可以接收远程图像，并进行操作且测试没有问题
This commit is contained in:
@@ -1,215 +1,341 @@
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#!/usr/bin/env python3
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# -*- coding: utf-8 -*-
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"""
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远程显示 Web 服务 - Flask 实现
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远程显示 Web 服务 - Flask + WebSocket 实现
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通过 RemoDispBus 协议与 DTU 装置通信，将远程 LCD 画面以 Web 页面形式展示。
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前端通过 WebSocket 连接，服务端主动推送屏幕数据，实现低延迟传输。
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用法: python remo_disp_server.py [装置IP]
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启动后访问 http://localhost:8181
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依赖: pip install flask
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依赖: pip install flask flask-socketio pillow
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"""
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# base64：将二进制 PNG 编码为字符串，便于通过 JSON/WebSocket 传输
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import base64
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# socket：与 DTU 装置的 TCP 通信
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import socket
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# struct：将整数打包为二进制（如起始地址 4 字节）
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import struct
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import time
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# threading：后台线程持续拉取屏幕并推送
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import threading
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# sys：读取命令行参数（装置 IP）
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import sys
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# os：获取当前脚本目录，拼接 favicon 路径
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import os
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# io：BytesIO 用于在内存中保存 PNG
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import io
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from typing import Optional, Tuple
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# typing：类型注解
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from typing import Optional, Tuple, Set
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from flask import Flask, request, jsonify, send_file, Response
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# Flask：Web 框架，提供 HTTP 路由
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from flask import Flask, request, send_file
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# SocketIO：WebSocket 支持，实现实时双向通信
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from flask_socketio import SocketIO, emit
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# 协议常量
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# =============================================================================
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# 协议常量（RemoDispBus）
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# =============================================================================
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# TAG_CLIENT 0xAA：客户端发送帧的帧头标识
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# TAG_DEVICE 0xBB：设备回复帧的帧头标识
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TAG_CLIENT, TAG_DEVICE = 0xAA, 0xBB
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# PORT 7003：RemoDispBus 协议默认端口
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PORT = 7003
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# CMD_KEEPLIVE 0：保活
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# CMD_INIT 1：初始化，获取屏幕宽高、显存大小
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# CMD_KEY 2：按键
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# CMD_LCDMEM 3：读取显存（屏幕画面）
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CMD_KEEPLIVE, CMD_INIT, CMD_KEY, CMD_LCDMEM = 0, 1, 2, 3
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# 全局连接
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# =============================================================================
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# 全局状态
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# =============================================================================
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# _sock：与 DTU 装置的 TCP socket，None 表示未连接
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_sock: Optional[socket.socket] = None
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# _init_info：初始化信息（width/height/mem_size），由 CMD_INIT 获取
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_init_info: Optional[dict] = None
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# _screen_clients：当前需要接收屏幕推送的 WebSocket 客户端 sid 集合
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_screen_clients: Set[str] = set()
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# _refresh_thread：后台刷新线程，持续拉取屏幕并推送
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_refresh_thread: Optional[threading.Thread] = None
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# _refresh_stop：Event，set 时刷新线程退出
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_refresh_stop = threading.Event()
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# =============================================================================
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# 协议帧编解码
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# =============================================================================
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def calc_crc(data: bytes) -> int:
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crc = 0
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"""
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对数据区逐字节异或，取低 8 位作为 CRC 校验码。
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协议规定：CRC = data[0] ^ data[1] ^ ... ^ data[n-1]，取低 8 位。
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"""
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crc = 0 # 初始值为 0
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for b in data:
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crc ^= b
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return crc & 0xFF
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crc ^= b # 逐字节异或
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return crc & 0xFF # 取低 8 位作为最终 CRC
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def build_frame(cmd: int, data: bytes) -> bytes:
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length = len(data)
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"""
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构造一帧发送数据，格式: [TAG(1)][cmd(1)][len_hi(1)][len_lo(1)][data][crc(1)]
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length 大端 2 字节；crc 对 data 计算。
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"""
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length = len(data) # 数据区长度
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# 构造帧头：TAG_CLIENT + cmd + 长度高字节 + 长度低字节（大端序）
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header = bytes([TAG_CLIENT, cmd & 0xFF, (length >> 8) & 0xFF, length & 0xFF])
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return header + data + bytes([calc_crc(data)])
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return header + data + bytes([calc_crc(data)]) # 帧头 + 数据 + CRC
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def parse_frame(raw: bytes) -> Optional[Tuple[int, bytes]]:
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if len(raw) < 6 or raw[0] != TAG_DEVICE:
