pytube项目
最近我家姑娘的幼儿园外教需要一整套YouTube的教学儿歌《Singing Walrus Music》，在家长群里发出求助后，作为程序员的老爸必须把这个事情安排的明明白白的。
Github地址
https://github.com/nficano/pytube
文档地址
https://python-pytube.readthedocs.io
安装方式
快速上手
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| from pytube import YouTube
YouTube('http://youtube.com/watch?v=9bZkp7q19f0').streams.first().download()
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- pytube的
first() 方法，按照作者的解释，会选取最高分辨率的视频进行下载，但亲测后发现效果并不理想。 - YouTube的是采用DASH Streams的技术架构，其中的DASH技术会将视频、音频进行独立拆分，比如视频有480p video，720p video，音频有44100采样 audio，22050采样audio。通过以下代码即可输出DASH的Representation描述信息：
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| yt = YouTube('http://youtube.com/watch?v=9bZkp7q19f0')
yt.streams.all()
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| [<Stream: itag="22" mime_type="video/mp4" res="720p" fps="30fps" vcodec="avc1.64001F" acodec="mp4a.40.2">,
<Stream: itag="43" mime_type="video/webm" res="360p" fps="30fps" vcodec="vp8.0" acodec="vorbis">,
<Stream: itag="18" mime_type="video/mp4" res="360p" fps="30fps" vcodec="avc1.42001E" acodec="mp4a.40.2">,
<Stream: itag="36" mime_type="video/3gpp" res="240p" fps="30fps" vcodec="mp4v.20.3" acodec="mp4a.40.2">,
<Stream: itag="17" mime_type="video/3gpp" res="144p" fps="30fps" vcodec="mp4v.20.3" acodec="mp4a.40.2">,
<Stream: itag="137" mime_type="video/mp4" res="1080p" fps="30fps" vcodec="avc1.640028">,
<Stream: itag="248" mime_type="video/webm" res="1080p" fps="30fps" vcodec="vp9">,
<Stream: itag="136" mime_type="video/mp4" res="720p" fps="30fps" vcodec="avc1.4d401f">,
<Stream: itag="247" mime_type="video/webm" res="720p" fps="30fps" vcodec="vp9">,
<Stream: itag="135" mime_type="video/mp4" res="480p" fps="30fps" vcodec="avc1.4d401e">,
<Stream: itag="244" mime_type="video/webm" res="480p" fps="30fps" vcodec="vp9">,
<Stream: itag="134" mime_type="video/mp4" res="360p" fps="30fps" vcodec="avc1.4d401e">,
<Stream: itag="243" mime_type="video/webm" res="360p" fps="30fps" vcodec="vp9">,
<Stream: itag="133" mime_type="video/mp4" res="240p" fps="30fps" vcodec="avc1.4d4015">,
<Stream: itag="242" mime_type="video/webm" res="240p" fps="30fps" vcodec="vp9">,
<Stream: itag="160" mime_type="video/mp4" res="144p" fps="30fps" vcodec="avc1.4d400c">,
<Stream: itag="278" mime_type="video/webm" res="144p" fps="30fps" vcodec="vp9">,
<Stream: itag="140" mime_type="audio/mp4" abr="128kbps" acodec="mp4a.40.2">,
<Stream: itag="171" mime_type="audio/webm" abr="128kbps" acodec="vorbis">,
<Stream: itag="249" mime_type="audio/webm" abr="50kbps" acodec="opus">,
<Stream: itag="250" mime_type="audio/webm" abr="70kbps" acodec="opus">,
<Stream: itag="251" mime_type="audio/webm" abr="160kbps" acodec="opus">]
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- 其中
itag="22" 的视频为720p并带有音频（ acodec="mp4a.40.2" ）的视频文件；而 itag="136" 同样的720p的，却是无声版视频文件。 - 回到之前的pytube的
first() 方法，该方法会优先混合音频的视频源，再选择无声版视频源。这就导致一种极端情况发生， first() 会简单粗暴的选择了低分辨率的混合版视频源，忽略了高清版视频源。 - 我自己对视频筛选逻辑进行重新改写，后面会说明。
视频筛选
1、传统混合音频的视频源
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| yt.streams.filter(progressive=True).all()
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| [<Stream: itag="22" mime_type="video/mp4" res="720p" fps="30fps" vcodec="avc1.64001F" acodec="mp4a.40.2">,
<Stream: itag="43" mime_type="video/webm" res="360p" fps="30fps" vcodec="vp8.0" acodec="vorbis">,
<Stream: itag="18" mime_type="video/mp4" res="360p" fps="30fps" vcodec="avc1.42001E" acodec="mp4a.40.2">,
<Stream: itag="36" mime_type="video/3gpp" res="240p" fps="30fps" vcodec="mp4v.20.3" acodec="mp4a.40.2">,
<Stream: itag="17" mime_type="video/3gpp" res="144p" fps="30fps" vcodec="mp4v.20.3" acodec="mp4a.40.2">]
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2、DASH流的视频源
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| yt.streams.filter(adaptive=True).all()
