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• Trying to convert code to be compatible with macOS by not using the .exe version of FFmpeg and FFmprobe. Cant open the .mp4 file when i go to run code

  9 juillet 2024, par Bruno Hawkins

  I am attempting to edit some code in python for extracting frames from a video (using parallel processing to make it faster) a friend created that works on windows, so that it can be used on macOS. However, i am running into some issues and i am not sure what the problem is.

  


  Essentially, when i go to run the frame extractor and try to select a video in the formats specified, it wont let me select it.

  


  i have commented my code best i can. i am an amateur programmer so apologies if it is straightforward.

  


  import os
import subprocess
import multiprocessing
import tkinter as tk
from tkinter import ttk, filedialog, messagebox

def extract_frames(video_path, output_folder, fps, start_time, duration, process_number):
    video_name = os.path.splitext(os.path.basename(video_path))[0]
    part_output_folder = os.path.join(output_folder, f"part_{process_number}")
    if not os.path.exists(part_output_folder):
        os.makedirs(part_output_folder)

    # Using 'ffmpeg' instead of 'ffmpeg.exe' for macOS compatibility
    ffmpeg_command = [
        'ffmpeg', '-ss', str(start_time), '-t', str(duration), '-i', video_path, '-vf', f'fps={fps}',
        os.path.join(part_output_folder, f'{video_name}_frame_%07d.png')
    ]

    print(f"Running FFmpeg command: {' '.join(ffmpeg_command)}")

    try:
        process = subprocess.run(ffmpeg_command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        if process.returncode != 0:
            print(f"Cannot process the file {video_path}: {process.stderr.decode('utf-8')}")
            return part_output_folder, 0
    except Exception as e:
        print(f"Failed to run FFmpeg command: {str(e)}")
        return part_output_folder, 0

    frame_count = len([f for f in os.listdir(part_output_folder) if f.endswith('.png')])
    return part_output_folder, frame_count

def worker_function(queue, video_path, output_folder, fps, start_time, duration, process_number):
    result = extract_frames(video_path, output_folder, fps, start_time, duration, process_number)
    queue.put(result)

def parallel_frame_extraction(video_path, output_folder, fps, num_processes):
    # Use 'ffprobe' instead of 'ffprobe.exe' for macOS compatibility
    ffprobe_command = [
        'ffprobe', '-v', 'error', '-select_streams', 'v:0', '-show_entries', 'format=duration', '-of',
        'default=noprint_wrappers=1:nokey=1', video_path
    ]

    try:
        result = subprocess.run(ffprobe_command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        duration = float(result.stdout.strip())
    except Exception as e:
        messagebox.showerror("Error", f"Failed to get video duration: {str(e)}")
        return

    chunk_duration = duration / num_processes
    processes = []
    manager = multiprocessing.Manager()
    queue = manager.Queue()

    if not os.path.exists(output_folder):
        os.makedirs(output_folder)

    for i in range(num_processes):
        start_time = i * chunk_duration
        p = multiprocessing.Process(target=worker_function,
                                    args=(queue, video_path, output_folder, fps, start_time, chunk_duration, i))
        p.start()
        processes.append(p)

    for p in processes:
        p.join()

    global_frame_offset = 0
    while not queue.empty():
        part_output_folder, frame_count = queue.get()
        frame_files = sorted([f for f in os.listdir(part_output_folder) if f.endswith('.png')])
        for i, frame_file in enumerate(frame_files):
            new_name = os.path.join(output_folder,
                                    f'{os.path.basename(video_path)}_frame_{global_frame_offset + i:07d}.png')
            os.rename(os.path.join(part_output_folder, frame_file), new_name)
        global_frame_offset += frame_count
        os.rmdir(part_output_folder)

    messagebox.showinfo("Complete",
                        f"Frame extraction completed for {video_path}. Total frames extracted: {global_frame_offset}")

def start_frame_extraction():
    video_path = filedialog.askopenfilename(filetypes=[("Video files", "*.mp4;*.avi;*.mkv")])
    if not video_path:
        return

    output_folder = output_folder_var.get()
    if not output_folder:
        return

    fps = int(fps_var.get())
    num_processes = int(num_processes_var.get())

    parallel_frame_extraction(video_path, output_folder, fps, num_processes)

if __name__ == "__main__":
    root = tk.Tk()
    root.title("Frame Extraction")

    output_folder_var = tk.StringVar()
    fps_var = tk.StringVar(value="1")
    num_processes_var = tk.StringVar(value="4")

    def browse_output_folder():
        folder_selected = filedialog.askdirectory()
        output_folder_var.set(folder_selected)

    tk.Label(root, text="Output Folder:").grid(row=0, column=0, padx=10, pady=10)
    tk.Entry(root, textvariable=output_folder_var, width=50).grid(row=0, column=1, padx=10, pady=10)
    tk.Button(root, text="Browse", command=browse_output_folder).grid(row=0, column=2, padx=10, pady=10)

    tk.Label(root, text="FPS:").grid(row=1, column=0, padx=10, pady=10)
    tk.Entry(root, textvariable=fps_var, width=10).grid(row=1, column=1, padx=10, pady=10)

    tk.Label(root, text="Number of Processes:").grid(row=2, column=0, padx=10, pady=10)
    tk.Entry(root, textvariable=num_processes_var, width=10).grid(row=2, column=1, padx=10, pady=10)

    tk.Button(root, text="Start Frame Extraction", command=start_frame_extraction).grid(row=3, column=0, columnspan=3,
                                                                                        padx=10, pady=20)

    root.mainloop()


