CaptureToUserMemory.cpp

The CaptureToUserMemory program is based on the ContinuousCapture.cpp example. It consists of 4 steps which demonstrate image acquisition and display using different acquisition memory mechanisms. Impact Acquire can either automatically allocate and manage capture memory or if needed can directly acquire into user supplied memory. How to use memory allocated by a user application is shown here. In addition to that also some code that shows how to create OpenCV (http://http://opencv.org/) buffers efficiently is part of this application.

Program location

The source file CaptureToUserMemory.cpp can be found under:

%INSTALLDIR%\apps\CaptureToUserMemory\

Note

If you have installed the package without example applications, this file will not be available. On Windows® the sample application can be installed or removed from the target system at any time by simply restarting the installation package.

CaptureToUserMemory example:

1. Opens a Balluff device.
2. Snaps images continuously.

Console Output

[0]: BF000306 (mvBlueFOX-202C, Family: mvBlueFOX, interface layout: DeviceSpecific)

Please enter the number in front of the listed device followed by [ENTER] to open it: 0
Using device number 0.
Initialising the device. This might take some time...
The device will try to capture continuously into memory automatically allocated by the device driver.
This is the default behaviour.
Press [ENTER] to end the continuous acquisition.
Info from BF000306: FramesPerSecond: 28.655669, ErrorCount: 0, CaptureTime_s: 0.104219

The device will now try to capture continuously into user supplied memory.
Press [ENTER] to end the continuous acquisition.
Info from BF000306: FramesPerSecond: 28.652999, ErrorCount: 0, CaptureTime_s: 0.104366

The device will try to capture continuously into memory automatically allocated by the device driver again.
This is the default behaviour.
Press [ENTER] to end the continuous acquisition.
Info from BF000306: FramesPerSecond: 28.653142, ErrorCount: 0, CaptureTime_s: 0.104201

Now the device will try to capture one frame into a specific user supplied buffer
Capture into specific user supplied buffer done.
Press [ENTER] to end the application...

How it works

For the continuous acquisition, this sample uses ContinuousCapture.cpp as a basis.

• First of all, the user will be prompted to select the device he wants to use for this sample (function: getDeviceFromUserInput(); included from exampleHelper.h ).
• Then the program initializes the display window.
• Afterwards, the device itself will be initialized (function: open()) as well as the structure CaptureParameter that serves as a container for all objects handles and pointers, that will be used within the sample application.
• Now 4 consecutive steps will be executed to display the different memory modes, that are available: The sample will try to capture
  1. continuously into memory automatically allocated and managed by the device driver,
  2. continuously into user supplied memory, (after this step the program will remove and free user supplied buffers; function freeCaptureBuffers())
  3. continuously into memory automatically allocated by the device driver again and finally,
  4. one frame into a specific user supplied buffer.

  Note

  To end the current step ENTER must be pressed.

• After the last step the sample will terminate.

Function: checkCaptureBufferAddress()

This function checks whether a buffer returned from the driver is actually a buffer that should appear at this stage of the sample. It checks for driver errors. E.g. when a request should contain a user supplied buffer but the request returned to the user contains a pointer to a memory location not supplied by the user, this function will complain about it and will write a message into the standard output.

This function is called whenever a complete request (one that e.g. didn't time out) has been returned back to the user.

checkCaptureBufferAddress( pRequest, pCaptureParams->boUserSuppliedMemoryUsed, pCaptureParams->buffers );

which again is used in the first three continuous capture steps of the sample.

Function: createCaptureBuffers()

This function creates a new user supplied heap buffer. This function is called during the second continuous capture step which shows a continuous capture into the user supplied memory. This function can be replaced by the 'real' allocator function of a 'real' application.

The function calls mvIMPACT::acquire::FunctionInterface::imageRequestConfigure first to set a request into configuration mode. Only requests, that are currently not queued into the drivers acquisition engine and are not locked can be put into configuration mode. If e.g. a locked request is passed to a call to mvIMPACT::acquire::FunctionInterface::imageRequestConfigure the function will return an error code.

In configuration mode certain properties of a request will become writeable. Then a user supplied buffer can be registered at this request object. If the user registers a specific user supplied buffer with more than one request the behaviour is undefined as then e.g. if the user requests data into two requests referencing the same buffer can never be sure whether the data returned by the driver stays valid until he is done working with it. The device driver will NOT check for identical user supplied buffers as sometimes this behaviour might be desired as well.

