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ray-project--ray/doc/source/serve/tutorials/video-analysis/deployments/encoder.py
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2026-07-13 13:17:40 +08:00

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4.7 KiB
Python

"""VideoEncoder deployment - GPU-based frame encoding using SigLIP."""
import asyncio
import logging
from typing import List
import numpy as np
import torch
from ray import serve
from transformers import AutoModel, AutoProcessor
from constants import MODEL_NAME
from utils.video import frames_to_pil_list
logger = logging.getLogger(__name__)
@serve.deployment(
num_replicas="auto",
ray_actor_options={"num_gpus": 1, "num_cpus": 2},
# GPU utilization is at 100% when this is set to 2. with L4
# aka number on ongoing chunks that can be processed at once.
max_ongoing_requests=2,
autoscaling_config={
"min_replicas": 1,
"max_replicas": 10,
"target_num_ongoing_requests": 2,
},
)
class VideoEncoder:
"""
Encodes video frames into embeddings using SigLIP.
Returns both per-frame embeddings and pooled embedding.
"""
def __init__(self):
self.device = "cuda" if torch.cuda.is_available() else "cpu"
print(f"VideoEncoder initializing on {self.device}")
# Load SigLIP model and processor
self.processor = AutoProcessor.from_pretrained(MODEL_NAME)
self.model = AutoModel.from_pretrained(MODEL_NAME).to(self.device)
self.model.eval()
# Get embedding dimension
self.embedding_dim = self.model.config.vision_config.hidden_size
print(f"VideoEncoder ready (embedding_dim={self.embedding_dim})")
def encode_frames(self, frames: np.ndarray) -> np.ndarray:
"""
Encode frames and return per-frame embeddings.
Args:
frames: np.ndarray of shape (T, H, W, 3) uint8 RGB
Returns:
np.ndarray of shape (T, D) float32, L2-normalized per-frame embeddings
"""
# Convert to PIL images
pil_images = frames_to_pil_list(frames)
# Process images
inputs = self.processor(images=pil_images, return_tensors="pt").to(self.device)
# Get embeddings
with torch.no_grad():
with torch.amp.autocast(device_type=self.device, enabled=self.device == "cuda"):
outputs = self.model.get_image_features(**inputs)
# get_image_features returns BaseModelOutputWithPooling; use pooler_output for embeddings
frame_embeddings = torch.nn.functional.normalize(outputs.pooler_output, p=2, dim=1)
# Move to CPU and convert to numpy
result = frame_embeddings.cpu().numpy().astype(np.float32)
return result
async def encode_unbatched(self, frames: np.ndarray) -> dict:
"""
Unbatched entry point - processes single request directly.
Args:
frames: np.ndarray of shape (T, H, W, 3)
Returns:
dict with 'frame_embeddings' and 'embedding_dim'
"""
print(f"Unbatched: {frames.shape[0]} frames")
frame_embeddings = await asyncio.to_thread(self.encode_frames, frames)
return {
"frame_embeddings": frame_embeddings,
"embedding_dim": self.embedding_dim,
}
@serve.batch(max_batch_size=2, batch_wait_timeout_s=0.1)
async def encode_batched(self, frames_batch: List[np.ndarray]) -> List[dict]:
"""
Batched entry point - collects multiple requests into single GPU call.
Args:
frames_batch: List of frame arrays, each of shape (T, H, W, 3)
Returns:
List of dicts, each with 'frame_embeddings' and 'embedding_dim'
"""
frame_counts = [f.shape[0] for f in frames_batch]
total_frames = sum(frame_counts)
print(f"Batched: {len(frames_batch)} requests ({total_frames} total frames)")
# Concatenate all frames into single batch
all_frames = np.concatenate(frames_batch, axis=0)
# Single forward pass for all frames
all_embeddings = await asyncio.to_thread(self.encode_frames, all_frames)
# Split results back per request
results = []
offset = 0
for n_frames in frame_counts:
chunk_embeddings = all_embeddings[offset:offset + n_frames]
results.append({
"frame_embeddings": chunk_embeddings,
"embedding_dim": self.embedding_dim,
})
offset += n_frames
return results
async def __call__(self, frames: np.ndarray, use_batching: bool = False) -> dict:
"""
Main entry point. Set use_batching=False for direct comparison.
"""
if use_batching:
return await self.encode_batched(frames)
else:
return await self.encode_unbatched(frames)