Files
BiliNote/backend/app/downloaders/youtube_downloader.py
T
huangjianwuandClaude Opus 4.6 f4801d5be7 feat(youtube): 使用 youtube-transcript-api 优先获取字幕,有字幕时跳过音频下载
- 新增 YouTubeSubtitleFetcher 模块,通过 youtube-transcript-api 获取字幕
- 重构笔记生成流程:缓存 → 平台字幕 → 按需下载 → 转写 fallback
- 有字幕时仅提取视频元信息,不下载音视频文件
- 添加 youtube-transcript-api 依赖

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-23 17:31:30 +08:00

124 lines
4.1 KiB
Python

import os
import logging
from abc import ABC
from typing import Union, Optional, List
import yt_dlp
from app.downloaders.base import Downloader, DownloadQuality
from app.downloaders.youtube_subtitle import YouTubeSubtitleFetcher
from app.models.notes_model import AudioDownloadResult
from app.models.transcriber_model import TranscriptResult
from app.utils.path_helper import get_data_dir
from app.utils.url_parser import extract_video_id
logger = logging.getLogger(__name__)
class YoutubeDownloader(Downloader, ABC):
def __init__(self):
super().__init__()
def download(
self,
video_url: str,
output_dir: Union[str, None] = None,
quality: DownloadQuality = "fast",
need_video: Optional[bool] = False,
skip_download: bool = False,
) -> AudioDownloadResult:
if output_dir is None:
output_dir = get_data_dir()
if not output_dir:
output_dir = self.cache_data
os.makedirs(output_dir, exist_ok=True)
output_path = os.path.join(output_dir, "%(id)s.%(ext)s")
ydl_opts = {
'format': 'bestaudio[ext=m4a]/bestaudio/best',
'outtmpl': output_path,
'noplaylist': True,
'quiet': False,
}
if skip_download:
ydl_opts['skip_download'] = True
with yt_dlp.YoutubeDL(ydl_opts) as ydl:
info = ydl.extract_info(video_url, download=not skip_download)
video_id = info.get("id")
title = info.get("title")
duration = info.get("duration", 0)
cover_url = info.get("thumbnail")
ext = info.get("ext", "m4a")
audio_path = os.path.join(output_dir, f"{video_id}.{ext}")
return AudioDownloadResult(
file_path=audio_path,
title=title,
duration=duration,
cover_url=cover_url,
platform="youtube",
video_id=video_id,
raw_info={'tags': info.get('tags')},
video_path=None,
)
def download_video(
self,
video_url: str,
output_dir: Union[str, None] = None,
) -> str:
"""
下载视频,返回视频文件路径
"""
if output_dir is None:
output_dir = get_data_dir()
video_id = extract_video_id(video_url, "youtube")
video_path = os.path.join(output_dir, f"{video_id}.mp4")
if os.path.exists(video_path):
return video_path
os.makedirs(output_dir, exist_ok=True)
output_path = os.path.join(output_dir, "%(id)s.%(ext)s")
ydl_opts = {
'format': 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]',
'outtmpl': output_path,
'noplaylist': True,
'quiet': False,
'merge_output_format': 'mp4', # 确保合并成 mp4
}
with yt_dlp.YoutubeDL(ydl_opts) as ydl:
info = ydl.extract_info(video_url, download=True)
video_id = info.get("id")
video_path = os.path.join(output_dir, f"{video_id}.mp4")
if not os.path.exists(video_path):
raise FileNotFoundError(f"视频文件未找到: {video_path}")
return video_path
def download_subtitles(self, video_url: str, output_dir: str = None,
langs: List[str] = None) -> Optional[TranscriptResult]:
"""
通过 YouTube InnerTube API 直接获取字幕(优先人工字幕,其次自动生成)。
比 yt_dlp 方式更轻量,无需写临时文件到磁盘。
:param video_url: 视频链接
:param output_dir: 未使用(保留接口兼容)
:param langs: 优先语言列表
:return: TranscriptResult 或 None
"""
if langs is None:
langs = ['zh-Hans', 'zh', 'zh-CN', 'zh-TW', 'en', 'en-US', 'ja']
video_id = extract_video_id(video_url, "youtube")
fetcher = YouTubeSubtitleFetcher()
print(
f"尝试获取字幕,video_id={video_id}, langs={langs}"
)
return fetcher.fetch_subtitles(video_id, langs)