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"""
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解析设备回复帧，返回 (cmd, data) 或 None。
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帧格式: [TAG(1)][cmd(1)][len_hi(1)][len_lo(1)][data(length)][crc(1)]
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"""
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if len(raw) < 6 or raw[0] != TAG_DEVICE: # 至少 6 字节且帧头为 TAG_DEVICE
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return None
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length = (raw[2] << 8) | raw[3]
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if len(raw) < 5 + length + 1:
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length = (raw[2] << 8) | raw[3] # 大端序解析数据区长度
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if len(raw) < 4 + length + 1: # 检查是否收齐整帧（头4字节+数据+CRC1字节）
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return None
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data = raw[4:4 + length]
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if calc_crc(data) != raw[4 + length]:
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data = raw[4:4 + length] # 提取数据区
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if calc_crc(data) != raw[4 + length]: # CRC 校验失败
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return None
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return (raw[1], data)
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return (raw[1], data) # 返回 (命令码, 数据)
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# =============================================================================
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# 连接与收发
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# =============================================================================
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def connect(host: str, port: int = PORT) -> bool:
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"""
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建立与 DTU 装置的 TCP 连接。
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若有旧连接则先关闭；连接时超时 3 秒；连接成功后设为 2 秒。
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"""
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global _sock, _init_info
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try:
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if _sock:
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_sock.close()
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_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
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_sock.settimeout(5.0)
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_sock.connect((host, port))
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_sock.settimeout(2.0)
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_init_info = _request_init()
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_sock.close() # 关闭旧连接
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_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # 创建 TCP socket
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_sock.settimeout(3.0) # 连接阶段超时 3 秒
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_sock.connect((host, port)) # 连接目标主机和端口
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_sock.settimeout(2.0) # 连接成功后收发超时 2 秒
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return True
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except Exception:
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return False
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def _send(cmd: int, data: bytes = b"") -> bool:
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"""发送一帧到设备"""
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if not _sock:
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return False
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try:
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_sock.sendall(build_frame(cmd, data))
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_sock.sendall(build_frame(cmd, data)) # 构造帧并一次性发送
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return True
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except Exception:
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return False
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def _recv() -> Optional[Tuple[int, bytes]]:
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"""
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从设备接收一帧，一次性 recv 最多 256KB。
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至少需 5 字节（4 字节头+1 字节数据或 CRC）；根据头中 length 检查是否收齐整帧。
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"""
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if not _sock:
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return None
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try:
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header = _sock.recv(5)
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if len(header) < 5:
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data = _sock.recv(256 * 1024) # 单次接收最多 256KB
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if len(data) < 5: # 至少需要 5 字节（4 头 + 1 数据/CRC）
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return None
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length = (header[2] << 8) | header[3]
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rest = _sock.recv(length + 1)
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if len(rest) < length + 1:
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length = (data[2] << 8) | data[3] # 解析数据区长度
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if len(data) < 4 + length + 1: # 数据不完整
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return None
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return parse_frame(header + rest)
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return parse_frame(data[:4 + length + 1]) # 解析并返回 (cmd, data)
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except Exception:
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return None
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def _request_init() -> Optional[dict]:
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if not _send(CMD_INIT):
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return None
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for _ in range(30):
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result = _recv()
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if result and result[0] == CMD_INIT:
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data = result[1]
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if len(data) >= 29:
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return {
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"width": (data[0] << 8) | data[1],
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"height": (data[2] << 8) | data[3],
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"mem_size": (data[5] << 24) | (data[6] << 16) | (data[7] << 8) | data[8],
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}
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time.sleep(0.05)
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return None
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def send_key(code: int) -> bool:
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return _send(CMD_KEY, bytes([code & 0xFF]))
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"""发送按键码到设备"""
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return _send(CMD_KEY, bytes([code & 0xFF])) # 按键码单字节
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def fetch_screen() -> Optional[bytes]:
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global _init_info
