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• Open CV Codec FFMPEG Error fallback to use tag 0x7634706d/'mp4v'

  22 May 2019, by Cohen

  Doing a filter recording and all is fine. The code is running, but at the end the video is not saved as MP4. I have this error:

  OpenCV: FFMPEG: tag 0x44495658/'XVID' is not supported with codec id 12 and format 'mp4 / MP4 (MPEG-4 Part 14)'
  
  OpenCV: FFMPEG: fallback to use tag 0x7634706d/'mp4v'

  Using a MAC and the code is running correctly, but is not saving. I tried to find more details about this error, but wasn’t so fortunate. I use as editor Sublime. The code run on Atom tough but is giving this error:

  OpenCV: FFMPEG: tag 0x44495658/'XVID' is not supported with codec id 12 and format 'mp4 / MP4 (MPEG-4 Part 14)'
  
  OpenCV: FFMPEG: fallback to use tag 0x7634706d/'mp4v'
  
  2018-05-28 15:04:25.274 Python[17483:2224774] AVF: AVAssetWriter status: Cannot create file

  ....

  import numpy as np
  
  import cv2
  
  import random
  
  from utils import CFEVideoConf, image_resize
  
  import glob
  
  import math
  
  
  
  
  
  cap = cv2.VideoCapture(0)
  
  
  
  frames_per_seconds = 24
  
  save_path='saved-media/filter.mp4'
  
  config = CFEVideoConf(cap, filepath=save_path, res='360p')
  
  out = cv2.VideoWriter(save_path, config.video_type, frames_per_seconds, config.dims)
  
  
  
  
  
  def verify_alpha_channel(frame):
  
      try:
  
          frame.shape[3] # looking for the alpha channel
  
      except IndexError:
  
          frame = cv2.cvtColor(frame, cv2.COLOR_BGR2BGRA)
  
      return frame
  
  
  
  
  
  def apply_hue_saturation(frame, alpha, beta):
  
      hsv_image = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
  
      h, s, v = cv2.split(hsv_image)
  
      s.fill(199)
  
      v.fill(255)
  
      hsv_image = cv2.merge([h, s, v])
  
  
  
      out = cv2.cvtColor(hsv_image, cv2.COLOR_HSV2BGR)
  
      frame = verify_alpha_channel(frame)
  
      out = verify_alpha_channel(out)
  
      cv2.addWeighted(out, 0.25, frame, 1.0, .23, frame)
  
      return frame
  
  
  
  
  
  def apply_color_overlay(frame, intensity=0.5, blue=0, green=0, red=0):
  
      frame = verify_alpha_channel(frame)
  
      frame_h, frame_w, frame_c = frame.shape
  
      sepia_bgra = (blue, green, red, 1)
  
      overlay = np.full((frame_h, frame_w, 4), sepia_bgra, dtype='uint8')
  
      cv2.addWeighted(overlay, intensity, frame, 1.0, 0, frame)
  
      return frame
  
  
  
  
  
  def apply_sepia(frame, intensity=0.5):
  
      frame = verify_alpha_channel(frame)
  
      frame_h, frame_w, frame_c = frame.shape
  
      sepia_bgra = (20, 66, 112, 1)
  
      overlay = np.full((frame_h, frame_w, 4), sepia_bgra, dtype='uint8')
  
      cv2.addWeighted(overlay, intensity, frame, 1.0, 0, frame)
  
      return frame
  
  
  
  
  
  def alpha_blend(frame_1, frame_2, mask):
  
      alpha = mask/255.0 
  
      blended = cv2.convertScaleAbs(frame_1*(1-alpha) + frame_2*alpha)
  
      return blended
  
  
  
  
  
  def apply_circle_focus_blur(frame, intensity=0.2):
  
      frame = verify_alpha_channel(frame)
  
      frame_h, frame_w, frame_c = frame.shape
  
      y = int(frame_h/2)
  
      x = int(frame_w/2)
  
  
  
      mask = np.zeros((frame_h, frame_w, 4), dtype='uint8')
  
      cv2.circle(mask, (x, y), int(y/2), (255,255,255), -1, cv2.LINE_AA)
  
      mask = cv2.GaussianBlur(mask, (21,21),11 )
  
  
  
      blured = cv2.GaussianBlur(frame, (21,21), 11)
  
      blended = alpha_blend(frame, blured, 255-mask)
  
      frame = cv2.cvtColor(blended, cv2.COLOR_BGRA2BGR)
  
      return frame
  
  
  
  
  
  def portrait_mode(frame):
  
      cv2.imshow('frame', frame)
  
      gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
  
      _, mask = cv2.threshold(gray, 120,255,cv2.THRESH_BINARY)
  
  
  
      mask = cv2.cvtColor(mask, cv2.COLOR_GRAY2BGRA)
  
      blured = cv2.GaussianBlur(frame, (21,21), 11)
  
      blended = alpha_blend(frame, blured, mask)
  
      frame = cv2.cvtColor(blended, cv2.COLOR_BGRA2BGR)
  
      return frame
  
  
  
  
  
  def apply_invert(frame):
  
      return cv2.bitwise_not(frame)
  
  
  
  while(True):
  
      # Capture frame-by-frame
  
      ret, frame = cap.read()
  
      frame = cv2.cvtColor(frame, cv2.COLOR_BGR2BGRA) 
  
      #cv2.imshow('frame',frame)
  
  
  
  
  
      hue_sat = apply_hue_saturation(frame.copy(), alpha=3, beta=3)
  
      cv2.imshow('hue_sat', hue_sat)
  
  
  
      sepia = apply_sepia(frame.copy(), intensity=.8)
  
      cv2.imshow('sepia',sepia)
  
  
  
      color_overlay = apply_color_overlay(frame.copy(), intensity=.8, red=123, green=231)
  
      cv2.imshow('color_overlay',color_overlay)
  
  
  
      invert = apply_invert(frame.copy())
  
      cv2.imshow('invert', invert)
  
  
  
      blur_mask = apply_circle_focus_blur(frame.copy())
  
      cv2.imshow('blur_mask', blur_mask)
  
  
  
      portrait = portrait_mode(frame.copy())
  
      cv2.imshow('portrait',portrait)
  
  
  
      if cv2.waitKey(20) & 0xFF == ord('q'):
  
          break
  
  
  
  # When everything done, release the capture
  
  cap.release()
  
  cv2.destroyAllWindows()

• Extract alpha from video ffmpeg

  23 October 2018, by Yarik Denisyk

  I want to overlay transparent video on the background image. I have a video where the top half is RGB object and bottom half is an alpha mask.

  Now, for making this I do next steps:

  1) I am extracting all frames from video and save to the folder

  2) Each frame splitting to top and bottom half bitmap

  3) Top bitmap composite with bottom mask for extract alpha and get a frame with transparent background

  3) I am drawing each frame on the background and save to a folder

  4) Create a video using FFmpeg

  The problem is step 2, 3 and 4, they very slow. Maybe has another way to overlay transparent video on the background image?

• drawertext color with conditon ffmpeg

  31 October 2022, by abderrahim khadri

  I have a coin price banner where I use ffmpeg to stream it and use reload:1 to render it in real time. I want to color the negative with red and the positive with green , haw to do it and is it posible with fflmpeg

  


  -vf 'drawtext=enable='between(t,18.93,20.28)':fontfile=fonts/cousine-bold.ttf:fontsize=144:fontcolor_expr=%{eif\\: if(between(0,1000)\, green\, red) \\: x}:x=82:y=288:text=coinsprice.txt:reload:1'