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| import os |
| from threading import Thread |
|
|
| import numpy as np |
| import torch |
| from PIL import Image |
| from tqdm import tqdm |
|
|
|
|
| def _load_img_as_tensor(img_path, image_size): |
| img_pil = Image.open(img_path) |
| img_np = np.array(img_pil.convert("RGB").resize((image_size, image_size))) |
| if img_np.dtype == np.uint8: |
| img_np = img_np / 255.0 |
| else: |
| raise RuntimeError(f"Unknown image dtype: {img_np.dtype} on {img_path}") |
| img = torch.from_numpy(img_np).permute(2, 0, 1) |
| video_width, video_height = img_pil.size |
| return img, video_height, video_width |
|
|
|
|
| class AsyncVideoFrameLoader: |
| """ |
| A list of video frames to be load asynchronously without blocking session start. |
| """ |
|
|
| def __init__( |
| self, |
| img_paths, |
| image_size, |
| offload_video_to_cpu, |
| img_mean, |
| img_std, |
| compute_device, |
| ): |
| self.img_paths = img_paths |
| self.image_size = image_size |
| self.offload_video_to_cpu = offload_video_to_cpu |
| self.img_mean = img_mean |
| self.img_std = img_std |
| |
| self.images = [None] * len(img_paths) |
| |
| self.exception = None |
| |
| self.video_height = None |
| self.video_width = None |
| self.compute_device = compute_device |
|
|
| |
| |
| self.__getitem__(0) |
|
|
| |
| def _load_frames(): |
| try: |
| for n in tqdm(range(len(self.images)), desc="frame loading (JPEG)"): |
| self.__getitem__(n) |
| except Exception as e: |
| self.exception = e |
|
|
| self.thread = Thread(target=_load_frames, daemon=True) |
| self.thread.start() |
|
|
| def __getitem__(self, index): |
| if self.exception is not None: |
| raise RuntimeError("Failure in frame loading thread") from self.exception |
|
|
| img = self.images[index] |
| if img is not None: |
| return img |
|
|
| img, video_height, video_width = _load_img_as_tensor( |
| self.img_paths[index], self.image_size |
| ) |
| self.video_height = video_height |
| self.video_width = video_width |
| |
| img -= self.img_mean |
| img /= self.img_std |
| if not self.offload_video_to_cpu: |
| img = img.to(self.compute_device, non_blocking=True) |
| self.images[index] = img |
| return img |
|
|
| def __len__(self): |
| return len(self.images) |
|
|
|
|
| def load_video_frames( |
| video_path, |
| image_size, |
| offload_video_to_cpu, |
| img_mean=(0.485, 0.456, 0.406), |
| img_std=(0.229, 0.224, 0.225), |
| async_loading_frames=False, |
| compute_device=torch.device("cuda"), |
| ): |
| """ |
| Load the video frames from video_path. The frames are resized to image_size as in |
| the model and are loaded to GPU if offload_video_to_cpu=False. This is used by the demo. |
| """ |
| is_bytes = isinstance(video_path, bytes) |
| is_str = isinstance(video_path, str) |
| is_mp4_path = is_str and os.path.splitext(video_path)[-1] in [".mp4", ".MP4"] |
| if is_bytes or is_mp4_path: |
| return load_video_frames_from_video_file( |
| video_path=video_path, |
| image_size=image_size, |
| offload_video_to_cpu=offload_video_to_cpu, |
| img_mean=img_mean, |
| img_std=img_std, |
| compute_device=compute_device, |
| ) |
| elif is_str and os.path.isdir(video_path): |
| return load_video_frames_from_jpg_images( |
| video_path=video_path, |
| image_size=image_size, |
| offload_video_to_cpu=offload_video_to_cpu, |
| img_mean=img_mean, |
| img_std=img_std, |
| async_loading_frames=async_loading_frames, |
| compute_device=compute_device, |
| ) |
| else: |
| raise NotImplementedError( |
| "Only MP4 video and JPEG folder are supported at this moment" |
