[pitivi] render: Add a static _factory_formats static field.

[Thibault Saunier <tsaunier src gnome org>]

commit 9244b9339ce74e8a2db6cb43a5fb0f5d3ed0bf54
Author: Mathieu Duponchelle <mduponchelle1 gmail com>
Date:   Wed Oct 2 19:05:26 2013 +0200

    render: Add a static _factory_formats static field.
    
    This field is used because of introspection problems in
    fixating the static_pad_templates, for some reason we can't do
    it more than once, so we keep the result stored.

 pitivi/render.py |   29 +++++++++++++++++++----------
 1 files changed, 19 insertions(+), 10 deletions(-)
---
diff --git a/pitivi/render.py b/pitivi/render.py
index 3ac588d..2f7962b 100644
--- a/pitivi/render.py
+++ b/pitivi/render.py
@@ -313,6 +313,8 @@ class RenderDialog(Loggable):
     """
     INHIBIT_REASON = _("Currently rendering")
 
+    _factory_formats = {}
+
     def __init__(self, app, project, pipeline=None):
 
         from pitivi.preset import RenderPresetManager
@@ -886,16 +888,23 @@ class RenderDialog(Loggable):
         self.progress = RenderingProgressDialog(self.app, self)
         self.window.hide()  # Hide the rendering settings dialog while rendering
 
-        # Now find a format to set on the restriction caps.
-        # The reason is we can't send different formats on the encoders.
-        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()
-                fixed = caps.fixate()
-                fmt = fixed.get_structure(0).get_value("format")
-                self.project.video_profile.get_restriction()[0]["format"] = fmt
-                break
+        encoder_string = self.project.vencoder
+        try:
+            fmt = self._factory_formats[encoder_string]
+            self.project.video_profile.get_restriction()[0]["format"] = fmt
+        except KeyError:
+            # Now find a format to set on the restriction caps.
+            # The reason is we can't send different formats on the encoders.
+            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()
+                    fixed = caps.fixate()
+                    fmt = fixed.get_structure(0).get_value("format")
+                    self.project.video_profile.get_restriction()[0]["format"] = fmt
+                    self._factory_formats[encoder_string] = fmt
+                    break
 
         self._pipeline.set_render_settings(self.outfile, self.project.container_profile)
         self.startAction()