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• Create thumbnails of sections of a torrent stream

  14 juillet 2015, par Ortixx

  I’m trying to create a little application in nodejs using the torrent-stream library to create thumbnails of a video without actually having to download the entire file. I was thinking of downloading only 10 parts, out of which I would extract an image, but then the encoding comes into play : without an I-frame I cannot extract an image out of the stream, and there is no way of me knowing where the I-frame is.

  So any ideas on how to do this ? Basically I was hoping to create 10 tiny files which I could then open in ffmpeg in order to save a thumbnail (this would give me 10 thumbnails which is want I want). I’m just not sure how to handle the stream.

• How to create thumbnail about torrent without downloading video files ? [on hold]

  1er septembre 2019, par tty78

  Most of time, torrent sites like RARBG/The Pirate Bay/KickAss would return many query results even through I have typed in many detailed keywords, which is not strange because there are many people upload it.

  So, when i want to watch/download a torrent movie, it’s better to check the video first to find out that :

  • is it a fake video
  • is the video watermarked
  • is there some AD in the video
  • is it 1980*1080 or 640*480 ??

  What i want to do is creating thumbnail of the videos without download them, so that i can save a lot of broadband, disk space and time.

  Now I can create thumbnail with a python tool - vcsi, but it depends on the video file stored in disk.
  In fact, vcsi get meta information with ffprobe and create thumbnail using ffmpeg.

  def probe_media(self, path):
  
      """Probe video file using ffprobe
  
      """
  
      ffprobe_command = [
  
          "ffprobe",
  
          "-v", "quiet",
  
          "-print_format", "json",
  
          "-show_format",
  
          "-show_streams",
  
          path
  
      ]
  
  
  
      try:
  
          output = subprocess.check_output(ffprobe_command)
  
          self.ffprobe_dict = json.loads(output.decode("utf-8"))
  
      except FileNotFoundError:
  
          error = "Could not find 'ffprobe' executable. Please make sure ffmpeg/ffprobe is installed and is in your PATH."
  
          error_exit(error)

  ffmpeg_command = [
  
          "ffmpeg",
  
          "-ss", skip_time,
  
          "-i", self.path,
  
          "-ss", skip_delay,
  
          "-vframes", "1",
  
          "-s", "%sx%s" % (width, height),
  
      ]

  WebTorrent may be a solution but it’s not good because I have a lot of torrent file to scan.
  I want to create thumbnail on a ubuntu VPS because it can run day and night, and i can post thumbnail under the torrent comments.
  Some key frame, resolution and duration are enough, maybe.
  

• Merge .mkv files with already included subtitles using ffmpeg-python

  9 mars 2023, par Eeshe

  I'm trying to merge two (and more in the future) .mkv files that already have subtitles included in them, this means I DO NOT have .srt files that need to be encoded. Let's call the .mkv files intro.mkv and episode.mkv.

  


  However, the way I want to merge them is so a portion of the episode.mkv file is played until a specified timestamp, then intro.mkv plays completely, and after that the rest of episode.mkv.

  


  I've managed to get close with the following code.

  


  import ffmpeg

initial_episode_video = ffmpeg.input('episode.mkv', to='00:00:34.033', hwaccel='cuvid')
intro_video = ffmpeg.input('intro.mkv', hwaccel='cuvid')
remaining_episode_video = ffmpeg.input('episode.mkv', ss='00:00:34.033', hwaccel='cuvid')

full_episode_video = ffmpeg.concat(initial_episode_video, intro_video, remaining_episode_video)

output_video = ffmpeg.output(
    full_episode_video,
    filter_complex='[0:v][0:a][1:v][1:a][2:v][2:a]concat=n=3:v=1:a=1',
    vprofile='main', 
    vcodec='h264_nvenc',
    pix_fmt='yuv420p',
    crf=22,
    map="0:s",
    filename=f'Output/{episode_path}')
ffmpeg.run(output_video)


  


  With this code, the videos are correctly trimmed. The problem is that once intro.mkv starts playing, it doesn't show the subtitles corresponding to it, instead it shows the episode.mkv subtitles corresponding to the '00:00:34.033' timestamp.

  


  My objective is to display the subtitles of intro.mkv, and then, once the full intro is played, continue with the subtitles from episode.mkv.

  


  NOTE : I am aware that I am re-encoding both the episode.mkv and intro.mkv files. If possible, I'd prefer if it only re-encodes episode.mkv, since intro.mkv only needs to be re-encoded once (I can do that individually). I am re-encoding to go from H.264 Hi 10 to H.264 main profile.