
    stream_type_custom_sensor(const char* strSensorType)
    {
        adtf::streaming::set_property<adtf::util::cString>(*this,
                                                           stream_meta_type_custom_sensor::SensorType,
                                                           strSensorType);
    }
};

stream_type_mounted_sensor.h

 
#pragma once
#include <adtffiltersdk/adtf_filtersdk.h>
#include "sensor_data.h"
 
// This a stream type that has some properties and a description of the sample data.
// Input Pins with this type, will accept any streams that have the same meta type (name),
// no matter which values the properties are set to.
struct stream_meta_type_mounted_sensor
{
    static constexpr const tChar* const MetaTypeName = "demo/mounted_sensor";
 
    static constexpr const tChar* const SensorMountX = "sensor_mount_x";
    static constexpr const tChar* const SensorMountY = "sensor_mount_y";
    static constexpr const tChar* const SensorMountZ = "sensor_mount_z";
 
    static void SetProperties(const adtf::ucom::iobject_ptr<adtf::base::IProperties>& pProperties)
    {
        adtf::base::set_property(*pProperties.Get(), SensorMountX, 0.0);
        adtf::base::set_property(*pProperties.Get(), SensorMountY, 0.0);
        adtf::base::set_property(*pProperties.Get(), SensorMountZ, 0.0);
 
        // this will set the md_description, md_struct etc. properties based on the type definition.
        adtf::mediadescription::set_media_description_properties(*pProperties.Get(), get_sensor_data_type_definition());
    }
 
    // if we do not define an IsCompatible method readers will check only if the meta type name matches
};
 
// once again a helper class to create a stream type with the given property values.
struct stream_type_mounted_sensor: public adtf::streaming::stream_type<stream_meta_type_mounted_sensor>
{
    stream_type_mounted_sensor() = default;
 
    stream_type_mounted_sensor(double fMountX,
                               double fMountY,
                               double fMountZ)
    {
        adtf::streaming::set_property(*this, stream_meta_type_mounted_sensor::SensorMountX, fMountX);
        adtf::streaming::set_property(*this, stream_meta_type_mounted_sensor::SensorMountY, fMountY);
        adtf::streaming::set_property(*this, stream_meta_type_mounted_sensor::SensorMountZ, fMountZ);
    }
};

stream_type_raw.h

 
#pragma once
#include <adtffiltersdk/adtf_filtersdk.h>
 
 
// This is the most simple stream meta type, it just defines a name
// Everyone who uses this type has to know exactly what to do with the stream data
// as this provides no further information.
struct stream_meta_type_raw_data_that_only_i_understand
{
    static constexpr const tChar* const MetaTypeName = "demo/raw_data_that_only_i_understand";
};

stream_type_raw_with_properties.h

 
#pragma once
#include <adtffiltersdk/adtf_filtersdk.h>
 
// This is a stream meta type that has a property
// This still has no defintion of the data structures that the samples contain.
// Everyone has to aggree on how to interpret sample data via other mechanisms.
struct stream_meta_type_raw_data_with_properties
{
    static constexpr const tChar* const MetaTypeName = "demo/raw_data_with_properties";
 
    static constexpr const tChar* const MyProperty = "my_property";
 
    static void SetProperties(const adtf::ucom::iobject_ptr<adtf::base::IProperties>& pProperties)
    {
        adtf::base::set_property<int32_t>(*pProperties.Get(), MyProperty, 0);
    }
 
    // if we do not define an IsCompatible method readers will check only if the meta type name matches
};
 
// This is a helper class to easily create a stream type instance, set the stream meta type to
// stream_meta_type_raw_data_with_properties and set the property to a given value.
// without this, you would need to write the following snippet, that does the same:
//
// auto pType = make_object_ptr<cStreamType>(stream_meta_type_raw_data_with_properties());
// adtf::streaming::set_property(*pType, stream_meta_type_raw_data_with_properties::MyProperty, 123);
// CreateOutputPin("output", pType);
//
// instead of
//
// CreateOutputPin("output", stream_type_raw_data_with_properties(123));
//
struct stream_type_raw_data_with_properties: public adtf::streaming::stream_type<stream_meta_type_raw_data_with_properties>
{
    stream_type_raw_data_with_properties() = default;
 
    stream_type_raw_data_with_properties(int nMyProperty)
    {
        adtf::streaming::set_property(*this, stream_meta_type_raw_data_with_properties::MyProperty, nMyProperty);
    }
};