Never free memory that is referenced by at least one request that has been sent to the device driver. If this is done, the behaviour is undefined. To remove a user supplied buffer from a request, this request must be set into configuration mode again. After removing a buffer from every request it has been assigned to it is save to free the memory associated with the buffer.

Note

Certain device drivers need a special memory alignment in order to perform efficiently. The memory assigned to request object has to be aligned. Otherwise a consecutive call to mvIMPACT::acquire::FunctionInterface::imageRequestUnlock will fail. Buffers, that violate the alignment requirements of a device driver can't be sent to the acquisition engine. The alignment requirements for various device drivers might differ. One possible approach that will always work correctly is displayed in the small helper class 'UserSuppliedHeapBuffer' of this sample.

Function: freeCaptureBuffers()

This function is used to free resources hold by the user supplied buffers.

OpenCV support

This example can also be built with OpenCV support. In order to do that the macro BUILD_WITH_OPENCV_SUPPORT must be defined at compile time. Some additional things might be needed which are explained in the source code within the first #ifdef BUILD_WITH_OPENCV_SUPPORT block. When OpenCV support is enabled the example will show two addition display windows. One with the original image data displayed in an OpenCV window, one with the processed result of the very same image.

Source code

//
// @description: Example applications for Impact Acquire
// @copyright: Copyright (C) 2008 - 2022 Balluff GmbH
// @authors: APIs and drivers development team at Balluff GmbH
// @initial date: 2008-08-11
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice (including the next paragraph) shall be included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,i
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
 
#include <iostream>
#include <memory>
#include <thread>
#include <apps/Common/exampleHelper.h>
#include <common/minmax.h>
#include <mvIMPACT_CPP/mvIMPACT_acquire.h>
#ifdef _WIN32
#   include <mvDisplay/Include/mvIMPACT_acquire_display.h>
using namespace mvIMPACT::acquire::display;
#   define USE_DISPLAY
#elif defined(linux) || defined(__linux) || defined(__linux__) || defined(__APPLE__)
#   if defined(__x86_64__) || defined(__aarch64__) || defined(__powerpc64__) // -m64 makes GCC define __powerpc64__
using UINT_PTR = uint64_t;
#   elif defined(__i386__) || defined(__arm__) || defined(__powerpc__) // and -m32 __powerpc__
using UINT_PTR = uint32_t;
#   endif
#endif // #ifdef _WIN32
 
#ifdef BUILD_WITH_OPENCV_SUPPORT
// In order to build this application with OpenCV support there are 2 options:
// a) Use Visual Studio 2013 or later with OpenCV 2.4.13. With this version this example project already contains
//    project configurations 'Debug OpenCV' and 'Release OpenCV'. The only thing left to do in that case is to define
//    an environment variable 'OPENCV_DIR' that points to the top-level folder of the OpenCV 2.4.13 package. Afterwards
//    when restarting Visual Studio the application can be built with a simple OpenCV example.
//    - Different OpenCV versions can be used as well, but you need to state the OpenCV lib names matching your
//      version in the linker section then as the libraries contain the version in their name
// b) Older Visual Studio versions or Linux/gcc approaches must make sure that the include and lib paths to
//    OpenCV are set up correctly. However information on how to efficiently create OpenCV buffers can be extracted
//    from the code without compiling this application as well. Simply look for every occurrence of 'BUILD_WITH_OPENCV_SUPPORT'
//    in this source file.
#   include <opencv2/core/core.hpp>
#   include <opencv2/highgui/highgui.hpp>
#   include <opencv2/imgproc/imgproc.hpp>
#endif // #ifdef BUILD_WITH_OPENCV_SUPPORT
 
using namespace std;
using namespace mvIMPACT::acquire;
 
static bool s_boTerminated = false;
 
//-----------------------------------------------------------------------------
// the buffer we pass to the device driver must be aligned according to its requirements
// As we can't allocate aligned heap memory we will align it 'by hand'
class UserSuppliedHeapBuffer
//-----------------------------------------------------------------------------
{
    unique_ptr<char[]> pBuf_;
    int bufSize_;
    int alignment_;
public:
    explicit UserSuppliedHeapBuffer( int bufSize, int alignment ) : pBuf_(), bufSize_( bufSize ), alignment_( alignment )
    {
        if( bufSize_ > 0 )
        {
            pBuf_ = unique_ptr<char[]>( new char[bufSize_ + alignment_] );
        }
    }
    char* getPtr( void ) const
    {
        if( alignment_ <= 1 )
        {
            return pBuf_.get();
        }
        return reinterpret_cast<char*>( align( reinterpret_cast<UINT_PTR>( pBuf_.get() ), static_cast<UINT_PTR>( alignment_ ) ) );
    }
    int getSize( void ) const
    {
        return bufSize_;
    }
};
 
using CaptureBufferContainer = std::vector<shared_ptr<UserSuppliedHeapBuffer>>;
 
