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• How to append an image to a video using OpenCV or FFMPEG or Moviepy or other libraries ?

  19 juillet 2022, par Trần Tiến Văn

  Do you know a library in Python to add a frame image to an existing video ? The result video must have the same quality as the image.

  


  I tried to use OpenCV to add google image : https://www.google.com/search?q=google&sxsrf=ALiCzsZhrdoHnOTmg0We4dxtguCqzma5Jg:1657603343101&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiTh8bTzfL4AhWhplYBHfXNAKwQ_AUoAXoECAIQAw&biw=1492&bih=739&dpr=1.25#imgrc=PRtenhDnrVrfOM

  


  But the quality decreases when the video elongates.

  


  Here is the final result video : https://drive.google.com/file/d/1ArDvoX-kN9H_oLbACk3kU1Cid93SMczC/view?usp=sharing

  


  Here is my code using OpenCV :

  


          image = cv2.imread(path_image)
        height, width, dimensions = image.shape
            
        video = cv2.VideoCapture(path_video)
        
        
        frames = []
        while(True):
            
            ret, frame = video.read()
            
            if ret == True: 
                frames.append(frame)
                # frame = frame.resize(frame, (width, height), fx=0, fy=0, interpolation = cv2.INTER_CUBIC)
                
                # Press S on keyboard 
                # to stop the process
                if cv2.waitKey(1) & 0xFF == ord('s'):
                    break
            # Break the loop
            else:
                break
            
        video2 = cv2.VideoWriter(path_video,cv2.VideoWriter_fourcc('M','J','P','G'), 30, (width, height))
        for frame in frames:
            video2.write(frame)
        video2.write(image)
        video2.release()  # releasing the video generated     
        print("Added {}".format(image_name))


  


  I hope to improve the quality of this video.

  


• Python subprocess.Popen + ffmpeg breaks terminal input

  16 décembre 2020, par Barney Suit

  I was writing a module to create random screenshots from a video and used subprocess.Popen to run multiple commands in parallel but this leads to terminal refusing from showing any input once the python program is finished running. But it still accepts most inputs given from the keyboard it just doesn't display it.

  


  Only if I type the reset command terminal starts working fine
This happened on ssh with putty and other ssh clients even ssh with powershell on windows and directly running on terminal with VNC

  


  But without ssh directly running the same command on windows ssh works fine and and inputs are visible

  


  here's a gif example for whats happening


  


  and code to replicate it

  


  #!/usr/bin/env python3.8
from subprocess import Popen

def create_screenshots():

    commands = ['ffmpeg -hide_banner -loglevel panic -ss 329  -i "/home/user/file.mkv" -y -vframes 1   "/home/user/file.329.frame.png"',
                'ffmpeg -hide_banner -loglevel panic -ss 312  -i "/home/user/file.mkv" -y -vframes 1   "/home/user/file.312.frame.png"',
                'ffmpeg -hide_banner -loglevel panic -ss 533  -i "/home/user/file.mkv" -y -vframes 1   "/home/user/file.533.frame.png"',
                'ffmpeg -hide_banner -loglevel panic -ss 444  -i "/home/user/file.mkv" -y -vframes 1   "/home/user/file.444.frame.png"',
                'ffmpeg -hide_banner -loglevel panic -ss 411  -i "/home/user/file.mkv" -y -vframes 1   "/home/user/file.411.frame.png"',
                'ffmpeg -hide_banner -loglevel panic -ss 413  -i "/home/user/file.mkv" -y -vframes 1   "/home/user/file.413.frame.png"']
    screenshot_files = []
    processes = [Popen(command, shell=True) for command in commands]
    for process in processes:
        process.wait()
    
    return screenshot_files


create_screenshots()


  


• The Future of the VP8 Bitstream

  17 juin 2010, par noreply@blogger.com (John Luther) — vp8

  Recently we’ve seen software products such as VLC, FFmpeg, Logitech Vid, Flumotion and Tixeo adopting and using WebM and VP8 (the video codec in WebM) in exciting new ways.

  In addition to software developers, many hardware vendors have committed to shipping VP8-accelerated products based on our current bitstream in 2011 . Devices that use hardware acceleration for video are a very small percentage of overall web traffic today, but they are a rapidly growing segment of the market and our project must be mindful of these vendors’ needs. Given the longer lead times for changes in chipsets, hardware companies implementing the codec today need to be confident that it will be stable and supported as VP8 content proliferates.

  Like every codec, WebM is not immune to change ; the difference in our project is that the improvements are publicly visible, and compatibility and implementation issues can be worked through in an open forum.

  So, to maintain codec stability while also allowing for quality and performance improvements in VP8, we have added an experimental branch to the VP8 source tree. The WebM community can use this unstable branch to propose changes to VP8 that will produce the best video codec possible, but without the constraints of a frozen bitstream. At some point in the future, when the experimental branch proves significantly better than the stable branch, we will create a new version of the codec.

  Teams dedicated to improving WebM are actively investigating and evaluating new techniques, and are committed to do so for the long term. We encourage the WebM community to keep contributing as well. To learn more about the experimental branch and get involved, see our repository layout page.

  Jim Bankoski is Codec Engineering Manager at Google.