Access

demo_custom_stream_type_access_filter.h

 
#pragma once
#include <adtffiltersdk/filter.h>
 
#ifndef ADTF_EXAMPLES_CID
#define ADTF_EXAMPLES_CID ".local.cid"
#endif

class cCustomStreamTypesDataAccess final : public adtf::filter::cFilter
{
    public:
        ADTF_CLASS_ID_NAME(cCustomStreamTypesDataAccess,
                           "demo_custom_stream_types_access.filter" ADTF_EXAMPLES_CID,
                           "Demo Custom Stream Types Data Access");
 
        cCustomStreamTypesDataAccess();
        ~cCustomStreamTypesDataAccess() override;
        tResult AcceptType(adtf::streaming::ISampleReader* pReader, const adtf::ucom::iobject_ptr<const adtf::streaming::IStreamType>& pType) override;
        tResult ProcessInput(adtf::streaming::ISampleReader* pReader, const adtf::ucom::iobject_ptr<const adtf::streaming::ISample>& pSample) override;
 
    private:
        adtf::streaming::ISampleReader* m_pRawDataReader = nullptr;
        adtf::streaming::ISampleReader* m_pRawDataWithPropertyReader = nullptr;
        adtf::streaming::ISampleReader* m_pUnspecifiedSensorReader = nullptr;
        adtf::streaming::ISampleReader* m_pMountedSensorReader = nullptr;
        adtf::streaming::ISampleReader* m_pSensorAReader = nullptr;
        adtf::streaming::ISampleReader* m_pSensorBReader = nullptr;
 
        int32_t m_nCurrentMyPropertyValue = 0;
        struct tSensorMountPosition
        {
            double fX;
            double fY;
            double fZ;
        };
        tSensorMountPosition m_sSensorMountPosition;
};

demo_custom_stream_type_access_filter.cpp

 
#include "demo_custom_stream_type_access_filter.h"
 
#include "stream_type_raw.h"
#include "stream_type_raw_with_properties.h"
#include "stream_type_mounted_sensor.h"
#include "stream_type_custom_sensor.h"
 
#include "sensor_data.h"
 
using namespace adtf::base;
using namespace adtf::streaming;
using namespace adtf::filter;
using namespace adtf::mediadescription;
 
cCustomStreamTypesDataAccess::cCustomStreamTypesDataAccess()
{
    // this pin accepts only streams with the given stream_meta_type
    m_pRawDataReader = CreateInputPin("raw", stream_meta_type_raw_data_that_only_i_understand());
    SetDescription("raw", "Input data based on raw stream type");
 
    // this pin accepts only streams with the given stream_meta_type, we will access property later on.
    m_pRawDataWithPropertyReader = CreateInputPin("raw_with_property", stream_type_raw_data_with_properties());
    SetDescription("raw_with_property", "Input data based on a raw stream type with setted property");
 
    // this pin accepts any stream that transmits samples that contain tSensorData.
    m_pUnspecifiedSensorReader = CreateInputPin("unspecified_sensor", get_sensor_data_type_definition());
    SetDescription("unspecified_sensor", "Input data for an unspecified sensor");
 
    // this pin accepts only streams of stream_meta_type_mounted_sensor, but we don't care about specific property values.
    m_pMountedSensorReader = CreateInputPin("mounted_sensor", stream_type_mounted_sensor());
    SetDescription("mounted_sensor", "Input data compatible with a specified mounted_sensor");
 
    // this pin accepts only streams of stream_meta_type_custom_sensor, where the sensor type must match "SensorA".
    m_pSensorAReader = CreateInputPin("sensor_a", stream_type_custom_sensor("SensorA"));
    SetDescription("sensor_a", "Input data compatible with a specified Sensor A");
 
