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• ffplay / ffmpeg with audio and video filters

  20 juillet 2018, par user10104150

  i tried to modify a already existing code for ffplay for hours, but I could not get it.
  I could not find a manual for vertical and horizontal stacking parameters. I’m always getting invalid argument errors when I try to adopt it to my needs.
  So I’m asking here for help.

  My idea is based on that : ffplay / ffmpeg setup table with audio and video filters

  The working code that I modified a little but want to modify further without luck is :

  ffplay -f lavfi \
  
           "amovie=in.mp4,asplit=3[sv][eb][av]; \
  
            [sv]showvolume=b=4:f=0:ds=log:c=VOLUME:w=720:h=68[sv-v]; \
  
            [eb]ebur128=video=1:size=720x540:meter=18[eb-v][out1]; \
  
            [av]avectorscope=s=720x540:zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7[av-v]; \
  
            [sv-v][eb-v][av-v]vstack=3[1c]; \
  
            movie=in.mp4,split=4[v][wf][wfc][vs]; \
  
            [wf]waveform=m=1:d=0:r=0:c=7[wf-vus]; \
  
            [wf-vus][v]scale2ref=iw:1220-ih[wf-va][sig]; \
  
            [wf-va]setsar=1[wf-v]; \
  
            [wfc]waveform=m=0:d=0:r=0:c=7,scale=610x610,setsar=1[wfc-v]; \
  
            [vs]vectorscope=m=color3:g=color,scale=610x610,setsar=1[vs-v]; \
  
            [sig][wf-v]vstack[2c]; \
  
            [wfc-v][vs-v]vstack[3c]; \
  
            [1c][2c][3c]hstack=3,scale=1920:-1[out0]"

  I’d like to change it to that style - I’m not yet allowed to post images directly in this question, so I need to link it :

  Link to image how I’d like the layout to be

  I’d like to have the video shown in 1920x1080 (keeping aspect ratio, downscale if necessary).

• How to create a ffmpeg filter that zooms by a set value over a time while playing the video ?

  13 janvier 2023, par Highmastdon

  I'd like to create a zoom effect where I start at 1 * inputwidth and end with 1.1 * inputwidth over a set time.

  


  I tried using zoompan but it :

  


  

  • pauses the frame, zooms in over the amount of time specified, continues sound while zooming.

  


  • zooms to the top-left corner, instead of center.

  


  • leaves the frame smaller than it was before. Do I need to upscale afterwards ?

  


  


  $ ffmpeg -i in.mp4 -t 10 \
-vf "fps=60,zoompan=z='if(lte(it,2),it/2*0.1+1,1.1)':d=1,scale=iw:ih" out.mp4


  


  I tried using scale with crop, but then I get the error shown below. I assume this isn't to be as a function of time.

  


  $ ffmpeg -i in.mp4 -t 10 \
-vf "fps=60, scale='t/5*2*iw':-1, crop='iw/2*t/5':'ih/2*t/5'" out.mp4

Expressions with frame variables 'n', 't', 'pos' are not valid in init eval_mode.


  


  If there's an other tool besides ffmpeg, that would be fine, except it should not be a gui-only way.

  


• Better vertical stabilization when simultaneously cropping to widescreen format

  21 juillet 2016, par Kelley van Evert

  First of all : forgive me for maybe asking a stupid or somewhat uninformed question. I’m totally new to post processing video, stabilization, etc..

  I’m shooting 1920x1080 compressed movie files with my Canon 5D2, and afterwards crop then to cinematic 1920x800 (2.4:1). (With Magic Lantern I use an overlay bitmap when shooting. And yes, I know that with magic lantern I can shoot RAW, but my cards as well as computer are not fast enough to deal with that much data.)

  Before doing any production, I convert the big .MOV files to smaller ones, simultaneously stabilizing the video a bit, and cropping it to 1920x800. I do this with ffmpeg roughly as follows :

  ffmpeg -i f.MOV -vf vidstabdetect -f null -
  
  ffmpeg -i f.MOV -c:v libx264 -profile:v high -crf 18 -vf "vidstabtransform, crop=in_w:in_h-280" -c:a aac -strict experimental f2.mp4

  However, the fact that a great deal of the vertical resolution is being cropped is not being used to be able to handle the stabilizing transforms better. Often, the image is stretched/skewed vertically, when this is not really needed given the crop used.

  Is it possible in any way to use the crop befenificially in the stabilizing transforms ?

  An example is the frame below. Here, I would rather have that the image is not stretched vertically at all, and just get away with a slight static zoom (crop), because the horizontal black border is the only problem in this frame.