爬虫下载B站视频简单程序（仅供学习）

请输入视频链接：https://www.bilibili.com/video/BV1owFSeREoh （示例地址）                                 程序显示结果如下：              
下载进度: 100.00%
下载完成
视频已保存到: ./video.mp4

核心功能

1. 视频信息解析

• 自动识别B站视频格式（新版DASH/旧版FLV）

• 提取最高画质视频流地址

• 支持分段视频检测

2.下载

• 多线程分块下载（1MB/块）

• 自动重试机制（最多5次）

• 实时下载进度显示

• 支持代理和反爬策略

- 通过正则提取B站视频核心数据

• 包含分辨率、码率、分段地址等关键信息   re.search(r'<script>window\.__playinfo__=(.*?)</script>', html)

注意：

• 仅下载已获得观看权限的内容

• 本代码仅供学习使用，请遵守B站用户协议和版权法规

import re
import json
import requests
from urllib.parse import urlparse
import subprocess
import timeclass BilibiliDownloader:def __init__(self, url):self.url = urlself.headers = {'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36','Referer': 'https://www.bilibili.com/'}def get_video_info(self):# 获取视频页面源码response = requests.get(self.url, headers=self.headers)html = response.text# 提取JSON格式的视频信息match = re.search(r'<script>window\.__playinfo__=(.*?)</script>', html)if match:return json.loads(match.group(1))else:raise Exception("无法提取视频信息")def download_video(self, save_path='./video.mp4'):# 获取视频下载链接video_info = self.get_video_info()# 处理不同视频格式（优先dash格式）try:if video_info['data'].get('dash'):# Dash格式视频流video_list = video_info['data']['dash']['video']best_quality = max(video_list, key=lambda x: x['bandwidth'])video_url = best_quality['baseUrl']else:  # 旧版FLV格式video_list = video_info['data']['durl']best_quality = max(video_list, key=lambda x: x['size'])video_url = best_quality['url']# 处理分段视频（需要合并多个flv）if len(video_list) > 1:print("检测到分段视频，需要合并多个文件...")return self._download_flv_segments(video_list, save_path)except KeyError as e:raise Exception(f"不支持的视频格式: {str(e)}")# 使用requests流式下载（带重试机制）max_retries = 5timeout = 15  # 设置超时时间（秒）chunk_size = 1024 * 1024  # 1MB chunksfor attempt in range(max_retries):try:with requests.get(video_url, headers=self.headers, stream=True, timeout=timeout) as r:r.raise_for_status()total_size = int(r.headers.get('content-length', 0))with open(save_path, 'wb') as f:downloaded = 0for chunk in r.iter_content(chunk_size=chunk_size):if chunk:  # 过滤保持连接的空白chunkf.write(chunk)downloaded += len(chunk)print(f"\r下载进度: {downloaded/total_size:.2%}", end='')print("\n下载完成")breakexcept (requests.exceptions.Timeout, requests.exceptions.ConnectionError) as e:print(f"\n第 {attempt+1} 次尝试失败: {str(e)}")if attempt == max_retries - 1:raise Exception("多次尝试下载失败，请检查网络连接")time.sleep(2 ** attempt)  # 指数退避# 合并音视频（需要ffmpeg）self._merge_audio_video(save_path)print(f"视频已保存到: {save_path}")def _download_flv_segments(self, segments, save_path):"""下载并合并FLV分段视频"""temp_files = []for i, seg in enumerate(segments):part_url = seg['url']part_file = f"{save_path}.part{i}"temp_files.append(part_file)with requests.get(part_url, headers=self.headers, stream=True) as r:with open(part_file, 'wb') as f:for chunk in r.iter_content(chunk_size=8192):f.write(chunk)self._merge_files(temp_files, save_path)if __name__ == "__main__":video_url = input("请输入视频链接：")downloader = BilibiliDownloader(video_url)downloader.download_video()