[longomatch/livecapture: 9/9] Improve error handling creating new elements like muxers and encoder that might be unavailable

[Andoni Morales Alastruey <amorales src gnome org>]

commit 23de41681329d477f65d63413c32546810f8af52
Author: Andoni Morales Alastruey <ylatuya gmail com>
Date:   Mon Mar 29 01:16:44 2010 +0200

    Improve error handling creating new elements like muxers and encoder that might be unavailable

 CesarPlayer/Capturer/GstCameraCapturer.cs |   48 +++++++++-------
 libcesarplayer/src/gst-camera-capturer.c  |   88 +++++++++++++++++++---------
 libcesarplayer/src/gst-camera-capturer.h  |   21 +++----
 3 files changed, 96 insertions(+), 61 deletions(-)
---
diff --git a/CesarPlayer/Capturer/GstCameraCapturer.cs b/CesarPlayer/Capturer/GstCameraCapturer.cs
index 50f05ce..5fa1880 100644
--- a/CesarPlayer/Capturer/GstCameraCapturer.cs
+++ b/CesarPlayer/Capturer/GstCameraCapturer.cs
@@ -237,25 +237,6 @@ namespace LongoMatch.Video.Capturer {
 		}
 
 		[DllImport("libcesarplayer.dll")]
-		static extern bool gst_camera_capturer_set_video_muxer(IntPtr raw, int type);
-
-		public bool SetVideoMuxer(LongoMatch.Video.Capturer.GccVideoMuxerType type) {
-			bool raw_ret = gst_camera_capturer_set_video_muxer(Handle, (int) type);
-			bool ret = raw_ret;
-			return ret;
-		}
-
-		
-		[DllImport("libcesarplayer.dll")]
-		static extern bool gst_camera_capturer_set_video_encoder(IntPtr raw, int type);
-
-		public bool SetVideoEncoder(LongoMatch.Video.Capturer.GccVideoEncoderType type) {
-			bool raw_ret = gst_camera_capturer_set_video_encoder(Handle, (int) type);
-			bool ret = raw_ret;
-			return ret;
-		}
-
-		[DllImport("libcesarplayer.dll")]
 		static extern void gst_camera_capturer_init_backend(out int argc, IntPtr argv);
 
 		public static int InitBackend(string argv) {
@@ -293,12 +274,37 @@ namespace LongoMatch.Video.Capturer {
 		public void Run() {
 			gst_camera_capturer_run(Handle);
 		}
+		
+		[DllImport("libcesarplayer.dll")]
+		static extern bool gst_camera_capturer_set_video_muxer(IntPtr raw, int type, out IntPtr error);
 
+		public bool SetVideoMuxer(LongoMatch.Video.Capturer.GccVideoMuxerType type) {
+			IntPtr error = IntPtr.Zero;
+			bool raw_ret = gst_camera_capturer_set_video_muxer(Handle, (int) type, out error);
+			if (error != IntPtr.Zero) throw new GLib.GException (error);
+			bool ret = raw_ret;
+			return ret;
+		}
+
+		
 		[DllImport("libcesarplayer.dll")]
-		static extern bool gst_camera_capturer_set_audio_encoder(IntPtr raw, int type);
+		static extern bool gst_camera_capturer_set_video_encoder(IntPtr raw, int type, out IntPtr error);
+
+		public bool SetVideoEncoder(LongoMatch.Video.Capturer.GccVideoEncoderType type) {
+			IntPtr error = IntPtr.Zero;
+			bool raw_ret = gst_camera_capturer_set_video_encoder(Handle, (int) type, out error);
+			if (error != IntPtr.Zero) throw new GLib.GException (error);
+			bool ret = raw_ret;
+			return ret;
+		}
+
+		[DllImport("libcesarplayer.dll")]
+		static extern bool gst_camera_capturer_set_audio_encoder(IntPtr raw, int type, out IntPtr error);
 
 		public bool SetAudioEncoder(LongoMatch.Video.Capturer.GccAudioEncoderType type) {
-			bool raw_ret = gst_camera_capturer_set_audio_encoder(Handle, (int) type);
+			IntPtr error = IntPtr.Zero;			
+			bool raw_ret = gst_camera_capturer_set_audio_encoder(Handle, (int) type, out error);
+			if (error != IntPtr.Zero) throw new GLib.GException (error);
 			bool ret = raw_ret;
 			return ret;
 		}
diff --git a/libcesarplayer/src/gst-camera-capturer.c b/libcesarplayer/src/gst-camera-capturer.c
index b320ba1..fe3fc4c 100644
--- a/libcesarplayer/src/gst-camera-capturer.c
+++ b/libcesarplayer/src/gst-camera-capturer.c
@@ -971,45 +971,58 @@ gst_camera_capturer_stop (GstCameraCapturer * gcc)
 
