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• How to display instant preview without exporting FFmpeg video ? [closed]

  3 juin 2021, par Virani Vivek

  I am using FFMPEG to generate video from images but the problem is that I can only show the preview of the video after executing FFMPEG command and it’s takes time to generate output.

  


  On terminal I can get instant preview of video using FFPLAY. But, how to do that same thing in iOS.

  


• how to integrate c header files of ffmpeg into Xcode 9.2 using objective C

  14 mars 2016, par Nirbhay

  I am facing the problem while integrating the ffmpeg library into my Xcode project. I have successfully configure ffmpeg and lame library from terminal. Only I encounter the problem in the next i.e interating the ffmpeg library into my Xcode project.. Please help !!

• Run avconv in python and direct stdout/stderr to a file

  19 février 2016, par tdk

  I wish to run Avconv commands and record the logs in a file. In the Ubuntu terminal this can be accomplished using &>> operator after the actual command enclosed in parenthesis i.e.

  (avconv -i SRCFILE -ss 00:15:00 -t 00:30:00 TARGETFILE -threads auto) &>> LOGFILE

  The above command works perfectly when run in the terminal.

  Now I have a number of such commands to run, and thought running them through Python would be good.

  1. I tried using the os.system(command_string) way
     , which when run does not pack the Avconv output to the LOGFILE, and the avconv command seems to execute after the Python script is done - evidenced by some string outputs I put in for debugging. I’m also getting some permission errors. Here is how the first portion of output looks like

     AVCONV COMMAND EXECUTED
     
     sh: 1: : Permission denied
     
     sh: 1: : Permission denied
     
     sh: 1: 
     
     
     
     
     
     PROGRAM DONE
     
     : Permission denied
     
     $ avconv version 11.2-6:11.2-1, Copyright (c) 2000-2014 the Libav developers
     
       built on Jan 18 2015 05:12:33 with gcc 4.9.2 (Ubuntu 4.9.2-10ubuntu2)
     
     Trailing options were found on the commandline.
     
     Input #0, mov,mp4,m4a,3gp,3g2,mj2, from ...

  2. I also tried using the subprocess.call() method for which I get the following error (NOTE : all files exist)

     Traceback (most recent call last):
     
       File "/home/usr/cnv.py", line 61, in <module>
     
         main()
     
       File "/home/usr/cnv.py", line 46, in main
     
         subprocess.call(newcmd)
     
       File "/usr/lib/python2.7/subprocess.py", line 522, in call
     
         return Popen(*popenargs, **kwargs).wait()
     
       File "/usr/lib/python2.7/subprocess.py", line 710, in __init__
     
         errread, errwrite)
     
       File "/usr/lib/python2.7/subprocess.py", line 1335, in _execute_child
     
         raise child_exception
     
     OSError: [Errno 2] No such file or directory
     
     </module>

  I wish to run multiple (think 50+) commands of Avconv similar to the version shown at the top, and have the logs saved in a file instead of in stdout. How do I do this - in Python or otherwise ?