//-----------------------------------------------------------------------------
struct CaptureParameter
//-----------------------------------------------------------------------------
{
    Device* pDev;
#ifdef USE_DISPLAY
    shared_ptr<ImageDisplayWindow> pDisplayWindow;
#endif // #ifdef USE_DISPLAY
#ifdef BUILD_WITH_OPENCV_SUPPORT
    std::string             openCVDisplayTitle;
    std::string             openCVResultDisplayTitle;
#endif // #ifdef BUILD_WITH_OPENCV_SUPPORT
    FunctionInterface       fi;
    ImageRequestControl     irc;
    Statistics              statistics;
    bool                    boUserSuppliedMemoryUsed;
    bool                    boAlwaysUseNewUserSuppliedBuffers;
    int                     bufferSize;
    int                     bufferAlignment;
    int                     bufferPitch;
    CaptureBufferContainer  buffers;
    explicit CaptureParameter( Device* p ) : pDev{p}, fi{p}, irc{p}, statistics{p}, boUserSuppliedMemoryUsed{false},
        boAlwaysUseNewUserSuppliedBuffers{false}, bufferSize{0}, bufferAlignment{0}, bufferPitch{0}, buffers()
    {
#ifdef USE_DISPLAY
        // IMPORTANT: It's NOT safe to create multiple display windows in multiple threads!!!
        pDisplayWindow = make_shared<ImageDisplayWindow>( "mvIMPACT_acquire sample, Device " + pDev->serial.read() );
#endif // #ifdef USE_DISPLAY
#ifdef BUILD_WITH_OPENCV_SUPPORT
        openCVDisplayTitle = string( "mvIMPACT_acquire sample, Device " + pDev->serial.read() + ", OpenCV display" );
        openCVResultDisplayTitle = openCVDisplayTitle + "(Result)";
#endif // #ifdef BUILD_WITH_OPENCV_SUPPORT
    }
    CaptureParameter( const CaptureParameter& src ) = delete;
    CaptureParameter& operator=( const CaptureParameter& rhs ) = delete;
};
 
void checkCaptureBufferAddress( const Request* const pRequest, bool boShouldContainUserSuppliedMemory, const CaptureBufferContainer& buffers );
int  createCaptureBuffer( FunctionInterface& fi, CaptureBufferContainer& buffers, const int bufferSize, const int bufferAlignment, const int bufferPitch, unsigned int requestNr );
int  createCaptureBuffers( FunctionInterface& fi, CaptureBufferContainer& buffers, const int bufferSize, const int bufferAlignment, const int bufferPitch );
void freeCaptureBuffer( FunctionInterface& fi, CaptureBufferContainer& buffers, unsigned int requestNr );
void freeCaptureBuffers( FunctionInterface& fi, CaptureBufferContainer& buffers );
void runLiveLoop( CaptureParameter& captureParams );
 
//-----------------------------------------------------------------------------
/// \brief This function checks whether a buffer returned from an acquisition into a
/// request that has been assigned a user supplied buffer really contains a buffer
/// pointer that has been assigned by the user.
void checkCaptureBufferAddress( const Request* const pRequest, bool boShouldContainUserSuppliedMemory, const CaptureBufferContainer& buffers )
//-----------------------------------------------------------------------------
{
    if( boShouldContainUserSuppliedMemory && ( pRequest->imageMemoryMode.read() != rimmUser ) )
    {
        cout << "ERROR: Request number " << pRequest->getNumber() << " is supposed to contain user supplied memory, but claims that it doesn't." << endl;
        return;
    }
    else if( !boShouldContainUserSuppliedMemory )
    {
        if( pRequest->imageMemoryMode.read() == rimmUser )
        {
            cout << "ERROR: Request number " << pRequest->getNumber() << " is supposed NOT to contain user supplied memory, but claims that it does." << endl;
        }
        return;
    }
 
    const void* const pAddr = pRequest->imageData.read();
    for( const auto& buffer : buffers )
    {
        if( pAddr == buffer->getPtr() )
        {
            // found the buffer that has been assigned by the user
            return;
        }
    }
 
    cout << "ERROR: A buffer has been returned, that doesn't match any of the buffers assigned as user memory in request number " << pRequest->getNumber() << "." << endl;
    cout << "Buffer got: 0x" << pAddr << endl;
    cout << "Buffers allocated:" << endl;
    const CaptureBufferContainer::size_type vSize = buffers.size();
    for( CaptureBufferContainer::size_type j = 0; j < vSize; j++ )
    {
        cout << "[" << j << "]: 0x" << reinterpret_cast<void*>( buffers[j]->getPtr() ) << endl;
    }
}
 
