[pitivi] factories/base.py: refactor SourceFactory._makeStreamBin for more flexibility

[Edward Hervey <edwardrv src gnome org>]

commit 3a6cde5a099445e018e70a178eded099ef513193
Author: Brandon Lewis <brandon_lewis alum berkeley edu>
Date:   Fri Jan 15 15:03:50 2010 -0800

    factories/base.py: refactor SourceFactory._makeStreamBin for more flexibility
    
    Allow subclassses to pass a bin when the chain up to which we will link to
    both source and sink pads. This allows us to do both upstream and downstream
    processing at each level of abstraction.

 pitivi/factories/base.py |   21 ++++++++++++++++++---
 1 files changed, 18 insertions(+), 3 deletions(-)
---
diff --git a/pitivi/factories/base.py b/pitivi/factories/base.py
index d322a72..e2c0328 100644
--- a/pitivi/factories/base.py
+++ b/pitivi/factories/base.py
@@ -341,13 +341,16 @@ class SourceFactory(ObjectFactory):
             bin.remove_pad(bin.ghostpad)
             del bin.ghostpad
 
-    def _makeStreamBin(self, output_stream):
+    def _makeStreamBin(self, output_stream, child_bin=None):
         self.debug("output_stream:%r", output_stream)
         b = gst.Bin()
         b.decodebin = self.singleDecodeBinClass(uri=self.uri, caps=output_stream.caps,
                                            stream=output_stream)
         b.decodebin.connect("pad-added", self._singlePadAddedCb, b)
         b.decodebin.connect("pad-removed", self._singlePadRemovedCb, b)
+        if child_bin:
+            b.child = child_bin
+            b.add(child_bin)
 
         if isinstance(output_stream, AudioStream):
             self.debug("Adding volume element")
@@ -356,7 +359,12 @@ class SourceFactory(ObjectFactory):
             b.ares = gst.element_factory_make("audioresample", "internal-audioresample")
             b.volume = gst.element_factory_make("volume", "internal-volume")
             b.add(b.volume, b.ares, b.aconv)
-            gst.element_link_many(b.aconv, b.ares, b.volume)
+            if child_bin:
+                gst.element_link_many(b.aconv, b.ares, b.child, b.volume)
+                b.child.sync_state_with_parent()
+            else:
+                gst.element_link_many(b.aconv, b.ares, b.volume)
+                
             b.aconv.sync_state_with_parent()
             b.ares.sync_state_with_parent()
             b.volume.sync_state_with_parent()
@@ -369,7 +377,12 @@ class SourceFactory(ObjectFactory):
             b.csp = gst.element_factory_make("ffmpegcolorspace", "internal-colorspace")
             b.alpha = gst.element_factory_make("alpha", "internal-alpha")
             b.add(b.queue, b.csp, b.alpha)
-            gst.element_link_many(b.queue, b.csp, b.alpha)
+            gst.element_link_many(b.queue, b.csp)
+            if child_bin:
+                gst.element_link_many(b.csp, b.child, b.alpha)
+                b.child.sync_state_with_parent()
+            else:
+                gst.element_link_many(b.csp, b.alpha)
             b.queue.sync_state_with_parent()
             b.csp.sync_state_with_parent()
             b.alpha.sync_state_with_parent()
@@ -379,6 +392,8 @@ class SourceFactory(ObjectFactory):
 
     def _singlePadAddedCb(self, dbin, pad, topbin):
         self.debug("dbin:%r, pad:%r, topbin:%r", dbin, pad, topbin)
+        if hasattr(topbin, "child"):
+            topbin.child.sync_state_with_parent()
         if hasattr(topbin, "volume"):
             # make sure audio elements reach our same state. This is needed
             # since those elements are still unlinked downstream at this point,