[rygel] core: Stop pipeline on link error

[Jens Georg <jensgeorg src gnome org>]

commit 4470fb39e9fef721b5ba808d233405cad27a2066
Author: Jens Georg <mail jensge org>
Date:   Tue Oct 25 10:09:03 2011 +0200

    core: Stop pipeline on link error
    
    If decodebin and encodebin fail to link, post an error to the pipeline.
    Otherwise the pipeline is stuck in PAUSED for some corrupt source
    files. This is a work-around for
    https://bugzilla.gnome.org/show_bug.cgi?id=661747

 src/rygel/rygel-transcoder.vala |   24 ++++++++++++++++++++++++
 1 files changed, 24 insertions(+), 0 deletions(-)
---
diff --git a/src/rygel/rygel-transcoder.vala b/src/rygel/rygel-transcoder.vala
index cc4da30..e7a92c9 100644
--- a/src/rygel/rygel-transcoder.vala
+++ b/src/rygel/rygel-transcoder.vala
@@ -39,6 +39,8 @@ internal abstract class Rygel.Transcoder : GLib.Object {
     dynamic Element decoder;
     dynamic Element encoder;
 
+    private bool link_failed;
+
     // Primary UPnP item class that this transcoder is meant for, doesn't
     // necessarily mean it cant be used for other classes.
     public string upnp_class { get; protected set; }
@@ -49,6 +51,7 @@ internal abstract class Rygel.Transcoder : GLib.Object {
         this.mime_type = mime_type;
         this.dlna_profile = dlna_profile;
         this.upnp_class = upnp_class;
+        this.link_failed = true;
     }
 
     /**
@@ -75,6 +78,7 @@ internal abstract class Rygel.Transcoder : GLib.Object {
 
         decoder.pad_added.connect (this.on_decoder_pad_added);
         decoder.autoplug_continue.connect (this.on_autoplug_continue);
+        decoder.no_more_pads.connect (this.on_no_more_pads);
 
         var pad = encoder.get_static_pad ("src");
         var ghost = new GhostPad (null, pad);
@@ -182,8 +186,28 @@ internal abstract class Rygel.Transcoder : GLib.Object {
             warning ("Failed to link pad '%s' to '%s'",
                      new_pad.name,
                      sinkpad.name);
+        } else {
+            this.link_failed = false;
         }
 
         return;
     }
+
+    private void on_no_more_pads (Element decodebin) {
+        // We haven't found any pads we could link
+        if (this.link_failed) {
+            // Signalize that error
+            var bin = this.encoder.get_parent () as Bin;
+            const string description = "Encoder and decoder are not " +
+                                       "compatible";
+            var error = new IOError.FAILED ("Could not link");
+            var message = new Message.error (bin,
+                                             error,
+                                             description);
+
+
+            var bus = bin.get_bus ();
+            bus.post (message);
+        }
+    }
 }