In this lesson we show you how to understand the great mystery known as Gstreamer. Most folks using the NVIDIA Jetson Nano or the NVIDIA Jetson Exavier NX just copy and past the launch string they found on the internet, but do not have a clue how Gstreamer actually works. In this video we will take you through it step-by-step, and show you how to actually understand what you are doing, and how to design your own pipes for maximum performance and image quality. Below are all the commands we used in the video lesson

gst-launch-1.0 audiotestsrc ! alsasink

gst-inspect-1.0 audiotestsrc

gst-launch-1.0 audiotestsrc freq=500 ! alsasink

gst-launch-1.0 audiotestsrc freq=500 ! alsasink

gst-inspect-1.0 audiotestsrc

gst-launch-1.0 audiotestsrc freq=500 ! audio/x-raw, format=U8 ! alsasink

gst-launch-1.0 audiotestsrc freq=500 ! audio/x-raw, format=U18LE ! alsasink

gst-launch-1.0 audiotestsrc freq=500 ! audio/x-raw, format=U18LE ! audioconvert ! audio/x-raw, format=U8 ! alsasink

gst-launch-1.0 videotestsrc ! ximagesink

gst-inspect-1.0 videotestsrc

gst-launch-1.0 videotestsrc pattern=11 ! ximagesink

gst-launch-1.0 videotestsrc pattern=0 ! video/x-raw, format=BGR ! ximagesink

gst-inspect-1.0 autovideoconvert

gst-launch-1.0 videotestsrc pattern=0 ! video/x-raw, format=BGR ! autovideoconvert ! ximagesink

gst-launch-1.0 videotestsrc pattern=0 ! video/x-raw, format=BGR ! autovideoconvert ! videoconvert ! video/x-raw, width=1280, height=960 !  ximagesink 

gst-launch-1.0 videotestsrc pattern=0 ! video/x-raw, format=BGR ! autovideoconvert ! videoconvert ! video/x-raw, width=1280, height=960, framerate=30/1 !  ximagesink

gst-launch-1.0 videotestsrc pattern=0 ! video/x-raw, format=BGR ! autovideoconvert ! videoconvert ! video/x-raw, width=1280, height=960, framerate=1/1 !  ximagesink

gst-launch-1.0 nvarguscamerasrc ! autovideo

gst-launch-1.0 nvarguscamerasrc !  nvvidconv flip-method=2 ! video/x-raw,width=1280,height=840 ! autovideoconvert  !  ximagesink

gst-launch-1.0 nvarguscamerasrc ! "video/x-raw(memory:NVMM),width=3264,height=2464,format=NV12,framerate=21/1" !  nvvidconv flip-method=2 ! video/x-raw,width=640,height=480 ! autovideoconvert  !  ximagesink

gst-launch-1.0 nvarguscamerasrc ! "video/x-raw(memory:NVMM),width=3264,height=2464,format=NV12,framerate=21/1" !  nvvidconv flip-method=2 ! video/x-raw,width=640,height=480 ! autovideoconvert  ! agingtv ! ximagesink

gst-launch-1.0 nvarguscamerasrc ! "video/x-raw(memory:NVMM),width=3264,height=2464,format=NV12,framerate=21/1" !  nvvidconv flip-method=2 ! video/x-raw,width=640,height=480 ! autovideoconvert  ! agingtv ! ximagesink


gst-launch-1.0 nvarguscamerasrc ! "video/x-raw(memory:NVMM),width=3264,height=2464,format=NV12,framerate=21/1" !  nvvidconv flip-method=2 ! video/x-raw,width=1280,height=960 ! autovideoconvert  ! agingtv ! coloreffects preset=sepia ! ximagesink

gst-launch-1.0  v4l2src device=/dev/video1 ! xvimagesink

gst-launch-1.0  v4l2src device=/dev/video1 ! video/x-raw,framerate=20/1,width=864,height=480 ! xvimagesink

gst-launch-1.0 audiotestsrc ! alsasink

gst-inspect-1.0 audiotestsrc

gst-launch-1.0 audiotestsrc freq=500 ! alsasink

gst-inspect-1.0 audiotestsrc

gst-launch-1.0 audiotestsrc freq=500 ! audio/x-raw, format=U8 ! alsasink

gst-launch-1.0 audiotestsrc freq=500 ! audio/x-raw, format=U18LE ! alsasink

gst-launch-1.0 audiotestsrc freq=500 ! audio/x-raw, format=U18LE ! audioconvert ! audio/x-raw, format=U8 ! alsasink

gst-launch-1.0 videotestsrc ! ximagesink

gst-inspect-1.0 videotestsrc

gst-launch-1.0 videotestsrc pattern=11 ! ximagesink

gst-launch-1.0 videotestsrc pattern=0 ! video/x-raw, format=BGR ! ximagesink

gst-inspect-1.0 autovideoconvert

gst-launch-1.0 videotestsrc pattern=0 ! video/x-raw, format=BGR ! autovideoconvert ! ximagesink

