Fix tracks splitting for tracks that have sub-tracks (#6968)

When uploading annotations for the whole task that has few jobs our
server splits tracks. Each track we divide into a few tracks in that way
that each track corresponds to only one job and all shapes of the track
do not extend beyond the frame range corresponding to that job.

It mainly works, but we have a problem with skeleton tracks. Due to this
problem we if upload skeleton tracks for the whole task all our tracks
will be duplicated for each job but not split, it means that we will
have tracks that extend beyond the frame range of jobs and it leads to
bad side effects, in this case, our exported annotations from such task
could be incorrect or we won't be able to export annotations at all.

And the reason for this problem is this small bug, which this PR fixes.
Our code really slices sub-tracks for the skeleton track, but after this
slicing server doesn't save the result.

changelog.d/20231010_113810_sizow.k.d_fix_tracks_splitting.md

@@ -0,0 +1,4 @@
+### Fixed
+
+- Splitting skeleton tracks on jobs
+  (<https://github.com/opencv/cvat/pull/6968>)

cvat/apps/dataset_manager/annotation.py

@@ -100,9 +100,12 @@ def filter_track_shapes(shapes):
         track = deepcopy(track_)
         segment_shapes = filter_track_shapes(deepcopy(track['shapes']))
 
+        track["elements"] = [
+            cls._slice_track(element, start, stop, dimension)
+            for element in track.get('elements', [])
+        ]
+
         if len(segment_shapes) < len(track['shapes']):
-            for element in track.get('elements', []):
-                element = cls._slice_track(element, start, stop, dimension)
             interpolated_shapes = TrackManager.get_interpolated_shapes(
                 track, start, stop, dimension)
             scoped_shapes = filter_track_shapes(interpolated_shapes)
@@ -909,7 +912,7 @@ def propagate(shape, end_frame, *, included_frames=None):
                 break # The track finishes here
 
             if prev_shape:
-                assert curr_frame > prev_shape["frame"] # Catch invalid tracks
+                assert curr_frame > prev_shape["frame"], f"{curr_frame} > {prev_shape['frame']}. Track id: {track['id']}" # Catch invalid tracks
 
                 # Propagate attributes
                 for attr in prev_shape["attributes"]:

cvat/apps/dataset_manager/task.py

@@ -161,7 +161,7 @@ def _add_missing_shape(self, track, first_shape):
             missing_shape = deepcopy(first_shape)
             missing_shape["frame"] = track["frame"]
             missing_shape["outside"] = True
-            missing_shape.pop("id")
+            missing_shape.pop("id", None)
             track["shapes"].append(missing_shape)
 
     def _correct_frame_of_tracked_shapes(self, track):

tests/python/rest_api/test_tasks.py

@@ -34,6 +34,7 @@
 from shared.utils.config import (
     BASE_URL,
     USER_PASS,
+    delete_method,
     get_method,
     make_api_client,
     patch_method,
@@ -534,6 +535,63 @@ def test_remove_first_keyframe(self):
         response = patch_method("admin1", endpoint, annotations, action="update")
         assert response.status_code == HTTPStatus.OK
 
+    def test_can_split_skeleton_tracks_on_jobs(self, jobs):
+        # https://github.com/opencv/cvat/pull/6968
+        task_id = 21
+
+        task_jobs = [job for job in jobs if job["task_id"] == task_id]
+
+        frame_ranges = {}
+        for job in task_jobs:
+            frame_ranges[job["id"]] = set(range(job["start_frame"], job["stop_frame"] + 1))
+
+        # skeleton track that covers few jobs
+        annotations = {
+            "tracks": [
+                {
+                    "frame": 0,
+                    "label_id": 58,
+                    "shapes": [{"type": "skeleton", "frame": 0, "points": []}],
+                    "elements": [
+                        {
+                            "label_id": 59,
+                            "frame": 0,
+                            "shapes": [
+                                {"type": "points", "frame": 0, "points": [1.0, 2.0]},
+                                {"type": "points", "frame": 2, "points": [1.0, 2.0]},
+                                {"type": "points", "frame": 7, "points": [1.0, 2.0]},
+                            ],
+                        },
+                    ],
+                }
+            ]
+        }
+
+        # clear task annotations
+        response = delete_method("admin1", f"tasks/{task_id}/annotations")
+        assert response.status_code == 204, f"Cannot delete task's annotations: {response.content}"
+
+        # create skeleton track that covers few jobs
+        response = patch_method(
+            "admin1", f"tasks/{task_id}/annotations", annotations, action="create"
+        )
+        assert response.status_code == 200, f"Cannot update task's annotations: {response.content}"
+
+        # check that server splitted skeleton track's elements on jobs correctly
+        for job_id, job_frame_range in frame_ranges.items():
+            response = get_method("admin1", f"jobs/{job_id}/annotations")
+            assert response.status_code == 200, f"Cannot get job's annotations: {response.content}"
+
+            job_annotations = response.json()
+            assert len(job_annotations["tracks"]) == 1, "Expected to see only one track"
+
+            track = job_annotations["tracks"][0]
+            assert track.get("elements", []), "Expected to see track with elements"
+
+            for element in track["elements"]:
+                element_frames = set(shape["frame"] for shape in element["shapes"])
+                assert element_frames <= job_frame_range, "Track shapes get out of job frame range"
+
 
 @pytest.mark.usefixtures("restore_db_per_class")
 class TestGetTaskDataset: