Recherche avancée

Sur d’autres sites (9887)

• Trouble understanding XHR streams and express

  17 janvier 2017, par Jon

  I’m having some trouble understanding how I can trigger an XHR response from an express server res.write.

  I’m creating a request on the client with the following code :

   var xhr = new XMLHttpRequest();
  
  
  
   xhr.open(opts.method || 'get', url);
  
  
  
   for (var k in opts.headers||{}) {
  
     xhr.setRequestHeader(k, opts.headers[k]);
  
   }
  
  
  
   xhr.onload = e => res(e.target.responseText);
  
   xhr.onerror = rej;
  
  
  
   if (xhr.upload && progressCb) {
  
     xhr.upload.onprogress = progressCb;
  
   }
  
  
  
   xhr.send(opts.body);

  On the node server, I’m doing multiple res.write() in response to this request.

  For example, I’m creating a video using ffmpeg() and throughout the creation process, I’ll res.write() a JSON.stringified status update.

  The client will receive the last .write(), but the xhr.upload.onprogress callback is not triggered, so I don’t think I understand how to use it correctly. I’m guessing that the xhr.upload.onprogress is meant solely for callbacks related to uploading data to the server, not for triggering a response to multiple writes

  Is there a way for an XHR request to fire a callback every time it receives a res.write() from express ? If not, what’s a better way of achieving this goal ?

• AForge.Video.FFMPEG XamlParseException

  10 février 2017, par tobloef

  I’m trying to set up a simple C# application where I want to record multiple USB webcams and save their feeds to some files. I’m using AForge.NET since this seems to be the most popular option for this sort of application. I can record video fine using the AForge.Video.VFW AVIWriter but due to a number of reasons I need to use the AForge.Video.FFMPEG VideoFileWriter. Whenever I try to use this class however, I get a System.Windows.Markup.XamlParseException with no additional information or inner exceptions apart from a little additional information which is quite useless.

  

  I have a simple code example to trigger the exception :

  using AForge.Video.FFMPEG;
  
  
  
  namespace CameraPrototype {
  
      public partial class MainWindow {
  
          public MainWindow() {
  
              InitializeComponent();
  
  
  
              VideoFileWriter videoFileWriter = new VideoFileWriter();
  
          }
  
      }
  
  }

  I’ve also googled a bit around and tried some suggestion mentioned elsewhere :

  • Checking all the boxes in Exceptions Settings, enabling breaks on all types of exceptions. I had hoped this would give me some more info when the exception was thrown, unfortunately it doesn’t change anything.
  • Copying the FFMPEG DLLs (swscale-2.dll, postproc-52.dll, etc) into the same folder as the application’s built executable (../bin/Debug/). I ’m pretty sure the exception has something to do with ffmpeg, but this particular solution isn’t working. Perhaps I’m doing something wrong here or I’m missing something for ffmpeg to work ?

  If anyone have any idea what I might be doing wrong or how I can get more information about the exception, I would really appreciate any help. Let me know if I need to post any other information. Thanks !

  Edit :
  Though it doesn’t really answer the question, I’m also open to suggestions for alternatives to AForge.NET, as long as it lets me record and save video from multiple USB webcams.

• Merge commit ’aa37d2bf4505afc106e2a23c44afc722bb204a8e’

  19 mars 2017, par Clément Bœsch

  Merge commit ’aa37d2bf4505afc106e2a23c44afc722bb204a8e’
  * commit ’aa37d2bf4505afc106e2a23c44afc722bb204a8e’ :
  
    swscale : Kill non-compiling disabled cruft
  The isGray() chunk is not merged as an alternative patch actually fixing
  
  the dead code is currently under review on the mailing-list.
  The SWS_X chunk is merged, with an additional cosmetic.
  Merged-by : Clément Bœsch <u@pkh.me>
  

  • [DH] libswscale/utils.c