从QCamera或QVideoWidget获取视频字节

Question

如何从QCamera或QVideoWidget获得字节数组(帧)？

我成功地从相机和麦克风捕捉视频和音频，现在我想将它们发送到socket TCP通道，以创建一个简单的视频/音频调用软件。

我尝试过的：

• I已经重新实现了QAbstractVideoSurface方法，

但是“现在”的方法并没有被调用。怎么啦？

如何在QCameraViewfinder中使用这个类？

这是我的代码

#include <QtMultimedia/QAbstractVideoSurface>
class QMyAbstractVideoSurface :
    public QAbstractVideoSurface
{
    Q_OBJECT
public:
    explicit QMyAbstractVideoSurface(QObject* parent = 0);
    ~QMyAbstractVideoSurface();

    QList<QVideoFrame::PixelFormat> supportedPixelFormats(QAbstractVideoBuffer::HandleType handleType) const;

    bool present(const QVideoFrame& frame);

    bool start(const QVideoSurfaceFormat& format);

    void stop();
};

#include "QMyAbstractVideoSurface.h"
#include <QDebug>

QMyAbstractVideoSurface::QMyAbstractVideoSurface(QObject* parent) {
}

bool QMyAbstractVideoSurface::start(const QVideoSurfaceFormat& format) {
    return QAbstractVideoSurface::start(format);

}

void QMyAbstractVideoSurface::stop() {
    QAbstractVideoSurface::stop();
}

bool QMyAbstractVideoSurface::present(const QVideoFrame& frame) {

    QVideoFrame cloneFrame(frame);
    QByteArray a((char*)cloneFrame.bits());

    qDebug() << "present";
    qDebug() << a.toBase64();

    return true;
}

QList<QVideoFrame::PixelFormat> QMyAbstractVideoSurface::
supportedPixelFormats(QAbstractVideoBuffer::HandleType handleType) const
{
    Q_UNUSED(handleType);
    return QList<QVideoFrame::PixelFormat>()
        << QVideoFrame::Format_ARGB32
        << QVideoFrame::Format_ARGB32_Premultiplied
        << QVideoFrame::Format_RGB32
        << QVideoFrame::Format_RGB24
        << QVideoFrame::Format_RGB565
        << QVideoFrame::Format_RGB555
        << QVideoFrame::Format_ARGB8565_Premultiplied
        << QVideoFrame::Format_BGRA32
        << QVideoFrame::Format_BGRA32_Premultiplied
        << QVideoFrame::Format_BGR32
        << QVideoFrame::Format_BGR24
        << QVideoFrame::Format_BGR565
        << QVideoFrame::Format_BGR555
        << QVideoFrame::Format_BGRA5658_Premultiplied
        << QVideoFrame::Format_AYUV444
        << QVideoFrame::Format_AYUV444_Premultiplied
        << QVideoFrame::Format_YUV444
        << QVideoFrame::Format_YUV420P
        << QVideoFrame::Format_YV12
        << QVideoFrame::Format_UYVY
        << QVideoFrame::Format_YUYV
        << QVideoFrame::Format_NV12
        << QVideoFrame::Format_NV21
        << QVideoFrame::Format_IMC1
        << QVideoFrame::Format_IMC2
        << QVideoFrame::Format_IMC3
        << QVideoFrame::Format_IMC4
        << QVideoFrame::Format_Y8
        << QVideoFrame::Format_Y16
        << QVideoFrame::Format_Jpeg
        << QVideoFrame::Format_CameraRaw
        << QVideoFrame::Format_AdobeDng;
}

QMyAbstractVideoSurface::~QMyAbstractVideoSurface()
{}

Answer 1

您可能正在寻找一个QVideoSink：https://doc-snapshots.qt.io/qt6-dev/qvideosink.html。

QVideoSink类可用于从Qt多媒体逐帧检索视频数据。

它应该设置在QMediaCaptureSession：https://doc-snapshots.qt.io/qt6-dev/qmediacapturesession.html#setVideoSink上。

对于Qt5，您有QAbstractVideoSurface https://doc.qt.io/qt-5/qabstractvideosurface.html或QVideoProbe https://doc.qt.io/qt-5/qvideoprobe.html。