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• JavaCV FFmpegFrameRecorder save images to video

  2 décembre 2024, par Learning from masters

  I am a bit confused about the use of JavaCV FFmpegFrameRecorder. I have several byte[] or short[] arrays (depending if my images are 8 or 16 bit) were I have the data related for several images. Now, my idea is to use JavaCPP to send each image to ffmpeg so it creates me a mute video from this collection at the framerate I wish. Up to now I have :

  



  package ffmpeg;

import java.awt.EventQueue;
import java.io.File;
import java.nio.Buffer;
import java.nio.ByteBuffer;

import javax.swing.JFrame;

public class rwa {

    private JFrame frame;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    rwa window = new rwa();
                    window.frame.setVisible(true);

                    Frame myframe = new Frame();
                    myframe .imageHeight = 100;
                    myframe .imageWidth = 200;
                    myframe .imageChannels = 1;
                    myframe .imageDepth = 8;

                    byte[] myimage = new byte[20000];

                    //all black
                    for (int j = 0; j/FFmpegFrameGrabber grabber = new FFmpegFrameGrabber(dest);
                    record.setFrameRate(0.04);
                    record.setVideoCodec(13);
                    record.setFormat("mp4");
                    record.setPixelFormat(0);
                    record.setImageHeight(100);
                    record.setImageWidth(200);
                    record.setVideoBitrate(1000000);

                    record.start();
                    for (int i=0; i<100; i++){

                        if (myimage.length*(1+i)<20000) {
                         //this is just for debugging it. I'm creating a different image each frame to see if it works. In practice, I will read in each step the propper image
                        for (int j = myimage.length*i; j/record.record(myframe);
                    }
                    record.stop();
                    record.close();

                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the application.
     */
    public rwa() {
        initialize();
    }

    /**
     * Initialize the contents of the frame.
     */
    private void initialize() {
        frame = new JFrame();
        frame.setBounds(100, 100, 450, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

}


  



  But I am getting errors like

  



  


  A fatal error has been detected by the Java Runtime Environment :

  
 


  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x000007fefe4511d3, pid=6432, tid=0x000000000000027c

  


  



  what is wrong there ? And how should I select the bitrate ? My images, at maximum, will be 16bit 1 channel 2048*2048 pixels.

  



  Thanks !

  


• Streaming rtsp data to local mp4 file

  11 juillet 2017, par Pankhuri Agarwal

  How can I save live streaming data from a local camera transported by rtsp to my local memory in a .mp4 format.

  I am using Ubuntu 16.04 LTS and tried using ffmpeg 3.3 but nothing seemed to work properly.

  The goal will be to provide live feed by mp4 by html5 and perform some modification on mp4 data.

  Can anyone suggest how to make ffmpeg work or any other way ?

• openCV save frames from RTSP non blocking

  1er janvier 2020, par Jacob nighFor

  I am building an app that records frames from IP camera through RTSP.

  My engine is in charge to save a video in mp4 with Opencv VideoWriter working well.
  What I am looking for is to create a startRecord and a stopRecord class method that will respectively start and stop recording according to a trigger (it could be an argument that I pass to the thread).
  Is anyone know what the best way to do that kind of stuff ?

  Here is my class :

  from threading import Thread
  
  import cv2
  
  import time
  
  import multiprocessing
  
  import threading
  
  class RTSPVideoWriterObject(object):
  
      def __init__(self, src=0):
  
          # Create a VideoCapture object
  
          self.capture = cv2.VideoCapture(src)
  
  
  
          # Start the thread to read frames from the video stream
  
          self.thread = Thread(target=self.update, args=())
  
          self.thread.daemon = True
  
          self.thread.start()
  
  
  
      def update(self):
  
          # Read the next frame from the stream in a different thread
  
          while True:
  
              if self.capture.isOpened():
  
                  (self.status, self.frame) = self.capture.read()
  
  
  
      def endRecord(self):
  
          self.capture.release()
  
          self.output_video.release()
  
          exit(1)
  
  
  
      def startRecord(self,endRec):
  
  
  
          self.frame_width = int(self.capture.get(3))
  
          self.frame_height = int(self.capture.get(4))
  
          self.codec = cv2.VideoWriter_fourcc(*'mp4v')
  
          self.output_video = cv2.VideoWriter('fileOutput.mp4', self.codec, 30, (self.frame_width, self.frame_height))
  
          while True:          
  
              try:
  
                  self.output_video.write(self.frame)
  
                  if endRec:
  
                      self.endRecord()
  
              except AttributeError:
  
                  pass
  
  
  
  
  
  
  
  
  
  if __name__ == '__main__':
  
  
  
      rtsp_stream_link = 'rtsp://foo:192.5545....'
  
      video_stream_widget = RTSPVideoWriterObject(rtsp_stream_link)
  
  
  
      stop_threads = False
  
      t1 = threading.Thread(target = video_stream_widget.startRecord, args =[stop_threads]) 
  
      t1.start() 
  
      time.sleep(15)
  
      stop_threads = True

  As you can see in the main I reading frames and store them in a separate thread. Then I am starting to record (record method is with an infinite loop so blocking) and then after 15 sec, I am trying to pass a ’stop_record’ argument to stop recording properly.

  A part of the code comes from Storing RTSP stream as video file with OpenCV VideoWriter

  Is someone have an idea ?
  I read a lot that OpenCV can be very tricky for multithreading

  N.