fix #283 remove / add split will change input order (#284)

* fix #283 remove / add split will change input order

* add more test case

src/ffmpeg/dag/tests/test_validate.py

@@ -4,7 +4,7 @@
 from syrupy.assertion import SnapshotAssertion
 
 from ...base import input
-from ...filters import concat
+from ...filters import amix, concat
 from ...utils.snapshot import DAGSnapshotExtenstion
 from ..context import DAGContext
 from ..schema import Stream
@@ -54,9 +54,35 @@ def complex_stream() -> Any:
     return pytest.param(graph, id="complex-stream")
 
 
+def amix_stream() -> Any:
+    input1 = input("input1.mp4")
+
+    graph = amix(input1.audio.areverse().areverse(), input1.audio.areverse(), duration="firat").output(
+        filename="tmp.mp4"
+    )
+    return pytest.param(graph, id="amix-stream")
+
+
+def amix_stream_2() -> Any:
+    input1 = input("input1.mp4")
+
+    graph = amix(input1.audio.areverse(), input1.audio.areverse().areverse(), duration="firat").output(
+        filename="tmp.mp4"
+    )
+    return pytest.param(graph, id="amix-stream-2")
+
+
 @pytest.mark.parametrize(
     "graph",
-    [reduntant_split_duplicate(), redundant_split_outputs_1(), not_utilize_split(), reuse_input(), complex_stream()],
+    [
+        reduntant_split_duplicate(),
+        redundant_split_outputs_1(),
+        not_utilize_split(),
+        reuse_input(),
+        complex_stream(),
+        amix_stream(),
+        amix_stream_2(),
+    ],
 )
 def test_rebuild_graph(graph: Stream, snapshot: SnapshotAssertion) -> None:
     context = DAGContext.build(graph.node)

src/ffmpeg/dag/validate.py

@@ -40,13 +40,17 @@ def remove_split(current_stream: Stream, mapping: dict[Stream, Stream] = None) -
             mapping[current_stream] = mapping[current_stream.node.inputs[0]]
             return mapping[current_stream.node.inputs[0]], mapping
 
-    inputs = []
-    for input_stream in sorted(current_stream.node.inputs, key=lambda stream: -len(stream.node.upstream_nodes)):
+    inputs = {}
+    for idx, input_stream in sorted(
+        enumerate(current_stream.node.inputs), key=lambda idx_stream: -len(idx_stream[1].node.upstream_nodes)
+    ):
         new_stream, _mapping = remove_split(current_stream=input_stream, mapping=mapping)
-        inputs.append(new_stream)
+        inputs[idx] = new_stream
         mapping |= _mapping
 
-    new_node = replace(current_stream.node, inputs=tuple(inputs))
+    new_node = replace(
+        current_stream.node, inputs=tuple(stream for idx, stream in sorted(inputs.items(), key=lambda x: x[0]))
+    )
     new_stream = replace(current_stream, node=new_node)
 
     mapping[current_stream] = new_stream
@@ -69,18 +73,20 @@ def add_split(
     if (current_stream, down_node, down_index) in mapping:
         return mapping[(current_stream, down_node, down_index)], mapping
 
-    inputs = []
+    inputs = {}
 
     for idx, input_stream in sorted(
         enumerate(current_stream.node.inputs), key=lambda idx_stream: -len(idx_stream[1].node.upstream_nodes)
     ):
         new_stream, _mapping = add_split(
             current_stream=input_stream, down_node=current_stream.node, down_index=idx, mapping=mapping, context=context
         )
-        inputs.append(new_stream)
+        inputs[idx] = new_stream
         mapping |= _mapping
 
-    new_node = replace(current_stream.node, inputs=tuple(inputs))
+    new_node = replace(
+        current_stream.node, inputs=tuple(stream for idx, stream in sorted(inputs.items(), key=lambda x: x[0]))
+    )
     new_stream = replace(current_stream, node=new_node)
 
     num = len(context.get_outgoing_nodes(current_stream))

src/ffmpeg/tests/__snapshots__/test_base/test_audio_video_pipeline.json

@@ -1,14 +1,14 @@
 [
   "ffmpeg",
   "-i",
-  "in2.mp4",
-  "-i",
   "in1.mp4",
+  "-i",
+  "in2.mp4",
   "-filter_complex",
-  "[0:v]reverse[s0];[0:a]areverse[s1];[1:v]hflip[s2];[s0]hue=s=0[s3];[s1]aphaser[s4];[s3][s4][s2][1:a]concat=v=1:a=1[s5#0][s5#1];[s5#1]volume=volume=0.8[s6]",
-  "-map",
-  "[s6]",
+  "[0:v]hflip[s0];[1:v]reverse[s1];[1:a]areverse[s2];[s1]hue=s=0[s3];[s2]aphaser[s4];[s0][0:a][s3][s4]concat=v=1:a=1[s5#0][s5#1];[s5#1]volume=volume=0.8[s6]",
   "-map",
   "[s5#0]",
+  "-map",
+  "[s6]",
   "out.mp4"
 ]