gst-launch-1.0 videotestsrc pattern=0 ! video/x-raw, format=BGR ! autovideoconvert ! videoconvert ! video/x-raw, width=1280, height=960 ! ximagesink

gst-launch-1.0 videotestsrc pattern=0 ! video/x-raw, format=BGR ! autovideoconvert ! videoconvert ! video/x-raw, width=1280, height=960, framerate=30/1 ! ximagesink

gst-launch-1.0 videotestsrc pattern=0 ! video/x-raw, format=BGR ! autovideoconvert ! videoconvert ! video/x-raw, width=1280, height=960, framerate=1/1 ! ximagesink

gst-launch-1.0 nvarguscamerasrc ! autovideo

gst-launch-1.0 nvarguscamerasrc ! nvvidconv flip-method=2 ! video/x-raw,width=1280,height=840 ! autovideoconvert ! ximagesink

gst-launch-1.0 nvarguscamerasrc ! "video/x-raw(memory:NVMM),width=3264,height=2464,format=NV12,framerate=21/1" ! nvvidconv flip-method=2 ! video/x-raw,width=640,height=480 ! autovideoconvert ! ximagesink

gst-launch-1.0 nvarguscamerasrc ! "video/x-raw(memory:NVMM),width=3264,height=2464,format=NV12,framerate=21/1" ! nvvidconv flip-method=2 ! video/x-raw,width=1280,height=960 ! autovideoconvert ! agingtv ! coloreffects preset=sepia ! ximagesink

gst-launch-1.0 v4l2src device=/dev/video1 ! xvimagesink

gst-launch-1.0 v4l2src device=/dev/video1 ! video/x-raw,framerate=20/1,width=864,height=480 ! xvimagesink

Arduino, Tutorial

Arduino Tutorial 65: Creating Useful Commands from IR Remote Buttons

June 9, 2020 admin

In this lesson we show you how to map button pushes on the Infrared Remote Control to useful functions in the Arduino. This code can serve as the basis for using the remote control in many different applications.

We are building this with parts from our Elegoo Kit , and our actual build is using an Arduino Nano, which allows the project to be built on a single breadboard. You can get the neat jumper wires HERE.

The code developed in the video is available below:

#include <IRremote.h>
int IRpin=9;
IRrecv IR(IRpin);
decode_results cmd;
String myCom;
void setup()
{
Serial.begin(9600);
IR.enableIRIn();
}

void loop() {
  while (IR.decode(&cmd)==0){ 
}
delay(1500);
IR.resume();

if (cmd.value==0xFF6897){
  myCom="zero";
  Serial.println(myCom); 
}
if (cmd.value==0xFF30CF){
  myCom="one";
  Serial.println(myCom); 
}
if (cmd.value==0xFF18E7){
  myCom="two";
  Serial.println(myCom); 
}
if (cmd.value==0xFF7A85){
  myCom="three";
  Serial.println(myCom); 
}
if (cmd.value==0xFF10EF){
  myCom="four";
  Serial.println(myCom); 
}
if (cmd.value==0xFF38C7){
  myCom="five";
  Serial.println(myCom); 
}
if (cmd.value==0xFF5AA5){
  myCom="six";
  Serial.println(myCom); 
}
if (cmd.value==0xFF42BD){
  myCom="seven";
  Serial.println(myCom); 
}
if (cmd.value==0xFF4AB5){
  myCom="eight";
  Serial.println(myCom); 
}
if (cmd.value==0xFF52AD){
  myCom="nine";
  Serial.println(myCom); 
}

if (cmd.value==0xFFA25D){
  myCom="pwr";
  Serial.println(myCom); 
}
if (cmd.value==0xFF629D){
  myCom="v+";
  Serial.println(myCom);
}
if (cmd.value==0xFFE21D){
  myCom="fun";
  Serial.println(myCom);
}
if (cmd.value==0xFF22DD){
  myCom="rew";
  Serial.println(myCom);
}
if (cmd.value==0xFF02FD){
  myCom="play";
  Serial.println(myCom);
}
if (cmd.value==0xFFC23D){
  myCom="ff";
  Serial.println(myCom);
}
if (cmd.value==0xFFE01F){
  myCom="dn";
  Serial.println(myCom);
}
if (cmd.value==0xFFA857){
  myCom="v-";
  Serial.println(myCom);
}
if (cmd.value==0xFF906F){
  myCom="up";
  Serial.println(myCom);
}
if (cmd.value==0xFF9867){
  myCom="eq";
  Serial.println(myCom);
}
if (cmd.value==0xFFB04F
){
  myCom="st";
  Serial.println(myCom);
}

