Dump YUV buffer with libargus

[932315769]

Hi,NVIDIA:
I have wrote a sample to capture yuv image accroding to the sample of oneShot.
Here is the main code:

EGLStream::Image *image = iFrame->getImage();
EXIT_IF_NULL(image, “Failed to get Image from iFrame->getImage()”);
EGLStream::IImageHeaderlessFile *iHeaderlessFile = Argus::interface_castEGLStream::IImageHeaderlessFile(image);
if (!iHeaderlessFile)
{
EXIT_IF_NULL(iHeaderlessFile,“Devil : --------------------------- Failed to get IImageHeaderlessFile interface.\n”);
}
status = iHeaderlessFile->writeHeaderlessFile(FILE_PREFIX “devil_yuv.yuv”);
EXIT_IF_NOT_OK(status,“Devil : ---------------------------- faileed to write yuv \n”)
printf("Devil : --------- " FILE_PREFIX “devil_yuv.yuv\n”);

Also,I wanted to dump the yuv buffer as below:

char buf[128];
printf("\n buffer count : %d \n buffer size : %d",iImage->getBufferCount(),iImage->getBufferSize());
snprintf(buf,sizeof(buf),"/home/image-3261//fDocumentsrame%d.yuv",requestId);
int devil_fd = open(buf,O_RDWR|O_CREAT,0777);
if(devil_fd){
int length = write(devil_fd,iImage->mapBuffer(5),12807203/2);
close(devil_fd);
}else{
printf(“Devil : fd is null”);
}

But the buffer I dumped can’t be recognized as a yuv image.Is there any error with my code or process?

[ShaneCCC]

Have reference to argus_camera to capture the headless(nv12) files.

[932315769]

I have capture the headless file successfully, but I want to get the yuv buffer not only capture a image.I use the mapbuffer function to get the buffer,but it occurs some question.The buffer I saved to a file couldn’t be recognized as a yuv image.

[ShaneCCC]

Have a check the yuvJpeg sample code.

        // Print out some capture metadata from the frame.
        IArgusCaptureMetadata *iArgusCaptureMetadata = interface_cast<IArgusCaptureMetadata>(frame);
        if (!iArgusCaptureMetadata)
            ORIGINATE_ERROR("Failed to get IArgusCaptureMetadata interface.");
        CaptureMetadata *metadata = iArgusCaptureMetadata->getMetadata();
        ICaptureMetadata *iMetadata = interface_cast<ICaptureMetadata>(metadata);
        if (!iMetadata)
            ORIGINATE_ERROR("Failed to get ICaptureMetadata interface.");
        CONSUMER_PRINT("\tSensor Timestamp: %llu, LUX: %f\n",
                       static_cast<unsigned long long>(iMetadata->getSensorTimestamp()),
                       iMetadata->getSceneLux());

        // Print out image details, and map the buffers to read out some data.
        Image *image = iFrame->getImage();
        IImage *iImage = interface_cast<IImage>(image);
        IImage2D *iImage2D = interface_cast<IImage2D>(image);
        for (uint32_t i = 0; i < iImage->getBufferCount(); i++)
        {
            const uint8_t *d = static_cast<const uint8_t*>(iImage->mapBuffer(i));
            if (!d)
                ORIGINATE_ERROR("\tFailed to map buffer\n");

            Size2D<uint32_t> size = iImage2D->getSize(i);
            CONSUMER_PRINT("\tIImage(2D): "
                           "buffer %u (%ux%u, %u stride), "
                           "%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
                           i, size.width(), size.height(), iImage2D->getStride(i),
                           d[0], d[1], d[2], d[3], d[4], d[5],
                           d[6], d[7], d[8], d[9], d[10], d[11]);
        }

[932315769]

Hi,Shane:
I have print the info as below:
Capturing from device 0 using sensor mode 4 (1280x720)
count : 2
Devil :
count : 0
height : 720
width : 1280
stride : 1280
Devil :
count : 1
height : 360
width : 640
stride : 1280

buffer count : 2

And I saved buffer with iImage->mapbuffer(1) as a yuv file, but I can’t preview normal picture in this file.

[932315769]

Could you please share the source code of WriteHeadlessFile() or tell me how to save yuv image from the buffer?

[DaneLLL]

Hi,
Please check the sample and do modification:

/usr/src/jetson_multimedia_api/samples/09_camera_jpeg_capture

The default code is

        if (m_dmabuf == -1)
        {
            m_dmabuf = iNativeBuffer->createNvBuffer(iStream->getResolution(),
                                                     NvBufferColorFormat_YUV420,
                                                     NvBufferLayout_BlockLinear);
            if (m_dmabuf == -1)
                CONSUMER_PRINT("\tFailed to create NvBuffer\n");
        }
        else if (iNativeBuffer->copyToNvBuffer(m_dmabuf) != STATUS_OK)
        {
            ORIGINATE_ERROR("Failed to copy frame to NvBuffer.");
        }

Please modify NvBufferLayout_BlockLinear to NvBufferLayout_Pitch and then you can dump the frames with following code:

        char filename[256];
	
        sprintf(filename,"output000.yuv",(unsigned)frameNumber);

        std::ofstream *outputFile = new std::ofstream(filename);
        dump_dmabuf(m_dmabuf,0,outputFile);
        dump_dmabuf(m_dmabuf,1,outputFile);
        dump_dmabuf(m_dmabuf,2,outputFile);

        delete outputFile;

[932315769]

I have dumped the buffer successfully.
Thanks a lot.

[932315769]

Hi,Dane
What does the plane of “1”,“2”,“3” mean?
Is the plane 1 corresponding Y buffer,2 corresponding U buffer and 3 corresponding V buffer?

[932315769]

I use the NvBufferParams to get the num_planes is 3,but I still would like to know what does each plane mean.

[DaneLLL]

Hi,

@932315769

What does the plane of “1”,“2”,“3” mean?
Is the plane 1 corresponding Y buffer,2 corresponding U buffer and 3 corresponding V buffer?

Yes, this is correct. For NvBufferColorFormat_YUV420, there are 3 planes, in Y, U, and V planes.

[932315769]

OK,thank u very much.