[PATCH] == Sequencer ==

This patch adds adjustment layer tracks to the sequencer and does some cleaning
up of the code.

What's an adjustment layer?

Think of it as an effect track, which takes no explicit input, but alters
the output of everything down the layer stack.

So: you can add several stages of color correction with it.

And: you can even use it with metastrips to group several adjustments together.

release/scripts/startup/bl_ui/space_sequencer.py

@@ -213,6 +213,7 @@ class SEQUENCER_MT_add_effect(bpy.types.Menu):
         layout.operator("sequencer.effect_strip_add", text="Color").type = 'COLOR'
         layout.operator("sequencer.effect_strip_add", text="Speed Control").type = 'SPEED'
         layout.operator("sequencer.effect_strip_add", text="Multicam Selector").type = 'MULTICAM'
+        layout.operator("sequencer.effect_strip_add", text="Adjustment Layer").type = 'ADJUSTMENT'
 
 
 class SEQUENCER_MT_strip(bpy.types.Menu):
@@ -391,7 +392,7 @@ class SEQUENCER_PT_effect(SequencerButtonsPanel, bpy.types.Panel):
                               'CROSS', 'GAMMA_CROSS', 'MULTIPLY', 'OVER_DROP',
                               'PLUGIN',
                               'WIPE', 'GLOW', 'TRANSFORM', 'COLOR', 'SPEED',
-                              'MULTICAM'}
+                              'MULTICAM', 'ADJUSTMENT'}
 
     def draw(self, context):
         layout = self.layout
@@ -530,7 +531,7 @@ class SEQUENCER_PT_input(SequencerButtonsPanel, bpy.types.Panel):
                               'CROSS', 'GAMMA_CROSS', 'MULTIPLY', 'OVER_DROP',
                               'PLUGIN',
                               'WIPE', 'GLOW', 'TRANSFORM', 'COLOR',
-                              'MULTICAM', 'SPEED'}
+                              'MULTICAM', 'SPEED', 'ADJUSTMENT'}
 
     def draw(self, context):
         layout = self.layout
@@ -680,7 +681,7 @@ class SEQUENCER_PT_filter(SequencerButtonsPanel, bpy.types.Panel):
                               'CROSS', 'GAMMA_CROSS', 'MULTIPLY', 'OVER_DROP',
                               'PLUGIN',
                               'WIPE', 'GLOW', 'TRANSFORM', 'COLOR',
-                              'MULTICAM', 'SPEED'}
+                              'MULTICAM', 'SPEED', 'ADJUSTMENT'}
 
     def draw(self, context):
         layout = self.layout