}

100

101

102

103

104

105

#include <IRremote.h>

int IRpin=9;

IRrecv IR(IRpin);

decode_results cmd;

String myCom;

void setup()

{

Serial.begin(9600);

IR.enableIRIn();

}

void loop() {

while (IR.decode(&cmd)==0){

}

delay(1500);

IR.resume();

if (cmd.value==0xFF6897){

myCom="zero";

Serial.println(myCom);

}

if (cmd.value==0xFF30CF){

myCom="one";

Serial.println(myCom);

}

if (cmd.value==0xFF18E7){

myCom="two";

Serial.println(myCom);

}

if (cmd.value==0xFF7A85){

myCom="three";

Serial.println(myCom);

}

if (cmd.value==0xFF10EF){

myCom="four";

Serial.println(myCom);

}

if (cmd.value==0xFF38C7){

myCom="five";

Serial.println(myCom);

}

if (cmd.value==0xFF5AA5){

myCom="six";

Serial.println(myCom);

}

if (cmd.value==0xFF42BD){

myCom="seven";

Serial.println(myCom);

}

if (cmd.value==0xFF4AB5){

myCom="eight";

Serial.println(myCom);

}

if (cmd.value==0xFF52AD){

myCom="nine";

Serial.println(myCom);

}

if (cmd.value==0xFFA25D){

myCom="pwr";

Serial.println(myCom);

}

if (cmd.value==0xFF629D){

myCom="v+";

Serial.println(myCom);

}

if (cmd.value==0xFFE21D){

myCom="fun";

Serial.println(myCom);

}

if (cmd.value==0xFF22DD){

myCom="rew";

Serial.println(myCom);

}

if (cmd.value==0xFF02FD){

myCom="play";

Serial.println(myCom);

}

if (cmd.value==0xFFC23D){

myCom="ff";

Serial.println(myCom);

}

if (cmd.value==0xFFE01F){

myCom="dn";

Serial.println(myCom);

}

if (cmd.value==0xFFA857){

myCom="v-";

Serial.println(myCom);

}

if (cmd.value==0xFF906F){

myCom="up";

Serial.println(myCom);

}

if (cmd.value==0xFF9867){

myCom="eq";

Serial.println(myCom);

}

if (cmd.value==0xFFB04F

){

myCom="st";

Serial.println(myCom);

}

NVIDIA Jetson Xavier NX

Jetson Xavier NX Lesson 3: Using a WEB cam or Raspberry Pi camera in OpenCV with Gstreamer

June 3, 2020 admin

In this video lesson we learn how to launch the Raspberry Pi Camera or a simple WEB cam on the Jetson Xavier NX using openCV and a Gstreamer command. This simple code shows you how to set up the camera, and then how to grab a frame and show a frame to create live video from the cameras.

import cv2
print(cv2.__version__)
width=1280
height=720
flip=2
camSet='nvarguscamerasrc sensor-id=0 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink'
#camSet ='v4l2src device=/dev/video1 ! video/x-raw,width='+str(width)+',height='+str(height)+',framerate=24/1 ! videoconvert ! appsink'
cam=cv2.VideoCapture(camSet)
while True:
    _, frame = cam.read()
    cv2.imshow('myCam',frame)
    cv2.moveWindow('myCam',0,0)
    if cv2.waitKey(1)==ord('q'):
        break
cam.release()
cv2.destroyAllWindows()

import cv2

print(cv2.__version__)

width=1280

height=720

flip=2

camSet='nvarguscamerasrc sensor-id=0 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink'

#camSet ='v4l2src device=/dev/video1 ! video/x-raw,width='+str(width)+',height='+str(height)+',framerate=24/1 ! videoconvert ! appsink'

cam=cv2.VideoCapture(camSet)

while True:

_, frame = cam.read()

cv2.imshow('myCam',frame)

cv2.moveWindow('myCam',0,0)

if cv2.waitKey(1)==ord('q'):

break

cam.release()

cv2.destroyAllWindows()

Arduino, Tutorial

Arduino Tutorial 64: Understanding and Using the Infrared (IR) Remote to Control a Project

June 2, 2020 admin

The Elegoo Kit contains a simple IR module and remote which allow you to add remote control to your arduino project. In this lesson we show you how to connect the remote, and then how to send signals to the arduino using the remote unit. This video takes you through the process step by step.

The code below will get you started, and then you can expand the code to map all the buttons to simple string commands.

