add separate video loader class

video_loader.py

@@ -0,0 +1,52 @@
+from enum import Enum
+from data.library import ArkiteData, ArkiteDetection, ArkiteRecording
+from cv2util import to_8_bit_image
+from typing import Iterable
+import numpy
+from recording_grouper import RecordingGrouper
+
+class VideoType(Enum):
+    IR = 0
+    DEPTH = 1
+
+class VideoLoader:
+    def __init__(self, projects_path: str):
+        self.projects_path = projects_path
+        # Search folders with depth of 1:
+        self.data = ArkiteData(self.projects_path, 1)
+
+    def get_all_recordings(self) -> Iterable[ArkiteRecording]:
+        # Loop over projects
+        for detection in self.data.detections(self.data.use_cases()):
+            for recording in detection.recordings():
+                yield recording
+
+    def get_recordings_grouped(self):
+        grouper = RecordingGrouper(self.data)
+        return grouper.getRecordingGroups()
+    
+    @staticmethod
+    def extract_frames(recording: ArkiteRecording, video_type: VideoType = None) -> Iterable[numpy.ndarray]:
+        if video_type == VideoType.IR or video_type == None:
+            disp_min = 100
+            disp_max = 8000
+            with recording.ir() as ir:
+                frames = ir.frame_sequence()
+                for frame in frames:
+                    yield to_8_bit_image(frame, display_min=disp_min, display_max=disp_max)
+        elif video_type == VideoType.DEPTH:
+            # TODO: check if these values make sense for depth images.
+            disp_min = 100
+            disp_max = 8000
+            with recording.depth() as depth:
+                frames = depth.frame_sequence()
+                for frame in frames:
+                    yield to_8_bit_image(frame, display_min=disp_min, display_max=disp_max)
+        else:
+            raise NotImplementedError("VideoType \'{}\' not implemented".format(video_type))
+
+    # Yielding in sub method after "with" statement in top method does not work!
+    # @staticmethod
+    # def frames_to_8_bit(frame_sequence, disp_min=None, disp_max=None):
+    #     for frame in frame_sequence:
+    #         yield to_8_bit_image(frame, display_min=disp_min, display_max=disp_max)