Recherche avancée

Sur d’autres sites (9866)

• ffmpeg use pipe fails with : Unable to find a suitable output format for 'pipe:1 :'

  2 mai 2019, par lin yuansen

  Using pipe protocol
  ffmpy can read input from STDIN and write output to STDOUT. This can be achieved by using the FFmpeg pipe protocol.

  The following example reads data from a file containing raw video frames in RGB format and passes it to ffmpy on STDIN ; ffmpy in its turn will encode raw frame data with H.264 and pack it in an MP4 container passing the output to STDOUT (note that you must redirect STDOUT of the process to a pipe by using subprocess.PIPE as stdout value, otherwise the output will get lost) :

  >>> import subprocess
  
  >>> ff = FFmpeg(
  
  ...     inputs={'pipe:0': '-f rawvideo -pix_fmt rgb24 -s:v 640x480'},
  
  ...     outputs={'pipe:1': '-c:v h264 -f mp4'}
  
  ... )
  
  >>> ff.cmd
  
  'ffmpeg -f rawvideo -pix_fmt rgb24 -s:v 640x480 -i pipe:0 -c:v h264 -f mp4 pipe:1'
  
  >>> stdout, stderr = ff.run(input_data=open('rawvideo', 'rb').read(), stdout=subprocess.PIPE)

  But the above code does not work for me.

• Pipe opencv images to ffmpeg using python

  16 avril 2022, par jlarsch

  How can I pipe openCV images to ffmpeg (running ffmpeg as a subprocess) ?
(I am using spyder/anaconda)

  



  I am reading frames from a video file and do some processing on each frame.

  



  import cv2   
cap = cv2.VideoCapture(self.avi_path)
img = cap.read()
gray = cv2.cvtColor(img[1], cv2.COLOR_BGR2GRAY)
bgDiv=gray/vidMed #background division


  



  then, to pipe the processed frame to ffmpeg, I found this command in a related question :

  



  sys.stdout.write( bgDiv.tostring() )


  



  next, I am trying to run ffmpeg as a subprocess :

  



  cmd='ffmpeg.exe -f rawvideo -pix_fmt gray -s 2048x2048 -r 30 -i - -an -f avi -r 30 foo.avi'
sp.call(cmd,shell=True)


  



  (this also from the mentioned post)
However, this fills my IPython console with cryptic hieroglyphs and then crashes it. any advice ?

  



  ultimately, I would like to pipe out 4 streams and have ffmpeg encode those 4 streams in parallel.

  


• Video and Audio stream in Python pipe to ffmpeg

  29 avril 2019, par Praveen P K

  Raw video from Python pipe is converted to udp stream using FFMPEG is working correctly using following code :

  command = [ 'ffmpeg',
  
              '-y', # (optional) overwrite output file if it exists
  
              '-r', '25', # frames per second
  
              '-i', '-', # The imput comes from a pipe
  
              '-an', # Tells FFMPEG not to expect any audio
  
              '-r', '25',
  
              '-c:v', 'copy',
  
              '-f', 'mpegts', 
  
              'udp://ip:port'
  
          ]
  
  devl  = open(os.devnull, 'w')
  
  file_name = '/tmp/file.txt'
  
  err1 = open(file_name, 'w')
  
  pipe  = sp.Popen( command, stdin=sp.PIPE, stdout=devl, stderr=err1) 

  But when audio stream also coming in same python pipe, how i should change the program to get both audio and video stream to udp stream.