Recherche avancée

Sur d’autres sites (8051)

• Pulseaudio record multiple xfbv screens with python

  10 octobre 2020, par Eric Lagarda

  I’m trying to do something complicated and I need some help.

  


  I’m able to record a session (video and audio) with python using xvfb and ffmpeg.

  


  I just want to visit a page using selenium and record the video and audio. It’s working but when I try to run multiple instances, the audio is mixing between records.

  


  How can achieve that ? I’m using pulseaudio. I know that with alsa you can set like a interface per instance, but I don’t know how to do it.

  


  Thanks for you support and comments.

  


• Convert mp4 video to avi video using imageio package

  3 février 2018, par Li.Chenyang

  I use the python imageio package to convert a .mp4 video to a .avi video, keeping the fps and size same. The following is my code :

  import imageio
  
  
  
  src_dir = "my/source/video.mp4"
  
  dst_dir = "my/dst/video.avi"
  
  
  
  reader = imageio.get_reader(src_dir)
  
  fps = reader.get_meta_data()['fps']
  
  writer = imageio.get_writer(dst_dir, fps=fps)
  
  
  
  for im in reader:
  
      writer.append_data(im[:, :, :])
  
  writer.close()

  I successfully make it.
  However, I find that the video.mp4 is 27.1 MB, while the video.avi is only 3.70 MB.
  Then I use cv2 to do the same thing :

  import cv2
  
  
  
  src_dir = "my/source/video.mp4"
  
  dst_dir = "my/dst/video_1.avi"
  
  
  
  video_cap = cv2.VideoCapture(src_dir)
  
  fps = video_cap.get(cv2.cv.CV_CAP_PROP_FPS)
  
  size = (int(video_cap.get(cv2.cv.CV_CAP_PROP_FRAME_WIDTH)),   
  
          int(video_cap.get(cv2.cv.CV_CAP_PROP_FRAME_HEIGHT)))  
  
  video_writer = cv2.VideoWriter(dst_dir, cv2.cv.CV_FOURCC('M', 'J', 'P', 'G'), fps, size) 
  
  
  
  success, frame = video_cap.read()
  
  while success:
  
      video_writer.write(frame)
  
      success, frame = video_cap.read()

  This time I get a video_1.avi, which is 65.6 MB.
  My questions :

  1. What is the different between these two method, why the video.avi (using imageio method) is so small ;
  2. Is there any problem to use the video.avi (using imageio method) to train a 3D-CNN instead of using video_1.avi (using cv2 method) ?

  ---

  supplement
  Here is the information of my video file :

  lichenyang@lichenyang-All-Series:~/chalearn2014/script$ file video.mp4
  
  video.mp4: ISO Media, MPEG v4 system, version 2
  
  lichenyang@lichenyang-All-Series:~/chalearn2014/script$ file video.avi
  
  video.avi: RIFF (little-endian) data, AVI, 640 x 480, 20.00 fps, video: H.264 X.264 or H.264
  
  lichenyang@lichenyang-All-Series:~/chalearn2014/script$ file video_1.avi
  
  video_1.avi: RIFF (little-endian) data, AVI, 640 x 480, 20.00 fps, video: Motion JPEG

• convert multivideos from 1080p to 720p and add watermarks with subtitles ?

  20 novembre 2020, par shady melad

  0

  


  i will ask again i have many videos like series (dark - la casa de papel - game of thrones ) all of them without any subtitle or watermark first i burn subtitles with handbrake sec i use ffmpeg to burn watermark with videos by this code

  


  for %i in ("C :\Users\shady\Downloads\convert\01*.mp4") do ffmpeg -i "%i" -i C :\Users\fady\Downloads\convert\shady.png -filter_complex "overlay=main_w-overlay_w-10:10" -codec:a copy "C :\Users\shady\Downloads\convert\new01% ni.mp4"

  


  then i convert it to 720p with this code

  


  for %i in (C :\Users\shady\Downloads\convert\01*.mp4) do ffmpeg -i "%i" -c:a copy -s hd720 "C :\Users\shady\Downloads\convert\new01% ni.mp4"

  


  my question now if i want to burn subtitle for series dark all seasons with my watermark and the final file get out with 720p with subtitle with watermark on top at right

  


  can i do that ?

  


  watermark png subtitle srt movies come with mkv not mp4 ( i want the final file come with mp4 )