class constants:
    def __init__(self):
        # 如果 AV 有多个，可以这样定义
        AVAILABLE_SOURCES = [
            {"type": 0x33, "id": 0x01, "name": "HDMI 1"},
            {"type": 0x35, "id": 0x01, "name": "DVI 1"},
            {"type": 0x32, "id": 0x01, "name": "AV 1"},  # SourceType=0x32, Sourceld=0x01
            {"type": 0x32, "id": 0x02, "name": "AV 2"},
        ]