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info = _init_info or _request_init()
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if not info:
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"""
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向设备请求当前屏幕显存，返回 1bpp 位图数据。
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发送 CMD_LCDMEM + 起始地址 0；设备回复 payload 前 4 字节为地址，后续为位图，返回 payload[4:]。
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"""
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if not _sock:
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return None
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mem_size = info["mem_size"]
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buffer = bytearray(mem_size)
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pos = 0
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while pos < mem_size:
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if not _send(CMD_LCDMEM, struct.pack(">I", pos)):
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return None
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for _ in range(40):
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result = _recv()
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if result and result[0] == CMD_LCDMEM:
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payload = result[1]
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if len(payload) >= 4:
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start = struct.unpack(">I", payload[:4])[0]
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chunk = payload[4:]
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buffer[start : start + len(chunk)] = chunk
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pos = start + len(chunk)
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break
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time.sleep(0.02)
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else:
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return None
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return bytes(buffer)
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if not _send(CMD_LCDMEM, struct.pack(">I", 0)): # 发送读取显存命令，起始地址 0（大端 4 字节）
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return None
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result = _recv() # 接收设备回复
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if result and result[0] == CMD_LCDMEM: # 确认为 LCDMEM 回复
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payload = result[1] # 数据区
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if len(payload) >= 4: # 前 4 字节为地址，后面是位图
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return payload[4:]
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return payload or None
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return None
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def mono_to_png(data: bytes, width: int, height: int) -> Optional[bytes]:
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"""
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将 1bpp 位图转为 PNG 字节流。
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每字节 8 像素，高位在前；bi=(y*w+x)//8 为字节索引，bit=7-(x%8) 为位索引；1 为白 255，0 为黑 0。
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"""
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try:
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from PIL import Image
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img = Image.new("1", (width, height))
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pix = img.load()
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img = Image.new("1", (width, height)) # 创建 1bpp 黑白图像
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pix = img.load() # 获取像素访问对象
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for y in range(height):
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for x in range(width):
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bi = (y * width + x) // 8
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bit = 7 - (x % 8)
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pix[x, y] = 255 if (bi < len(data) and (data[bi] >> bit) & 1) else 0
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buf = io.BytesIO()
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img.save(buf, format="PNG")
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return buf.getvalue()
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bi = (y * width + x) // 8 # 字节索引：每 8 像素一字节
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bit = 7 - (x % 8) # 位索引：高位在前
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pix[x, y] = 255 if (bi < len(data) and (data[bi] >> bit) & 1) else 0 # 1→白 0→黑
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buf = io.BytesIO() # 内存缓冲区
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img.save(buf, format="PNG") # 保存为 PNG 格式
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return buf.getvalue() # 返回 PNG 字节流
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except ImportError:
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return None
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app = Flask(__name__)
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def disconnect_device():
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"""关闭与设备的连接"""
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global _sock, _init_info
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try:
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if _sock:
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_sock.close() # 关闭 socket
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_sock = None # 清空引用
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_init_info = None # 清空初始化信息
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except Exception:
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pass
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# =============================================================================
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# 屏幕推送线程
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# =============================================================================
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def _screen_refresh_loop():
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"""
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后台线程：每约 100ms 拉取一帧屏幕，转 PNG 后 base64 推送给各 WebSocket 客户端。
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_refresh_stop.wait(0.1) 既作间隔，也便于收到 set 时快速退出。
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"""
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global _screen_clients, _refresh_stop
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while not _refresh_stop.is_set(): # 未被要求停止时持续循环
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if _screen_clients and _sock: # 有客户端且已连接设备
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data = fetch_screen() # 拉取屏幕位图
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if data:
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info = _init_info or {} # 获取宽高，缺省 160x160
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w, h = info.get("width", 160), info.get("height", 160)
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png = mono_to_png(data, w, h) # 转为 PNG
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if png:
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b64 = base64.b64encode(png).decode("ascii") # base64 编码便于 JSON 传输
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for sid in list(_screen_clients): # 复制列表避免迭代时修改
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try:
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socketio.emit("screen", {"png": b64, "w": w, "h": h}, room=sid) # 推送给该客户端