 gboolean
 gst_camera_capturer_set_video_encoder (GstCameraCapturer * gcc,
-                                       GccVideoEncoderType type)
+                                       GccVideoEncoderType type,
+                                       GError ** err)
 {
+  gchar *name = NULL;
+
   g_return_val_if_fail (GST_IS_CAMERA_CAPTURER (gcc), FALSE);
+
   switch (type)
     {
     case GCC_VIDEO_ENCODER_TYPE_MPEG4:
       gcc->priv->videoenc =
         gst_element_factory_make ("ffenc_mpeg4", "video-encoder");
-      g_object_set (gcc->priv->camerabin, "video-encoder", gcc->priv->videoenc,
-                    NULL);
+      name = "FFmpeg mpeg4 video encoder";
       break;
 
     case GCC_VIDEO_ENCODER_TYPE_XVID:
       gcc->priv->videoenc = gst_element_factory_make ("xvid_enc", "video-encoder");
-      g_object_set (gcc->priv->camerabin, "video-encoder", gcc->priv->videoenc,
-                    NULL);
+      name = "Xvid video encoder";
       break;
 
     case GCC_VIDEO_ENCODER_TYPE_THEORA:
       gcc->priv->videoenc =
         gst_element_factory_make ("theoraenc", "video-encoder");
-      g_object_set (gcc->priv->camerabin, "video-encoder", gcc->priv->videoenc,
-                    NULL);
+      name = "Theora video encoder";
       break;
 
     case GCC_VIDEO_ENCODER_TYPE_H264:
       gcc->priv->videoenc = gst_element_factory_make ("x264enc", "video-encoder");
-      g_object_set (gcc->priv->camerabin, "video-encoder", gcc->priv->videoenc,
-                    NULL);
+      name = "X264 video encoder";
       break;
-
+    }
+    if (!gcc->priv->videoenc){
+      g_set_error (err, 
+                  GCC_ERROR, 
+                  GCC_ERROR_PLUGIN_LOAD,
+                  "Failed to create the %s element. "
+                  "Please check your GStreamer installation.",
+                  name);
+    } else {
+      g_object_set (gcc->priv->camerabin, "audio-encoder", gcc->priv->audioenc,
+                  NULL);
     }
   return TRUE;
 }
 
 gboolean
 gst_camera_capturer_set_audio_encoder (GstCameraCapturer * gcc,
-                                       GccAudioEncoderType type)
+                                       GccAudioEncoderType type,
+                                       GError ** err)
 {
+  gchar *name = NULL;
+
   g_return_val_if_fail (GST_IS_CAMERA_CAPTURER (gcc), FALSE);
 
   switch (type)
@@ -1017,60 +1030,79 @@ gst_camera_capturer_set_audio_encoder (GstCameraCapturer * gcc,
     case GCC_AUDIO_ENCODER_MP3:
       gcc->priv->audioenc =
         gst_element_factory_make ("ffenc_libmp3lame", "audio-encoder");
-      g_object_set (gcc->priv->camerabin, "audio-encoder", gcc->priv->audioenc,
-                    NULL);
+      name = "Mp3 audio encoder";
       break;
 
     case GCC_AUDIO_ENCODER_AAC:
       gcc->priv->audioenc = gst_element_factory_make ("faac", "audio-encoder");
-      g_object_set (gcc->priv->camerabin, "audio-encoder", gcc->priv->audioenc,
-                    NULL);
+      name = "AAC audio encoder";
       break;
 
     case GCC_AUDIO_ENCODER_VORBIS:
       gcc->priv->audioenc =
         gst_element_factory_make ("vorbisenc", "audio-encoder");
-      g_object_set (gcc->priv->camerabin, "audio-encoder", gcc->priv->audioenc,
-                    NULL);
+      name = "Vorbis audio encoder";
       break;
     }
+    
+    if (!gcc->priv->audioenc){
+      g_set_error (err, 
+                  GCC_ERROR, 
+                  GCC_ERROR_PLUGIN_LOAD,
+                  "Failed to create the %s element. "
+                  "Please check your GStreamer installation.",
+                  name);
+    } else {
+      g_object_set (gcc->priv->camerabin, "audio-encoder", gcc->priv->audioenc,
+                  NULL);
+    }
 
