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• Overlaying a list of video files on top of another list of video files

  2 août 2023, par sybr

  I'm currently working on a way to improve my production process for the videos that I'm making. The source files consist of a list of two side-by-side clips that I handpick and stitch together in Premiere Pro. I recently came across FFmpeg and thought, 'surely there's a way to automate the rendering of these videos'.

  


  I've managed to get the general overlay working, where I have one clip overlaid on top of the other one, but the overlaid clip doesn't have any audio, and the overlaid clip currently doesn't scale to the height of the background clip.

  


  Here's what i'd like it to look like :


  


  As illustrated in the image, I want to overlay the overlay clip on top of the background clip, preserving audio for both clips, and shift the background clip's position to the right by 33%. Now, instead of both "clips" being just one clip, I want to use two folders with each about 1 hour's worth of clips to compile an hour-long video containing both folders.

  


  Is there a way to achieve what I want to do here ? Or would it make more sense to compile two separate videos first by concatenating all videos in their respective folders first, and then overlaying one video on top of the other one ?

  


  Would love some help here, also eager to learn more about FFmpeg, so some explanation would be highly appreciated !

  


• openCV image Stitching wide angle 160 degrees

  4 janvier 2020, par a.masri

  I’m trying to Stitching image wide angle 160.5 degree but the result is not a good

  i’m using OpenCV 4 and ffmpeg to get frames from video

  ffmpeg command to get 15 frame per sec :

  ffmpeg -i first.mp4 -vf fps=15  preview%05d.jpg

  OpenCV Stitching code

  import cv2
  
  import numpy as np
  
  
  
  images = []
  
  for i in range(70):
  
      name = ('preview%05d.jpg' % (i+1))
  
      print(name)
  
      images.append(cv2.imread(name , cv2.IMREAD_COLOR))
  
  
  
  
  
  print("start ")
  
  stitcher = cv2.Stitcher_create()
  
  ret, pano = stitcher.stitch(images)
  
  
  
  if ret == cv2.STITCHER_OK:
  
      cv2.imshow('panorama', pano)
  
      cv2.waitKey()
  
      cv2.destroyAllWindows()
  
  else:
  
      print(cv2.STITCHER_ERR_NEED_MORE_IMGS)
  
      print(cv2.STITCHER_ERR_HOMOGRAPHY_EST_FAIL)
  
      print(cv2.STITCHER_ERR_CAMERA_PARAMS_ADJUST_FAIL)
  
      print(ret)
  
      print('Error during stiching')

  actual result :

  

  expected result :

  

• FFmpeg Audio Merge Delays

  26 novembre 2016, par Matt Wall

  I’m trying to run this kind if FFmpeg command to stitch two videos together and merge the audio.

   ffmpeg -i C:\Santa\Staging\santa_2016.11.21.12.01.33_Komo_Kwigly.flv -i C:\Santa\Staging\door_2016.11.21.12.01.33_Komo_Kwigly.flv -loop 1 -i C:\watermark.png -filter_complex "[0]setpts=PTS-STARTPTS,transpose=1[a];[1]setpts=PTS-STARTPTS,transpose=1[b];[a][b]hstack[c];[c][2]overlay=W-w-5:H-h-5:shortest=1[v];[0][1]amerge,pan=stereo:c0code>

  And I’m getting this strange error and audio sync issues :

  

  Does anyone have any tips for what to do ? I’ve tried a lot and cannot seem to change the behavior. The sources are fine, too.

  The only other relevant log seems to be :

  [Parsed_pan_7 @ 00000000006a8440] This syntax is deprecated. Use '|' to separate the list items.
  
  [Parsed_pan_7 @ 00000000006a8ac0] This syntax is deprecated. Use '|' to separate the list items.
  
  [Parsed_amerge_6 @ 00000000006a8440] No channel layout for input 1
  
  [Parsed_amerge_6 @ 00000000006a8440] Input channel layouts overlap: output layout will be determined by the number of di    stinct input channels