Label-based order of outputs from multiple-output filters

Author: komar007

ffmpeg/_run.py

@@ -84,7 +84,7 @@ def _allocate_filter_stream_names(filter_nodes, outgoing_edge_maps, stream_name_
     stream_count = 0
     for upstream_node in filter_nodes:
         outgoing_edge_map = outgoing_edge_maps[upstream_node]
-        for upstream_label, downstreams in list(outgoing_edge_map.items()):
+        for upstream_label, downstreams in sorted(outgoing_edge_map.items()):
             if len(downstreams) > 1:
                 # TODO: automatically insert `splits` ahead of time via graph transformation.
                 raise ValueError(

ffmpeg/dag.py

@@ -100,7 +100,7 @@ def get_incoming_edges(downstream_node, incoming_edge_map):
 
 def get_outgoing_edges(upstream_node, outgoing_edge_map):
     edges = []
-    for upstream_label, downstream_infos in list(outgoing_edge_map.items()):
+    for upstream_label, downstream_infos in sorted(outgoing_edge_map.items()):
         for downstream_info in downstream_infos:
             downstream_node, downstream_label, downstream_selector = downstream_info
             edges += [