//-----------------------------------------------------------------------------
int createCaptureBuffer( FunctionInterface& fi, CaptureBufferContainer& buffers, const int bufferSize, const int bufferAlignment, const int /*bufferPitch*/, unsigned int requestNr )
//-----------------------------------------------------------------------------
{
    int functionResult = DMR_NO_ERROR;
    Request* pRequest = fi.getRequest( requestNr );
    shared_ptr<UserSuppliedHeapBuffer> pBuffer = make_shared<UserSuppliedHeapBuffer>( bufferSize, bufferAlignment );
    if( ( functionResult = pRequest->attachUserBuffer( pBuffer->getPtr(), pBuffer->getSize() ) ) != DMR_NO_ERROR )
    {
        cout << "An error occurred while attaching a buffer to request number " << requestNr << ": " << ImpactAcquireException::getErrorCodeAsString( functionResult ) << "." << endl;
        return -1;
    }
    buffers.push_back( pBuffer );
    return 0;
}
 
//-----------------------------------------------------------------------------
int createCaptureBuffers( FunctionInterface& fi, CaptureBufferContainer& buffers, const int bufferSize, const int bufferAlignment, const int bufferPitch )
//-----------------------------------------------------------------------------
{
    freeCaptureBuffers( fi, buffers );
 
    unsigned int requestCnt = fi.requestCount();
    for( unsigned int i = 0; i < requestCnt; i++ )
    {
        try
        {
            const int result = createCaptureBuffer( fi, buffers, bufferSize, bufferAlignment, bufferPitch, i );
            if( result != 0 )
            {
                freeCaptureBuffers( fi, buffers );
                return result;
            }
        }
        catch( const ImpactAcquireException& e )
        {
            freeCaptureBuffers( fi, buffers );
            return e.getErrorCode();
        }
    }
    return 0;
}
 
//-----------------------------------------------------------------------------
void freeCaptureBuffer( FunctionInterface& fi, CaptureBufferContainer& buffers, unsigned int requestNr )
//-----------------------------------------------------------------------------
{
    try
    {
        int functionResult = DMR_NO_ERROR;
        Request* pRequest = fi.getRequest( requestNr );
        if( pRequest->imageMemoryMode.read() == rimmUser )
        {
            if( ( functionResult = pRequest->detachUserBuffer() ) != DMR_NO_ERROR )
            {
                cout << "An error occurred while detaching a buffer from request number " << requestNr << " : " << ImpactAcquireException::getErrorCodeAsString( functionResult ) << "." << endl;
            }
        }
        const void* const pAddr = pRequest->imageData.read();
        CaptureBufferContainer::iterator it = find_if( buffers.begin(), buffers.end(), [pAddr]( const shared_ptr<UserSuppliedHeapBuffer>& buffer )
        {
            return pAddr == buffer->getPtr();
        } );
        if( it != buffers.end() )
        {
            buffers.erase( it );
        }
    }
    catch( const ImpactAcquireException& e )
    {
        cout << "An error occurred while changing the mode of request number " << requestNr << ": " << e.getErrorCodeAsString() << "." << endl;
    }
}
 
//-----------------------------------------------------------------------------
void freeCaptureBuffers( FunctionInterface& fi, CaptureBufferContainer& buffers )
//-----------------------------------------------------------------------------
{
    const unsigned int requestCnt = fi.requestCount();
    for( unsigned int i = 0; i < requestCnt; i++ )
    {
        freeCaptureBuffer( fi, buffers, i );
    }
 
    if( !buffers.empty() )
    {
        cout << "Error! The buffer container should be empty now but still contains " << buffers.size() << " elements!" << endl;
    }
}
 
