implemented for all pipelines (downloading, saving, running on a particular device, etc.).  __call__  < source > ( prompt: Union prompt_2: Union = None video_length: Optional = 8 height: Optional = None width: Optional = None num_inference_steps: int = 50 denoising_end: Optional = None guidance_scale: float = 7.5 negative_prompt: Union = None negative_prompt_2: Union = None num_videos_per_prompt: Optional = 1 eta: float = 0.0 generator: Union = None frame_ids: Optional = None prompt_embeds: Optional = None negative_prompt_embeds: Optional = None pooled_prompt_embeds: Optional = None negative_pooled_prompt_embeds: Optional = None latents: Optional = None motion_field_strength_x: float = 12 motion_field_strength_y: float = 12 output_type: Optional = 'tensor' return_dict: bool = True callback: Optional = None callback_steps: int = 1 cross_attention_kwargs: Optional = None guidance_rescale: float = 0.0 original_size: Optional = None crops_coords_top_left: Tuple = (0, 0) target_size: Optional = None t0: int = 44 t1: int = 47  )   Parameters   prompt (str or List[str], optional) —