[VLM] Replace decord with torchcodec for video decoding (#20055)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: BakerBunker <17872844+BakerBunker@users.noreply.github.com>

examples/runtime/multimodal/llava_onevision_server.py

@@ -15,11 +15,12 @@ import numpy as np
 import openai
 import pybase64
 import requests
-from decord import VideoReader, cpu
 from PIL import Image
 
+from sglang.srt.utils.video_decoder import VideoDecoderWrapper
+
 # pip install httpx==0.23.3
-# pip install decord
+# pip install torchcodec
 # pip install protobuf==3.20.0
 
 
@@ -200,13 +201,13 @@ def video_speed_test(client, video_path):
 
 def prepare_video_messages(video_path):
     max_frames_num = 32
-    vr = VideoReader(video_path, ctx=cpu(0))
-    total_frame_num = len(vr)
+    decoder = VideoDecoderWrapper(video_path)
+    total_frame_num = len(decoder)
     uniform_sampled_frames = np.linspace(
         0, total_frame_num - 1, max_frames_num, dtype=int
     )
     frame_idx = uniform_sampled_frames.tolist()
-    frames = vr.get_batch(frame_idx).asnumpy()
+    frames = decoder.get_frames_at(frame_idx)
 
     base64_frames = []
     for frame in frames: