Recherche avancée

Sur d’autres sites (10326)

• Texai Remote Presence System Using VP8 Video

  19 novembre 2010, par noreply@blogger.com (John Luther)

  Guest blogger Josh Tyler is a member of the Texai team at Willow Garage.

  Willow Garage is busy building the next version of its Texai remote presence platform with VP8, the video codec used in WebM.

  In short, Texai is a two-way videoconferencing app on a tele-operated robotic platform (for more details, see the piece about Texai in the New York Times). Video and audio quality are critical to providing the best user experience on Texai. We’ve evaluated several video codecs and found VP8’s image quality, low latency and tolerance to packet loss far better than anything else we tested.

  The video below shows VP8 running on one of our systems.

  (If you have a WebM-enabled browser and are enrolled in the YouTube HTML5 beta the video will play in WebM HTML5, otherwise it will play in Flash Player.)

  We’re also looking for help ! If you’re interested in helping us create an incredible, high-fidelity user experience, either by joining our team, partnering on development, or by being added to our early customer interest list, please email us at texai-info@willowgarage.com.

  

• Identification of Frame Type using Xuggle

  1er décembre 2012, par Samveen

  I'm trying to extract just the I-Frames from a video using the Xuggle API. I took the first example from the Xuggle source from here and removing the display code, added the following code snippet to identify the frame type of the current frame :

  //    Decode loop {
  
            if (picture.isComplete()) {
  
                com.xuggle.xuggler.IVideoPicture.PictType type = picture.getPictureType()
  
                if(type == com.xuggle.xuggler.IVideoPicture.PictType.I_TYPE)
  
                    System.out.println("(I-Frame)\n");
  
                else if(type == com.xuggle.xuggler.IVideoPicture.PictType.B_TYPE)
  
                    System.out.println("(B-Frame)\n");
  
                else if(type == com.xuggle.xuggler.IVideoPicture.PictType.P_TYPE)
  
                    System.out.println("(P-Frame)\n");
  
                else if(type == com.xuggle.xuggler.IVideoPicture.PictType.S_TYPE)
  
                    System.out.println("(S-Frame)\n");
  
                else if(type ==com.xuggle.xuggler.IVideoPicture.PictType.DEFAULT_TYPE)
  
                    System.out.println("(Default)\n");
  
                else
  
                    System.out.println("(Other)\n");
  
            }
  
  //    }

  Using this code, I never get an I-Frame in my test video, which by definition of being it being a video is impossible (every video's first frame MUST be an I-Frame) and every frame is identified as

  When I use mplayer to extract the I-Frames from the same video using :

  mplayer video20.mp4 -benchmark -nosound -noaspect -noframedrop -ao null \
  
          -vo png:z=6 -vf framestep=I

  I correctly get a set of I-Frames.

  The number of frames displayed by my code is identical to that extracted by mplayer without the framestep filter

  mplayer video20.mp4 -benchmark -nosound -noaspect -noframedrop -ao null \
  
          -vo png:z=6

  The input video in question is an H264 encoded video.

  My question is that what can I do to correctly get the I-Frames from the video using xuggle

  I picked up the method from Java - Keyframe extraction from a video

• matlab 'system'command in linux

  30 octobre 2014, par Liu Jingyu

  I can run my program on terminal. but if I type the same command in matlab like system('myprogram'), the program would cause a runtime error. The program is to use ffmpeg to play a video, and I know ffmpeg (if not well installed) can cause the problem. But now ffmpeg is well installed and configured. Also, PATH in matlab and linux are the same. So I think in no sense this would happen, but why ?