YouTube long video (>1 hour) full verbatim transcription and translation workflow. Use when user needs to (1) Extract subtitles from YouTube videos, (2) Translate English transcripts to Chinese, (3) Handle long videos that exceed session limits, (4) Process DownSub API responses and generate formatted documents.

YouTube长视频（超过1小时）完整逐字转录与翻译流程。适用于用户需要：（1）从YouTube视频中提取字幕，（2）将英文转录文本翻译为中文，（3）处理超出会话限制的长视频，（4）处理DownSub API响应并生成格式化文档