[New Feature] Support SAM 2.1 (#59)

* support sam 2.1

* refine config path and ckpt path

* update README

demo/backend/server/app.py

@@ -0,0 +1,140 @@
+# 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 logging
+from typing import Any, Generator
+
+from app_conf import (
+    GALLERY_PATH,
+    GALLERY_PREFIX,
+    POSTERS_PATH,
+    POSTERS_PREFIX,
+    UPLOADS_PATH,
+    UPLOADS_PREFIX,
+)
+from data.loader import preload_data
+from data.schema import schema
+from data.store import set_videos
+from flask import Flask, make_response, Request, request, Response, send_from_directory
+from flask_cors import CORS
+from inference.data_types import PropagateDataResponse, PropagateInVideoRequest
+from inference.multipart import MultipartResponseBuilder
+from inference.predictor import InferenceAPI
+from strawberry.flask.views import GraphQLView
+
+logger = logging.getLogger(__name__)
+
+app = Flask(__name__)
+cors = CORS(app, supports_credentials=True)
+
+videos = preload_data()
+set_videos(videos)
+
+inference_api = InferenceAPI()
+
+
+@app.route("/healthy")
+def healthy() -> Response:
+    return make_response("OK", 200)
+
+
+@app.route(f"/{GALLERY_PREFIX}/<path:path>", methods=["GET"])
+def send_gallery_video(path: str) -> Response:
+    try:
+        return send_from_directory(
+            GALLERY_PATH,
+            path,
+        )
+    except:
+        raise ValueError("resource not found")
+
+
+@app.route(f"/{POSTERS_PREFIX}/<path:path>", methods=["GET"])
+def send_poster_image(path: str) -> Response:
+    try:
+        return send_from_directory(
+            POSTERS_PATH,
+            path,
+        )
+    except:
+        raise ValueError("resource not found")
+
+
+@app.route(f"/{UPLOADS_PREFIX}/<path:path>", methods=["GET"])
+def send_uploaded_video(path: str):
+    try:
+        return send_from_directory(
+            UPLOADS_PATH,
+            path,
+        )
+    except:
+        raise ValueError("resource not found")
+
+
+# TOOD: Protect route with ToS permission check
+@app.route("/propagate_in_video", methods=["POST"])
+def propagate_in_video() -> Response:
+    data = request.json
+    args = {
+        "session_id": data["session_id"],
+        "start_frame_index": data.get("start_frame_index", 0),
+    }
+
+    boundary = "frame"
+    frame = gen_track_with_mask_stream(boundary, **args)
+    return Response(frame, mimetype="multipart/x-savi-stream; boundary=" + boundary)
+
+
+def gen_track_with_mask_stream(
+    boundary: str,
+    session_id: str,
+    start_frame_index: int,
+) -> Generator[bytes, None, None]:
+    with inference_api.autocast_context():
+        request = PropagateInVideoRequest(
+            type="propagate_in_video",
+            session_id=session_id,
+            start_frame_index=start_frame_index,
+        )
+
+        for chunk in inference_api.propagate_in_video(request=request):
+            yield MultipartResponseBuilder.build(
+                boundary=boundary,
+                headers={
+                    "Content-Type": "application/json; charset=utf-8",
+                    "Frame-Current": "-1",
+                    # Total frames minus the reference frame
+                    "Frame-Total": "-1",
+                    "Mask-Type": "RLE[]",
+                },
+                body=chunk.to_json().encode("UTF-8"),
+            ).get_message()
+
+
+class MyGraphQLView(GraphQLView):
+    def get_context(self, request: Request, response: Response) -> Any:
+        return {"inference_api": inference_api}
+
+
+# Add GraphQL route to Flask app.
+app.add_url_rule(
+    "/graphql",
+    view_func=MyGraphQLView.as_view(
+        "graphql_view",
+        schema=schema,
+        # Disable GET queries
+        # https://strawberry.rocks/docs/operations/deployment
+        # https://strawberry.rocks/docs/integrations/flask
+        allow_queries_via_get=False,
+        # Strawberry recently changed multipart request handling, which now
+        # requires enabling support explicitly for views.
+        # https://github.com/strawberry-graphql/strawberry/issues/3655
+        multipart_uploads_enabled=True,
+    ),
+)
+
+
+if __name__ == "__main__":
+    app.run(host="0.0.0.0", port=5000)