Recherche avancée

Sur d’autres sites (11818)

• Anomalie #3024 : spip_loader.php et IE8 (oui.... les pros du C/S traditionnels l’exigent !)

  26 janvier 2014, par jluc -

  Avec ou sans rapport, spip_loader n’a pas marché (pour FF26 sous Ubuntu 13.10). Un fichier pclzip.php et un tradloader.php étaient installés à la racine puis un long moulinage révèlait une err500. Aucun log spécifique dans tmp.

• Merge individual frame to video file using Opencv and FFmpeg

  16 août 2022, par Rohit

  I am trying to stack a individual frame to a video file using Opencv. I want to combine two different code together to make the individual frame.
Following code help me extract the individual frame

  


  while True:
ret, frame=cap.read()
mask = object_detector.apply(frame)
_, mask  = cv2.threshold(mask,254,255,cv2.THRESH_BINARY)       
contours,_ = cv2.findContours(mask, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
res = cv2.bitwise_and(frame,frame,mask=mask)
for cnt in contours:
    area = cv2.contourArea(cnt)
    if area>1000:   
        #print("Area of contour:", area)
        cv2.drawContours(frame, [cnt], -1, (0,255,0),2)
        cv2.imwrite("file%d.jpg"%count, frame)


  


  And I attach the frame together separately using following code using ffmpeg command

  


  ffmpeg -r 3 -i frame%03d.jpg -c:v libx264 -vf fps=25 -pix_fmt yuv420p video.mp4


  


  I tried storing the individual frame in array, but it didn't work. It doesn't show any error, but pc crash.

  


• How to reproject and join these two clips with ffmpeg ?

  20 janvier 2023, par jumpjack

  I have two videoclips embedded in this single video :

  


  https://sci.esa.int/web/cassini-huygens/-/39218-huygens-descent-to-titan-surface

  


  Download lo-res : link

  


  The timings which I calculated to sync the two clips are :

  


  

  • 01:33.233 - 02:24.133

  


  • 02:33.700 - 03:24.600

  


  


  I want to join them into a single view ; I thought that cropping the video between the dots which mark east and west was enough, but it is not : I tried this, but with terrible results :

  


  #echo off
# Cut east and west clips:
@echo cut east...
ffmpeg -ss 01:33.233 -to 02:24.133 -i %1 -vf "crop=900:450:73:0, pad=w=iw:h=2*ih:x=0:y=ih:color=black" -y east-crop.mp4
@echo cut west...
ffmpeg -ss 02:33.700 -to 03:24.600 -i %1 -vf "crop=900:450:73:0, pad=w=iw:h=2*ih:x=0:y=ih:color=black" -y west-crop.mp4

@echo merge...
ffmpeg -i west-crop.mp4 -i east-crop.mp4 -filter_complex hstack=inputs=2 -y combined.mp4


  


  I think I have also to reproject... but I have no idea of which is the projection used.

  


  Any suggestion ?

  


  Example east/west frames :

  


  

  


  

  


  I would like to obtain a single equirectangular image which reprojects into a full sphere when seen into a VR viewer.

  


  Instead, I am getting this :