Use id as hash value for source nodes to make sure they're not singletons

ffmpeg/nodes.py

@@ -5,6 +5,7 @@ from .dag import KwargReprNode
 from ._utils import escape_chars, get_hash_int
 from builtins import object
 import os
+import uuid
 
 
 def _is_of_types(obj, types):
@@ -305,6 +306,7 @@ class FilterNode(FilterableNode):
 # noinspection PyMethodOverriding
 class SourceNode(FilterableNode):
     def __init__(self, name, args=[], kwargs={}):
+        self.source_node_id = uuid.uuid4()
         super(SourceNode, self).__init__(
             stream_spec=None,
             name=name,
@@ -316,6 +318,13 @@ class SourceNode(FilterableNode):
             kwargs=kwargs
         )
 
+    def __hash__(self):
+        """Two source nodes with the same options should _not_ be considered
+        the same node. For this reason we create a uuid4 on node instantiation,
+        and use that as our hash.
+        """
+        return self.source_node_id.int
+
 
 # noinspection PyMethodOverriding
 class OutputNode(Node):

ffmpeg/tests/test_ffmpeg.py

@@ -673,6 +673,27 @@ def test_sources():
 
 
 
+def test_same_source_multiple_times():
+    out = (ffmpeg
+        .concat(
+            ffmpeg.source("testsrc").trim(end=5),
+            ffmpeg.source("testsrc").trim(start=10, end=14).filter(
+                "setpts", "PTS-STARTPTS"
+            ),
+        )
+        .output(TEST_OUTPUT_FILE1)
+    )
+
+    assert out.get_args() == [
+        '-filter_complex',
+        'testsrc[s0];[s0]trim=end=5[s1];testsrc[s2];[s2]trim=end=14:start=10[s3];[s3]setpts=PTS-STARTPTS[s4];[s1][s4]concat=n=2[s5]',
+        '-map',
+        '[s5]',
+        TEST_OUTPUT_FILE1
+    ]
+
+
+
 def test_pipe():
     width = 32
     height = 32