Android下QVideoFrame转QImage不成功记录

1.由于QVideoFrame::image() const : unsupported pixel format Format_ABGR32 ，在转换时需要做个特殊处理如下,增加了android手机下的特殊格式处理:

if(frame.pixelFormat() == QVideoFrame::Format_ABGR32) 此部分代码

QImage imageFromVideoFrame(QVideoFrame &frame)
{
    qDebug() << "resolution:(" << frame.width() << ", " << frame.height() << ")";
    QImage image;
    if(frame.map(QAbstractVideoBuffer::ReadOnly)){
        QImage::Format fmt = QVideoFrame::imageFormatFromPixelFormat(frame.pixelFormat());
        if(fmt != QImage::Format_Invalid){
            qDebug() << "not invalid format.";
            image = QImage(frame.bits(), frame.width(), frame.height(), /*v.bytesPerLine(),*/fmt);
        }
        else if(frame.pixelFormat() == QVideoFrame::Format_ABGR32){
            const auto max = frame.width() * frame.height() * 4;
            std::vector< uchar > buf;
            buf.reserve( max );
            uchar * bits = frame.bits();

            static const size_t i1 = ( Q_BYTE_ORDER == Q_LITTLE_ENDIAN ? 2 : 0 );
            static const size_t i2 = ( Q_BYTE_ORDER == Q_LITTLE_ENDIAN ? 1 : 3 );
            static const size_t i3 = ( Q_BYTE_ORDER == Q_LITTLE_ENDIAN ? 0 : 2 );
            static const size_t i4 = ( Q_BYTE_ORDER == Q_LITTLE_ENDIAN ? 3 : 1 );

            for( auto i = 0; i < max; )
            {
                buf.push_back( bits[ i1 ] );
                buf.push_back( bits[ i2 ] );
                buf.push_back( bits[ i3 ] );
                buf.push_back( bits[ i4 ] );

                bits += 4;
                i += 4;
            }

            image = QImage( &buf[ 0 ], frame.width(), frame.height(), frame.bytesPerLine(),
                           QImage::Format_ARGB32 ).copy();

        }
        else
        {
            int nbytes = frame.mappedBytes();
            qDebug() << "invalid format. nbytes=" << nbytes;
            image = QImage::fromData(frame.bits(), nbytes);

            //image = frame.image();
        }
        frame.unmap();
    }
    return image.mirrored(true, true);
}