Recherche avancée

Sur d’autres sites (14568)

• Evolution #3822 : ventiler les CSS concernant les formulaires de spip.css -> form.css

  14 août 2017, par tetue tetue

  Euh, pas certain. La feuille spip.css a vocation a centraliser les styles spécifiques associés au code généré par SPIP. Bref, des styles dont il est difficile de se passer, si on veut que les documents insérés par SPIP restent correctement alignés, que les messages des formulaires SPIP soient correctement stylés, etc.

  Tandis que dans form.css chacun·e met ce qu’il veut pour les formulaires, qui Bootstrap, qui KNACSS, qui juste un reset des forms (comme actuellement proposé par SPIP)…

  Les styles spip.css viennent en surcharge et c’est important qu’ils passent après d’une part, et qu’ils soient isolés pour pouvoir les conserver (ou les supprimer) facilement, sans risquer de les écraser par erreur.

• Picturebox from AForge FFMPEG empty - C#/WinForms

  1er août 2017, par Jake Delson

  I’ve done a ton of research and looked at a lot of questions here but can’t seem to find anything to help me. I should preface I’m very new to C#, Windows Forms, and SO ! I’m a 1st year CompSci student coming from C++ experimenting with my own projects for the summer. I’m trying to display a series of bitmaps from a .avi using the AForge.Video.FFMPEG video file reader.

  It seems to be finding the file, getting its’ data (console prints dimensions, framerate, and codec) and creating the picturebox, but the picturebox comes up blank/empty. I get the bitmap from the frames of a .avi :

  From AForge example code here

  Then I’m trying to display it with a picture box :

  From MS example code here as well

  And here’s my code. Essentially a combination of the two :

      public class Simple : Form
  
  {
  
      Bitmap videoFrame;
  
  
  
      public Simple()
  
      {
  
          try
  
          {
  
              // create instance of video reader
  
              VideoFileReader reader = new VideoFileReader();
  
              // open video file
  
              reader.Open(@"C:\Users\User\Desktop\ScanTest3.AVI");
  
              // check some of its attributes
  
              Console.WriteLine("width:  " + reader.Width);
  
              Console.WriteLine("height: " + reader.Height);
  
              Console.WriteLine("fps:    " + reader.FrameRate);
  
              Console.WriteLine("codec:  " + reader.CodecName);
  
  
  
              PictureBox pictureBox1 = new PictureBox();
  
  
  
              // read 100 video frames out of it
  
              for (int i = 0; i < 100; i++)
  
              {
  
                  videoFrame = reader.ReadVideoFrame();
  
  
  
                  pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
  
                  pictureBox1.ClientSize = new Size(videoFrame.Width, videoFrame.Height);
  
                  pictureBox1.Image = videoFrame;
  
  
  
                  // dispose the frame when it is no longer required
  
                  videoFrame.Dispose();
  
              }
  
  
  
              reader.Close();
  
          }
  
  
  
          catch
  
          {
  
              Console.WriteLine("Nope");
  
          }
  
  
  
      }
  
  }
  
  
  
  class MApplication
  
  {
  
      public static void Main()
  
      {
  
          Application.Run(new Simple());
  
      }
  
  }

  So that’s it pretty much. Just a blank picture box coming up, when it should have the first frame of the video, even though no exception caught (though I’m pretty confident I’m using the try/catch very poorly), and the console printing the correct data for the file :

  width:  720
  
  height: 480
  
  fps:    29
  
  codec:  dvvideo
  
  [swscaler @ 05E10060] Warning: data is not aligned! This can lead to a speedloss

  Though if anyone could tell me what that warning means, that would be great as well, but I’m mainly just lost as to why there’s no picture printing to the screen.

  Thanks !

• Yes or no, will ffmpeg api do hardware decoding on iOS ?

  15 janvier 2019, par Fattie

  There seems to be conflicting information on this.

  https://trac.ffmpeg.org/wiki/HWAccelIntro

  notice the first diagram, it firmly marks iOS as “Y” on VideoToolbox

  

  however in the comments down the bottom it says

  VideoToolbox. ​VideoToolbox, only supported on macOS. H.264 decoding is available in FFmpeg/libavcodec.

  And in the confusing second diagram it says "Standalone" is not done for VideoToolbox.

  We have found that using ffmpeg compiled in to iOS .... it seems to not use hardware decoding, which is really a pain.

  1. With avcodec_get_hw_config() we get AV_PIX_FMT_VIDEOTOOLBOX, AV_HWDEVICE_TYPE_VIDEOTOOLBOX which is seemingly correct.

  2. But usage and framerates clearly shows everything is being done in CPU. The code is in ff_hevc_hls_residual_coding all the time. (That’s fffmpeg’s software decoder.)

  3. This very diff very long git.videolan.org URL here seems to suggest again it should all be working.

  4. Have tried every iPhone etc. of course