    By default, for batch size B, and image size H x W x C:</p>
        <ul>
            <li> self.inputs[0] tensor has the images. If the image downsample factor is s then the size of this tensor is [B, H//s, W//s, C].
            <li> self.inputs[1] tensor has the locations in an array of [B, N, 2]
            <li> self.inputs[2] tensor has the [movie_id, frame_id, animal_id] information. Mostly useful for debugging.
            <li> self.inputs[3] tensor has the heatmaps, which in most cases will be used