fix: extract frames for map faces fallback (#1824)

Verified this fix. Confirmed the bug by reverting just the `modules/core.py` hunk and
re-running the new regression test — with the old code, `process_video`/`create_video`
run against a temp directory that was never populated when `map_faces=True`, since
`create_temp`/`extract_frames` were skipped for that case. That means map-faces video
runs were silently broken (empty or failed output).

The fix removes the `map_faces` guard so extraction always runs before the disk-based
fallback, which is correct for both cases that reach this branch (map_faces=True, and
non-map-faces pipe failures). `create_temp` is idempotent (mkdir exist_ok=True), so the
double-call for the non-map-faces path is harmless.

modules/core.py

@@ -276,10 +276,9 @@ def start() -> None:
             update_status('Falling back to disk-based processing...')
 
         extraction_start = time.time()
-        if not modules.globals.map_faces:
-            create_temp(modules.globals.target_path)
-            update_status('Extracting frames...')
-            extract_frames(modules.globals.target_path)
+        create_temp(modules.globals.target_path)
+        update_status('Extracting frames...')
+        extract_frames(modules.globals.target_path)
         extraction_time = time.time() - extraction_start
 
         temp_frame_paths = get_temp_frame_paths(modules.globals.target_path)

tests/test_core_map_faces_fallback.py

@@ -0,0 +1,137 @@
+import importlib
+import sys
+import types
+import unittest
+from contextlib import contextmanager
+from unittest.mock import patch
+
+
+@contextmanager
+def _patched_core_import_stubs(calls, pipe_result=False):
+    class Processor:
+        NAME = "test_processor"
+
+        def pre_start(self):
+            return True
+
+        def pre_check(self):
+            return True
+
+        def process_image(self, *_args, **_kwargs):
+            raise AssertionError("image path should not be used")
+
+        def process_video(self, source_path, frame_paths):
+            calls.append(("process_video", source_path, tuple(frame_paths)))
+
+    stubs = {
+        "cv2": types.SimpleNamespace(
+            IMREAD_COLOR=1,
+            imdecode=lambda *_args, **_kwargs: None,
+            imencode=lambda *_args, **_kwargs: (
+                True,
+                types.SimpleNamespace(tofile=lambda *_a, **_k: None),
+            ),
+        ),
+        "numpy": types.SimpleNamespace(uint8=object, fromfile=lambda *_args, **_kwargs: b""),
+        "torch": types.SimpleNamespace(
+            cuda=types.SimpleNamespace(empty_cache=lambda: None)
+        ),
+        "onnxruntime": types.SimpleNamespace(
+            get_available_providers=lambda: ["CPUExecutionProvider"]
+        ),
+        "tensorflow": types.SimpleNamespace(),
+        "modules.metadata": types.SimpleNamespace(name="Deep-Live-Cam", version="test"),
+        "modules.ui": types.SimpleNamespace(
+            check_and_ignore_nsfw=lambda *_args, **_kwargs: False,
+            update_status=lambda *_args, **_kwargs: None,
+            init=lambda *_args, **_kwargs: types.SimpleNamespace(mainloop=lambda: None),
+        ),
+        "modules.processors.frame.core": types.SimpleNamespace(
+            get_frame_processors_modules=lambda _names: [Processor()],
+            process_video_in_memory=lambda *_args, **_kwargs: calls.append(("pipe",))
+            or pipe_result,
+        ),
+        "modules.utilities": types.SimpleNamespace(
+            has_image_extension=lambda _path: False,
+            is_image=lambda _path: False,
+            is_video=lambda _path: True,
+            detect_fps=lambda _path: 24.0,
+            create_video=lambda target_path, fps: calls.append(
+                ("create_video", target_path, fps)
+            )
+            or True,
+            extract_frames=lambda target_path: calls.append(
+                ("extract_frames", target_path)
+            ),
+            get_temp_frame_paths=lambda target_path: [f"{target_path}/0001.png"],
+            restore_audio=lambda *_args, **_kwargs: calls.append(("restore_audio",)),
+            create_temp=lambda target_path: calls.append(("create_temp", target_path)),
+            move_temp=lambda target_path, output_path: calls.append(
+                ("move_temp", target_path, output_path)
+            ),
+            clean_temp=lambda target_path: calls.append(("clean_temp", target_path)),
+            normalize_output_path=lambda _source, _target, output: output,
+        ),
+    }
+    with patch.dict(sys.modules, stubs, clear=False):
+        sys.modules.pop("modules.core", None)
+        yield importlib.import_module("modules.core")
+        sys.modules.pop("modules.core", None)
+
+
+def _configure_video_run(core, *, map_faces):
+    core.modules.globals.source_path = "source.jpg"
+    core.modules.globals.target_path = "target.mp4"
+    core.modules.globals.output_path = "output.mp4"
+    core.modules.globals.frame_processors = ["face_swapper"]
+    core.modules.globals.headless = True
+    core.modules.globals.keep_fps = False
+    core.modules.globals.keep_audio = False
+    core.modules.globals.keep_frames = False
+    core.modules.globals.map_faces = map_faces
+    core.modules.globals.nsfw_filter = False
+    core.modules.globals.execution_threads = 1
+    core.modules.globals.execution_providers = ["CPUExecutionProvider"]
+    core.modules.globals.max_memory = None
+
+
+class MapFacesFallbackTests(unittest.TestCase):
+    def test_map_faces_disk_fallback_extracts_frames_before_processing(self):
+        calls = []
+        with _patched_core_import_stubs(calls, pipe_result=False) as core:
+            _configure_video_run(core, map_faces=True)
+
+            with patch.object(core.os.path, "isfile", return_value=True):
+                core.start()
+
+        self.assertNotIn(("pipe",), calls)
+        self.assertIn(("create_temp", "target.mp4"), calls)
+        self.assertIn(("extract_frames", "target.mp4"), calls)
+        self.assertIn(("process_video", "source.jpg", ("target.mp4/0001.png",)), calls)
+        self.assertIn(("create_video", "target.mp4", 30.0), calls)
+        self.assertIn(("move_temp", "target.mp4", "output.mp4"), calls)
+
+        step_indices = {}
+        for index, call in enumerate(calls):
+            step_indices.setdefault(call[0], index)
+
+        self.assertLess(step_indices["create_temp"], step_indices["extract_frames"])
+        self.assertLess(step_indices["extract_frames"], step_indices["process_video"])
+        self.assertLess(step_indices["process_video"], step_indices["create_video"])
+        self.assertLess(step_indices["create_video"], step_indices["move_temp"])
+
+    def test_non_map_faces_pipe_success_does_not_extract_frames(self):
+        calls = []
+        with _patched_core_import_stubs(calls, pipe_result=True) as core:
+            _configure_video_run(core, map_faces=False)
+
+            with patch.object(core.os.path, "isfile", return_value=True):
+                core.start()
+
+        self.assertIn(("pipe",), calls)
+        self.assertNotIn(("extract_frames", "target.mp4"), calls)
+        self.assertNotIn(("process_video", "source.jpg", ("target.mp4/0001.png",)), calls)
+
+
+if __name__ == "__main__":
+    unittest.main()