//-----------------------------------------------------------------------------
void displayImage( CaptureParameter* pCaptureParameter, Request* pRequest )
//-----------------------------------------------------------------------------
{
#if !defined(USE_DISPLAY) && !defined(BUILD_WITH_OPENCV_SUPPORT)
    // suppress compiler warnings
    ( void )pRequest;
    ( void )pCaptureParameter;
#endif // #if !defined(USE_DISPLAY) && !defined(BUILD_WITH_OPENCV_SUPPORT)
#ifdef USE_DISPLAY
    pCaptureParameter->pDisplayWindow->GetImageDisplay().SetImage( pRequest );
    pCaptureParameter->pDisplayWindow->GetImageDisplay().Update();
#endif // #ifdef USE_DISPLAY
#ifdef BUILD_WITH_OPENCV_SUPPORT
    int openCVDataType = CV_8UC1;
    switch( pRequest->imagePixelFormat.read() )
    {
    case ibpfMono8:
        openCVDataType = CV_8UC1;
        break;
    case ibpfMono10:
    case ibpfMono12:
    case ibpfMono14:
    case ibpfMono16:
        openCVDataType = CV_16UC1;
        break;
    case ibpfMono32:
        openCVDataType = CV_32SC1;
        break;
    case ibpfBGR888Packed:
    case ibpfRGB888Packed:
        openCVDataType = CV_8UC3;
        break;
    case ibpfRGBx888Packed:
        openCVDataType = CV_8UC4;
        break;
    case ibpfRGB101010Packed:
    case ibpfRGB121212Packed:
    case ibpfRGB141414Packed:
    case ibpfRGB161616Packed:
        openCVDataType = CV_16UC3;
        break;
    case ibpfMono12Packed_V1:
    case ibpfMono12Packed_V2:
    case ibpfBGR101010Packed_V2:
    case ibpfRGB888Planar:
    case ibpfRGBx888Planar:
    case ibpfYUV422Packed:
    case ibpfYUV422_10Packed:
    case ibpfYUV422_UYVYPacked:
    case ibpfYUV422_UYVY_10Packed:
    case ibpfYUV422Planar:
    case ibpfYUV444Packed:
    case ibpfYUV444_10Packed:
    case ibpfYUV444_UYVPacked:
    case ibpfYUV444_UYV_10Packed:
    case ibpfYUV444Planar:
    case ibpfYUV411_UYYVYY_Packed:
        cout << "ERROR! Don't know how to render this pixel format (" << pRequest->imagePixelFormat.readS() << ") in OpenCV! Select another one e.g. by writing to mvIMPACT::acquire::ImageDestination::pixelFormat!" << endl;
        exit( 42 );
        break;
    }
    cv::Mat openCVImage( cv::Size( pRequest->imageWidth.read(), pRequest->imageHeight.read() ), openCVDataType, pRequest->imageData.read(), pRequest->imageLinePitch.read() );
    cv::imshow( pCaptureParameter->openCVDisplayTitle, openCVImage );
    // OpenCV event handling: you need this!
    cv::waitKey( 5 );
    // apply Canny Edge detection and display the result too
    cv::Mat edgesMat;
    switch( openCVDataType )
    {
    case CV_16UC3:
        cout << "This format seems to crash the Canny Edge detector. Will display the original image instead!" << endl;
        edgesMat = openCVImage;
        break;
    default:
        cv::Canny( openCVImage, edgesMat, 35.0, 55.0 );
        break;
    }
    cv::imshow( pCaptureParameter->openCVResultDisplayTitle, edgesMat );
    // OpenCV event handling: you need this!
    cv::waitKey( 5 );
#endif // #ifdef BUILD_WITH_OPENCV_SUPPORT
}
 
//-----------------------------------------------------------------------------
void liveLoop( CaptureParameter* pParameter )
//-----------------------------------------------------------------------------
{
    // Send all requests to the capture queue. There can be more than 1 queue for some devices, but for this sample
    // we will work with the default capture queue. If a device supports more than one capture or result
    // queue, this will be stated in the manual. If nothing is mentioned about it, the device supports one
    // queue only. This loop will send all requests currently available to the driver. To modify the number of requests
    // use the property mvIMPACT::acquire::SystemSettings::requestCount at runtime or the property
    // mvIMPACT::acquire::Device::defaultRequestCount BEFORE opening the device.
    TDMR_ERROR result = DMR_NO_ERROR;
    while( ( result = static_cast<TDMR_ERROR>( pParameter->fi.imageRequestSingle() ) ) == DMR_NO_ERROR ) {};
    if( result != DEV_NO_FREE_REQUEST_AVAILABLE )
    {
        cout << "'FunctionInterface.imageRequestSingle' returned with an unexpected result: " << result
             << "(" << ImpactAcquireException::getErrorCodeAsString( result ) << ")" << endl;
    }
 
