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• Can´t convert .mp4 file to .mjpeg file with ffmpeg

  19 février 2018, par Herr HupfDohle

  I use ffmpeg to convert a .mp4 file to a .mjpeg file and I fail doing so.
  What i tried so far :
  Converting directly from .mp4 to .mjpeg with one of these :

      "ffmpeg -i input.mp4 output.mjpeg"
  
      "ffmpeg -i input.mp4 -framerate 25 output.mjpeg"

  Getting all the individual images of my video (which worked fine) and put them together to a .mjpeg file did not work as well.

      "ffmpeg -i input.mp4 image%d.jpeg"
  
      "ffmpeg -f image2 -i image%d.jpeg output.mjpeg", or
  
      "ffmpeg -f image2 -i image%d.jpeg -framerate 25 output.mjpeg"

  "Solutions" like the following one did not work, cause I need a file extension .mjpeg so -c:v mjpeg is not enough cause I end up with sth. like .mov !

  "ffmpeg -i input.mov -c:v mjpeg -q:v 3 -huffman optimal -an output.mov"

  To view my files I use vlc player.

  I always end up with a .mjpeg file which has the length of 10 seconds and only shows the very first image of my 4000 pictures.

• 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.

  


• html5 video wont play ANY mp4 encodes on ipad

  9 septembre 2016, par nickg

  Im trying to embed a mp4 on a page with the HTML5 video tag. Everything works fine on Desktop but nothing will work on an iPad Version 9.3.4.
  I have the mime types in an .htaccess file. I’ve tried various encodes with handbrake, Miro and FFmpeg conversions.

  Even sample videos like at w3schools and videojs don’t play.
  The video will play if i actually sync it to the iPad, but nothing works over the web. An older iPad actually plays mp4s through the HTML5 video player.
  I’m ready to throw this POS iPad through a window.

   <video autoplay="false" width="320" height="240" controls="true">
  
    <source src="http://webnamehere.com/video/bunny.mp4" type="video/mp4; codecs=&quot;avc1.42E01E, mp4a.40.2&quot;">
  
  
  
  Your browser does not support the video tag.
  
  </source></video>

  Has anyone found a way to fix this ? Is there ANY encoding that this thing will actually play ? Thank you in advance for any help.