   return TRUE;
-
 }
 
 gboolean
 gst_camera_capturer_set_video_muxer (GstCameraCapturer * gcc,
-                                     GccVideoMuxerType type)
+                                     GccVideoMuxerType type,
+                                     GError ** err)
 {
+  gchar *name = NULL;
+
   g_return_val_if_fail (GST_IS_CAMERA_CAPTURER (gcc), FALSE);
 
   switch (type)
     {
     case GCC_VIDEO_MUXER_OGG:
+      name = "OGG muxer";
       gcc->priv->videomux = gst_element_factory_make ("oggmux", "video-muxer");
-      g_object_set (gcc->priv->camerabin, "video-muxer", gcc->priv->videomux,
-                    NULL);
       break;
     case GCC_VIDEO_MUXER_AVI:
+      name = "AVI muxer";
       gcc->priv->videomux = gst_element_factory_make ("avimux", "video-muxer");
-      g_object_set (gcc->priv->camerabin, "video-muxer", gcc->priv->videomux,
-                    NULL);
       break;
     case GCC_VIDEO_MUXER_MP4:
+      name = "MP4 muxer";
       gcc->priv->videomux =
         gst_element_factory_make ("qtmux", "video-muxer");
-      g_object_set (gcc->priv->camerabin, "video-muxer", gcc->priv->videomux,
-                    NULL);
       break;    
     case GCC_VIDEO_MUXER_MATROSKA:
+      name = "Matroska muxer";
       gcc->priv->videomux =
         gst_element_factory_make ("matroskamux", "video-muxer");
-      g_object_set (gcc->priv->camerabin, "video-muxer", gcc->priv->videomux,
-                    NULL);
       break;
     }
-
+    
+    if (!gcc->priv->videomux){
+      g_set_error (err, 
+                  GCC_ERROR, 
+                  GCC_ERROR_PLUGIN_LOAD,
+                  "Failed to create the %s element. "
+                  "Please check your GStreamer installation.",
+                  name);
+    } else {
+      g_object_set (gcc->priv->camerabin, "video-muxer", gcc->priv->videomux,
+                  NULL);
+    }
+  
   return TRUE;
 }
 
diff --git a/libcesarplayer/src/gst-camera-capturer.h b/libcesarplayer/src/gst-camera-capturer.h
index 094ada8..152ac22 100644
--- a/libcesarplayer/src/gst-camera-capturer.h
+++ b/libcesarplayer/src/gst-camera-capturer.h
@@ -127,18 +127,15 @@ EXPORT void gst_camera_capturer_run (GstCameraCapturer * gcc);
 EXPORT void gst_camera_capturer_start (GstCameraCapturer * gcc);
 EXPORT void gst_camera_capturer_toggle_pause (GstCameraCapturer * gcc);
 EXPORT void gst_camera_capturer_stop (GstCameraCapturer * gcc);
-EXPORT gboolean gst_camera_capturer_set_video_encoder (GstCameraCapturer
-                                                      * gcc,
-                                                      GccVideoEncoderType
-                                                      type);
-EXPORT gboolean gst_camera_capturer_set_audio_encoder (GstCameraCapturer
-                                                      * gcc,
-                                                      GccAudioEncoderType
-                                                      type);
-EXPORT gboolean gst_camera_capturer_set_video_muxer (GstCameraCapturer *
-                                                    gcc,
-                                                    GccVideoMuxerType
-                                                    type);
+EXPORT gboolean gst_camera_capturer_set_video_encoder (GstCameraCapturer * gcc,
+                                                      GccVideoEncoderType type,
+                                                      GError ** err);
+EXPORT gboolean gst_camera_capturer_set_audio_encoder (GstCameraCapturer * gcc,
+                                                      GccAudioEncoderType type,
+                                                      GError ** err);
+EXPORT gboolean gst_camera_capturer_set_video_muxer (GstCameraCapturer * gcc,
+                                                    GccVideoMuxerType type,
+                                                    GError ** err);
 EXPORT GValueArray gst_camera_capturer_enum_devices (GstCameraCapturer * gcc);
 
 G_END_DECLS