OpenCV Mat Object And Saving Image Data 09_camera_jepg_capture

Robotics & Edge Computing Jetson Systems Jetson Nano
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5

I’m still very confused.

In the 09_camera_jepg_capture program, I know that bool ConsumerThread::threadExecute() captures the incoming video frames and I was under the impression that I could just use/copy m_dmabuf instead of creating another buffer.

Am I correct with that assumption or no?

My second question is that once either the m_dmabuf is either copied again or a second buffer is created what’s the best way to get the height/width of the image that’s saved in the mentioned buffer(s)?

For what it’s worth, here’s where I currently stand with the 09_camera_jpeg_capture example with the bool ConsumerThread::threadExecute() function

bool ConsumerThread::threadExecute()
    {
        IEGLOutputStream *iEglOutputStream = interface_cast<IEGLOutputStream>(m_stream);
        IFrameConsumer *iFrameConsumer = interface_cast<IFrameConsumer>(m_consumer);

        /* Wait until the producer has connected to the stream. */
        CONSUMER_PRINT("Waiting until producer is connected...\n");
        if (iEglOutputStream->waitUntilConnected() != STATUS_OK)
            ORIGINATE_ERROR("Stream failed to connect.");
        CONSUMER_PRINT("Producer has connected; continuing.\n");
        int second_dmabuf = -1;
        while (true)
        {
            /* Acquire a frame. */
            UniqueObj<Frame> frame(iFrameConsumer->acquireFrame());
            IFrame *iFrame = interface_cast<IFrame>(frame);
            if (!iFrame)
                break;

            /* Get the IImageNativeBuffer extension interface. */
            // Get access to image data through iFrame->getImage();
            // Image data can be retrieved and processed through ' IImageNativeBuffer interface.
            NV::IImageNativeBuffer *iNativeBuffer = interface_cast<NV::IImageNativeBuffer>(iFrame->getImage());
            if (!iNativeBuffer)
                ORIGINATE_ERROR("IImageNativeBuffer not supported by Image.");

            /* If we don't already have a buffer, create one from this image.
               Otherwise, just blit to our buffer. */
            if (m_dmabuf == -1)
            {
                /*
                    virtual int EGLStream::NV::IImageNativeBuffer::createNvBuffer(Argus::Size2D<...> size, NvBufferColorFormat format, NvBufferLayout layout, EGLStream::NV::Rotation rotation = EGLStream::NV::ROTATION_0, Argus::Status *status = (Argus::Status *)__null) const

                    Returns -1 on failure
                    Returns valid dmabuf-fd on success

                */
                m_dmabuf = iNativeBuffer->createNvBuffer(iEglOutputStream->getResolution(),
                                                         NvBufferColorFormat_YUV420,
                                                         NvBufferLayout_BlockLinear);

                second_dmabuf = iNativeBuffer->createNvBuffer(iEglOutputStream->getResolution(),
                                                              NvBufferColorFormat_YUV420,
                                                              NvBufferLayout_BlockLinear);

                if (m_dmabuf == -1 || second_dmabuf == -1)
                    CONSUMER_PRINT("\tFailed to create NvBuffer\n");
                else
                    CONSUMER_PRINT("\nBUFFER CREATED\n");
            }
            else if (iNativeBuffer->copyToNvBuffer(m_dmabuf) != STATUS_OK || iNativeBuffer->copyToNvBuffer(second_dmabuf) != STATUS_OK)
            {
                ORIGINATE_ERROR("Failed to copy frame to NvBuffer.");
            }

            /* Process frame to be written. */
            //     bool CaptureConsumerThread::processV4L2Fd(int32_t fd, uint64_t frameNumber)
            
            processV4L2Fd(m_dmabuf, iFrame->getNumber());
        }

        CONSUMER_PRINT("Done.\n");

        requestShutdown();

        return true;
    }