    manuallyStartAcquisitionIfNeeded( pParameter->pDev, pParameter->fi );
    // run thread loop
    unsigned int cnt = {0};
    const unsigned int timeout_ms = {500};
    Request* pRequest = nullptr;
    // we always have to keep at least 2 images as the display module might want to repaint the image, thus we
    // cannot free it unless we have a assigned the display to a new buffer.
    Request* pPreviousRequest = nullptr;
    while( !s_boTerminated )
    {
        // wait for results from the default capture queue
        const int requestNr = pParameter->fi.imageRequestWaitFor( timeout_ms );
        pRequest = pParameter->fi.isRequestNrValid( requestNr ) ? pParameter->fi.getRequest( requestNr ) : 0;
        if( pRequest != nullptr )
        {
            if( pRequest->isOK() )
            {
                ++cnt;
                // here we can display some statistical information every 100th image
                if( cnt % 100 == 0 )
                {
                    cout << "Info from " << pParameter->pDev->serial.read()
                         << ": " << pParameter->statistics.framesPerSecond.name() << ": " << pParameter->statistics.framesPerSecond.readS()
                         << ", " << pParameter->statistics.errorCount.name() << ": " << pParameter->statistics.errorCount.readS()
                         << ", " << pParameter->statistics.captureTime_s.name() << ": " << pParameter->statistics.captureTime_s.readS()
                         << ", CaptureDimension: " << pRequest->imageWidth.read() << "x" << pRequest->imageHeight.read() << "(" << pRequest->imagePixelFormat.readS() << ")" << endl;
                }
                displayImage( pParameter, pRequest );
                checkCaptureBufferAddress( pRequest, pParameter->boUserSuppliedMemoryUsed, pParameter->buffers );
            }
            else
            {
                cout << "Error: " << pRequest->requestResult.readS() << endl;
            }
            if( pPreviousRequest != nullptr )
            {
                // this image has been displayed thus the buffer is no longer needed...
                pPreviousRequest->unlock();
                if( pParameter->boAlwaysUseNewUserSuppliedBuffers )
                {
                    // attach a fresh piece of memory
                    freeCaptureBuffer( pParameter->fi, pParameter->buffers, pPreviousRequest->getNumber() );
                    createCaptureBuffer( pParameter->fi, pParameter->buffers, pParameter->bufferSize, pParameter->bufferAlignment, pParameter->bufferPitch, pPreviousRequest->getNumber() );
                }
            }
            pPreviousRequest = pRequest;
            // send a new image request into the capture queue
            pParameter->fi.imageRequestSingle();
        }
        //else
        //{
        // Please note that slow systems or interface technologies in combination with high resolution sensors
        // might need more time to transmit an image than the timeout value which has been passed to imageRequestWaitFor().
        // If this is the case simply wait multiple times OR increase the timeout(not recommended as usually not necessary
        // and potentially makes the capture thread less responsive) and rebuild this application.
        // Once the device is configured for triggered image acquisition and the timeout elapsed before
        // the device has been triggered this might happen as well.
        // The return code would be -2119(DEV_WAIT_FOR_REQUEST_FAILED) in that case, the documentation will provide
        // additional information under TDMR_ERROR in the interface reference.
        // If waiting with an infinite timeout(-1) it will be necessary to call 'imageRequestReset' from another thread
        // to force 'imageRequestWaitFor' to return when no data is coming from the device/can be captured.
        // cout << "imageRequestWaitFor failed (" << requestNr << ", " << ImpactAcquireException::getErrorCodeAsString( requestNr ) << ")"
        //   << ", timeout value too small?" << endl;
        //}
    }
    manuallyStopAcquisitionIfNeeded( pParameter->pDev, pParameter->fi );
#ifdef USE_DISPLAY
    // stop the display from showing freed memory
    pParameter->pDisplayWindow->GetImageDisplay().RemoveImage();
#endif // #ifdef USE_DISPLAY
#ifdef BUILD_WITH_OPENCV_SUPPORT
    cv::destroyAllWindows();
#endif // #ifdef BUILD_WITH_OPENCV_SUPPORT
    // In this sample all the next lines are redundant as the device driver will be
    // closed now, but in a real world application a thread like this might be started
    // several times an then it becomes crucial to clean up correctly.
 
