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• avdevice/decklink_common : Move DECKLINK_* string functions into header

  25 mai 2018, par Jon Morley

  avdevice/decklink_common : Move DECKLINK_* string functions into header
  This allows other decklink source access to these cross-platform
  
  convenience functions.
  Signed-off-by : Marton Balint <cus@passwd.hu>
  

  • [DH] libavdevice/decklink_common.cpp
  • [DH] libavdevice/decklink_common.h

• Python complex string interpolation on shell command

  2 mai 2018, par Rex Low

  I have a shell command that I would like to execute, with a python script. It’s a combination of ffmpeg, grep, gawk and several other ffmpeg options.

  The command

  ffmpeg -i http://0.0.0.0:8080/stream/video.mjpeg -vcodec copy -map 0 -f segment -segment_time 2 -loglevel 40 -segment_format mp4 capture-%05d.mp4 2>&1 | grep --line-buffered -Eo "segment:.+ended" | gawk -F "'" '{print $2; system("")}'

  If you run this command on terminal, it should return a string

  capture-00001.mp4

  Now, my objective is to run this with subprocess on Python3. Since the command is rather complex with mixed single and double quotes, it needs to be treated correctly otherwise it will complain EOL while scanning string literal, invalid syntax, etc, etc.

  I have tried several string formating methods but none work. Below is one of the ways I’ve tried.

  Script

  import os
  
  import datetime
  
  import subprocess
  
  
  
  first = "segment:.+ended"
  
  second = "'"
  
  third = '{print $2; system("")}'
  
  
  
  if __name__ == "__main__":
  
      fScript = "ffmpeg -i http://0.0.0.0:8080/stream/video.mjpeg -vcodec copy -map 0 -f segment -segment_time 2 -loglevel 40 -segment_format mp4 capture-%05d.mp4 2>&1 | grep --line-buffered -Eo {} | gawk -F {} {}".format(first, second, third)
  
      try:
  
          result = subprocess.check_output(fScript, shell=True).decode('utf-8')
  
          print(result)
  
      except subprocess.CalledProcessError as e:
  
          print(e.output)

• ffmpeg android applying multiple filters in string array commands causes error

  13 février 2018, par Nikhil Solanki

  String[] command = {"-y",
  
              "-i",
  
              selectedVideoPath,
  
              "-vf",
  
              "hue=s=0",
  
              "scale=-1:'min(ih,720)'",
  
              "-vcodec",
  
              "mpeg4",
  
              "-ss",
  
              startMs,
  
              "-to",
  
              endMs,
  
              "-preset",
  
              "ultrafast",
  
              "-strict",
  
              "experimental",
  
              getAppPath(context) + fileName};

  I am using above command in FFMPEG.execute() but its give error in Logcat :

  Unable to find a suitable output format for ’scale=-1 :’min(ih,720)’’
  scale=-1 :’min(ih,720)’ : Invalid argument

  So may be there is different technique to execute multiple filters command which I want know.

  Note : selectedVideoPath and getAppPath(context) + fileName is source video path and destination video path with file name proper.