Recherche avancée

Sur d’autres sites (11689)

• FFMPEG dshow format not working Windows 10

  22 octobre 2016, par Jonathan Beaudoin

  I’d like to use this library for my remote desktop software but it does not seem to be working. It works fine if I run ffmpeg from command line.

  Here is my test class :

  public class FFMPEG {
  
  
  
      public static void main(String[] args) throws Exception {
  
          FFmpegFrameGrabber grabber = new FFmpegFrameGrabber("video=\"screen-capture-recorder\"");
  
          grabber.setFormat("dshow");
  
          grabber.setImageWidth(2560);
  
          grabber.setImageHeight(1440);
  
          grabber.start();
  
  
  
          CanvasFrame frame = new CanvasFrame("Screen Capture");
  
          while (frame.isVisible()) {
  
              frame.showImage(grabber.grab());
  
          }
  
          frame.dispose();
  
          grabber.stop();
  
      }
  
  
  
  }

  and here is what I have in my gradle.build

  repositories {
  
      mavenCentral()
  
  }
  
  
  
  configurations {
  
      all*.exclude group: 'org.bytedeco', module: 'javacpp-presets'
  
  }
  
  
  
  dependencies {
  
      compile "org.bytedeco:javacv:1.2"
  
      compile "org.bytedeco:javacpp:1.2.1"
  
  
  
      compile group: 'org.bytedeco.javacpp-presets', name: 'ffmpeg', version: '3.1.2-1.2'
  
      compile group: 'org.bytedeco.javacpp-presets', name: 'ffmpeg', version: '3.1.2-1.2', classifier: 'windows-x86_64'
  
  }

  Here is the error I get when running that class :

  Exception in thread "main" org.bytedeco.javacv.FrameGrabber$Exception: avformat_open_input() error -5: Could not open input "video="screen-capture-recorder"". (Has setFormat() been called?)
  
      at org.bytedeco.javacv.FFmpegFrameGrabber.startUnsafe(FFmpegFrameGrabber.java:437)
  
      at org.bytedeco.javacv.FFmpegFrameGrabber.start(FFmpegFrameGrabber.java:385)
  
      at FFMPEG.main(FFMPEG.java:14)
  
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
  
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  
      at java.lang.reflect.Method.invoke(Method.java:498)
  
      at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
  
  [dshow @ 000000000179c5e0] Could not enumerate video devices (or none found).
  
  [dshow @ 000000000179c5e0] Could not enumerate video devices (or none found)

• A process' child doesn't get killed from killing the parent process

  2 avril 2022, par Impasse

  I am developing an Electron application. In this application, I am spawning a Python process with a file's path as an argument, and the file itself is then passed to ffmpeg (through the ffmpeg-python module) and then goes through some Tensorflow functions.

  


  I am trying to handle the case in which the user closes the Electron app while the whole background process is going. From my tests though, it seems like ffmpeg's process stays up no matter what. I'm on Windows and I'm looking at the task manager and I'm not sure what's going on : when closing the Electron app's window, sometimes ffmpeg.exe will be a single process, some other times it will stay in an Electron processes group.

  


  I have noticed that if I kill Electron's process through closing the window, the python process will also close once ffmpeg has done its work, so I guess this is half-working. The problem is, ffmpeg is doing intensive stuff and if the user needs to close the window, then the ffmpeg process also NEEDS to be killed. But I can't achieve that in any way.

  


  I have tried a couple things, so I'll paste some code :

  


  main.js

  


  // retrieve video data
ipcMain.handle('get-games', async (event, arg) => {
    const spawn = require('child_process').spawn;
    const pythonProcess = spawn('python', ["./backend/predict_games.py", arg]);

    // sets pythonProcess as a global variable to be accessed when quitting the app
    global.childProcess = pythonProcess;

    return new Promise((resolve, reject) => {
        let result = "";

        pythonProcess.stdout.on('data', async (data) => {
            data = String(data);

            if (data.startsWith("{"))
                result = JSON.parse(data);
        });

        pythonProcess.on('close', () => {
            resolve(result);
        })

        pythonProcess.on('error', (err) => {
            reject(err);
        });
    })
});

app.on('before-quit', function () {
    global.childProcess.kill('SIGINT');
});


  


  predict_games.py (the ffmpeg part)

  


  def convert_video_to_frames(fps, input_file):
    # a few useful directories
    local_dir = os.path.dirname(os.path.abspath(__file__))
    snapshots_dir = fr"{local_dir}/snapshots/{input_file.stem}"

    # creates snapshots folder if it doesn't exist
    Path(snapshots_dir).mkdir(parents=True, exist_ok=True)

print(f"Processing: {Path(fr'{input_file}')}")
try:
    (
        ffmpeg.input(Path(input_file))
        .filter("fps", fps=fps)
        .output(f"{snapshots_dir}/%d.jpg", s="426x240", start_number=0)
        .run(capture_stdout=True, capture_stderr=True)
    )
except ffmpeg.Error as e:
    print("stdout:", e.stdout.decode("utf8"))
    print("stderr:", e.stderr.decode("utf8"))


  


  Does anyone have any clue ?

  


• Ble with record video

  24 juillet 2017, par Vitaly

  I’m working on rpi3.
  When I try to run the command :

  sudo ffmpeg -f video4linux2 -i /dev/video0 -video_size 640x480 -r 25 output.avi

  to record a video using ffmpeg.

  In this time,I try to connect with Bluetooth.

  The BT cannot connect.

  the exception I get is :
  A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.

  top result :

  1156 root 20 0 299860 197172 137736 S 80.6 20.9 40:21.35 ffmpeg

  80.6 % cpu and 20.9 % mem.

  all the other processes take less than 1%.

  Did you encounter with this ?
  Do you have a clue what can be done ?

  Thanks