youtube-dl 是一款开源的视频下载工具，通过它我们可以很方便的下载 YouTube 上的视频，还可以进行各种选项设置。

安装

本人使用的是 python3，安装使用 pip ：

pip install youtube-dl

使用

最简单的用法：

youtube-dl https://www.youtube.com/watch?v=kcMaxo0OaZo&index=3&list=PLC6RoM2FxOWMvFnGZ4a15MKa-iSaadkdp&t=0s

指定音频视频的质量

如果要指定视频的解析度，比如选择最好的：

youtube-dl -f best https://www.youtube.com/watch?v=kcMaxo0OaZo&index=3&list=PLC6RoM2FxOWMvFnGZ4a15MKa-iSaadkdp&t=0s

如果想自定义下载最好的音视频, 那么, 先列出所有的格式再选择:

youtube-dl -F https://www.youtube.com/watch?v=M2NIfqE4H1o

youtube-dl -F https://www.youtube.com/watch?v=M2NIfqE4H1o
[youtube] M2NIfqE4H1o: Downloading webpage
[youtube] M2NIfqE4H1o: Downloading video info webpage
[info] Available formats for M2NIfqE4H1o:
format code  extension  resolution note
249          webm       audio only DASH audio   72k , opus @ 50k, 1.81MiB
250          webm       audio only DASH audio   93k , opus @ 70k, 2.37MiB
171          webm       audio only DASH audio  110k , vorbis@128k, 2.96MiB
140          m4a        audio only DASH audio  130k , m4a_dash container, mp4a.40.2@128k, 3.61MiB
251          webm       audio only DASH audio  172k , opus @160k, 4.46MiB
160          mp4        256x144    144p   84k , avc1.4d400c, 24fps, video only, 1.46MiB
278          webm       256x144    144p   96k , webm container, vp9, 24fps, video only, 2.46MiB
133          mp4        426x240    240p  152k , avc1.4d4015, 24fps, video only, 2.69MiB
242          webm       426x240    240p  206k , vp9, 24fps, video only, 4.18MiB
134          mp4        640x360    360p  356k , avc1.4d401e, 24fps, video only, 6.74MiB
243          webm       640x360    360p  389k , vp9, 24fps, video only, 7.85MiB
135          mp4        854x480    480p  679k , avc1.4d401e, 24fps, video only, 13.21MiB
244          webm       854x480    480p  683k , vp9, 24fps, video only, 13.45MiB
136          mp4        1280x720   720p 1225k , avc1.4d401f, 24fps, video only, 24.05MiB
247          webm       1280x720   720p 1328k , vp9, 24fps, video only, 27.04MiB
137          mp4        1920x1080  1080p 2159k , avc1.640028, 24fps, video only, 42.73MiB
248          webm       1920x1080  1080p 2445k , vp9, 24fps, video only, 49.17MiB
271          webm       2560x1440  1440p 6899k , vp9, 24fps, video only, 117.11MiB
17           3gp        176x144    small   78k , mp4v.20.3, mp4a.40.2@ 24k (22050Hz), 2.19MiB
36           3gp        320x180    small  216k , mp4v.20.3, mp4a.40.2 (22050Hz), 6.02MiB
18           mp4        640x360    medium  525k , avc1.42001E, mp4a.40.2@ 96k (44100Hz), 14.64MiB (best)

接着只要指定 format code 即可.

youtube-dl -f 137+140 --merge-output-format mp4 https://www.youtube.com/watch?v=M2NIfqE4H1o

常用的组合:

组合:
137+140

音频
140          m4a        audio only DASH audio  128k , m4a_dash container, mp4a.40.2@128k

视频
134          mp4        640x360    360p
135          mp4        854x480    480p
137

由于上面是 video only + audio 两个文件 , 我们需要合并 video 和 audio

youtube-dl -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/bestvideo+bestaudio' --merge-output-format mp4 'http://www.youtube.com/watch?v=M2NIfqE4H1o'
[youtube] M2NIfqE4H1o: Downloading webpage
[youtube] M2NIfqE4H1o: Downloading video info webpage
WARNING: You have requested multiple formats but ffmpeg or avconv are not installed. The formats won't be merged.
[download] Destination: My Funny Valentine (Richard Rodgers) - Alexandra Whittingham-M2NIfqE4H1o.f137.mp4
[download] 100% of 42.73MiB in 02:07
[download] Destination: My Funny Valentine (Richard Rodgers) - Alexandra Whittingham-M2NIfqE4H1o.f140.m4a
[download] 100% of 3.61MiB in 00:10

