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• Unable to set thumbnail image to mp3 file using ffmpeg sending it's output to console (ffmpeg pipe:1) [duplicate]

  3 mai 2019, par remort

  This question already has an answer here :

  • Metadata in mp3 not working when piping from ffmpeg with album art
    
    1 answer
    

  I need to add thumbnails (album art) to mp3 (and other) files programmatically (using python) and save ffmpeg output in memory (to be able to send resulting bytes to another process).

  Pay attention to '-f', 'mp3', 'pipe:1' in last example please. Ffmpeg breaks working with pipe unless you set format for resulting stream.

  What I have now :
  1. This example bash oneliner works as expected making proper mp3 files with thimbnails (Telegram plays audio and shows thumbnail) :

  ffmpeg -i qwe.mp3 -i asd.png -acodec copy -map 0 -map 1 -disposition:v:1 attached_pic out.mp3

  2. This python code does the same with same result :

  subprocess.run(['ffmpeg', '-i', 'qwe.mp3', '-i', 'asd.png', '-acodec', 'copy', '-map', '0', '-map', '1', '-disposition:v:1', 'attached_pic', 'out.mp3'])

  3. But I need bytes, not file on file system, so I do the following and get bytes. But then, if I save those bytes to file, it results to broken mp3 file. I cant play it with Deadbeef and Telegram.

  audio_data = subprocess.run(['ffmpeg', '-i', 'qwe.mp3', '-i', 'asd.png', '-acodec', 'copy', '-map', '0', '-map', '1', '-disposition:v:1', 'attached_pic', '-f', 'mp3', 'pipe:1'], stdin=None, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
  
  
  
  len(audio_data.stdout)
  
  2621690  # 2,6 Mbytes, it's ok
  
  
  
  
  
  with open('out.mp3', 'wb') as f:                                                                                                                                                                                                                                     
  
      f.write(audio_data.stdout)

  Last example gives me a broken mp3 file. It can’t be played in deadbeef and Telegram.

  I suggest that problem is somewhere around several streams (-map parameters) or/and with -f mp3 directive (since I have an image inside an mp3 stream or something like that).

  I tried setting additional id2v3 tags and changing other options but no luck. Any suggestions in this ?

• 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.