    // free the last potentially locked request
    if( pRequest != nullptr )
    {
        pRequest->unlock();
    }
    // clear all queues
    pParameter->fi.imageRequestReset( 0, 0 );
}
 
//-----------------------------------------------------------------------------
void runLiveLoop( CaptureParameter& parameter )
//-----------------------------------------------------------------------------
{
    s_boTerminated = false;
    thread myThread( liveLoop, &parameter );
    cin.get();
    s_boTerminated = true;
    myThread.join();
}
 
//-----------------------------------------------------------------------------
int main( void )
//-----------------------------------------------------------------------------
{
    DeviceManager devMgr;
    Device* pDev = getDeviceFromUserInput( devMgr );
    if( pDev == nullptr )
    {
        cout << "Unable to continue! Press [ENTER] to end the application" << endl;
        cin.get();
        return 1;
    }
 
    cout << "Initialising the device. This might take some time..." << endl;
    try
    {
        pDev->open();
    }
    catch( const ImpactAcquireException& e )
    {
        // this e.g. might happen if the same device is already opened in another process...
        cout << "An error occurred while opening device " << pDev->serial.read()
             << "(error code: " << e.getErrorCodeAsString() << ")." << endl
             << "Press [ENTER] to end the application..." << endl;
        cin.get();
        return 1;
    }
 
    CaptureParameter captureParams( pDev );
 
    //=============================================================================
    //========= Capture loop into memory managed by the driver (default) ==========
    //=============================================================================
    cout << "The device will try to capture continuously into memory automatically allocated be the device driver." << endl
         << "This is the default behaviour." << endl;
    cout << "Press [ENTER] to end the continuous acquisition." << endl;
    runLiveLoop( captureParams );
 
    //=============================================================================
    //========= Capture loop into memory managed by the user (advanced) ===========
    //=============================================================================
    cout << "The device will now try to capture continuously into user supplied memory." << endl;
    captureParams.boUserSuppliedMemoryUsed = true;
    // find out the size of the resulting buffer by requesting a dummy request
    int bufferAlignment = {0};
    Request* pCurrentCaptureBufferLayout = nullptr;
    int result = captureParams.fi.getCurrentCaptureBufferLayout( captureParams.irc, &pCurrentCaptureBufferLayout, &bufferAlignment );
    if( result != 0 )
    {
        cout << "An error occurred while querying the current capture buffer layout for device " << captureParams.pDev->serial.read()
             << "(error code: " << ImpactAcquireException::getErrorCodeAsString( result ) << ")." << endl
             << "Press [ENTER] to end the application..." << endl;
        cin.get();
        return 1;
    }
    int bufferSize = pCurrentCaptureBufferLayout->imageSize.read() + pCurrentCaptureBufferLayout->imageFooterSize.read();
    int bufferPitch = pCurrentCaptureBufferLayout->imageLinePitch.read();
    result = createCaptureBuffers( captureParams.fi, captureParams.buffers, bufferSize, bufferAlignment, bufferPitch );
    if( result != 0 )
    {
        cout << "An error occurred while setting up the user supplied buffers for device " << captureParams.pDev->serial.read()
             << "(error code: " << ImpactAcquireException::getErrorCodeAsString( result ) << ")." << endl
             << "Press [ENTER] to end the application..." << endl;
        cin.get();
        return 1;
    }
    cout << "Press [ENTER] to end the continuous acquisition into user supplied memory." << endl;
    runLiveLoop( captureParams );
 
    //=============================================================================
    //========= unregister user supplied buffers again ============================
    //=============================================================================
    freeCaptureBuffers( captureParams.fi, captureParams.buffers );
 
    //=============================================================================
    //========= Capture loop into memory managed by the user using a fresh ========
    //========= buffer for each image(advanced) ===================================
    //=============================================================================
    cout << "The device will now try to capture continuously into user supplied memory using a new buffer for each image thus constantly re-allocating and freeing user memory." << endl;
    captureParams.boUserSuppliedMemoryUsed = true;
    captureParams.boAlwaysUseNewUserSuppliedBuffers = true;
    captureParams.bufferSize = bufferSize;
    captureParams.bufferAlignment = bufferAlignment;
    captureParams.bufferPitch = bufferPitch;
    result = createCaptureBuffers( captureParams.fi, captureParams.buffers, bufferSize, bufferAlignment, bufferPitch );
    if( result != 0 )
    {
        cout << "An error occurred while setting up the user supplied buffers for device " << captureParams.pDev->serial.read()
             << "(error code: " << ImpactAcquireException::getErrorCodeAsString( result ) << ")." << endl
             << "Press [ENTER] to end the application..." << endl;
        cin.get();
        return 1;
    }
    cout << "Press [ENTER] to end the continuous acquisition." << endl;
    runLiveLoop( captureParams );
 
