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• Large Panorama to Panning Video in FFMPEG

  7 octobre 2018, par Sogree

  I have been looking for a command line based solution for panning panorama’s like this : Large Panorama to Panning Video Based on that answer I’ve been experimenting with switches and formulas but they are a bit too complex for me (even after reading the ffmpeg command line help functions). What I would like to do :

  Pan an image from left to right. The input file is an PSD that has a large resolution (for example 3350x13140 pixels) but this is variable. So I would like ffmpeg to :

  1) Resize/scale the image to a set height of 1080 (so the height is set, but the width is flexible for the Pan) (is this step needed ??)

  2) Crop (and loop=1) the image to 1920x1080 (for me, combining scale and crop gives an error)

  3) But before starting the pan I would like it to wait for 2 seconds (so the most left part of the image would stand still for 2 seconds before panning)

  4) And after finishing the pan I would like it to wait for 2 seconds again (so the most right part of the image would stand still for 2 seconds before panning)

  5) Panning speed : Based on the width of the image (in this case 13140 pixels) I would like the panning speed to be 3,5 seconds per 1000 pixels. So in this case 46 seconds for the pan (and the end result (video length) would be 50 seconds (2 + 46 + 2).

  Only bullet 2 (with 1) I seem to be able to do.

  ffmpeg -loop 1 -framerate 60 -i in.psd -vf crop=1920:ih :’min((iw/10)*t,9*iw/10)’:0 -t 20 -c:v out.mp4

  So how should I alter the above options ? And in another posting this was listed :

  ffmpeg -loop 1 -r 60 -i in.psd -vf crop=1920:1080:n:0 -frames:v 11220 -pix_fmt yuv420p -preset fast -crf 25 out.mkv

  https://www.reddit.com/r/ffmpeg/comments/9051f1/i_want_to_pan_across_an_image_from_left_to_right/e2ukaah/

  But that command does not rescale the image (only pans the top (1920x1080) of the image).

  Maybe I need a combination of the two ? Or is using the zoompan command (with zoom set to off ?) a better option ?

• ffmpeg nginx "Past duration ... too large" [duplicate]

  25 août 2017, par Philip Kirkbride

  This question already has an answer here :

  • What does ’Past duration X.XXX too large’ mean ?
    
    3 answers
    

  I have nginx compiled with the rtmp module. I start nginx and run the following to start streaming my webcam :

  ffmpeg -i /dev/video0 -f flv rtmp://localhost/live/test    

  Which works, I can then connect to my stream at rtmp://localhost/live/test

  The logs look like :

  frame=51 fps=34 q=31.0 size=203kB time=00:00:02.60 bitrate=638.9
  
  frame=66 fps=33 q=31.0 size=239kB time=00:00:03.10 bitrate=632.0 
  
  frame=82 fps=33 q=31.0 size=271kB time=00:00:03.63 bitrate=611.6
  
  ...

  With a new line being output every second or so. After streaming for 3-4 minutes I start getting logs like these about 5 per second :

  Past duration 0.987877 too large
  
  Past duration 0.911079 too large
  
  Past duration 0.949013 too large

  Despite the warnings the stream still seems to be live and working.

  I believe nginx is triggering the following ffmpeg command :

  exec ffmpeg -i rtmp://localhost:1935/encode/$name
  
    -c:a libfdk_aac -b:a 128k -c:v libx264 -b:v 1000k -f flv -g 30 -r 30 -s 854x480 -preset superfast -profile:v baseline rtmp://localhost:1935/live/$name
  
  ;

  Complete nginx.conf file.

  Does anyone know what this warning is referring to ?

• ffmpeg output file is too large

  6 juin 2017, par David Page

  I want to burn a subtitle file(.srt) to a mp4 video.My command is :

  ffmpeg -i input.mp4 -c:v mpeg4 -q:v 1 -vf subtitles=input.srt out.mp4

  It output a video with a good quality,but its size is 1.12GB while the input file is 213MB.

  I think the problem is kbps of output file is too high.the bitrate of input file is 568 kb/s but the output file is 3154 kb/s.

  So I want to set the kps,now here is my code :

  ffmpeg -i input.mp4 -b:v 569k -minrate 568k -maxrate 570k -c:v mpeg4 -q:v 1 -vf subtitles=input.srt out.mp4

  Although the output file become smaller(538MB),the video’s quality is awful(Compare with input file)...
  So how to make the output file smaller and in good quality ?Thanks.