#include <IRremote.h> //Make sure to install the library
int IRpin=9;
IRrecv IR(IRpin);
decode_results cmd;
String myCom;
void setup()
{
Serial.begin(9600);
IR.enableIRIn();
}

void loop() {
  while (IR.decode(&cmd)==0){ 
}
Serial.println(cmd.value,HEX);
delay(1500);
IR.resume();

if (cmd.value==0xFF6897){
  myCom="zero";
  Serial.println(myCom); 
}
if (cmd.value==0xFFA25D){
  myCom="pwr";
  Serial.println(myCom); 
}

}

#include <IRremote.h> //Make sure to install the library

int IRpin=9;

IRrecv IR(IRpin);

decode_results cmd;

String myCom;

void setup()

{

Serial.begin(9600);

IR.enableIRIn();

}

void loop() {

while (IR.decode(&cmd)==0){

}

Serial.println(cmd.value,HEX);

delay(1500);

IR.resume();

if (cmd.value==0xFF6897){

myCom="zero";

Serial.println(myCom);

}

if (cmd.value==0xFFA25D){

myCom="pwr";

Serial.println(myCom);

}

We are building this with parts from our Elegoo Kit , and our actual build is using an Arduino Nano, which allows the project to be built on a single breadboard. You can get the neat jumper wires HERE.

Jetson Nano

AI on the Jetson Nano LESSON 42: Recognizing and Identifying Faces from Live Video on OpenCV

May 30, 2020 admin

In this video lesson we show how to recognize and identify faces in live video on the Jestson Nano using OpenCV. We have a separate program that trains the system based on known faces, and this work was described in an earlier lesson in this series. Below is a copy of the code we develop in the video above.

import face_recognition
import cv2
import os
import pickle
import time
print(cv2.__version__)

Encodings=[]
Names=[]

with open('train.pkl','rb') as f:
    Names=pickle.load(f)
    Encodings=pickle.load(f)
font=cv2.FONT_HERSHEY_SIMPLEX

cam= cv2.VideoCapture(1)

while True:

    _,frame=cam.read()
    frameSmall=cv2.resize(frame,(0,0),fx=.25,fy=.25)
    frameRGB=cv2.cvtColor(frameSmall,cv2.COLOR_BGR2RGB)
    facePositions=face_recognition.face_locations(frameRGB,model='cnn')
    allEncodings=face_recognition.face_encodings(frameRGB,facePositions)
    for (top,right,bottom,left),face_encoding in zip(facePositions,allEncodings):
        name='Unkown Person'
        matches=face_recognition.compare_faces(Encodings,face_encoding)
        if True in matches:
            first_match_index=matches.index(True)
            name=Names[first_match_index]
        top=top*4
        right=right*4
        bottom=bottom*4
        left=left*4
        cv2.rectangle(frame,(left,top),(right, bottom),(0,0,255),2)
        cv2.putText(frame,name,(left,top-6),font,.75,(0,0,255),2)
    cv2.imshow('Picture',frame)
    cv2.moveWindow('Picture',0,0)
    if cv2.waitKey(1)==ord('q'):
        break

cam.release()
cv2.destroyAllWindows()

import face_recognition

import cv2

import os

import pickle

import time

print(cv2.__version__)

Encodings=[]

Names=[]

with open('train.pkl','rb') as f:

Names=pickle.load(f)

Encodings=pickle.load(f)

font=cv2.FONT_HERSHEY_SIMPLEX

cam= cv2.VideoCapture(1)

while True:

_,frame=cam.read()

frameSmall=cv2.resize(frame,(0,0),fx=.25,fy=.25)

frameRGB=cv2.cvtColor(frameSmall,cv2.COLOR_BGR2RGB)

facePositions=face_recognition.face_locations(frameRGB,model='cnn')

allEncodings=face_recognition.face_encodings(frameRGB,facePositions)

for (top,right,bottom,left),face_encoding in zip(facePositions,allEncodings):

name='Unkown Person'

matches=face_recognition.compare_faces(Encodings,face_encoding)

if True in matches:

first_match_index=matches.index(True)

name=Names[first_match_index]

top=top*4

right=right*4

bottom=bottom*4

left=left*4

cv2.rectangle(frame,(left,top),(right, bottom),(0,0,255),2)

cv2.putText(frame,name,(left,top-6),font,.75,(0,0,255),2)

cv2.imshow('Picture',frame)

cv2.moveWindow('Picture',0,0)

if cv2.waitKey(1)==ord('q'):

break

cam.release()

cv2.destroyAllWindows()

Technology Tutorials

Jetson Xavier NX Lesson 4: Understanding and Using Gstreamer for Absolute Beginners

Arduino Tutorial 65: Creating Useful Commands from IR Remote Buttons

Jetson Xavier NX Lesson 3: Using a WEB cam or Raspberry Pi camera in OpenCV with Gstreamer

Arduino Tutorial 64: Understanding and Using the Infrared (IR) Remote to Control a Project

AI on the Jetson Nano LESSON 42: Recognizing and Identifying Faces from Live Video on OpenCV

Making The World a Better Place One High Tech Project at a Time. Enjoy!