import cv2
import os

def extract_frames(video_path, output_folder="frames"):

    os.makedirs(output_folder, exist_ok=True)

    cap = cv2.VideoCapture(video_path)

    # ดึง FPS ของวิดีโอ
    fps = cap.get(cv2.CAP_PROP_FPS)

    # save 2 frames ต่อ 1 วินาที
    frame_skip = int(fps / 2)

    frame_count = 0
    saved_count = 0

    while True:

        success, frame = cap.read()

        if not success:
            break

        # save every N frames
        if frame_count % frame_skip == 0:

            frame_path = os.path.join(
                output_folder,
                f"frame_{saved_count}.jpg"
            )

            cv2.imwrite(frame_path, frame)

            saved_count += 1

        frame_count += 1

    cap.release()

    return saved_count