make it easier to tweak the appsink settings without doing a rebuild:…

… add XPRA_SOURCE_APPSINK env var for that

git-svn-id: https://xpra.org/svn/Xpra/trunk@9529 3bb7dfac-3a0b-4e04-842a-767bc560f471

src/xpra/sound/src.py

@@ -4,6 +4,7 @@
 # Xpra is released under the terms of the GNU GPL v2, or, at your option, any
 # later version. See the file COPYING for details.
 
+import os
 import sys
 import time
 
@@ -15,6 +16,8 @@
 from xpra.log import Logger
 log = Logger("sound")
 
+APPSINK = os.environ.get("XPRA_SOURCE_APPSINK", "appsink name=sink emit-signals=true max-buffers=10 drop=true sync=false async=false qos=false")
+
 
 class SoundSource(SoundPipeline):
 
@@ -56,16 +59,10 @@ def __init__(self, src_type=None, src_options={}, codecs=CODECS, codec_options={
         pipeline_els.append("volume name=volume volume=%s" % volume)
         pipeline_els += [encoder_str,
                         fmt,
-                        "appsink name=sink"]
+                        APPSINK]
         self.setup_pipeline_and_bus(pipeline_els)
         self.volume = self.pipeline.get_by_name("volume")
         self.sink = self.pipeline.get_by_name("sink")
-        self.sink.set_property("emit-signals", True)
-        self.sink.set_property("max-buffers", 10)
-        self.sink.set_property("drop", True)
-        self.sink.set_property("sync", False)
-        self.sink.set_property("async", False)
-        self.sink.set_property("qos", False)
         try:
             #Gst 1.0:
             self.sink.connect("new-sample", self.on_new_sample)