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

  22 mai 2019, par 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()

• FFMPEG - why zoompan causes stretching

  14 septembre 2020, par Sarmad S.

  I have two images as input, both are 1600x1066. I am vertically stacking them. Then I am drawing a box and vertically stacking that box under both of the image. Inside of the box I write text, then I output a video that is 1080x1920. Everything works well, until I use zoompan to zoom in on the images, I get weird behavior. basically all input images including the box stretchs (shrink) horizontally and no longer fit the entire height of the video which is 1920.

  


  The command (removed some drawtext commands from it) :

  


  -filter_complex 
"color=s=1600x1066:color=blue, drawtext=fontfile=font.otf: text='My Text':fontcolor=white: fontsize=30: x=50: y=50[box]; 
[0]scale=4000x4000,zoompan=z='min(zoom+0.0015,1.5)':x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':d=125:s=1600x1066[z0];
[1]scale=4000x4000,zoompan=z='min(zoom+0.0015,1.5)':x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':d=125:s=1600x1600[z1];
[z0][z1][box]vstack=inputs=3"


  


  How do I fix this ? I want to zoom in without stretching the images

  


  Before using zoompan this is how the video looks like (I want to keep it this way while zooming in the images) :


  


  After using zoompan this is how the video looks like :

  


  

  


• Correcting color cast with ffmpeg

  16 mai 2018, par Henry H

  I have two videos that have a pretty significant blue cast to them. I took some stills at the same time and I’m happy enough with the colors on those and I’d like to re-encode the videos, adjusting the colors to something similar to the stills.

  • A frame from the original video can be seen here : http://www.dotrose.com/temp/img_20180513_153484_original.png
  • An attempt at correcting the color, which would be acceptable : http://www.dotrose.com/temp/img_20180513_153484_corrected.png
  • A still image taken at the same time (but with some help from a flash) : http://www.dotrose.com/temp/img_20180513_153476.jpg

  I understand I could either create a large collection of jpg images from the video and color correct them before reassembling them into a new video or I could use ffmpeg’s color level’s filter to do it directly. What I don’t know is how to get the numbers to pass to the filter. I’m assuming I want to do something like this :

  ffmpeg -i video.mov -vf "colorlevels=rimin=##/255:gimin=##/255:bimin=#/255:rimax=###/255:gimax=###/255:bimax=###/255, eq=gamma=#.##" -y out.mov

  How do I get the values to use for each of the r, g, and b min and max settings and gamma to use in place of the ###s ? Assuming this is the right approach, of course.

  Update : Perhaps this question would be better asked in a forum for gimp or photoshop. But I know how to adjust the color in those. What I need to know is how I translate those changes to what ffmpeg is expecting.