[New Feature] Support SAM 2.1 (#59)

* support sam 2.1

* refine config path and ckpt path

* update README

demo/backend/server/data/loader.py

@@ -0,0 +1,92 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+# This source code is licensed under the license found in the
+# LICENSE file in the root directory of this source tree.
+
+import os
+import shutil
+import subprocess
+from glob import glob
+from pathlib import Path
+from typing import Dict, Optional
+
+import imagesize
+from app_conf import GALLERY_PATH, POSTERS_PATH, POSTERS_PREFIX
+from data.data_types import Video
+from tqdm import tqdm
+
+
+def preload_data() -> Dict[str, Video]:
+    """
+    Preload data including gallery videos and their posters.
+    """
+    # Dictionaries for videos and datasets on the backend.
+    # Note that since Python 3.7, dictionaries preserve their insert order, so
+    # when looping over its `.values()`, elements inserted first also appear first.
+    # https://stackoverflow.com/questions/39980323/are-dictionaries-ordered-in-python-3-6
+    all_videos = {}
+
+    video_path_pattern = os.path.join(GALLERY_PATH, "**/*.mp4")
+    video_paths = glob(video_path_pattern, recursive=True)
+
+    for p in tqdm(video_paths):
+        video = get_video(p, GALLERY_PATH)
+        all_videos[video.code] = video
+
+    return all_videos
+
+
+def get_video(
+    filepath: os.PathLike,
+    absolute_path: Path,
+    file_key: Optional[str] = None,
+    generate_poster: bool = True,
+    width: Optional[int] = None,
+    height: Optional[int] = None,
+    verbose: Optional[bool] = False,
+) -> Video:
+    """
+    Get video object given
+    """
+    # Use absolute_path to include the parent directory in the video
+    video_path = os.path.relpath(filepath, absolute_path.parent)
+    poster_path = None
+    if generate_poster:
+        poster_id = os.path.splitext(os.path.basename(filepath))[0]
+        poster_filename = f"{str(poster_id)}.jpg"
+        poster_path = f"{POSTERS_PREFIX}/{poster_filename}"
+
+        # Extract the first frame from video
+        poster_output_path = os.path.join(POSTERS_PATH, poster_filename)
+        ffmpeg = shutil.which("ffmpeg")
+        subprocess.call(
+            [
+                ffmpeg,
+                "-y",
+                "-i",
+                str(filepath),
+                "-pix_fmt",
+                "yuv420p",
+                "-frames:v",
+                "1",
+                "-update",
+                "1",
+                "-strict",
+                "unofficial",
+                str(poster_output_path),
+            ],
+            stdout=None if verbose else subprocess.DEVNULL,
+            stderr=None if verbose else subprocess.DEVNULL,
+        )
+
+        # Extract video width and height from poster. This is important to optimize
+        # rendering previews in the mosaic video preview.
+        width, height = imagesize.get(poster_output_path)
+
+    return Video(
+        code=video_path,
+        path=video_path if file_key is None else file_key,
+        poster_path=poster_path,
+        width=width,
+        height=height,
+    )