Qt：实时显示大华摄像头数据到QLabel上

环境

系统：Windows 10 64bit
编译器：VS 2013 64bit
Qt：5.10.0
大华播放库：576773_General_PlaySDK_Chn_Windows64_IS_V3.39.1.R.171130
大华网络库：696_524592_General_NetSDK_Chn_Win64_IS_V3.48.1.R.170622

pro文件

QT += core gui widgets concurrent

CONFIG += c++11

INCLUDEPATH *= $$PWD/dahua/include

SOURCES *= main.cpp

LIBS *= -L$$PWD/dahua/lib/ -ldhconfigsdk -ldhnetsdk -ldhplay

main.cpp文件

// Qt lib import
#include 
#include 
#include 
#include 
#include 
#include 

// Dahua lib import
#include "dhnetsdk.h"
#include "dhplay.h"

static LONG playPort = 0;
static QPointer< QLabel > label;
static QThreadPool yuvToRgbThreadPool;

void netRealDataCallback(LLONG /*lRealHandle*/, DWORD dwDataType, BYTE *pBuffer, DWORD dwBufSize, LONG /*param*/, LDWORD /*dwUser*/)
{
    if ( dwDataType ==  0 )
    {
        PLAY_InputData( playPort, pBuffer, dwBufSize );
    }
}