| ) |
|
|
|
|
| def load_video_frames_from_jpg_images( |
| video_path, |
| image_size, |
| offload_video_to_cpu, |
| img_mean=(0.485, 0.456, 0.406), |
| img_std=(0.229, 0.224, 0.225), |
| async_loading_frames=False, |
| compute_device=torch.device("cuda"), |
| ): |
| """ |
| Load the video frames from a directory of JPEG files ("<frame_index>.jpg" format). |
| |
| The frames are resized to image_size x image_size and are loaded to GPU if |
| `offload_video_to_cpu` is `False` and to CPU if `offload_video_to_cpu` is `True`. |
| |
| You can load a frame asynchronously by setting `async_loading_frames` to `True`. |
| """ |
| if isinstance(video_path, str) and os.path.isdir(video_path): |
| jpg_folder = video_path |
| else: |
| raise NotImplementedError( |
| "Only JPEG frames are supported at this moment. For video files, you may use " |
| "ffmpeg (https://ffmpeg.org/) to extract frames into a folder of JPEG files, such as \n" |
| "```\n" |
| "ffmpeg -i <your_video>.mp4 -q:v 2 -start_number 0 <output_dir>/'%05d.jpg'\n" |
| "```\n" |
| "where `-q:v` generates high-quality JPEG frames and `-start_number 0` asks " |
| "ffmpeg to start the JPEG file from 00000.jpg." |
| ) |
|
|
| frame_names = [ |
| p |
| for p in os.listdir(jpg_folder) |
| if os.path.splitext(p)[-1] in [".jpg", ".jpeg", ".JPG", ".JPEG"] |
| ] |
| frame_names.sort(key=lambda p: int(os.path.splitext(p)[0])) |
| num_frames = len(frame_names) |
| if num_frames == 0: |
| raise RuntimeError(f"no images found in {jpg_folder}") |
| img_paths = [os.path.join(jpg_folder, frame_name) for frame_name in frame_names] |
| img_mean = torch.tensor(img_mean, dtype=torch.float32)[:, None, None] |
| img_std = torch.tensor(img_std, dtype=torch.float32)[:, None, None] |
|
|
| if async_loading_frames: |
| lazy_images = AsyncVideoFrameLoader( |
| img_paths, |
| image_size, |
| offload_video_to_cpu, |
| img_mean, |
| img_std, |
| compute_device, |
| ) |
| return lazy_images, lazy_images.video_height, lazy_images.video_width |
|
|
| images = torch.zeros(num_frames, 3, image_size, image_size, dtype=torch.float32) |
| for n, img_path in enumerate(tqdm(img_paths, desc="frame loading (JPEG)")): |
| images[n], video_height, video_width = _load_img_as_tensor(img_path, image_size) |
| if not offload_video_to_cpu: |
| images = images.to(compute_device) |
| img_mean = img_mean.to(compute_device) |
| img_std = img_std.to(compute_device) |
| |
| images -= img_mean |
| images /= img_std |
| return images, video_height, video_width |
|
|
|
|
| def load_video_frames_from_video_file( |
| video_path, |
| image_size, |
| offload_video_to_cpu, |
| img_mean=(0.485, 0.456, 0.406), |
| img_std=(0.229, 0.224, 0.225), |
| compute_device=torch.device("cuda"), |
| ): |
| """Load the video frames from a video file.""" |
| import decord |
|
|
| img_mean = torch.tensor(img_mean, dtype=torch.float32)[:, None, None] |
| img_std = torch.tensor(img_std, dtype=torch.float32)[:, None, None] |
| |
| decord.bridge.set_bridge("torch") |
| video_height, video_width, _ = decord.VideoReader(video_path).next().shape |
| |
| images = [] |
| for frame in decord.VideoReader(video_path, width=image_size, height=image_size): |
| images.append(frame.permute(2, 0, 1)) |
|
|
| images = torch.stack(images, dim=0).float() / 255.0 |
| if not offload_video_to_cpu: |
| images = images.to(compute_device) |
| img_mean = img_mean.to(compute_device) |
| img_std = img_std.to(compute_device) |
| |
| images -= img_mean |
| images /= img_std |
| return images, video_height, video_width |
|
|