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• imagemagick pipe to ffmpeg

  16 juillet 2024, par user26389289

  I'm trying to write a batch file for a friend to make timelapse videos. I'm using avisynth, but she's even more clueless than I, so I tried to do most of the work with ffmpeg.
What I'd like to do is to pipe imagemagick output (a filtered sequence of jpeg images) to ffmpeg and create a video.
I've thrown out everything out of the batch file, and more or less here i am :

  


  magick jpg:- d:\54tldir\src\*.jpg | ffmpeg.exe -f image2pipe -i pipe: -c:v libx264 02video.mp4


  


  I'm sure I've missed 1 or a few or many things.
all help would be appreciated - on my level (very low).

  


• avformat/img2dec : assert no pipe on ts_from_file

  8 mai 2024, par Michael Niedermayer

  avformat/img2dec : assert no pipe on ts_from_file
  Help coverity with CID1500302 Uninitialized scalar variable
  Sponsored-by : Sovereign Tech Fund
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavformat/img2dec.c

• How can I read all the data from a pipe and prevent it from closing ?

  23 septembre 2014, par slhck

  I’m trying to read raw YUV data from a compressed file using ffmpeg and pipes with Python.
  The ffmpeg command correctly spits out frames as raw YUV data, and I’m reading it like this :

  def read_from_pipe(pipe, amount):
  
      raw = pipe.stdout.read(amount)
  
      pipe.stdout.flush()
  
      return raw
  
  
  
  pipe_ref = subprocess.Popen('ffmpeg -i "' + input + '" -r 30 -c:v rawvideo -pix_fmt yuv420p -an -f rawvideo -t 5 -', 
  
    shell = True, 
  
    stdout = subprocess.PIPE, 
  
    bufsize=1920*1080*3*2)
  
  
  
  frame_num = 0
  
  while True:
  
      data = read_from_pipe(pipe_ref, width*height*3)
  
  
  
      # no more data
  
      if (len(data) != width*height*3))
  
          return results
  
  
  
      image = extract_image_data(data, width, height)
  
      # do something with image, put it into "results" and print frame / SSIM values to console
  
      frame_num += 1

  The problem is, as soon as ffmpeg is done converting all frames, my program stops. Since the program is a little slower than ffmpeg, it will stop receiving data and exit.

  Basically, for example, I can only work up to frame 30, then ffmpeg finishes at frame 60, and my program also exits. The command line output would say :

  Frame=25 SSIM=0.990472732391
  
  Frame=26 SSIM=0.98359411819
  
  Frame=27 SSIM=0.981074433586
  
  Frame=28 SSIM=0.97850843075
  
  frame=   60 fps= 27 q=0.0 Lsize=  182250kB time=00:00:02.00 bitrate=746496.0kbits/s dup=12 drop=0    
  
  video:182250kB audio:0kB subtitle:0 data:0 global headers:0kB muxing overhead 0.000000%
  
  Frame=29 SSIM=0.977698849804
  
  frame=   60 fps= 27 q=0.0 Lsize=  182250kB time=00:00:02.00 bitrate=746496.0kbits/s dup=12 drop=0    
  
  video:182250kB audio:0kB subtitle:0 data:0 global headers:0kB muxing overhead 0.000000%

  How can I get it to work on all frames that are output by ffmpeg ? Or is there any other easier way of obtaining the raw YUV data from any file if not through a pipe ? (I need it to work concurrently)