Sur d’autres sites (15562)

• 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.

  


• Saving H.264 RTP stream without re-encoding ?

  13 avril 2012, par Gene Vincent

  My C++ application receives a H.264 RTP video stream.

  Right now it decodes the stream, saves it into a YUV file and later I use ffmpeg to re-ecode the file into something suitable to watch on a Windows PC (eg. Mpeg4 AVI).

  Shouldn't it be possible to save the H.264 stream into a AVI (or similar) container without having to decode and re-encode it ? That would require some H.264 decoder on the PC to watch, but it should be much more efficient.

  How could that be done ? Are there any libraries supporting that ?

• FFMPEG Imitation decoding artefacts [closed]

  17 juillet 2024, par Тимур Снежок

  I'd like to figure out influence decoding artefacts on my computer vision algorithm so i have to mess up my .mp4 file. Are there methods do this for ?

  


  I hope reach effect like effect dropping frame from stream or efffect corrupted files.

  


  Thanks !