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• subprocess.py returns a File Not Found error

  7 avril 2021, par wasneeplus

  As part of a video analysis script I wanted to find the duration of a video file. For this I found the script offered in the first answer to this question : How to get the duration of a video in Python ?

  


  import subprocess

def get_length(filename):
    result = subprocess.run(["ffprobe", "-v", "error", "-show_entries",
                             "format=duration", "-of",
                             "default=noprint_wrappers=1:nokey=1", filename],
        stdout=subprocess.PIPE,
        stderr=subprocess.STDOUT)
    return float(result.stdout)


  


  This code works fine when my friend runs it in a Jupyter server environment, but when I try it on my laptop the trouble starts.

  


  When I imput the following filename into the function :

  


  filename = "C:\\Users\\benja\\OneDrive - De Haagse Hogeschool\\Onderzoeken 3\\8V.mp4"


  


  I get the following error :

  


      Traceback (most recent call last):&#xA;  File "c:/Users/benja/OneDrive - De Haagse Hogeschool/Onderzoeken 3/python_script.py", line 9, in <module>&#xA;    num_of_frames = math.floor((pf.get_length(filename) - 1)) * 30&#xA;  File "c:\Users\benja\OneDrive - De Haagse Hogeschool\Onderzoeken 3\python_funcs.py", line 21, in get_length&#xA;    stderr=subprocess.STDOUT)&#xA;  File "C:\Users\benja\Anaconda3\lib\subprocess.py", line 466, in run&#xA;    with Popen(*popenargs, **kwargs) as process:&#xA;  File "C:\Users\benja\Anaconda3\lib\subprocess.py", line 769, in __init__&#xA;    restore_signals, start_new_session)&#xA;  File "C:\Users\benja\Anaconda3\lib\subprocess.py", line 1172, in _execute_child&#xA;    startupinfo)&#xA;FileNotFoundError: [WinError 2] Het systeem kan het opgegeven bestand niet vinden&#xA;</module>

  


  I do realise that my problem is almost identical to that of several other questions on here. However, their solutions don't seem to work for me. I have tried to :

  


  

  • Add the location of ffmpeg-win64-4.2.2.exe to the Path system variable.

  


  • Add the location of python.exe to the ComSpec system variable.

  


  • Put the videofile in the same directory as the script.

  


  


  I would be most grateful if someone could point me in the right direction. Thank you in advance.

  


• variable value does not change after for loop c#

  10 août 2022, par Dokoa

  I need to use the formula height to get a new int value for each cycle, but it is always equal to 180, provided that the index variable changes.

  


  internal class Program
{
    static void Main(string[] args)
    {
        ///some code
        WorkContainer.StartUp(Source, Mode, Output);
    }
}

internal class WorkContainer
{
    public static void StartUp(string Source, string Mode, string Output)
    {   
        ///some code
        int maxWidth = 180;
        int maxHeight = 420;
        int framerate = 30;

        switch (Mode)
        {
            case "Bouncing":
                int delta = 5;
                double bouncesPerSecond = 1.5;
                int index = 0;
                int height = (int)(index == 0 ? maxHeight : (Math.Floor(Math.Abs(Math.Cos(index / (framerate / bouncesPerSecond) * Math.PI) * (maxHeight - delta))) + delta));
                ffmpegWork.ffmpegPngChangeResolution(CurrentDirectory, RandomTempFolderIdentity, index, maxWidth, height);
                break;
        }
    }
}

internal class ffmpegWork 
{
    public static void ffmpegPngChangeResolution(string CurrentDirectory, string RandomTempFolderIdentity, int index, int maxWidth, int height)
    {
        int ImgValues = new DirectoryInfo($"{CurrentDirectory}/Temp{RandomTempFolderIdentity}/img/").GetFiles().Length;
        for (int i = 0; i < ImgValues; i++, index++)
        {
            try
            { 
                Process compiler = new Process();
                        compiler.StartInfo.FileName = $"{CurrentDirectory}/ffmpeg/bin/ffmpeg";
                        compiler.StartInfo.Arguments = $"-y -i {CurrentDirectory}/Temp{RandomTempFolderIdentity}/img/img-{i + 1}.png -vf scale={maxWidth}:{height} -c:a libvorbis {CurrentDirectory}/Temp{RandomTempFolderIdentity}/webmImg/img-{i + 1}.png";
                        compiler.StartInfo.RedirectStandardOutput = true;
                        compiler.StartInfo.CreateNoWindow = true;
                        compiler.StartInfo.UseShellExecute = false;
                        compiler.Start();
                Console.WriteLine($"png frame - {i + 1}/{ImgValues}\nheight={height}");
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
        }
    }
}


  


  console output>>>

  


  png frame - 1/n
height=180
png frame - 2/n
height=180
png frame - 3/n
height=180


  


• shorten : pad the internal bitstream buffer

  28 novembre 2013, par Anton Khirnov

  shorten : pad the internal bitstream buffer
  Fixes invalid reads.
  Found-by : Mateusz "j00ru" Jurczyk and Gynvael Coldwind
  
  CC:libav-stable@libav.org
  

  • [DH] libavcodec/shorten.c