Sur d’autres sites (13128)

• Anomalie #3575 : Regression GD2

  28 octobre 2015, par b b

  Salut Dani, il nous faudrait plus d’infos, la personne qui rencontre le bug a-t-elle bien le plugin-dist filtres_images activé ? Le fichier plugins-dist/filtres_images/filtres/images_transforme.php est-il bien présent ?

• Summary Video Accessibility Talk

  1er janvier 2014, par silvia

  I’ve just got off a call to the UK Digital TV Group, for which I gave a talk on HTML5 video accessibility (slides best viewed in Google Chrome).

  The slide provide a high-level summary of the accessibility features that we’ve developed in the W3C for HTML5, including :

  • Subtitles & Captions with WebVTT and the track element
  • Video Descriptions with WebVTT, the track element and speech synthesis
  • Chapters with WebVTT for semantic navigation
  • Audio Descriptions through synchronising an audio track with a video
  • Sign Language video synchronized with a main video

  I received some excellent questions.

  The obvious one was about why WebVTT and not TTML. While for anyone who has tried to implement TTML support, the advantages of WebVTT should be clear, for some the decision of the browsers to go with WebVTT still seems to be bothersome. The advantages of CSS over XSL-FO in a browser-context are obvious, but not as much outside browsers. So, the simplicity of WebVTT and the clear integration with HTML have to speak for themselves. Conversion between TTML and WebVTT was a feature that was being asked for.

  I received a question about how to support ducking (reduce the volume of the main audio track) when using video descriptions. My reply was to either use video descriptions with WebVTT and do ducking during the times that a cue is active, or when using audio descriptions (i.e. actual audio tracks) to add an additional WebVTT file of kind=metadata to mark the intervals in which to do ducking. In both cases some JavaScript will be necessary.

  I received another question about how to do clean audio, which I had almost forgotten was a requirement from our earlier media accessibility document. “Clean audio” consists of isolating the audio channel containing the spoken dialog and important non-speech information that can then be amplified or otherwise modified, while other channels containing music or ambient sounds are attenuated. I suggested using the mediagroup attribute to provide a main video element (without an audio track) and then the other channels as parallel audio tracks that can be turned on and off and attenuated individually. There is some JavaScript coding involved on top of the APIs that we have defined in HTML, but it can be implemented in browsers that support the mediagroup attribute.

  Another question was about the possibilities to extend the list of @kind attribute values. I explained that right now we have a proposal for a new text track kind=”forced” so as to provide forced subtitles for sections of video with foreign language. These would be on when no other subtitle or caption tracks are activated. I also explained that if there is a need for application-specific text tracks, the kind=”metadata” would be the correct choice.

  I received some further questions, in particular about how to apply styling to captions (e.g. color changes to text) and about how closely the browser are able to keep synchronization across multiple media elements. The earlier was easily answered with the ::cue pseudo-element, but the latter is a quality of implementation feature, so I had to defer to individual browsers.

  Overall it was a good exercise to summarize the current state of HTML5 video accessibility and I was excited to show off support in Chrome for all the features that we designed into the standard.

• How to Terminate a Process Normally Created using ProcessBuilder

  30 janvier 2015, par Bilal Ahmed Yaseen

  I am creating Processes using ProcessBuilder in my Java Application. The created process executes some FFMPEG commands which actually copy the RTSP streams in specified destination media file.

  ProcessBuilder builder = new ProcessBuilder("ffmpeg", "-i", RTSP_URL, "-f", fileFormat, destFilePath);
  
  Process processToExecute = builder.start();

  I want to close the process before it completes its execution. So, If I run this FFMPEG command directly in windows CMD and then press ’CTRL+C’ after 5 seconds then process get terminates with status ’2’. And I can play the media file created so far.

  So, If I do the same operation in my Java Application using :

   process.destroy(); //I call this method after 5 sec

  I get the status code ’1’ which means abnormal termination. I get the status by the following way :

   processToExecute.destroy();
  
   processToExecute.exitValue(); //This return me status '1'

  And I can’t play the media file and I think this is due to the abnormal termination of the process.

  So how I can terminate the process created using ProcessBuilder in the same way we do in CMD with (CTRL+C) so that I may play the created media file ?

  I want to terminate process (created using ProcessBuilder) in Java Application with status code of ’2’ that I get when I terminate process using CMD.

  EDIT#01 : --- Sharing Findings

  So, when I try to delete that file once app terminates, I get the following error :

  The Action Can't be Performed Because File is Opened in FFMPEG.exe

  Which means that process is not terminating the command it is executing. That command still has occupied this file that’s why I am not getting able to play it. Process gets terminate when I call :

   processToExecute.destroy();

  But, the task it is performing (that is execution of a command) is still active. Strange !!!!

  EDIT#02 : Sharing Ultimate Reason

  Actually If I directly press ’CTRL+C’ or ’q’ in cmd when process is running then it terminates the process successfully and this process is no more visible in the currently executing processes lists.

  And Programatically when I call method :

  cmd> processToExecute.destroy();

  It terminates the process but when I see the list of currently executing processes I can still see them over there.

  And same scenario exists If I try to terminate this process using ’taskkill’ or ’kill’ command in another CMD by specifying their’s name or pid that still process terminates abnormally.

  P.S. I use the following command to see the running processes :

  tasklist

  So from this it proves that destroy() method from Application and ’taskkill or kill’ command from another CMD is not terminating the process normally that pressing ’CTRL+C’ and ’q’ does.