Live Streaming over USB on Ubuntu and Linux, NVIDIA Jetson

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Thanks. I have the nvpmodel set to 0, which is the 10W mode. I have the 5V 4A 20W barrel connector power supply.

$ sudo nvpmodel --query
NVPM WARN: fan mode is not set!
NV Power Mode: MAXN
0
craig@jetson:~$

I do not have a fan on the CPU. There may be thermal throttling. Do you have a fan on your CPU?

Also, do you have any luck using C++ OpenCV applications on the Jetson? Do you have any advice?

$ g++ -L/usr/lib/aarch64-linux-gnu -I/usr/include/opencv4 frame.cpp -o frame  -lopencv_videoio
/usr/bin/ld: /tmp/ccPItXPw.o: undefined reference to symbol '_ZN2cv8fastFreeEPv'
//usr/lib/aarch64-linux-gnu/libopencv_core.so.4.1: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
craig@jetson:~/Documents/Development/opencv$

I’d like to compare the C++ and Python module performance, but I can’t seem to build a C++ program.

$ cat frame.cpp
#include "opencv2/opencv.hpp"
#include "opencv2/videoio.hpp"


using namespace cv;
int main(int argc, char** argv)
{
    VideoCapture cap;
    // open the default camera, use something different from 0 otherwise;
    // Check VideoCapture documentation.
    if(!cap.open(0))
        return 0;
    for(;;)
    {
          Mat frame;
          cap >> frame;
          if( frame.empty() ) break; // end of video stream
          imshow("this is you, smile! :)", frame);
          if( waitKey(10) == 27 ) break; // stop capturing by pressing ESC
    }
    // the camera will be closed automatically upon exit
    // cap.close();
    return 0;
}
craig@jetson:~/Documents/Development/opencv$

I am running Jetpack 4.4.

I would like to get a demo such as open pose or other running. Do you have a suggestion?

This article indicates that I can’t use open pose on Jetpack 4.4 due to move to CuDNN 8.0 and lack of support in caffe for this newer version of CuDNN.

Question Update: 8/26/2020

I’m now trying to use cv2.VideoWriter on the Jetson, but there seems to be a general problem with writing to file. If anyone has it working, please let me know the technique.

This guy indicated that he had to recompile OpenCV from source. I have not been able to source compile OpenCV on the Jetson Nano.

OpenCV Video Write Problem - #2 by DaneLLL - Jetson TX2 - NVIDIA Developer Forums

Several other people are having problems.

cv2.VideoWriter doesn't work well on Jetson Nano - #2 by DaneLLL - Jetson Nano - NVIDIA Developer Forums

Update on OpenCV 4.4 with cuda

I managed to compile OpenCV 4.4 on the nano and install it.

>>> import cv2
>>> cv2.__version__
'4.4.0'
>>> cv2.cuda.printCudaDeviceInfo(0)
*** CUDA Device Query (Runtime API) version (CUDART static linking) *** 

Device count: 1

Device 0: "NVIDIA Tegra X1"
  CUDA Driver Version / Runtime Version          10.20 / 10.20
  CUDA Capability Major/Minor version number:    5.3
  Total amount of global memory:                 3956 MBytes (4148391936 bytes)
  GPU Clock Speed:                               0.92 GHz
  Max Texture Dimension Size (x,y,z)             1D=(65536), 2D=(65536,65536), 3D=(4096,4096,4096)
  Max Layered Texture Size (dim) x layers        1D=(16384) x 2048, 2D=(16384,16384) x 2048
  Total amount of constant memory:               65536 bytes
  Total amount of shared memory per block:       49152 bytes
  Total number of registers available per block: 32768
  Warp size:                                     32
  Maximum number of threads per block:           1024
  Maximum sizes of each dimension of a block:    1024 x 1024 x 64
  Maximum sizes of each dimension of a grid:     2147483647 x 65535 x 65535
  Maximum memory pitch:                          2147483647 bytes
  Texture alignment:                             512 bytes
  Concurrent copy and execution:                 Yes with 1 copy engine(s)
...
 Compute Mode:
      Default (multiple host threads can use ::cudaSetDevice() with device simultaneously) 

deviceQuery, CUDA Driver = CUDART, CUDA Driver Version  = 10.20, CUDA Runtime Version = 10.20, NumDevs = 1

This repo worked.

I have a 12V fan blowing on the heat sink. The Nano is supposed to use a 5V fan, but the only fan I had in my drawer was this 12V one. It works so far.

image

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