    // this pin accepts only streams of stream_meta_type_custom_sensor, where the sensor type must match "SensorB".
    m_pSensorBReader = CreateInputPin("sensor_b", stream_type_custom_sensor("SensorB"));
    SetDescription("sensor_b", "Input data compatible with a specified Sensor B");
 
    // sets a short description for the component
    SetDescription("Use this filter to print received streaming data based on several custom stream types.");
 
    // set help link to jump to documentation from ADTF Configuration Editor
    SetHelpLink("$(ADTF_DIR)/doc/html/page_demo_custom_stream_types_data_access.html");
}
 
cCustomStreamTypesDataAccess::~cCustomStreamTypesDataAccess() = default;
 
tResult cCustomStreamTypesDataAccess::AcceptType(ISampleReader* pReader, const iobject_ptr<const IStreamType>& pType)
{
    // we want the default compatibility behaviour, so we call the base method first.
    RETURN_IF_FAILED(cFilter::AcceptType(pReader, pType));
 
    if (pReader == m_pRawDataWithPropertyReader)
    {
        // if we received a new type, we read its property value and store it.
        // you could of course store the stream type instance as well, but we ar only interested in the property value.
        m_nCurrentMyPropertyValue = get_property<int>(*pType.Get(), stream_meta_type_raw_data_with_properties::MyProperty);
    }
    else if (pReader == m_pMountedSensorReader)
    {
        // update the mount position.
        m_sSensorMountPosition = {get_property<double>(*pType.Get(), stream_meta_type_mounted_sensor::SensorMountX),
                                  get_property<double>(*pType.Get(), stream_meta_type_mounted_sensor::SensorMountY),
                                  get_property<double>(*pType.Get(), stream_meta_type_mounted_sensor::SensorMountZ) };
    }
 
    RETURN_NOERROR;
}
 
tResult cCustomStreamTypesDataAccess::ProcessInput(ISampleReader* pReader, const iobject_ptr<const ISample>& pSample)
{
    if (pReader == m_pRawDataReader)
    {
        LOG_INFO("received a raw sample");
    }
    else if (pReader == m_pRawDataWithPropertyReader)
    {
        LOG_INFO("received a raw sample, my_property is currently %d", m_nCurrentMyPropertyValue);
    }
    else if (pReader == m_pUnspecifiedSensorReader)
    {
        LOG_INFO("received a distance reading from unspecified sensor: %f",
                 sample_data<tSensorData>(pSample)->fDistance);
    }
    else if (pReader == m_pMountedSensorReader)
    {
        LOG_INFO("received a distance reading from sensor mounted at (%f, %f, %f): %f",
                 m_sSensorMountPosition.fX,
                 m_sSensorMountPosition.fY,
                 m_sSensorMountPosition.fZ,
                 sample_data<tSensorData>(pSample)->fDistance);
    }
    else if (pReader == m_pSensorAReader)
    {
        LOG_INFO("received a distance reading from sensor A: %f",
                 sample_data<tSensorData>(pSample)->fDistance);
    }
    else if (pReader == m_pSensorBReader)
    {
        LOG_INFO("received a distance reading from sensor B: %f",
                 sample_data<tSensorData>(pSample)->fDistance);
    }
 
    RETURN_NOERROR;
}
 

Generator

demo_custom_stream_type_generator_filter.h

 
#pragma once
#include <adtffiltersdk/filter.h>
 
#ifndef ADTF_EXAMPLES_CID
#define ADTF_EXAMPLES_CID ".local.cid"
#endif

class cCustomStreamTypesDataGenerator final : public adtf::filter::cFilter
{
    public:
        ADTF_CLASS_ID_NAME(cCustomStreamTypesDataGenerator,
                           "demo_custom_stream_types_generator.filter" ADTF_EXAMPLES_CID,
                           "Demo Custom Stream Types Data Generator");
 
