[New Feature] Support SAM 2.1 (#59)

* support sam 2.1

* refine config path and ckpt path

* update README

sam2/utils/misc.py

@@ -177,6 +177,47 @@ def load_video_frames(
     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).
@@ -236,6 +277,38 @@ def load_video_frames(
     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]
+    # Get the original video height and width
+    decord.bridge.set_bridge("torch")
+    video_height, video_width, _ = decord.VideoReader(video_path).next().shape
+    # Iterate over all frames in the video
+    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)
+    # normalize by mean and std
+    images -= img_mean
+    images /= img_std
+    return images, video_height, video_width
+
+
 def fill_holes_in_mask_scores(mask, max_area):
     """
     A post processor to fill small holes in mask scores with area under `max_area`.
@@ -256,7 +329,7 @@ def fill_holes_in_mask_scores(mask, max_area):
             f"{e}\n\nSkipping the post-processing step due to the error above. You can "
             "still use SAM 2 and it's OK to ignore the error above, although some post-processing "
             "functionality may be limited (which doesn't affect the results in most cases; see "
-            "https://github.com/facebookresearch/segment-anything-2/blob/main/INSTALL.md).",
+            "https://github.com/facebookresearch/sam2/blob/main/INSTALL.md).",
             category=UserWarning,
             stacklevel=2,
         )

sam2/utils/transforms.py

@@ -108,7 +108,7 @@ class SAM2Transforms(nn.Module):
                 f"{e}\n\nSkipping the post-processing step due to the error above. You can "
                 "still use SAM 2 and it's OK to ignore the error above, although some post-processing "
                 "functionality may be limited (which doesn't affect the results in most cases; see "
-                "https://github.com/facebookresearch/segment-anything-2/blob/main/INSTALL.md).",
+                "https://github.com/facebookresearch/sam2/blob/main/INSTALL.md).",
                 category=UserWarning,
                 stacklevel=2,
             )