Sur d’autres sites (10542)

• Piping the output of ffmpeg directly to Audacity

  21 décembre 2020, par colin baguley

  I'm trying to make a 2 stage process into one CLI command.

  


  First :- I want to extract the audio from a video file

  


  Second :- I want to open up that audio file in Audacity

  


  On the command line at the moment I do this :-

  


  -ffmpeg -i inputfile.mp4 -vn sound.wav ;  audacity sound.wav

  


  which works but involves writing the sound.wav to my disc ( I don't want to keep sound.wav)

  


  It strikes me that it would be quicker if I could just pipe the ffmpeg output directly into audacity but I can't seem to work out how to do it.

  


  Yes - I know that using the GUI of Audacity I can just 'open' the mp4 directly into audacity but I would like to use a CLI command

  


  Thank you for your help ( and have a peaceful and joyful Christmas !)

  


• Explicitly set soundManager.preferFlash = true for some demo/API/docs cases

  31 juillet 2011

  m demo/360-player/canvas-visualization-basic.html m demo/360-player/canvas-visualization.html m demo/animation-1/script/animation.js m demo/animation-2a/index.html m demo/animation-2b/script/animation.js m demo/api/index.html m demo/christmas-lights/christmaslights.js m (...)

• How to print Continuous output of Popen when reset character is used

  25 août 2022, par cclloyd

  I have a snippet of code that runs a video conversion using ffmpeg.

  


  I read the output to analyze it later in the application, and also want to print it to console, for user feedback.

  


  So I have

  


  p = Popen(['ffmpeg', *args], stderr=STDOUT, stdout=PIPE)
while True:
    line = p.stdout.readline()
    if not line: 
        break
    print(line.decode('utf-8'), end='')

p.wait()
if p.returncode == 0:
    pass



  


  Which works, somewhat. It prints the initial output of the ffmpeg command, as those are simple print statements.

  


  But once the conversion starts, all the output is updated on one line, presumably using some reset character to move the cursor position back to the start of the line.

  


  Is there a way to continue to print that output ?

  


  Edit :

  


  Answer

  


  p = subprocess.Popen(args, stderr=subprocess.STDOUT, stdout=subprocess.PIPE, universal_newlines=True)

with p.stdout:
    for line in iter(p.stdout.readline, None):
        if not line:
            break
        if line.startswith('frame'):
            print(f'\033[2K{line.strip()}\r', end='')
        else:
            print(line, end='')


  


  This includes the cursor return, and clears the current line before printing to it again. And still prints the part I want on the same line, like it normally does.