[pitivi] project: Avoid to work with read only caps

[Thibault Saunier <tsaunier src gnome org>]

commit bfe415419265ea025071cc0b13248cc99976c248
Author: Thibault Saunier <thibault saunier collabora com>
Date:   Thu Oct 17 17:42:29 2013 -0300

    project: Avoid to work with read only caps
    
    https://bugzilla.gnome.org/show_bug.cgi?id=709473

 pitivi/project.py |   46 ++++++++++++++++++++++++++++------------------
 pitivi/render.py  |    3 +--
 2 files changed, 29 insertions(+), 20 deletions(-)
---
diff --git a/pitivi/project.py b/pitivi/project.py
index 6dbb3e7..a07c59c 100644
--- a/pitivi/project.py
+++ b/pitivi/project.py
@@ -650,26 +650,42 @@ class Project(Loggable, GES.Project):
     # Encoding related properties
     def set_rendering(self, rendering):
         if rendering and self._has_rendering_values != rendering:
-            copy = Gst.Caps.from_string(self.video_profile.get_restriction().to_string())
-            self.video_profile.set_restriction(copy)
             self.videowidth = self.videowidth * self.render_scale / 100
             self.videoheight = self.videoheight * self.render_scale / 100
         elif self._has_rendering_values != rendering:
-            copy = Gst.Caps.from_string(self.video_profile.get_restriction().to_string())
-            self.video_profile.set_restriction(copy)
             self.videowidth = self.videowidth / self.render_scale * 100
             self.videoheight = self.videoheight / self.render_scale * 100
+        else:
+            restriction = self.video_profile.get_restriction().copy_nth(0)
+            self.video_profile.set_restriction(restriction)
+
+            restriction = self.audio_profile.get_restriction().copy_nth(0)
+            self.audio_profile.set_restriction(restriction)
         self._has_rendering_values = rendering
 
+    def set_video_restriction_value(self, name, value):
+        if self.video_profile.get_restriction()[0][name] != value and value:
+            restriction = self.video_profile.get_restriction().copy_nth(0)
+            restriction[0][name] = value
+            self.video_profile.set_restriction(restriction)
+            return True
+        return False
+
+    def set_audio_restriction_value(self, name, value):
+        if self.audio_profile.get_restriction()[0][name] != value and value:
+            restriction = self.audio_profile.get_restriction().copy_nth(0)
+            restriction[0][name] = value
+            self.audio_profile.set_restriction(restriction)
+            return True
+        return False
+
     @property
     def videowidth(self):
         return self.video_profile.get_restriction()[0]["width"]
 
     @videowidth.setter
     def videowidth(self, value):
-        value = int(value)
-        if self.video_profile.get_restriction()[0]["width"] != value and value:
-            self.video_profile.get_restriction()[0]["width"] = value
+        if self.set_video_restriction_value("width", int(value)):
             self._emitChange("rendering-settings-changed", "width", value)
 
     @property
@@ -679,8 +695,7 @@ class Project(Loggable, GES.Project):
     @videoheight.setter
     def videoheight(self, value):
         value = int(value)
-        if self.video_profile.get_restriction()[0]["height"] != value and value:
-            self.video_profile.get_restriction()[0]["height"] = value
+        if self.set_video_restriction_value("height", int(value)):
             self._emitChange("rendering-settings-changed", "height", value)
 
     @property
@@ -689,8 +704,7 @@ class Project(Loggable, GES.Project):
 
     @videorate.setter
     def videorate(self, value):
-        if self.video_profile.get_restriction()[0]["framerate"] != value and value:
-            self.video_profile.get_restriction()[0]["framerate"] = value
+        if self.set_video_restriction_value("framerate", value):
             self._emitChange("rendering-settings-changed", "videorate", value)
 
     @property
@@ -699,8 +713,7 @@ class Project(Loggable, GES.Project):
 
     @videopar.setter
     def videopar(self, value):
-        if self.video_profile.get_restriction()[0]["pixel-aspect-ratio"] != value and value:
-            self.video_profile.get_restriction()[0]["pixel-aspect-ratio"] = value
+        self.set_video_restriction_value("pixel-aspect-ratio", value)
 
     @property
     def audiochannels(self):
@@ -708,8 +721,7 @@ class Project(Loggable, GES.Project):
 
     @audiochannels.setter
     def audiochannels(self, value):
-        if self.audio_profile.get_restriction()[0]["channels"] != value and value:
-            self.audio_profile.get_restriction()[0]["channels"] = value
+        if self.set_audio_restriction_value("channels", value):
             self._emitChange("rendering-settings-changed", "channels", value)
 
     @property
@@ -721,9 +733,7 @@ class Project(Loggable, GES.Project):
 
     @audiorate.setter
     def audiorate(self, value):
-        if self.audio_profile.get_restriction()[0]["rate"] != value and \
-                value is not None:
-            self.audio_profile.get_restriction()[0]["rate"] = int(value)
+        if self.set_audio_restriction_value("rate", value):
             self._emitChange("rendering-settings-changed", "rate", value)
 
     @property
diff --git a/pitivi/render.py b/pitivi/render.py
index e9bfabe..6f88f61 100644
--- a/pitivi/render.py
+++ b/pitivi/render.py
@@ -899,8 +899,7 @@ class RenderDialog(Loggable):
             factory = Gst.ElementFactory.find(self.project.vencoder)
             for struct in factory.get_static_pad_templates():
                 if struct.direction == Gst.PadDirection.SINK:
-                    caps = struct.get_caps()
-                    caps = caps.copy()
+                    caps = Gst.Caps.from_string(struct.get_caps().to_string())
                     fixed = caps.fixate()
                     fmt = fixed.get_structure(0).get_value("format")
                     self.project.video_profile.get_restriction()[0]["format"] = fmt