void yuvToRgb(const int &frameWidth, const int &frameHeight, const QByteArray &yuvData)
{
    static int yuvToRgbFV1Table[ 256 ] = { -180, -179, -177, -176, -174, -173, -172, -170, -169, -167, -166, -165, -163, -162, -160, -159, -158, -156, -155, -153, -152, -151, -149, -148, -146, -145, -144, -142, -141, -139, -138, -137,  -135, -134, -132, -131, -130, -128, -127, -125, -124, -123, -121, -120, -118, -117, -115, -114, -113, -111, -110, -108, -107, -106, -104, -103, -101, -100, -99, -97, -96, -94, -93, -92, -90,  -89, -87, -86, -85, -83, -82, -80, -79, -78, -76, -75, -73, -72, -71, -69, -68, -66, -65, -64,-62, -61, -59, -58, -57, -55, -54, -52, -51, -50, -48, -47, -45, -44, -43, -41, -40, -38, -37,  -36, -34, -33, -31, -30, -29, -27, -26, -24, -23, -22, -20, -19, -17, -16, -15, -13, -12, -10, -9, -8, -6, -5, -3, -2, 0, 1, 2, 4, 5, 7, 8, 9, 11, 12, 14, 15, 16, 18, 19, 21, 22, 23, 25, 26, 28, 29, 30, 32, 33, 35, 36, 37, 39, 40, 42, 43, 44, 46, 47, 49, 50, 51, 53, 54, 56, 57, 58, 60, 61, 63, 64, 65, 67, 68, 70, 71, 72, 74, 75, 77, 78, 79, 81, 82, 84, 85, 86, 88, 89, 91, 92, 93, 95, 96, 98, 99, 100, 102, 103, 105, 106, 107, 109, 110, 112, 113, 114, 116, 117, 119, 120, 122, 123, 124, 126, 127, 129, 130, 131, 133, 134, 136, 137, 138, 140, 141, 143, 144, 145, 147, 148,  150, 151, 152, 154, 155, 157, 158, 159, 161, 162, 164, 165, 166, 168, 169, 171, 172, 173, 175, 176, 178 };
    static int yuvToRgbFV2Table[ 256 ] = { -92, -91, -91, -90, -89, -88, -88, -87, -86, -86, -85, -84, -83, -83, -82, -81, -81, -80, -79, -78, -78, -77, -76, -76, -75, -74, -73, -73, -72, -71, -71, -70, -69, -68, -68, -67, -66, -66, -65, -64, -63, -63, -62, -61, -61, -60, -59, -58, -58, -57, -56, -56, -55, -54, -53, -53, -52, -51, -51, -50, -49, -48, -48, -47, -46, -46, -45, -44, -43, -43, -42, -41, -41, -40, -39, -38, -38, -37, -36, -36, -35, -34, -33, -33, -32, -31, -31, -30, -29, -28, -28, -27, -26, -26, -25, -24, -23, -23, -22, -21, -21, -20, -19, -18, -18, -17, -16, -16, -15, -14, -13, -13, -12, -11, -11, -10, -9, -8, -8, -7, -6, -6, -5, -4, -3, -3, -2, -1, 0, 0, 1, 2, 2, 3, 4, 5, 5, 6, 7, 7, 8, 9, 10, 10, 11, 12, 12, 13, 14, 15, 15, 16, 17, 17, 18, 19, 20, 20, 21, 22, 22, 23, 24, 25, 25, 26, 27, 27, 28, 29, 30, 30, 31, 32, 32, 33, 34, 35, 35, 36, 37, 37, 38, 39, 40, 40, 41, 42, 42, 43, 44, 45, 45, 46, 47, 47, 48, 49, 50, 50, 51, 52, 52, 53, 54, 55, 55, 56, 57, 57, 58, 59, 60, 60, 61, 62, 62, 63, 64, 65, 65, 66, 67, 67, 68, 69, 70, 70, 71, 72, 72, 73, 74, 75, 75, 76, 77, 77, 78, 79, 80, 80, 81, 82, 82, 83, 84, 85, 85, 86, 87, 87, 88, 89, 90, 90 };
    static int yuvToRgbFU1Table[ 256 ] = { -44, -44, -44, -43, -43, -43, -42, -42, -42, -41, -41, -41, -40, -40, -40, -39, -39, -39, -38, -38, -38, -37, -37, -37, -36, -36, -36, -35, -35, -35, -34, -34, -33, -33, -33, -32, -32, -32, -31, -31, -31, -30, -30, -30, -29, -29, -29, -28, -28, -28, -27, -27, -27, -26, -26, -26, -25, -25, -25, -24, -24, -24, -23, -23, -22, -22, -22, -21, -21, -21, -20, -20, -20, -19, -19, -19, -18, -18, -18, -17, -17, -17, -16, -16, -16, -15, -15, -15, -14, -14, -14, -13, -13, -13, -12, -12, -11, -11, -11, -10, -10, -10, -9, -9, -9, -8, -8, -8, -7, -7, -7, -6, -6, -6, -5, -5, -5, -4, -4, -4, -3, -3, -3, -2, -2, -2, -1, -1, 0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15, 15, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19, 19, 20, 20, 20, 21, 21, 22, 22, 22, 23, 23, 23, 24, 24, 24, 25, 25, 25, 26, 26, 26, 27, 27, 27, 28, 28, 28, 29, 29, 29, 30, 30, 30, 31, 31, 31, 32, 32, 33, 33, 33, 34, 34, 34, 35, 35, 35, 36, 36, 36, 37, 37, 37, 38, 38, 38, 39, 39, 39, 40, 40, 40, 41, 41, 41, 42, 42, 42, 43, 43 };
    static int yuvToRgbFU2Table[ 256 ] = { -227, -226, -224, -222, -220, -219, -217, -215, -213, -212, -210, -208, -206, -204, -203, -201, -199, -197, -196, -194, -192, -190, -188, -187, -185, -183, -181, -180, -178, -176, -174, -173, -171, -169, -167, -165, -164, -162, -160, -158, -157, -155, -153, -151, -149, -148, -146, -144, -142, -141, -139, -137, -135, -134, -132, -130, -128, -126, -125, -123, -121, -119, -118, -116, -114, -112, -110, -109, -107, -105, -103, -102, -100, -98, -96, -94, -93, -91, -89, -87, -86, -84, -82, -80, -79, -77, -75, -73, -71, -70, -68, -66, -64, -63, -61, -59, -57, -55, -54, -52, -50, -48, -47, -45, -43, -41, -40, -38, -36, -34, -32, -31, -29, -27, -25, -24, -22, -20, -18, -16, -15, -13, -11, -9, -8, -6, -4, -2, 0, 1, 3, 5, 7, 8, 10, 12, 14, 15, 17, 19, 21, 23, 24, 26, 28, 30, 31, 33, 35, 37, 39, 40, 42, 44, 46, 47, 49, 51, 53, 54, 56, 58, 60, 62, 63, 65, 67, 69, 70, 72, 74, 76, 78, 79, 81, 83, 85, 86, 88, 90, 92, 93, 95, 97, 99, 101, 102, 104, 106, 108, 109, 111, 113, 115, 117, 118, 120, 122, 124, 125, 127, 129, 131, 133, 134, 136, 138, 140, 141, 143, 145, 147, 148, 150, 152, 154, 156, 157, 159, 161, 163, 164, 166, 168, 170, 172, 173, 175, 177, 179, 180, 182, 184, 186, 187, 189, 191, 193, 195, 196, 198, 200, 202, 203, 205, 207, 209, 211, 212, 214, 216, 218, 219, 221, 223, 225 };

