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• FFMPEG zoompan for continuous zoom in/zoom out from start duration

  10 juillet 2020, par Nikhil Solanki

  I am creating continues zoomin/zoomout effect for input image using this command :

  


  ffmpeg -i combine.mp4 -i image1.jpg -filter_complex "[0]split=2[color][alpha]; 
[color]crop=iw/2:ih:0:0[color]; [alpha]crop=iw/2:ih:iw/2:ih[alpha]; [colo][alpha]alphamerge[v1];
[1]scale=540*2:960*2, setsar=1, zoompan=z='if(lte(zoom,1.0),1.02,max(1.001,zoom-0.0015))':d=25*0.25:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':s=540x960[v2]; 
[v2]zoompan=z='if(gte(zoom,1.1),1.0,min(zoom+0.0015,1.1))':d=25*0.25:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':s=540x960[v2];
[v2]curves=vintage, format=yuv444p[v2];
[v2][v1] overlay=1" output_video.mp4 -y


  


  This command will continues zoomin and zoomout input image1.jpg for 1 second and stop after 1 second its OK. But problem is I want perform zoomin zoomout effect after 5 second of video. Video duration is 20s. So, how can I perform zoompan after some duration.

  


• FFMPEG performance on remote server

  9 avril 2022, par Haider Ali

  I am experiencing a completely different performance for FFMPEG on server as compare to development machine. Parameters used are

  


  ffmpeg -i input.mp4 -ss 00:00 -to 02:20 -codec:v libx264 -preset ultrafast -force_key_frames 'expr:gte(t,n_forced*4)' -hls_time 4 -hls_playlist_type vod -hls_segment_type mpegts output.mp4


  


  Development Machine Specs

  


  MacBook Pro (15-inch, 2019)
  
Processor 2.6 GHz 6-Core Intel Core i7
  
Memory 16 GB 2400 MHz DDR4
  
Graphics Intel UHD Graphics 630 1536 MB

  


  Remote Server Specs
  
8 VCPU
  
32 GB

  


  Does ffmpeg need to have special specs to run on server ?

  


  Same above command can take 15 to 20 minute on server while on development machine it only takes 2 minutes.

  


• How do I buffer and capture an RTSP stream to disk based on a trigger ?

  2 septembre 2022, par SJoshi

  I think what I'm asking about is similar to this ffmpeg post about how to capture a lightning strike (https://trac.ffmpeg.org/wiki/Capture/Lightning).

  


  I have a Raspberry Pi with an IP cam over RTSP, and what I'm wondering is how to maintain a continual 5 second live video buffer, until I trigger a "save" command which will pipe that 5 second buffer to disk, and continue streaming the live video to disk until I turn it off.

  


  Essentially, Pi boots up, this magic black box process starts and is saving live video into a fixed-size, 5-second buffer, and then let's say an hour later - I click a button, and it flushes that 5-second buffer to a file on disk and continues to pipe the video to disk, until I click cancel.

  


  In my environment, I'm able to use ffmpeg, gstreamer, or openRTSP. For each of these, I can connect to my RTSP stream and save it to disk, but I'm not sure how to create this ever-present 5 second cache.

  


  I feel like the gstreamer docs are alluding to it here (https://gstreamer.freedesktop.org/documentation/application-development/advanced/buffering.html?gi-language=c), but I guess I'm just not grokking how the buffering fits in with a triggered save. From that article, I get the impression that the end-time of the video is known in advance (I could artificially limit mine, I guess).

  


  I'm not in a great position to post-process the file, so using something like openRTSP, saving a whole bunch of video segments, and then merging them isn't really an option.

  


  Note : After a successful save, I wouldn't need to save another video for a minute or so, so that 5 second cache has plenty of time to fill back up before the next

  


  This is the closest similar question that I've found : https://video.stackexchange.com/questions/18514/ffmpeg-buffered-recording