        cCustomStreamTypesDataGenerator();
        ~cCustomStreamTypesDataGenerator() override;
        tResult Process(adtf::base::tNanoSeconds tmTrigger, adtf::streaming::IRunner* pRunner) override;
 
    private:
        adtf::streaming::ISampleWriter* m_pRawDataWriter = nullptr;
        adtf::streaming::ISampleWriter* m_pRawDataWithPropertyWriter = nullptr;
        adtf::streaming::ISampleWriter* m_pMountedSensorWriter = nullptr;
        adtf::streaming::ISampleWriter* m_pSensorAWriter = nullptr;
        adtf::streaming::ISampleWriter* m_pSensorBWriter = nullptr;
};

demo_custom_stream_type_generator_filter.cpp

 
#include "demo_custom_stream_type_generator_filter.h"
 
#include "stream_type_raw.h"
#include "stream_type_raw_with_properties.h"
#include "stream_type_mounted_sensor.h"
#include "stream_type_custom_sensor.h"
 
using namespace adtf::base;
using namespace adtf::streaming;
using namespace adtf::filter;
using namespace adtf::mediadescription;
 
cCustomStreamTypesDataGenerator::cCustomStreamTypesDataGenerator()
{
    m_pRawDataWriter = CreateOutputPin("raw", stream_meta_type_raw_data_that_only_i_understand());
    SetDescription("raw", "Provides data compatible with raw stream type");
 
    m_pRawDataWithPropertyWriter = CreateOutputPin("raw_with_property", stream_type_raw_data_with_properties(42));
    SetDescription("raw_with_property", "Provides data compatible with raw stream type with setted property");
 
    m_pMountedSensorWriter = CreateOutputPin("mounted_sensor", stream_type_mounted_sensor(1.0, 2.0, 3.0));
    SetDescription("mounted_sensor", "Provides data compatible with mounted_sensor");
 
    m_pSensorAWriter = CreateOutputPin("sensor_a", stream_type_custom_sensor("SensorA"));
    SetDescription("sensor_a", "Provides data compatible with Sensor A");
 
    m_pSensorBWriter = CreateOutputPin("sensor_b", stream_type_custom_sensor("SensorB"));
    SetDescription("sensor_b", "Provides data compatible with Sensor B");
 
    CreateRunner("generate_data", cTimerTriggerHint(std::chrono::seconds{1}));
    SetDescription("generate_data", "Runner to periodically trigger the function which generates the output samples");
 
    // sets a short description for the component
    SetDescription("Use this filter to generate data based on several custom stream types.");
 
    // set help link to jump to documentation from ADTF Configuration Editor
    SetHelpLink("$(ADTF_DIR)/doc/html/page_demo_custom_stream_types_data_generator.html");
}
 
cCustomStreamTypesDataGenerator::~cCustomStreamTypesDataGenerator() = default;
 
tResult cCustomStreamTypesDataGenerator::Process(tNanoSeconds tmTrigger, IRunner* /*pRunner*/)
{
    output_sample_data<uint8_t> oRawData(tmTrigger, 123);
    m_pRawDataWriter->Write(oRawData.Release());
 
    output_sample_data<uint8_t> oRawDataWithProperty(tmTrigger, 123);
    m_pRawDataWithPropertyWriter->Write(oRawDataWithProperty.Release());
 
    output_sample_data<tSensorData> oMountedSensorData(tmTrigger, {3.1415});
    m_pMountedSensorWriter->Write(oMountedSensorData.Release());
 
    output_sample_data<tSensorData> oSensorAData(tmTrigger, {3.1415});
    m_pSensorAWriter->Write(oSensorAData.Release());
 
    output_sample_data<tSensorData> oSensorBData(tmTrigger, {-3.1415});
    m_pSensorBWriter->Write(oSensorBData.Release());
 
    RETURN_NOERROR;
}

Plugin

plugin.cpp

 
#include "demo_string_sending_filter.h"
#include "demo_string_receiving_filter.h"

ADTF_PLUGIN("Demo String Handling Filters Plugin",
            cDemoStringSending,
            cDemoStringReceiving);