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except Exception:
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pass
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_refresh_stop.wait(timeout=0.1) # 等待 100ms，若被 set 则立即返回
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# =============================================================================
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# Flask + SocketIO
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# =============================================================================
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app = Flask(__name__) # 创建 Flask 应用
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app.config["SECRET_KEY"] = "remo_disp" # 会话密钥
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socketio = SocketIO(app, cors_allowed_origins="*") # 创建 SocketIO，允许跨域
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FAVICON_PATH = os.path.join(os.path.dirname(__file__), "static", "favicon.ico") # favicon 文件路径
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@app.route("/favicon.ico")
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def favicon():
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"""提供网站图标"""
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if os.path.exists(FAVICON_PATH):
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return send_file(FAVICON_PATH, mimetype="image/x-icon")
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return "", 404 # 不存在则返回 404
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@app.route("/")
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@app.route("/index.html")
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def index():
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"""主页，返回前端 HTML"""
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return send_file(
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os.path.join(os.path.dirname(__file__), "remo_disp_ui.html"),
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mimetype="text/html; charset=utf-8",
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)
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@app.route("/connect")
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def api_connect():
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host = request.args.get("host", "").strip()
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port = int(request.args.get("port", PORT))
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ok = connect(host, port)
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return jsonify(success=ok, error=None if ok else "connect failed")
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@socketio.on("connect")
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def on_connect():
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"""WebSocket 客户端连接时触发（可留空）"""
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pass
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@app.route("/key")
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def api_key():
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code = int(request.args.get("code", 0))
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send_key(code)
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return jsonify(ok=True)
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@socketio.on("disconnect")
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def on_disconnect():
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"""WebSocket 客户端断开（关标签页等）时，从 _screen_clients 移除，若无客户端则断开设备"""
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global _screen_clients, _refresh_thread, _refresh_stop
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sid = request.sid # 获取断开客户端的 session id
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if sid in _screen_clients:
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_screen_clients.discard(sid) # 从订阅列表移除
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if not _screen_clients: # 若无其他客户端
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_refresh_stop.set() # 通知刷新线程停止
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disconnect_device() # 断开设备连接
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@app.route("/screen")
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def api_screen():
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data = fetch_screen()
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if not data:
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return "", 500
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info = _init_info or {}
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w, h = info.get("width", 160), info.get("height", 160)
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png = mono_to_png(data, w, h)
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if png:
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return Response(png, mimetype="image/png")
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resp = Response(data, mimetype="application/octet-stream")
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resp.headers["X-Width"] = str(w)
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resp.headers["X-Height"] = str(h)
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return resp
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@socketio.on("connect_device")
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def on_connect_device(data):
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"""前端请求连接设备：连接成功后加入 _screen_clients，启动刷新线程，回复 connect_result"""
|
||||
global _screen_clients, _refresh_thread, _refresh_stop
|
||||
host = (data.get("host") or "").strip() # 从 data 取 host，去空格
|
||||
port = int(data.get("port") or PORT) # 从 data 取 port，缺省 7003
|
||||
ok = connect(host, port) # 建立 TCP 连接
|
||||
if ok:
|
||||
_screen_clients.add(request.sid) # 将当前客户端加入屏幕订阅
|
||||
_refresh_stop.clear() # 清除停止标志，允许刷新线程运行
|
||||
if _refresh_thread is None or not _refresh_thread.is_alive(): # 刷新线程未运行
|
||||
_refresh_thread = threading.Thread(target=_screen_refresh_loop, daemon=True) # 创建后台线程
|
||||
_refresh_thread.start() # 启动线程
|
||||
emit("connect_result", {"success": True}) # 回复连接成功
|
||||
else:
|
||||
emit("connect_result", {"success": False, "error": "connect failed"}) # 回复连接失败
|
||||
|
||||
|
||||
@socketio.on("disconnect_device")
|
||||
def on_disconnect_device():
|
||||
"""前端请求断开设备：从 _screen_clients 移除，若无客户端则断开设备，回复 disconnect_result"""
|
||||
global _screen_clients, _refresh_stop
|
||||
sid = request.sid
|
||||
_screen_clients.discard(sid) # 从订阅列表移除
|
||||
if not _screen_clients: # 若无其他客户端
|
||||
_refresh_stop.set() # 通知刷新线程停止
|
||||
disconnect_device() # 断开设备连接
|
||||
emit("disconnect_result", {"ok": True}) # 回复断开成功
|
||||
|
||||
|
||||
@socketio.on("key")
|
||||
def on_key(data):
|
||||
"""前端发送按键：从 data 取 code，转发给设备"""
|
||||
code = int(data.get("code", 0)) # 按键码，缺省 0
|
||||
send_key(code) # 发送给 DTU 设备
|
||||
|
||||
|
||||
# =============================================================================
|
||||
# 启动
|
||||
# =============================================================================
|
||||
|
||||
def main():
|
||||
port = 8181
|
||||
"""主入口：启动 Web 服务"""
|
||||
port = 8181 # HTTP 服务端口
|
||||
print(f"远程显示服务: http://localhost:{port}")
|
||||
print("在浏览器中打开上述地址，点击「连接」输入装置 IP")
|
||||
print("使用 WebSocket 传输，在浏览器中打开上述地址")
|
||||
if len(sys.argv) >= 2:
|
||||
connect(sys.argv[1])
|
||||
connect(sys.argv[1]) # 若命令行有 IP，预连接
|
||||
print(f"已预连接: {sys.argv[1]}")
|
||||
app.run(host="0.0.0.0", port=port, debug=False, threaded=True)
|
||||
socketio.run(app, host="0.0.0.0", port=port, debug=True, allow_unsafe_werkzeug=True) # 监听所有网卡
|
||||
|
||||
|
||||
if __name__ == "__main__":
|
||||
|
||||
Reference in New Issue
Block a user