gstreamer/gstreamer-sharp/Application.cs

//
// Application.cs: Framework initialization for GStreamer
//
// Authors:
//   Aaron Bockover (abockover@novell.com)
//   Alp Toker (alp@atoker.com)
//
// (C) 2006 Novell, Inc.
// (C) 2002 Alp Toker
//

using System;
using System.Runtime.InteropServices;

namespace Gst {
  public static class Application {
    public static void Init() {
      IntPtr argv = new IntPtr (0);
      int argc = 0;

      gst_init (ref argc, ref argv);
    }

    public static void Init (string progname, ref string [] args) {
      FullInit (progname, ref args, false);
    }

    public static void InitCheck (string progname, ref string [] args) {
      FullInit (progname, ref args, true);
    }

    public static void Deinit() {
      gst_deinit();
    }

    private static void FullInit (string progname, ref string [] args, bool check) {
      string [] progargs = new string[args.Length + 1];

      progargs[0] = progname;
      args.CopyTo (progargs, 1);

      GLib.Argv argv = new GLib.Argv (progargs);
      IntPtr argv_ptr = argv.Handle;
      int argc = progargs.Length;

      if (check) {
        IntPtr error_ptr;
        bool result = gst_init_check (ref argc, ref argv_ptr, out error_ptr);

        if (error_ptr != IntPtr.Zero) {
          string message = GError.GetMessage (error_ptr);

          if (message == String.Empty)
            message = "Reason unknown";

          GError.Free (error_ptr);

          throw new ApplicationException (String.Format ("gst_init_check() failed: {0}", message));
        } else if (!result) {
          throw new ApplicationException ("gst_init_check() failed: Reason unknown");
        }
      } else {
        gst_init (ref argc, ref argv_ptr);
      }

      if (argv_ptr != argv.Handle) {
        string init_call = check ? "gst_init_check()" : "gst_init()";
        throw new ApplicationException (init_call + " returned a new argv handle");
      }

      if (argc <= 1) {
        args = new string[0];
      } else {
        progargs = argv.GetArgs (argc);
        args = new string[argc - 1];
        Array.Copy (progargs, 1, args, 0, argc - 1);
      }
    }

    [DllImport ("gstreamer-0.10.dll") ]
    private static extern void gst_init (ref int argc, ref IntPtr argv);

    [DllImport ("gstreamer-0.10.dll") ]
    private static extern bool gst_init_check (ref int argc, ref IntPtr argv, out IntPtr error);

    [DllImport ("gstreamer-0.10.dll") ]
    private static extern void gst_deinit();
  }
}