  


  I tried changing the FFmpeg and FFmprobe path formats from

  


  ffmpeg_path = os.path.join(os.path.dirname(__file__), 'ffmpeg-7.0.1-essentials_build', 'bin', 'ffmpeg.exe')
ffprobe_path = os.path.join(os.path.dirname(__file__), 'ffmpeg-7.0.1-essentials_build', 'bin', 'ffprobe.exe')



  


  to

  


  ffmpeg_command = [
    'ffmpeg', '-ss', str(start_time), '-t', str(duration), '-i', video_path, '-vf', f'fps={fps}',
    os.path.join(part_output_folder, f'{video_name}_frame_%07d.png')
]

ffprobe_command = [
    'ffprobe', '-v', 'error', '-select_streams', 'v:0', '-show_entries', 'format=duration', '-of',
    'default=noprint_wrappers=1:nokey=1', video_path
]



  


  I found this online so im not sure if it is the correct thing to do.

  


  Thanks for any help.

  


• ffmpeg encoding slowly, not using much CPU

  30 juin 2012, par eblume

  I am using the latest (as of this post) version of ffmpeg on OS X as installed via homebrew (an OS X 3rd-party package manager with a good reputation.) I am trying to encode video that was recorded using Fraps on another machine to reduce the file size while preserving as much quality as is reasonably possible.

  Fraps records video in a .avi container and I believe does absolutely no encoding - instead, it's just a stream of image files. The resulting files are often enormous, obviously. I want to set up a cron job that finds recorded files and encodes them to H.264 with some sort of audio codec (I'm currently using libmp3lame but will revisit it when I get video working right - will probably switch to a lossless audio codec.)

  My problem is that while encoding seems to be working exactly how I want it - very few compression artifacts but about 5% of the original size - the encoding is taking forever. I'm averaging about 1.5 encoded frames per second, and these are 2-3 hours of 30FPS video. On top of that, my CPU is never fully utilized. On my dual-core CPU I am getting a median usage of about 40% of one core, with occasional peaks of 140% to 160%.

  So the question is : How can I speed up encoding ? I'm sure there's got to be some options I'm missing out on.

  Here's the command I use :

  ffmpeg -i INFILE -c copy -c:a libmp3lame -ar 44100 -q:a 5 \
  
                -threads 0 -c:v libx264 OUTFILE

  Thanks !

  EDIT : Actually, it looks like this command isn't compressing that well either - I'll do some digging but it seems that this might be being too generous with the bitrate for H.264. At first I was getting around 2Mb/s but it's gone up to almost 20Mb/s - looks like I'm basically not compressing at all.

• Cancelling ffpeg launched as a C# process

  22 avril 2016, par DarwinIcesurfer

  I’m launching ffmpeg in a c# process to encode a video. In a command window, ffmpeg can be interrupted by pressing CTRL-C. I have tried to achieve the same effect by closing the process, however ffmpeg does not appear to close (it is still visible in task manager and it does not release the handle on the file it was encoding)

  How can ffmpeg be interrupted programatically ?

  static Process proc;
  
  static BackgroundWorker bw;     
  
  
  
  public void EncodeVideoWithProgress(string filename, string arguments, BackgroundWorker worker, DoWorkEventArgs e)
  
  {
  
      proc = new Process();
  
  
  
      // assign the backgroud worker to a class member variable so all function within the class will have access
  
      bw = worker;
  
  
  
      proc.StartInfo.FileName = "ffmpeg";
  
      proc.StartInfo.Arguments = "-i " + " \"" + filename + "\" " + arguments;
  
  
  
      proc.StartInfo.UseShellExecute = false;
  
      proc.EnableRaisingEvents = true;
  
      proc.StartInfo.RedirectStandardError = true;
  
      proc.StartInfo.RedirectStandardOutput = false;
  
      proc.StartInfo.CreateNoWindow = true;
  
  
  
      proc.ErrorDataReceived += new DataReceivedEventHandler(NetErrorDataHandler);
  
  
  
      proc.Start();
  
      proc.BeginErrorReadLine();
  
  
  
      proc.WaitForExit();
  
  }
  
  
  
  private static void NetErrorDataHandler(object sendingProcess,
  
             DataReceivedEventArgs errLine)
  
  {
  
      if (bw.CancellationPending)
  
      {
  
          proc.CloseMainWindow();
  
          proc.Close();   
  
      }
  
      else 
  
      {
  
       // do other tasks
  
      }
  
  }