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• Trouble getting HTML5 vidio to play, in Firefox 33

  16 janvier 2015, par Randy

  I’m preparing to update some old pages to HTML5, and was surprised to see that it worked in Chrome, but not the latest Firefox (v.33.1... also tried v.32). What is odd is this... In Firefox it actually WILL play IF you "coax it". If you move the video position slider to someplace beyond the start (about 5 seconds in) and THEN click play, all is well. Further inspection showed that when I click play, the file pointer was jumping to the end of the file leaving my "poster" photo intact, leading the viewer to think there is nothing else they can do. If, however, you manually move the pointer back to anyplace beyond the first couple of seconds of the file (really !), and THEN click the PLAY button, FF will play the rest of the video fine.

  Sometimes i think that to the more technically minded among us, the universe doles out the weirder problems, while God laughs.

  I’d suspect video file corruption, but all my conversions were made with the very reliable ffmpeg utility, and tested with VLC. Again, it works fine from Chrome, which supposedly uses the same video format. Here’s a link...

  FF will play the older type ogv files, so if this is one of those things where FF, now at version 33 is at fault, I’ll have to detect the browser and write the order myself with a document.write(). But it would be nice to know if there is a more straigh forward solution.

  Note that I have tried adding the mime types to my HTACESS file. But the fact that the behavior is the same when point my browsers directly the file on my local machine, makles me doubt that is the problem.

  http://pixyland.org/peterpan/OurWedding2a.html

  And here is the page code

    
  
  
  
  
  
  
  
      
  
  
  
      
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  <table align="center" border="1"><tr><td align="center">
  
  <div align="center">
  
  
  
  <video width="640" height="480" controls="controls" poster="Imagezz/Wedding/arIMG_2280.JPG">
  
   <source src="../vids/Arrival.mp4" type="video/mp4">  
  
   <source src="../vids/Arrival.webm" type="video/webm"> 
  
   <source src="../vids/Arrival.ogv" type="video/ogg"> 
  
  
  
  
  
   
  
   <p>If you are unable to view the video, here are some links to download <br />
  
    in a a few well supported video formats. You may be able to just download <br />
  
    and play one of these files without the browser.<br /><br />
  
    <strong>Download Video:</strong>nbsp;
  
      nbsp;<a href="http://stackoverflow.com/feeds/vids/Arrival.mp4">"MP4"</a>
  
      nbsp;<a href="http://stackoverflow.com/feeds/vids/Arrival.webm">"WEBM"</a>
  
      nbsp;<a href="http://stackoverflow.com/feeds/vids/Arrival.ogv">"Ogg"</a>
  
   </p>
  
  
  
   </source></source></source></video>
  
   </div>
  
   </td></tr></table>

• Trouble getting video stream from Bebop 2 (python, open cv and ffmpeg)

  20 décembre 2018, par Seb A

  I’m currently working with the Bebop 2 drone from parrot and I would like to get the video stream from the bebop and to use the frame I get. To control the bebop I’m using this library : https://github.com/amymcgovern/pyparrot.

  First I’ve tried to use opencv by opening the sdp file used by the bebop to stream the video with this code :

  capture = cv2.VideoCapture('./bebop.sdp')
  
  
  
      while True :
  
          rt,img = capture.read()
  
          cv2.imshow("cam",img)
  
          cv2.waitKey(10)

  here is the content of the sdp file :

  c=IN IP4 192.168.42.1
  
  m=video 55004 RTP/AVP 96
  
  a=rtpmap:96 H264/90000

  but I got this error

  [rtp @ 0000020b890b3300] Protocol 'rtp' not on whitelist 'file,crypto'!
  
  warning: Error opening file (/build/opencv/modules/videoio/src/cap_ffmpeg_impl.hpp:808)
  
  warning: ./bebop.sdp (/build/opencv/modules/videoio/src/cap_ffmpeg_impl.hpp:809)
  
  False
  
  OpenCV Error: Assertion failed (size.width>0 && size.height>0) in cv::imshow, file C:\projects\opencv-python\opencv\modules\highgui\src\window.cpp, line 331
  