    //=============================================================================
    //========= unregister user supplied buffers again ============================
    //=============================================================================
    freeCaptureBuffers( captureParams.fi, captureParams.buffers );
 
    //=============================================================================
    //========= Capture loop into memory managed by the driver again (default) ====
    //=============================================================================
    captureParams.boUserSuppliedMemoryUsed = false;
    captureParams.boAlwaysUseNewUserSuppliedBuffers = false;
    cout << "The device will try to capture continuously into memory automatically allocated be the device driver again." << endl
         << "This is the default behaviour." << endl;
    cout << "Press [ENTER] to end the continuous acquisition." << endl;
    runLiveLoop( captureParams );
 
    //=============================================================================
    //========= Capture into a specific buffer managed by the user (advanced) =====
    //=============================================================================
    // by default the driver will decide which request will be used for an acquisition
    // requested by the user. However sometimes it can be necessary to make sure that a
    // certain request object will be used...
    cout << "Now the device will try to capture one frame into a specific user supplied buffer" << endl;
    UserSuppliedHeapBuffer buffer( bufferSize, bufferAlignment );
    const int REQUEST_TO_USE = {2};
    // we want to use request number 'REQUEST_TO_USE' (zero based) for this acquisition thus we have to make sure
    // that there are at least 'REQUEST_TO_USE + 1' requests
    SystemSettings ss( pDev );
    ss.requestCount.write( REQUEST_TO_USE + 1 );
    // associate a user supplied buffer with this request
    Request* pRequest = captureParams.fi.getRequest( REQUEST_TO_USE );
    try
    {
        int functionResult = pRequest->attachUserBuffer( buffer.getPtr(), buffer.getSize() );
        if( functionResult != DMR_NO_ERROR )
        {
            cout << "An error occurred while attaching a user buffer to request number " << REQUEST_TO_USE << ": " << ImpactAcquireException::getErrorCodeAsString( functionResult ) << "." << endl;
            cout << "Press [ENTER] to end the application." << endl;
            cin.get();
            return 1;
        }
    }
    catch( const ImpactAcquireException& e )
    {
        cout << "An error occurred while attaching a user buffer to request number " << REQUEST_TO_USE << ": " << ImpactAcquireException::getErrorCodeAsString( e.getErrorCode() ) << "." << endl;
        cout << "Press [ENTER] to end the application." << endl;
        cin.get();
        return 1;
    }
    // define that 'REQUEST_TO_USE' is used for the next acquisition
    captureParams.irc.requestToUse.write( REQUEST_TO_USE );
    // and capture the image
    int requestUsed = {INVALID_ID};
    result = captureParams.fi.imageRequestSingle( &captureParams.irc, &requestUsed );
    if( result != DMR_NO_ERROR )
    {
        cout << "An error occurred while requesting an image for request number " << REQUEST_TO_USE << ": " << ImpactAcquireException::getErrorCodeAsString( result ) << "." << endl;
        cout << "Press [ENTER] to end the application." << endl;
        cin.get();
        return 1;
    }
    if( requestUsed != REQUEST_TO_USE )
    {
        cout << "ERROR! An acquisition into buffer " << REQUEST_TO_USE << " was requested, but the driver did use " << requestUsed << " for this acquisition." << endl;
    }
 
    manuallyStartAcquisitionIfNeeded( pDev, captureParams.fi );
    // Wait for the buffer to get filled
    int requestNr = captureParams.fi.imageRequestWaitFor( -1 );
    manuallyStopAcquisitionIfNeeded( pDev, captureParams.fi );
 
    pRequest = captureParams.fi.getRequest( requestNr );
    if( !pRequest->isOK() )
    {
        cout << "Error: " << pRequest->requestResult.readS() << endl;
        cout << "Press [ENTER] to end the application..." << endl;
        cin.get();
        return 1;
    }
    cout << "Capture into specific user supplied buffer done." << endl;
    displayImage( &captureParams, pRequest );
 
    // and end the application
    cout << "Press [ENTER] to end the application..." << endl;
    cin.get();
    captureParams.fi.imageRequestUnlock( requestNr );
    captureParams.fi.imageRequestReset( 0, 0 );
    return 0;
}