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• HEVC File bigger after converting from h264

  26 janvier 2019, par Aaroknight

  I’m currently working an an automated Python script for indexing and converting all my movies and episodes with ffmpeg. I use subprocess.call() for running the ffmpeg command and tested this command with some movies. As expected the big h264 files were converted to merely one third of what they used to have.

  But now that I was testing the method I found that a converted episode (about 400MB in h264) had over 1,6GB in hevc. I have absolutely no idea why the new file would be that much bigger in hevc.
  This is my code :

  def convert(path):
  
      outvid = path.strip(".mkv") + "h265.mkv"
  
  
  
      cmd = ["ffmpeg", "-i", path, "-map", "0", "-map_metadata", "0", "-map_chapters", "0", "-c:v", "libx265",
  
             "-c:a", "copy", "-c:s", "copy", "-preset", "ultrafast", "-x265-params", "lossless=1", outvid]
  
      subprocess.call(cmd)
  
  
  
  convert("/Volumes/2TB/Black Butler/Season 1/Black Butler S01E01.mkv")

  I don’t have that much experience with ffmpeg, nor with subprocess. This is one of my first bigger projects. I hope someone can tell me what the problem might be.

  UPDATE
  Problem applies only for small video files. I now just check for the file size and skip the small files. Wouldn’t have made much of a difference anyway.

  

• How can I play an MPG file using Electron on windows without converting it ? [closed]

  1er novembre 2024, par Indy Singh

  I am trying to play MPG files in an Electron app on Windows. The files contain mpeg1 encoded video. I am using the video element. I can play MP4 files, but the MPG files do not play. One requirement is to be able to play the video from some arbitrary start time.

  


  Electron uses the Chrome engine to render output. Google Chrome app also cannot play MPG files.

  


  Electron uses ffmpeg.dll to play the video file. As far as I can tell ffmpeg.dll contains the mpeg1 decoder, but the video element does not appear to make use of it.

  


  I know I can convert the video before playing, however conversion takes several minutes and is not an ideal user experience. As a fallback I can convert small segments as needed, which still takes a bit of time, so it is not ideal.

  


  Streaming the video from a server process with on-the-fly conversion is possible, but I believe it may not work well with the need to seek. I could be wrong here.

  


  Any other suggestions would be welcome.

  


  EDIT 1 :
I am developing an Electron App using the programming languages TypeScript, JavaScript and HTML5 and the tools Nodejs and Electron. I did not post a code snippet as I am looking for an approach, not a fix for code. Not sure why this question got flagged as being 'not about programming'.

  


  A Google search does not show many options other than those mentioned below.

  


  EDIT 2 :
Thanks to the suggestion from VC.One I am looking at the JSMPEG library. It does look like it could possibly do the job but with 'numerous limitations'. It also say the other alternative called Broadway is 'huge, compiled with emscripten and quite complicated'

  


  EDIT 3 :
I am now looking hls.js, which I think will likely work for my needs. It integrates well with using the html5 video element. I can use it with on-demand decoding of the MPG MPEG1 video file in small segments.

  


• mediaReader.readPacket() blocks while trying to read rtsp stream in Xuggler

  29 novembre 2015, par user3601262

  I am trying to download a video (with a Xuggler 5.4 library) from rtsp stream to a file using the code below.

      String inputSource = "rtsp://[ip-address]:[port]/user=[username]&[password]=password&channel=1&stream=1.sdp";
  
      String outputFilename = "d:/downloadedrtsp.flv";
  
      try {
  
          IContainerFormat inFormat = IContainerFormat.make();
  
          inFormat.setInputFormat("h246");
  
  
  
          IMediaReader mediaReader = ToolFactory.makeReader(inputSource);
  
          mediaReader.setQueryMetaData(false);
  
  
  
          IMediaWriter mediaWriter = ToolFactory.makeWriter(outputFilename, mediaReader);
  
          mediaReader.addListener(mediaWriter);
  
  
  
          logger.info("before reading");
  
          IError error;
  
          while ((error = mediaReader.readPacket()) == null) {
  
              logger.info("reading packet");
  
          }
  
          logger.info("error: " + error.getDescription());
  
          logger.info(error.getType());
  
          logger.info(error.toString());
  
      } catch (Exception e) {
  
          e.printStackTrace();
  
      }

  The problem is that after printing "before reading" the code just stop executing, and after a long time it prints me three lines from logger :

  error : Unknown error

  ERROR_EOF

  Unknown error

  Stream works great when i am opening it in the VLC media player. I am shure there is some mistake in my mediaReader configuration, but i don’t know where exactly as i have a very little experience working with videos. Here is some information about video, taken from VLC :