  Traceback (most recent call last):
  
   File "pilotage.py", line 109, in <module>
  
     _main_(args)
  
   File "pilotage.py", line 56, in main
  
     cv2.imshow('drone view',im)
  
  cv2.error: C:\projects\opencv-python\opencv\modules\highgui\src\window.cpp:331: error: (-215) size.width>0 &amp;&amp; size.height>0 in function cv::imshow
  
  </module>

  I’ve seen that this is due to the ffmpeg command used by opencv that does not include the option -protocol_whitelist
  So I tried to get the image directly with ffmpeg by using this command

  "ffmpeg -protocol_whitelist \"file,rtp,udp\"  -i  ./bebop.sdp -r 30 -b:v 800k image_%03d.png &"

  But the images I got were awful and useless.
  Like this one :
  

  So I tried different options to improve the quality but I can’t get it to work.
  Thanks for your help.

  I’m on windows 10 and using latest python version

• Trouble using ffmpeg in c# how to correctly format string to upscale videos ?

  30 décembre 2020, par user14527374

  So I am writing an app in c# to upscale videos to a certain resolution. It uses ffmpeg to do this. What happens is after selecting the video file, and clicking 1080p it creates the directory folder but does not actually write the upscaled video to it.

  


  I think I must have a string format issue :

  


  private void HD_Click(object sender, EventArgs e)
        {
            if (textBox1.Text == null)
            {
                MessageBox.Show("You've not selected your video file yet. Please do so before continuing, cheers.");

            }
            else
            {
             
                    var originFilePath = textBox1.Text;
                    string name = Path.GetFileName(originFilePath);
                    byte[] bytes = null;
                    using (FileStream fileStream = new FileStream(originFilePath, FileMode.Open, FileAccess.Read))
                    {
                        using (MemoryStream ms = new MemoryStream())
                        {
                            fileStream.CopyTo(ms);
                            bytes = ms.ToArray();
                        }

                        var localStoragePath = Path.Combine(Path.GetTempPath(), name);
                        var directoryPath = Path.GetDirectoryName(localStoragePath);
                        Directory.CreateDirectory(directoryPath);
                        File.WriteAllBytes(localStoragePath, bytes);
                        Console.WriteLine($"File copy successful: {File.Exists(localStoragePath)}");
                        var readBack = File.ReadAllBytes(localStoragePath);
                        Console.WriteLine($"Read file Back: {readBack.Length}, {localStoragePath}");
                    var resizedFolderPath = @"C:\upscaledvideohere";
                        Directory.CreateDirectory(resizedFolderPath);
                        var resizedFiePath = Path.Combine(resizedFolderPath, Path.GetFileName(localStoragePath));

                        var psi = new ProcessStartInfo();
                        psi.FileName = @"C:\ffmpeg-2020-12-27-git-bff6fbead8-full_build\binffmpeg.exe";
                        psi.Arguments = $"-i \"{localStoragePath}\" -vf scale=1080 \"{resizedFiePath}\"";
                        psi.RedirectStandardOutput = false;
                        psi.RedirectStandardError = false;
                        psi.UseShellExecute = true;
                        Console.WriteLine($"Args: {psi.Arguments}");

                        try
                        {
                            using (Process exeProcess = Process.Start(psi))
                            {
                                Console.WriteLine($"process started with processId: {exeProcess.Id}");
                                exeProcess.WaitForExit();
                                Console.WriteLine($"Exit Code: {exeProcess.ExitCode}");
                            }
                        }
                        catch (Exception ex)
                        {
                            Console.WriteLine(ex.StackTrace.ToString());
                            Console.WriteLine(ex.Message.ToString());
                            return;
                        }
                        Console.WriteLine($"process completed");
                        Console.WriteLine($"Temp Out Exists: {File.Exists(resizedFiePath)}");
                    }

                    Console.ReadLine();
                }
            }
        
    


  


  I am wondering where the string format error could be ? Thank you.