Recherche avancée

Sur d’autres sites (12294)

• Remove random background from video using ffmpeg or Python

  20 avril 2024, par Raheel Shahzad

  I want to remove background from a person's video using ffmpeg or Python. If I record a video at any place, detect the person in the video and then remove anything except that person. Not asking for green or single color background as that can be done through chromakey and I am not looking for that.

  



  I've tried this (https://tryolabs.com/blog/2018/04/17/announcing-luminoth-0-1/) approach but it is giving me output of rectangular box. It is informative enough as area to explore is narrow down enough but still need to remove total background.
I've also tried grabcut (https://docs.opencv.org/4.1.0/d8/d83/tutorial_py_grabcut.html) but that need user interaction otherwise result isn't too good.
I've also tried to use ffmpeg and found this example (http://oioiiooixiii.blogspot.com/2016/09/ffmpeg-extract-foreground-moving.html) but it needs still image so I tried to take background picture before recording video with a person but there are many things required to take difference between background image and video frame.

  



  For opencv approach, I've tried this.

  



  img = cv.imread('pic.png')
mask = np.zeros(img.shape[:2], np.uint8)
bgdModel = np.zeros((1, 65), np.float64)
fgdModel = np.zeros((1, 65), np.float64)
rect = (39, 355, 1977, 2638)
cv.grabCut(img, mask, rect, bgdModel, fgdModel, 5, cv.GC_INIT_WITH_RECT)
mask2 = np.where((mask==2)|(mask==0), 0, 1).astype('uint8')
img = img*mask2[:, :, np.newaxis]
plt.imshow(img), plt.colorbar(), plt.show()


  



  But it is removing some of person's part too.
Also tried ffmpeg way but not a good result.

  



  ffmpeg -report -y -i "img.jpg" -i "vid.mov" -filter_complex "[1:v]format=yuva444p,lut=c3=128[video2withAlpha],[0:v][video2withAlpha]blend=all_mode=difference[out]" -map "[out]" "output.mp4"


  



  All I need is just a person's image/video take under any normal background without user interaction like area selection or any other thing like that. Luminoth has trained data but that is giving box of person not exact person so that I can remove. Any help or guidance to remove background will be appreciated.

  


• ffmpeg how to put color overlay over video

  13 mai 2020, par flieks

  I want to put a color overlay (blue, red or green or hex value) over a video giving it a Instagram filter like effect.

  



  I think it should be in the lines of :

  



  ffmpeg -i video.mp4 -i "red.png" -filter_complex "blend=all_mode='screen':all_opacity=0.7" output.mp4


  



  or maybe with all_mode=overlay

  



  But I get an error :

  



  First input link top parameters (SAR 0:1) do not match the corresponding second input link bottom parameters (SAR 1:1).


  



  I also tried with lutrgb=r=1.5, but that didn't give it a red color (it takes the red away).

  



  What am i doing wrong ?

  


• Create 30fps time-lapse video from 30fps source with frame interpolation

  29 janvier 2019, par 350D

  I’m trying to convert video source to time-lapse using this method :

  ffmpeg -i source.mp4 -an -filter:v "setpts=PTS/360" timelapse.mp4

  but I don’t like this choppy and jumpy output video due dropping frames with PTS/360 option. I’ve tried to use tblend=average,framestep=2,setpts=PTS/360 but it looks the same and doublicating this filter like

  tblend=average,framestep=2,tblend=average,framestep=2,tblend=average,framestep=2,...setpts=PTS/180

  doesn’t make any visible difference for me.

  Is there any other options with ffmpeg to blend 30 frames to 1 averaged frame and compile output 30fps video using these frames ?