[pitivi] base: mixer: Allow pass-through 'format' if alpha=1.0

[Edward Hervey <edwardrv src gnome org>]

commit a009586e5740ae84ffeee240c9be2599149f8d6b
Author: Robert Swain <robert swain collabora co uk>
Date:   Fri Jul 30 11:40:51 2010 +0200

    base: mixer: Allow pass-through 'format' if alpha=1.0
    
    In base we need to set the prefer-passthrough property of the alpha element. In
    mixer we need to remove the format cap from the capsfilter to avoid unnecessary
    colour space conversion.

 pitivi/elements/mixer.py |    2 +-
 pitivi/factories/base.py |    1 +
 2 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/pitivi/elements/mixer.py b/pitivi/elements/mixer.py
index 7d0d976..78aac17 100644
--- a/pitivi/elements/mixer.py
+++ b/pitivi/elements/mixer.py
@@ -156,7 +156,7 @@ class SmartVideomixerBin(gst.Bin):
 
         csp = gst.element_factory_make("ffmpegcolorspace", "csp-%d" % self.pad_count)
         capsfilter = gst.element_factory_make("capsfilter", "capsfilter-%d" % self.pad_count)
-        capsfilter.props.caps = gst.Caps("video/x-raw-yuv,format=(fourcc)AYUV")
+        capsfilter.props.caps = gst.Caps("video/x-raw-yuv")
 
         self.add(csp, capsfilter)
 
diff --git a/pitivi/factories/base.py b/pitivi/factories/base.py
index a6b003b..059d9c5 100644
--- a/pitivi/factories/base.py
+++ b/pitivi/factories/base.py
@@ -416,6 +416,7 @@ class SourceFactory(ObjectFactory):
                 b.csp = gst.element_factory_make("identity")
 
             b.alpha = gst.element_factory_make("alpha", "internal-alpha")
+            b.alpha.props.prefer_passthrough = True
             b.scale = gst.element_factory_make("videoscale")
             b.scale.props.add_borders = True
             b.capsfilter = gst.element_factory_make("capsfilter")