Newest 'ffmpeg' Questions - Stack Overflow

Les articles publiés sur le site

• Match radial lens distortion of two videos taken with two different actioncams with different FOV

  24 mai 2018, par Fabien Biller

  I have two different actioncams with different k1 and k2. How do I calculate k1 and k2 for one video not to be "defished", but have the same amount of distortion as the other video?

• Converting MP4 to HLS via ffmpeg producing stream with start delay

  24 mai 2018, par Eugene Alexeev

  I'm trying to convert mp4 to hls via this FFMpeg command:

  ffmpeg -i 1.mp4 -vcodec copy -q:v 5 -hls_time 5 -hls_list_size 0 -f hls 1.m3u8
  

  Command is working fine, without any errors whatsoever. BUT, when I'm trying to play brand-new HLS stream locally I noticed that it has a fixed start delay. I checked metadata of stream with ffprobe 1.m3u8 And that's what I got:

  Input #0, hls,applehttp, from '1.m3u8': Duration: 00:00:11.17, start: 1.400000, bitrate: 0 kb/s Program 0 Metadata: variant_bitrate : 0 Stream #0:0: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p(tv, smpte170m/bt709/bt709), 720x1280, 30 fps, 30 tbr, 90k tbn, 180k tbc Metadata: variant_bitrate : 0

  As you can see, parameter start has value of 1.400000 and I believe that's the reason of this annoying start delay. My question is - how can I get rid of that?

  I tried to set start time with -ss flag but it doesn't affect an output at all. Also input is perfectly fine, I tried to convert it with the same command but to .mp4 and I got correct results. Am I missing something here? I would be very appreciated for any help. Thanks.

• Quick conversion of mp4 to hls using ffmpeg

  24 mai 2018, par Abhishek

  I need to convert huge video(around 2-4GB) using ffmpeg from mp4 to hls format. The following takes very long to run, is there any quick conversion flag in ffmpeg.

  ffmpeg -i ad1.mp4 -strict -2 -profile:v baseline -level 3.0 -start_number 0 -hls_list_size 0 -hls_segment_filename 'sample-%06d.ts' -f hls sample.m3u8 
  

• Why am I getting an exit status of 1 ?

  24 mai 2018, par Akaisteph7

  So, I am writing this code to analyze this video but I am facing this issue when I try to run it in Spyder, Anaconda:

  import subprocess
  from subprocess import call
  import math
  
  ##Converts the given file into a series of images
  def Video_to_Image_Converter(fileName):
      res1 = call("ffmpeg -i " + fileName + " -vf fps=1 frame-%d.jpg", shell=True)
      print(res1)
      result = subprocess.Popen('ffprobe -i '+ fileName +' -show_entries format=duration -v quiet -of csv="p=0"', stdout=subprocess.PIPE,stderr=subprocess.STDOUT, shell=True)
      output = result.communicate()
      print(output)
      #return math.ceil(float(output[0])) + 1
  
  
  if __name__ == '__main__':
      videoLength = Video_to_Image_Converter('sampleVideo.wmv')
      print(videoLength)
  

  So, this code worked fine in iPython but I started having issues when trying to use Spyder. res1 should have an exit status of 0 if everything went well but it is 1. However, I do not know what went wrong. All it says when running subprocess.check_output on call is:

  Command 'ffmpeg -i sampleVideo.wmv -vf fps=1 frame-%d.jpg' returned non-zero exit status 1
  

  Please help.

• Exec () Creating two different process for FFMPEG

  23 mai 2018, par Bruno Andrade

  I run this command in exec () and it creates two FFMPEG processes one at the same time as the other but with different PID. Is this behavior normal? When I run the code directly in the shell this does not happen.

  $ffmpeg = "/home/user/bin/ffmpeg -hide_banner -loglevel verbose -n -i https://sitelink/list.m3u8 -map 0:4 -map 0:5 -acodec copy -bsf:a aac_adtstoasc -vcodec copy video.mp4 1> log.txt  2>&1";
  
      exec($ffmpeg, $output, $var);
  

  Example of the two processes created

  user+ 24414 24413  0 13:42 pts/2    00:00:00 sh -c /home/user/bin/ffmpeg -hide_banner -loglevel verbose -n -i https://sitelink/list.m3u8 -map 0:4 -map 0:5 -acodec copy -bsf:a aac_adtstoasc -vcodec copy video.mp4 1> log.txt  2>&1
  user+ 24415 24414  1 13:42 pts/2    00:00:00 /home/user/bin/ffmpeg -hide_banner -loglevel verbose -n -i https://sitelink/list.m3u8 -map 0:4 -map 0:5 -acodec copy -bsf:a aac_adtstoasc -vcodec copy video.mp4