
This PR provides new features and updates for SAM 2: - We now support `torch.compile` of the entire SAM 2 model on videos, which can be turned on by setting `vos_optimized=True` in `build_sam2_video_predictor` (it uses the new `SAM2VideoPredictorVOS` predictor class in `sam2/sam2_video_predictor.py`). * Compared to the previous setting (which only compiles the image encoder backbone), the new full model compilation gives a major speedup in inference FPS. * In the VOS prediction script `tools/vos_inference.py`, you can specify this option in `tools/vos_inference.py` via the `--use_vos_optimized_video_predictor` flag. * Note that turning on this flag might introduce a small variance in the predictions due to numerical differences caused by `torch.compile` of the full model. * **PyTorch 2.5.1 is the minimum version for full support of this feature**. (Earlier PyTorch versions might run into compilation errors in some cases.) Therefore, we have updated the minimum PyTorch version to 2.5.1 accordingly in the installation scripts. - We also update the implementation of the `SAM2VideoPredictor` class for the SAM 2 video prediction in `sam2/sam2_video_predictor.py`, which allows for independent per-object inference. Specifically, in the new `SAM2VideoPredictor`: * Now **we handle the inference of each object independently** (as if we are opening a separate session for each object) while sharing their backbone features. * This change allows us to relax the assumption of prompting for multi-object tracking. Previously (due to the batching behavior in inference), if a video frame receives clicks for only a subset of objects, the rest of the (non-prompted) objects are assumed to be non-existent in this frame (i.e., in such frames, the user is telling SAM 2 that the rest of the objects don't appear). Now, if a frame receives clicks for only a subset of objects, we do not make any assumptions about the remaining (non-prompted) objects (i.e., now each object is handled independently and is not affected by how other objects are prompted). As a result, **we allow adding new objects after tracking starts** after this change (which was previously a restriction on usage). * We believe that the new version is a more natural inference behavior and therefore switched to it as the default behavior. The previous implementation of `SAM2VideoPredictor` is backed up to in `sam2/sam2_video_predictor_legacy.py`. All the VOS inference results using `tools/vos_inference.py` should remain the same after this change to the `SAM2VideoPredictor` class.
93 lines
2.7 KiB
Python
93 lines
2.7 KiB
Python
# Copyright (c) Meta Platforms, Inc. and affiliates.
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# All rights reserved.
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# This source code is licensed under the license found in the
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# LICENSE file in the root directory of this source tree.
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import os
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import time
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import numpy as np
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import torch
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from tqdm import tqdm
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from sam2.build_sam import build_sam2_video_predictor
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# Only cuda supported
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assert torch.cuda.is_available()
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device = torch.device("cuda")
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torch.autocast(device_type="cuda", dtype=torch.bfloat16).__enter__()
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if torch.cuda.get_device_properties(0).major >= 8:
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# turn on tfloat32 for Ampere GPUs (https://pytorch.org/docs/stable/notes/cuda.html#tensorfloat-32-tf32-on-ampere-devices)
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torch.backends.cuda.matmul.allow_tf32 = True
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torch.backends.cudnn.allow_tf32 = True
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# Config and checkpoint
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sam2_checkpoint = "checkpoints/sam2.1_hiera_base_plus.pt"
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model_cfg = "configs/sam2.1/sam2.1_hiera_b+.yaml"
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# Build video predictor with vos_optimized=True setting
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predictor = build_sam2_video_predictor(
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model_cfg, sam2_checkpoint, device=device, vos_optimized=True
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)
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# Initialize with video
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video_dir = "notebooks/videos/bedroom"
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# scan all the JPEG frame names in this directory
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frame_names = [
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p
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for p in os.listdir(video_dir)
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if os.path.splitext(p)[-1] in [".jpg", ".jpeg", ".JPG", ".JPEG"]
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]
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frame_names.sort(key=lambda p: int(os.path.splitext(p)[0]))
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inference_state = predictor.init_state(video_path=video_dir)
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# Number of runs, warmup etc
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warm_up, runs = 5, 25
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verbose = True
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num_frames = len(frame_names)
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total, count = 0, 0
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torch.cuda.empty_cache()
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# We will select an object with a click.
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# See video_predictor_example.ipynb for more detailed explanation
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ann_frame_idx, ann_obj_id = 0, 1
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# Add a positive click at (x, y) = (210, 350)
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# For labels, `1` means positive click
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points = np.array([[210, 350]], dtype=np.float32)
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labels = np.array([1], np.int32)
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_, out_obj_ids, out_mask_logits = predictor.add_new_points_or_box(
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inference_state=inference_state,
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frame_idx=ann_frame_idx,
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obj_id=ann_obj_id,
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points=points,
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labels=labels,
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)
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# Warmup and then average FPS over several runs
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with torch.autocast("cuda", torch.bfloat16):
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with torch.inference_mode():
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for i in tqdm(range(runs), disable=not verbose, desc="Benchmarking"):
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start = time.time()
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# Start tracking
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for (
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out_frame_idx,
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out_obj_ids,
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out_mask_logits,
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) in predictor.propagate_in_video(inference_state):
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pass
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end = time.time()
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total += end - start
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count += 1
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if i == warm_up - 1:
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print("Warmup FPS: ", count * num_frames / total)
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total = 0
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count = 0
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print("FPS: ", count * num_frames / total)
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