    QImage image = QImage( frameWidth, frameHeight, QImage::Format_RGB888 );

    const long len = frameWidth * frameHeight;
    unsigned char const* yData = reinterpret_cast< unsigned char const * >( yuvData.constData() );
    unsigned char const* vData = &yData[ len ];
    unsigned char const* uData = &vData[ len >> 2 ];

    int bgr[ 3 ];

    for ( int i = 0; i < frameHeight; ++i )
    {
        for ( int j = 0; j < frameWidth; ++j )
        {
            const auto &&yIdx = i * frameWidth + j;
            const auto &&vIdx = ( i / 2 ) * ( frameWidth / 2 ) + ( j / 2 );
            const auto uIdx = vIdx;

            bgr[ 0 ] = yData[ yIdx ] + yuvToRgbFU2Table[ uData[ uIdx ] ];
            bgr[ 1 ] = yData[ yIdx ] - yuvToRgbFU1Table[ uData[ uIdx ] ] + yuvToRgbFV2Table[ vData[ vIdx ] ];
            bgr[ 2 ] = yData[ yIdx ] + yuvToRgbFV1Table[ vData[ vIdx ] ];

            for ( int k = 0; k < 3; ++k )
            {
                const auto &&idx = ( i * frameWidth +  j ) * 3 + k;

                if ( ( bgr[ k ] >= 0 ) && ( bgr[ k ] <= 255 ) )
                {
                    image.bits()[ idx ] = static_cast< unsigned char >( bgr[ k ] );
                }
                else
                {
                    image.bits()[ idx ] = ( bgr[ k ] < 0 ) ? ( 0 ) : ( 255 );
                }
            }
        }
    }

    QMetaObject::invokeMethod( label, "setPixmap", Q_ARG( QPixmap, QPixmap::fromImage( image ) ) );
}

void decodeCallback(LONG /*nPort*/, char *pBuf, LONG nSize, FRAME_INFO *pFrameInfo, void* /*pUserData*/, LONG /*nReserved2*/)
{
    if ( !yuvToRgbThreadPool.activeThreadCount() )
    {
        QtConcurrent::run( &yuvToRgbThreadPool, std::bind( yuvToRgb, pFrameInfo->nWidth, pFrameInfo->nHeight, QByteArray( pBuf, nSize ) ) );
    }
}

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    label = new QLabel;

    label->resize( 1920, 1080 );
    label->show();

    yuvToRgbThreadPool.setMaxThreadCount( 1 );


    PLAY_GetFreePort( &playPort );
    PLAY_SetStreamOpenMode( playPort, STREAME_REALTIME );

    qDebug() << "PLAY_OpenStream:" << PLAY_OpenStream( playPort, nullptr, 0, 1024 * 500 );
    qDebug() << "PLAY_SetDecCallBackEx:" << PLAY_SetDecCallBackEx( playPort, decodeCallback, NULL );
    qDebug() << "PLAY_Play:" << PLAY_Play( playPort, nullptr );


    qDebug() << "CLIENT_Init:" << CLIENT_Init( nullptr, 0 );

    NET_DEVICEINFO deviceInfo = { };

    const auto loginHandle = CLIENT_Login( "NVR的ip", 37777, "用户名", "密码", &deviceInfo );
    qDebug() << "CLIENT_Login: loginHandle:" << loginHandle;

    const auto &&channelId = CLIENT_RealPlay( loginHandle, 0, nullptr );
    qDebug() << "CLIENT_RealPlay: channelId:" << channelId;

    qDebug() << "CLIENT_SetRealDataCallBackEx:" << CLIENT_SetRealDataCallBackEx( channelId, netRealDataCallback, 0, static_cast< DWORD >( 0x1f ) );

    return a.exec();

    CLIENT_Logout( loginHandle );
    PLAY_Stop( playPort );
}

注意

• 因为要在QLabel上显示，需要把yuv转成rgb。代码中的方法是查表，性能不高，有性能要求的同学可以用其他第三方的方法来做。
• 考虑到实时性问题，当yuv转rgb线程繁忙的时候，会跳帧。
• 这些代码只是一个简单的demo，不包括异常处理、重连、多通道等特性。