Merge pull request #428 from pumpkinperson996/fix/ytdlp-zero-retries

fix(downloader): yt-dlp 未设 retries 时零重试，一次网络抖动就让任务失败

backend/app/downloaders/base.py

@@ -13,6 +13,19 @@ QUALITY_MAP = {
     "slow": "128"
 }
 
+# yt-dlp 的 `retries` 默认值(10)是命令行参数解析器给的，Python API 不套用它：
+# 不显式设置时 HttpFD 拿到的是 `self.params.get('retries')` == None，而
+# `RetryManager.__init__` 做的是 `self.retries = _retries or 0`——也就是
+# 一次都不重试。任何一次网络抖动（例如 B 站 CDN
+# upos-sz-mirror*.bilivideo.com 读超时）都会让整个笔记任务直接失败。
+#
+# 这里的值偏保守：笔记任务是用户在前台等的，重试太多不如早点失败让用户重来。
+YDL_RETRY_OPTS = {
+    "retries": 3,
+    "fragment_retries": 3,
+    "socket_timeout": 30,
+}
+
 
 class Downloader(ABC):
     def __init__(self):

backend/app/downloaders/bilibili_downloader.py

@@ -7,7 +7,7 @@ from typing import Union, Optional, List
 
 import yt_dlp
 
-from app.downloaders.base import Downloader, DownloadQuality, QUALITY_MAP
+from app.downloaders.base import Downloader, DownloadQuality, QUALITY_MAP, YDL_RETRY_OPTS
 from app.downloaders.bilibili_dm_patch import apply_bilibili_dm_img_patch
 from app.downloaders.bilibili_subtitle import BilibiliSubtitleFetcher
 from app.models.notes_model import AudioDownloadResult
@@ -63,6 +63,7 @@ class BilibiliDownloader(Downloader, ABC):
         output_path = os.path.join(output_dir, "%(id)s.%(ext)s")
 
         ydl_opts = {
+            **YDL_RETRY_OPTS,
             'format': 'bestaudio[ext=m4a]/bestaudio/best',
             'outtmpl': output_path,
             'http_headers': {'Referer': 'https://www.bilibili.com'},
@@ -122,6 +123,7 @@ class BilibiliDownloader(Downloader, ABC):
         output_path = os.path.join(output_dir, "%(id)s.%(ext)s")
 
         ydl_opts = {
+            **YDL_RETRY_OPTS,
             'format': 'bv*[ext=mp4]/bestvideo+bestaudio/best',
             'outtmpl': output_path,
             'http_headers': {'Referer': 'https://www.bilibili.com'},
@@ -183,6 +185,7 @@ class BilibiliDownloader(Downloader, ABC):
         video_id = extract_video_id(video_url, "bilibili")
 
         ydl_opts = {
+            **YDL_RETRY_OPTS,
             'writesubtitles': True,
             'writeautomaticsub': True,
             'subtitleslangs': langs,

backend/app/downloaders/youtube_downloader.py

@@ -5,7 +5,7 @@ from typing import Union, Optional, List
 
 import yt_dlp
 
-from app.downloaders.base import Downloader, DownloadQuality
+from app.downloaders.base import Downloader, DownloadQuality, YDL_RETRY_OPTS
 from app.downloaders.youtube_subtitle import YouTubeSubtitleFetcher
 from app.models.notes_model import AudioDownloadResult
 from app.models.transcriber_model import TranscriptResult
@@ -47,6 +47,7 @@ class YoutubeDownloader(Downloader, ABC):
         output_path = os.path.join(output_dir, "%(id)s.%(ext)s")
 
         ydl_opts = {
+            **YDL_RETRY_OPTS,
             'format': 'bestaudio[ext=m4a]/bestaudio/best',
             'outtmpl': output_path,
             'noplaylist': True,
@@ -100,6 +101,7 @@ class YoutubeDownloader(Downloader, ABC):
         output_path = os.path.join(output_dir, "%(id)s.%(ext)s")
 
         ydl_opts = {
+            **YDL_RETRY_OPTS,
             'format': 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]',
             'outtmpl': output_path,
             'noplaylist': True,