services/video_service.py

import cv2
import os

# Global state
VIDEO_DIR = "data"
video_files = [os.path.join(VIDEO_DIR, file) for file in sorted(os.listdir(VIDEO_DIR)) if file.endswith((".mp4", ".avi"))]
video_index = 0
cap = None
FRAME_SKIP = 3  # Skip more frames for faster processing
PRELOADED_FRAMES = []

def preload_video():
    global cap, video_index, PRELOADED_FRAMES
    if not video_files:
        return
    cap = cv2.VideoCapture(video_files[video_index])
    for _ in range(5):  # Preload 5 frames
        ret, frame = cap.read()
        if ret:
            frame = cv2.resize(frame, (320, 240))  # Reduce resolution for faster loading
            PRELOADED_FRAMES.append(frame)
        else:
            break
    cap.release()
    cap = None

def get_next_video_frame():
    global cap, video_index, PRELOADED_FRAMES

    if not video_files:
        raise RuntimeError("No video files found in the 'data' directory.")

    if PRELOADED_FRAMES:
        frame = PRELOADED_FRAMES.pop(0)
        return frame

    if cap is None or not cap.isOpened():
        cap = cv2.VideoCapture(video_files[video_index])

    for _ in range(FRAME_SKIP):
        ret, frame = cap.read()
        if not ret:
            cap.release()
            video_index = (video_index + 1) % len(video_files)
            cap = cv2.VideoCapture(video_files[video_index])
            ret, frame = cap.read()
            if not ret:
                raise RuntimeError(f"Cannot read video {video_files[video_index]}")
            break

    frame = cv2.resize(frame, (320, 240))  # Reduce resolution for faster processing
    return frame

def reset_video_index():
    global video_index
    video_index = 0
    preload_video()