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• Record window from CMD or PowerShell [closed]

  9 octobre 2023, par Pingui

  How can one record a window e.g. from the Command Promt or PowerShell ?

  


  I tried the following CMD-command which in principle works, but it cuts off the window (even with increased video_size 1920x1080, which seems to have no effect at all) :

  


  "C:\[your_path_to]\ffmpeg.exe" -f gdigrab -i title="New Tab - Google Chrome" -framerate 30 -video_size 1920x1080 -c:v libx264 -preset ultrafast -t 5 output.mp4


  


  The goal would be something like the above, but...

  


  

  1. Ideally, the window should be found not by its window title, but by its process name (e.g. chrome.exe)

  


  2. The video should be automatically fitted to the window size (even if larger than 1920x1080)

  


  3. The video-name.mp4 and video duration (-t) should be handed dynamically as input variables

  


  4. If the video-name.mp4 already exists, it should be overwritten without asking

  


  5. The windw should be recorded even if not on top

  


  


  Any solution in CMD, PowerShell or whatever can be called by Window's ShellExecuteW function and passed video-name.mp4 and video duration as inputs would be fine.

  


• ffmpeg : how to clear the audio from a specified time window in a mp4 video [closed]

  26 août 2023, par Shiping

  I have a mp4 file and I want to clear the audio in a time window. I've searched around and tried a few ways, but can't make it to work. The closest I managed to get is a command like the following, which cleared the audio in the video from 5 seconds to the end.

  


  ffmpeg -i in.mp4 -af afade=t=out:st=5:d=1 out.mp4


  


  Unfortunately d=1 here means to fade out the audio in 1 second. not to clear the audio for 1 second, which is what I want. I think what I want to do should be a common operation and ffmpeg should already have a way to achieve it. For example, ffmpeg could have a corresponding filter to fade in the audio, such as afade=t=in:st=10:d=1. Any help will be appreciated. Thanks.

  


• Issue with Asynchronous Video Processing and New Window Creation in Windows Forms Application

  2 août 2023, par sadra hoseini

  I have a Windows Forms application that uses FFmpeg for video processing tasks. In this application, I have a textBox2_TextChanged event handler that performs some video processing tasks based on user input.

  


  However, I noticed that when textBox2_TextChanged is called, the UI becomes unresponsive, and it seems like another window is being created but doesn't show up. I suspect that this issue is related to threading.

  


  Here's a simplified version of the problematic code :

  


  // Relevant code snippet:
private async void textBox2_TextChanged(object sender, EventArgs e)
{
    if (listBox1.Items.Count > 0 && int.TryParse(textBox2.Text, out int itemvalue) && int.TryParse(textBox1.Text, out int ratio))
    {
        await Task.Run(() =>
        {
            // Video processing code using FFmpeg (e.g., creating thumbnails).
            // This code seems to cause the UI to freeze and prevent new windows from showing up.
        });
    }
}


  


  Expected Behavior :

  


  When a user enters a valid input in textBox2, the video processing tasks should be executed in the background without freezing the UI. The application should remain responsive, and any new windows, including message boxes or progress dialogs, should show up as expected.

  


  Actual Behavior :

  


  When a user enters a valid input in textBox2, the video processing tasks appear to be running, but the UI becomes unresponsive, and new windows, such as message boxes, do not show up as expected. This makes it challenging to display any progress or error messages to the user during video processing.

  


  Steps to Reproduce :

  


  Open the Windows Forms application.
Add some video files to the list (listBox1) and provide valid input in textBox2.
Observe the UI behavior and any new windows that should be displayed, such as progress dialogs or message boxes.
Additional Notes :

  


  I am using Visual Studio [version] for development.
The application uses FFmpeg for video processing tasks, and I've verified that FFmpeg is functioning correctly.
I've also tried using proper error handling to catch any exceptions, but no exceptions are thrown during the video processing tasks.
Any help or suggestions on how to resolve this issue and enable new window creation during video processing would be greatly appreciated. Thank you !