上面提示 ffmpeg or avconv are not installed, 因此需要安装 ffmpeg.
安装完成后, 加上 --merge-output-format mp4 参数(其实不加也可以,会自动合并的), 重新执行

youtube-dl -f 160+140 --merge-output-format mp4 https://www.youtube.com/watch?v=M2NIfqE4H1o
[youtube] M2NIfqE4H1o: Downloading webpage
[youtube] M2NIfqE4H1o: Downloading video info webpage
[download] My Funny Valentine (Richard Rodgers) - Alexandra Whittingham-M2NIfqE4H1o.f160.mp4 has already been downloaded
[download] 100% of 1.46MiB
[download] My Funny Valentine (Richard Rodgers) - Alexandra Whittingham-M2NIfqE4H1o.f140.m4a has already been downloaded
[download] 100% of 3.61MiB
[ffmpeg] Merging formats into "My Funny Valentine (Richard Rodgers) - Alexandra Whittingham-M2NIfqE4H1o.mp4"
Deleting original file My Funny Valentine (Richard Rodgers) - Alexandra Whittingham-M2NIfqE4H1o.f160.mp4 (pass -k to keep)
Deleting original file My Funny Valentine (Richard Rodgers) - Alexandra Whittingham-M2NIfqE4H1o.f140.m4a (pass -k to keep)

其他 `-f` 格式参数：

# 常用
# 下载质量最好的 mp4 格式， 如果没有则下载其他格式质量最好的
'bestvideo[ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]/best'


# Download best format available but not better that 480p
# 下载质量最好的格式， 但不要超过 480p
'bestvideo[height<=480]+bestaudio/best[height<=480]'


# 最好mp4
youtube-dl -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/mp4' url

test niko 常用:

135+140, mp4 文件(480p):

'bestvideo[height<=480][ext=mp4]+bestaudio/best[height<=480]'

480p 格式大小的(手机常用): (不太好用,输出是.mkv文件)

'bestvideo[height<=480][ext=mp4]+bestaudio/best[height<=480]'

更多的功能可参考下面的文档。

选择字幕

Subtitle Options:
--write-sub                      Write subtitle file
--write-auto-sub                 Write automatically generated subtitle file
                                 (YouTube only)
--all-subs                       Download all the available subtitles of the
                                 video
--list-subs                      List all available subtitles for the video
--sub-format FORMAT              Subtitle format, accepts formats
                                 preference, for example: "srt" or
                                 "ass/srt/best"
--sub-lang LANGS                 Languages of the subtitles to download
                                 (optional) separated by commas, use --list-
                                 subs for available language tags

--write-sub 这个貌似是把字幕内容写到一个字幕文件里(vtt或者srt等等)

查询所有的:

youtube-dl --list-subs https://www.youtube.com/watch\?v\=rqoxYKtEWEc                
[youtube] rqoxYKtEWEc: Downloading webpage
[youtube] rqoxYKtEWEc: Looking for automatic captions
Available automatic captions for rqoxYKtEWEc:
...
zh-Hans  vtt, ttml, srv3, srv2, srv1
zh-Hant  vtt, ttml, srv3, srv2, srv1
en       vtt, ttml, srv3, srv2, srv1

Available subtitles for rqoxYKtEWEc:
Language formats
zh-Hans  vtt, ttml, srv3, srv2, srv1
en       vtt, ttml, srv3, srv2, srv1
fr       vtt, ttml, srv3, srv2, srv1
de       vtt, ttml, srv3, srv2, srv1
iw       vtt, ttml, srv3, srv2, srv1
ja       vtt, ttml, srv3, srv2, srv1
pt-BR    vtt, ttml, srv3, srv2, srv1
es-419   vtt, ttml, srv3, srv2, srv1

下载视频

貌似没有办法嵌入字幕到视频文件里
--write-sub 是写到独立字幕文件.
--sub-format srt 指定字幕文件的格式.

youtube-dl --write-sub --sub-format srt --sub-lang zh-Hans -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]/best' "https://www.youtube.com/watch?v=rqoxYKtEWEc"

多字幕:(逗号分割)
youtube-dl --write-sub --sub-lang zh-Hans,en -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]/best' "https://www.youtube.com/watch?v=rqoxYKtEWEc"

niko collect

下载最低质量的:
youtube-dl -f worst url

参考

https://github.com/rg3/youtube-dl/blob/master/README.md#readme
command line - How to select video quality from youtube-dl? - Ask Ubuntu

安装

使用