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• How to loop over gif file finite number of times while creating mp4 as output with ffmpeg

  16 mai 2020, par in-user

  I am able to convert gif file to mp4 using this command :

  



  ffmpeg -i animated.gif -movflags faststart -pix_fmt yuv420p -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" video.mp4


  



  What I want to do is to loop over gif animation 3 times and convert to mp4.

  



  I am able to do this with 2 shell commands. First one from above and then concatenate the same video 3 times.

  



  ffmpeg -f concat -safe 0 -i <(printf "file '$PWD/video.mp4'\n%.0s" {1..3}) -c copy videoloop.mp4


  



  I have also tried with -ignore_loop 0 option and setting time. It does work but it is not exactly what I am trying to do since I can extend the video but can not make exactly 3 loops.

  



  ffmpeg -ignore_loop 0 -i animated.gif -movflags faststart -pix_fmt yuv420p -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" -t 12 videoloop.mp4


  



  So as you can see I am already able to achieve what I want, but with 2 shell commands :

  



  ffmpeg -i animated.gif -movflags faststart -pix_fmt yuv420p -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" video.mp4
ffmpeg -f concat -safe 0 -i <(printf "file '$PWD/video.mp4'\n%.0s" {1..3}) -c copy videoloop.mp4


  



  Is it possible to do this with only one call to ffmpeg ?

  



  I tried with -loop option for the input file. It doesn't work for gifs. I also tried with -stream_loop. It creates something corrupted.

  


• Command is running different from expected when i use it trought Python

  17 septembre 2021, par Gustavo Marinho

  I have a code where i download a youtube video as 3gpp and convert it to a mp3, i need to use FFmpeg to do this, and it work well when using both cmd and powershell, but, when i tried to run the same command in Python, it didin't work at all.

  


  This is my command :

  


  ffmpeg -i  C:\YTDownloads\CurrentAudio.3gpp C:\YTDownloads\CurrentAudio.mp3

  


  I tried :

  


  subprocess.call(r'%SystemRoot%\system32\WindowsPowerShell\v1.0\powershell.exe ffmpeg -i  C:\YTDownloads\CurrentAudio.3gpp C:\YTDownloads\CurrentAudio.mp3', shell=True)

  


  subprocess.run(["ffmpeg","-i","C:\YTDownloads\CurrentAudio.3gpp","C:\YTDownloads\CurrentAudio.mp3]")


  


  os.system('powershell ffmpeg -i  C:\YTDownloads\CurrentAudio.3gpp C:\YTDownloads\CurrentAudio.mp3')


  


  subprocess.run([
    'ffmpeg',
    '-i', os.path.join(parent_dir, f"{newname}.3gpp"),
    os.path.join(parent_dir, f"{newname}.mp3")
]) 


  


  subprocess.call('C:\Windows\System32\powershell.exe ffmpeg -i  C:\YTDownloads\CurrentAudio.3gpp C:\YTDownloads\CurrentAudio.mp3', shell=True)


  


  all of them return some type of error, in some of them it returns that ffmpeg isn't a recognized as a internal command, in others it says that the system can't find the specified path, but none of them works, even thought it works perfectly when i use the exactly same command on cmd/powershell.

  


  sorry for my bad english :3

  


• Use ffmpeg to record 2 webcams on raspberry pi

  30 janvier 2021, par RaresBaaa

  I want to record 2 webcams using ffmpeg, i have a simple python script but it doesn't work when I run the 2 subprocesses at the same time.

  


  ROOT_PATH = os.getenv("ROOT_PATH", "/home/pi")
ENCODING = os.getenv("ENCODING", "copy")
new_dir = datetime.datetime.now().strftime("%Y_%m_%d_%H_%M_%S")
RECORDINGS_PATH1 = os.getenv("RECORDINGS_PATH", "RecordingsCam1")
RECORDINGS_PATH2 = os.getenv("RECORDINGS_PATH", "RecordingsCam2")
recording_path1 = os.path.join(ROOT_PATH, RECORDINGS_PATH1, new_dir)
recording_path2 = os.path.join(ROOT_PATH, RECORDINGS_PATH2, new_dir)
os.mkdir(recording_path1)
os.mkdir(recording_path2)
segments_path1 = os.path.join(recording_path1, "%03d.avi")
segments_path2 = os.path.join(recording_path2, "%03d.avi")
record1 = "ffmpeg -nostdin -i /dev/video0 -c:v {} -an -sn -dn -segment_time 30 -f segment {}".format(ENCODING, segments_path1)
record2 = "ffmpeg -nostdin -i /dev/video2 -c:v {} -an -sn -dn -segment_time 30 -f segment {}".format(ENCODING, segments_path2)
subprocess.Popen(record1, shell=True)
subprocess.Popen(record2, shell=True)


  


  Also, i tried capturing the 2 sources side by side but it gives the error :`Filtering and streamcopy cannot be used together.