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• Ream-time watermarking with MPEG-DASH

  14 juillet 2016, par Calvin W.

  In the system, I want to add a unique watermark (e.g. IP address of client and time stamp) into the video that he/she want to watch.

  But when I handled it with OpenCV, it spent 25 minute with a 15-min video. And I need to transcode to mp4 with ffmpeg.

  Now I’m trying the watermark function of ffmpeg, bit it still needs some time.

  It it possible to send the video to client side with MPEG-DASH while transcoding it with ffmpeg ?

  System spec :(Amazon EC2 c3.xlarge)
  Intel Xeon E5-2680 v2 (Ivy Bridge) - 4 vCPU
  7.5G RAM
  40GB SSD
  Ubuntu 14.04 LTS
  OpenCV2.4.13
  ffmpeg 3.1.1
  

  code :

  import cv2
  
  import sys
  
  import time
  
  from datetime import datetime as dt
  
  
  
  # frame of input video
  
  fps = float(sys.argv[4])
  
  # encode to AVC
  
  fourcc = cv2.cv.CV_FOURCC('A', 'V', 'C', '1')
  
  # transparency of text
  
  alpha = 0.1
  
  beta = 1 - alpha
  
  
  
  # input video
  
  cap = cv2.VideoCapture(sys.argv[3])
  
  
  
  # current frame index, start from 0
  
  frameIndex = 0
  
  
  
  # get input video's width/height
  
  width = int(cap.get(cv2.cv.CV_CAP_PROP_FRAME_WIDTH))
  
  height = int(cap.get(cv2.cv.CV_CAP_PROP_FRAME_HEIGHT))
  
  
  
  # config output (error using .mp4)
  
  out = cv2.VideoWriter('output.avi', fourcc, fps, (width, height))
  
  
  
  # access time
  
  timeStr = dt.fromtimestamp(time.time()).strftime('%Y-%m-%d %H:%M:%S')
  
  
  
  requestIP = sys.argv[1]
  
  username = sys.argv[2]
  
  text = "%s %s %s" % (requestIP, username, timeStr)
  
  
  
  
  
  # start loading video
  
  while(cap.isOpened()):
  
      ret, frame = cap.read()
  
      if ret:
  
          # add text between 10s - 20s
  
          if frameIndex > time10 and frameIndex < time20:
  
              # clone a new frame to add text
  
              overlay = frame.copy()
  
              cv2.putText(overlay, text, (100, 100), cv2.FONT_HERSHEY_PLAIN, 0.5, (255, 255, 255))
  
              # combine both frame and make text transparent
  
              cv2.addWeighted(overlay, alpha, frame, beta, 0, frame)
  
          # write frame to output
  
          out.write(frame)
  
          frameIndex += 1
  
      # wait for next frame
  
      if cap.get(cv2.cv.CV_CAP_PROP_POS_FRAMES) == cap.get(cv2.cv.CV_CAP_PROP_FRAME_COUNT):
  
          break
  
  # End of video
  
  # release
  
  cap.release()
  
  out.release()

• ffmpeg : Extracting the frames out of the video with corresponding time in ms [closed]

  13 mai 2013, par ph3n0m_aks

  I am using the following command :

   ffmpeg -i  image%d.png

  which outputs the image(frame number).png.

  But I have a requirement where I have to append time at which frame is extracted(in ms) in the image files.

  And also I want to extract the frames at each and every second.

  How should I go about it ?? Thanks in adavance..!

• Can you insert one audio file into another at specific time with ffmpeg ?

  9 août 2021, par KacperM

  My use case is to have an audio file that I need to add to another audio file at a specific time.
For example, the first file will be 1 hour long the second file 5 seconds long, and I want to insert it in the 30 minutes of the first time. The final file should be 1 hour 5 seconds long.

  


  If that is not possible with ffmpeg maybe there is other cmd tool that can do the described thing ?