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• JavaFX MediaPlayer unable to play local m3u8 file

  22 février 2020, par Lennart

  I want to show a live stream of a web cam in my JavaFX application using the MediaPlayer/MediaView. My attempt was to use ffmpeg to record a HLS and to play the resulting m3u8 file, but that throws the following exception (VLC plays the video without problems) :

  MediaException: UNKNOWN : com.sun.media.jfxmedia.MediaException: Could not create player! : com.sun.media.jfxmedia.MediaException: Could not create player!
  
      at javafx.scene.media.MediaException.exceptionToMediaException(MediaException.java:146)
  
      at javafx.scene.media.MediaPlayer.init(MediaPlayer.java:511)
  
      at javafx.scene.media.MediaPlayer.<init>(MediaPlayer.java:414)
  
      at de.fraunhofer.iosb.ias.flow.assessment.management.monitor.MonitorViewController.testStream(MonitorViewController.java:203)
  
      ... 58 more
  
  Caused by: com.sun.media.jfxmedia.MediaException: Could not create player!
  
      at com.sun.media.jfxmediaimpl.NativeMediaManager.getPlayer(NativeMediaManager.java:274)
  
      at com.sun.media.jfxmedia.MediaManager.getPlayer(MediaManager.java:118)
  
      at javafx.scene.media.MediaPlayer.init(MediaPlayer.java:467)
  
      ... 60 more
  
  </init>

  I debugged the player creation and the error occurs inside the constructor of GSTMediaPlayer when GSTMediaPlayer.gstInitPlayer() is called. This native method returns the error code 257, which javafx maps to MediaError.ERROR_MEDIA_NULL.

  I used the following ffmpeg command to record the video :

  ffmpeg -hide_banner -y -rtbufsize 250MB -f dshow -pixel_format yuv420p -video_size 960x720 -i video="Logitech HD Pro Webcam C920" -c:v libx264 -crf 20 -pix_fmt yuv420p out.m3u8

  I’m pretty sure that the encoding matches the requirements of javafx, because if I change the output container from m3u8 to mp4, the video is played without problems using the exact same ffmpeg command.

  This is the output of ffprobe for the m3u8 file :

  Input #0, hls,applehttp, from 'out.m3u8':
  
    Duration: 00:00:24.23, start: 1.466667, bitrate: 0 kb/s
  
    Program 0
  
      Metadata:
  
        variant_bitrate : 0
  
      Stream #0:0: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p, 960x720, 30 fps, 30 tbr, 90k tbn, 60 tbc

  And for the mp4 file :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'out.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf57.41.100
  
    Duration: 00:01:04.93, start: 0.000000, bitrate: 1676 kb/s
  
      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 960x720, 1673 kb/s, 30 fps, 30 tbr, 10000k tbn, 60 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler

  The resulting m3u8 file looks like this :

  #EXTM3U
  
  #EXT-X-VERSION:3
  
  #EXT-X-TARGETDURATION:9
  
  #EXT-X-MEDIA-SEQUENCE:0
  
  #EXTINF:8.333322,
  
  out0.ts
  
  #EXTINF:8.333333,
  
  out1.ts
  
  #EXTINF:7.133322,
  
  out2.ts
  
  #EXTINF:0.433333,
  
  out3.ts
  
  #EXT-X-ENDLIST

  Update : After I found this reference m3u file, I think that the problem is that the file is stored locally and isn’t delivered via HTTP. The video plays fine with this :

  Media media = new Media("http://download.oracle.com/otndocs/products/javafx/JavaRap/prog_index.m3u8");
  
  MediaPlayer player = new MediaPlayer(media);
  
  player.setAutoPlay(true);
  
  mediaView.setMediaPlayer(player);

  But after I downloaded the reference m3u and all of its segments and tried to open the local file like this, the error occurred again :

  File video = new File("H://Projects//Tools//ref//prog_index.m3u8");
  
  Media media = new Media(video.toURI().toString());
  
  MediaPlayer player = new MediaPlayer(media);
  
  player.setAutoPlay(true);
  
  mediaView.setMediaPlayer(player);

  I tried to change my m3u file so that the segements are referenced with absolute paths. I tried different notations (H:\f\out0.ts, H:/f/out0.ts, H://f//out0.ts, file:/H:/f/out0.ts, file:///H:/f/out0.ts), but I couldn’t get it to work.

• Save movie about open AI gym

  30 novembre 2019, par Andres

  I make a Reinforcement learning code on python with open AI gym.After training I want save the movie about reinforcement learning but on windows this is impossible.

  There is another way to save the movie of reinforcement learning MountainCar-v0 on windows ??

  if __name__ == "__main__":
  
      environment = gym.make("MountainCar-v0")
  
      agent = QLearner(environment)
  
      learned_policy = train(agent, environment)
  
      monitor_path = "./movie_output"
  
      environment = gym.wrappers.Monitor(environment, monitor_path, force=True)

  this is the error message

  DependencyNotInstalled : Found neither the ffmpeg nor avconv executables. On OS X, you can install ffmpeg via brew install ffmpeg. On most Ubuntu variants, sudo apt-get install ffmpeg should do it. On Ubuntu 14.04, however, you’ll need to install avconv with sudo apt-get install libav-tools.

• FFMPEG Conversion improve quality

  1er octobre 2019, par user726720

  I have some questions regarding ffmpeg :

  I need to convert the XDCAM HD422 (yuv422p) to AVC (h.264, mp4). I’m doing it as follows :

  ffmpeg.exe -y -i path\abc.mxf  -ab 128k -acodec aac -ac 2 -strict -2 -b:v 12000k -f mp4 -g 34 -pix_fmt yuv420p -r 25 -s 1920x1080 -vcodec h264 -preset ultrafast h264file.mp4

  I have check the mp4 on a broadcast monitor and there are some visible color saturation issue’s. The quality doesn’t match the original XDCAM HD422

  1. What changes do I need to make in the above parameters to fix this ?
  2. My original file is a yuv422p and I’m using yuv420p in the above ffmpeg command, does this make a difference in the quality.
  3. Should change the preset from ultrafast to Fast make a difference.
  4. Will using the libx264 make any difference ?
  5. How does ffmeg encode from one format to another. Does it simply do a direct conversion or does it extract the RAW (yuv) from the XDCAM and then encode it into MP4 ?

  I’m just brainstorming how to improve the quality so it matches the that of XDCAM, any suggestions would be highly appreciated.