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• 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.

• Web-based video editor

  13 avril 2021, par Danny

  We have a web-based editor currently that allows users to build animated web apps. The apps are made up of shapes, text, images, and videos. Except for videos, all other elements can also be animated around the screen. The result of building a animated app is basically a big blob of JSON.

  



  The playback code for the web app is web-based as well. It takes the JSON blob and constructs the HTML, which ends up playing back in some sort of browser environment. The problem is that most of the time this playback occurs on lower-end hardware like televisions and set-top boxes.

  



  These performance issues go away if there is some way to be able to convert a digital sign to video. Then the STB/smart TV simply plays a video, which is much more performant than playing back animations in a web view.

  



  Given a blob of JSON describing each layer and how to draw each type of object, its animation points, etc, how could I somehow take that and convert it to video on the server ?

  



  My first attempt at this was using PhantomJS to load the playback page in a headless browser, take a series of screenshots, and then use ffmpeg to merge those screenshots into a video. That worked great so long as there is no video. But it does not work with video since there is no HTML5 video tag support in PhantomJS, and even if there was, I would lose any audio.

  



  The other way I was thinking of doing it would be to again load the playback page in PhantomJS, but turn off the video layers and leave them transparent, then take screenshots as a series of PNGs with transparency. I would then combine these with the video layers.

  



  None of this feels very elegant though. I know there are web-based video editors out there that basically do what I'm trying to accomplish, so how do they do it ?

  


• Web-based video editor

  10 octobre 2014, par Danny

  We have a web-based editor currently that allows users to build animated web apps. The apps are made up of shapes, text, images, and videos. Except for videos, all other elements can also be animated around the screen. The result of building a animated app is basically a big blob of JSON.

  The playback code for the web app is web-based as well. It takes the JSON blob and constructs the HTML, which ends up playing back in some sort of browser environment. The problem is that most of the time this playback occurs on lower-end hardware like televisions and set-top boxes.

  These performance issues go away if there is some way to be able to convert a digital sign to video. Then the STB/smart TV simply plays a video, which is much more performant than playing back animations in a web view.

  Given a blob of JSON describing each layer and how to draw each type of object, its animation points, etc, how could I somehow take that and convert it to video on the server ?

  My first attempt at this was using PhantomJS to load the playback page in a headless browser, take a series of screenshots, and then use ffmpeg to merge those screenshots into a video. That worked great so long as there is no video. But it does not work with video since there is no HTML5 video tag support in PhantomJS, and even if there was, I would lose any audio.

  The other way I was thinking of doing it would be to again load the playback page in PhantomJS, but turn off the video layers and leave them transparent, then take screenshots as a series of PNGs with transparency. I would then combine these with the video layers.

  None of this feels very elegant though. I know there are web-based video editors out there that basically do what I’m trying to accomplish, so how do they do it ?