def sample()

in training/dataset/vos_sampler.py [0:0]

• 29 lines of code
• 11 McCabe index (conditional complexity)

    def sample(self, video, segment_loader, epoch=None):

        for retry in range(MAX_RETRIES):
            if len(video.frames) < self.num_frames:
                raise Exception(
                    f"Cannot sample {self.num_frames} frames from video {video.video_name} as it only has {len(video.frames)} annotated frames."
                )
            start = random.randrange(0, len(video.frames) - self.num_frames + 1)
            frames = [video.frames[start + step] for step in range(self.num_frames)]
            if random.uniform(0, 1) < self.reverse_time_prob:
                # Reverse time
                frames = frames[::-1]

            # Get first frame object ids
            visible_object_ids = []
            loaded_segms = segment_loader.load(frames[0].frame_idx)
            if isinstance(loaded_segms, LazySegments):
                # LazySegments for SA1BRawDataset
                visible_object_ids = list(loaded_segms.keys())
            else:
                for object_id, segment in segment_loader.load(
                    frames[0].frame_idx
                ).items():
                    if segment.sum():
                        visible_object_ids.append(object_id)

            # First frame needs to have at least a target to track
            if len(visible_object_ids) > 0:
                break
            if retry >= MAX_RETRIES - 1:
                raise Exception("No visible objects")

        object_ids = random.sample(
            visible_object_ids,
            min(len(visible_object_ids), self.max_num_objects),
        )
        return SampledFramesAndObjects(frames=frames, object_ids=object_ids)