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• Localization : Improve Finnish (fi) translation

  12 mai 2015, par Pietu1998

  Localization : Improve Finnish (fi) translation
  The current Finnish translations are partially wrong and partially
  
  clumsy. This change should improve them. Finnish is really a hard
  
  language to equivalently and clearly translate some strings to.
  Closes #1475
  

• ffmpeg : record 1 hour segment, right on the hour, no/little frame lost [closed]

  2 septembre 2024, par Jean-Michel

  I need to record 24/7 an incoming SRT stream into 1 hour chunks, starting right on the hour.
The start needs to be as close as XX:00:00.000 as possible and little to no frame lost between the recordings.

  


  For now I am using a systemd service with that ExecStart command :

  


  /usr/bin/ffmpeg -fflags +discardcorrupt -i 'srt://:4010?pkt_size=1316&mode=listener' -c copy -map 0:v:0 -map 0:a? -f segment -strftime 1 -segment_time 3600 -reset_timestamps 1 -segment_format ts '/somefolder/recording_%%d%%m%%Y_%%H%%M00.ts'


  


  And using a crontab to restart the service on the hour to insure the next file properly starts at the expected time.

  


  0 * * * * cd /etc/systemd/system && systemctl restart srt_recorder_4010.service


  


  Unfortunately, the restart of the service takes 5 to 10 seconds and we are loosing that duration in the recorded file.
If I'm not using the crontab, I get 1 hour files but I have no control on the start time.

  


  Any suggestion to get something more accurate ?
Could there be a way to combine ffmpeg internal ability to exactly segment 1 hour file but enforce to do it on the hour ?
Or externally, if there was a way to send a "next file" command (api, signal) to a perpetual running ffmpeg to change recording file ?

  


  Thanks

  


• How to de-warp 180 degree or 360 degree fisheye video with ffmpeg ?

  31 juillet 2021, par John Allard

  Let's say I have video from an IP-camera that has a 180 degree or 360 degree fisheye lens and I want to dewarp the image in some way. Ideally I would be able to select some rectangular area of the input image and dewarp that into a "normal" looking output video, but it would also be acceptable to dewarp the the video into some sort of Equirectangular or Equi-Angular Cubemap projection. The input video looks like this

  



  

  



  I'm aware of two filters that might be used for this

  



  


  1. lenscorrect filter - I think that this is on the right course but all of the example that I can find with this filter are only for "minor" fisheye lenses and I can't seem to get this to work correctly for videos with 360 degree fisheye lenses, it simply doesn't dewarp enough.

  


  2. v360 filter. I thought that this must be the correctly filter but it seems that it's intended for 360 videos and not 360 degree fisheye lenses ? I didn't know that there was a difference but I can't get it to work. When I try to take my input video and map it through an equirectangular projection I get some odd output like this

  


  



  

  



  I've tried a dozen or so different combinations of parameters but none of them seem to give me the output that I want which is a single dewarped image. Can someone help me with the filter graph parameters to use this filter ?

  



  Is there something that I'm missing ? Are either of these filters the correct way forward ?

  



  EDIT -

  



  I've been experimenting with the v360 filter and I think I've gotten closer. What I want to do is map a fisheye input to an equirectangular output, so I've tried this

  



  ffmpeg -i input.mp4 -vf v360=fisheye:equirect:id_fov=360 output.mp4

  



  This should mean that my input is a fisheye lens with a diagonal field of view of 360 degrees and I want my output to be an equirectangular projection but this is what I get