"""USB camera handling module."""
from typing import List
import cv2
from optic_mcp.validation import validate_file_path, validate_camera_index
def list_cameras() -> List[dict]:
"""
Scans for available USB cameras connected to the system.
Returns a list of available camera indices and their status.
It attempts to read a frame to ensure the camera is truly available.
"""
available_cameras = []
for index in range(10):
cap = cv2.VideoCapture(index)
if cap.isOpened():
ret, _ = cap.read()
if ret:
backend = cap.getBackendName()
available_cameras.append(
{
"index": index,
"status": "available",
"backend": backend,
"description": f"Camera {index} ({backend})",
}
)
cap.release()
return available_cameras
def save_image(file_path: str, camera_index: int = 0) -> str:
"""
Captures a frame from the specified camera and saves it to the given file path.
Returns a success message.
Args:
file_path: Path where the image will be saved. Must be in an allowed directory
and have a valid image extension (.jpg, .png, etc.)
camera_index: The camera index to capture from (0-100).
Returns:
Success message with file path.
Raises:
ValueError: If file_path or camera_index is invalid.
RuntimeError: If camera cannot be opened or frame cannot be captured.
"""
# Validate inputs
validated_path = validate_file_path(file_path)
validated_index = validate_camera_index(camera_index)
cap = cv2.VideoCapture(validated_index)
if not cap.isOpened():
raise RuntimeError(f"Could not open camera at index {validated_index}")
try:
for _ in range(5):
cap.read()
ret, frame = cap.read()
if not ret:
raise RuntimeError(f"Failed to capture frame from camera {validated_index}")
cv2.imwrite(validated_path, frame)
return f"Image saved to {validated_path}"
finally:
cap.release()