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| [<Stream: itag="137" mime_type="video/mp4" res="1080p" fps="30fps" vcodec="avc1.640028">,
<Stream: itag="248" mime_type="video/webm" res="1080p" fps="30fps" vcodec="vp9">,
<Stream: itag="136" mime_type="video/mp4" res="720p" fps="30fps" vcodec="avc1.4d401f">,
<Stream: itag="247" mime_type="video/webm" res="720p" fps="30fps" vcodec="vp9">,
<Stream: itag="135" mime_type="video/mp4" res="480p" fps="30fps" vcodec="avc1.4d401e">,
<Stream: itag="244" mime_type="video/webm" res="480p" fps="30fps" vcodec="vp9">,
<Stream: itag="134" mime_type="video/mp4" res="360p" fps="30fps" vcodec="avc1.4d401e">,
<Stream: itag="243" mime_type="video/webm" res="360p" fps="30fps" vcodec="vp9">,
<Stream: itag="133" mime_type="video/mp4" res="240p" fps="30fps" vcodec="avc1.4d4015">,
<Stream: itag="242" mime_type="video/webm" res="240p" fps="30fps" vcodec="vp9">,
<Stream: itag="160" mime_type="video/mp4" res="144p" fps="30fps" vcodec="avc1.4d400c">,
<Stream: itag="278" mime_type="video/webm" res="144p" fps="30fps" vcodec="vp9">,
<Stream: itag="140" mime_type="audio/mp4" abr="128kbps" acodec="mp4a.40.2">,
<Stream: itag="171" mime_type="audio/webm" abr="128kbps" acodec="vorbis">,
<Stream: itag="249" mime_type="audio/webm" abr="50kbps" acodec="opus">,
<Stream: itag="250" mime_type="audio/webm" abr="70kbps" acodec="opus">,
<Stream: itag="251" mime_type="audio/webm" abr="160kbps" acodec="opus">]
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3、其它过滤条件
only_audio=True ：只下载音频only_video ：只下载视频subtype='mp4' ：下载扩展名为“mp4”的文件，包括音频和视频res="720p" ：下载清晰度为720p的视频abr="64kbps" ：下载码率为64kbps的视频video_codec="vp9" ：下载压缩格式为vp9的视频audio_codec="vorbis" ：下载压缩格式为vorbis的音频
通过itag下载视频
- YouTube对每个DASH流的视频源的类型给了一个独立的id，称为itag
- 可通过
get_by_itag 方法下载对应视频
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| yt.streams.get_by_itag(22)
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| itag Code | Container | Content | Resolution | Bitrate | Range | VR / 3D |
|---|
| 5 | flv | audio/video | 240p | - | - | - |
| 6 | flv | audio/video | 270p | - | - | - |
| 17 | 3gp | audio/video | 144p | - | - | - |
| 18 | mp4 | audio/video | 360p | - | - | - |
| 22 | mp4 | audio/video | 720p | - | - | - |
| 34 | flv | audio/video | 360p | - | - | - |
| 35 | flv | audio/video | 480p | - | - | - |
| 36 | 3gp | audio/video | 180p | - | - | - |
| 37 | mp4 | audio/video | 1080p | - | - | - |
| 38 | mp4 | audio/video | 3072p | - | - | - |
| 43 | webm | audio/video | 360p | - | - | - |
| 44 | webm | audio/video | 480p | - | - | - |
| 45 | webm | audio/video | 720p | - | - | - |
| 46 | webm | audio/video | 1080p | - | - | - |
| 82 | mp4 | audio/video | 360p | - | - | 3D |
| 83 | mp4 | audio/video | 480p | - | - | 3D |
| 84 | mp4 | audio/video | 720p | - | - | 3D |
| 85 | mp4 | audio/video | 1080p | - | - | 3D |
| 92 | hls | audio/video | 240p | - | - | 3D |
| 93 | hls | audio/video | 360p | - | - | 3D |
| 94 | hls | audio/video | 480p | - | - | 3D |
| 95 | hls | audio/video | 720p | - | - | 3D |
| 96 | hls | audio/video | 1080p | - | - | - |
| 100 | webm | audio/video | 360p | - | - | 3D |
| 101 | webm | audio/video | 480p | - | - | 3D |
| 102 | webm | audio/video | 720p | - | - | 3D |
| 132 | hls | audio/video | 240p | - | - | |
| 133 | mp4 | video | 240p | - | - | |
| 134 | mp4 | video | 360p | - | - | |
| 135 | mp4 | video | 480p | - | - | |
| 136 | mp4 | video | 720p | - | - | |
| 137 | mp4 | video | 1080p | - | - | |
| 138 | mp4 | video | 2160p60 | - | - | |
| 139 | m4a | audio | - | 48k | - | |
| 140 | m4a | audio | - | 128k | - | |
| 141 | m4a | audio | - | 256k | - | |
| 151 | hls | audio/video | 72p | - | - | |
| 160 | mp4 | video | 144p | - | - | |
| 167 | webm | video | 360p | - | - | |
| 168 | webm | video | 480p | - | - | |
| 169 | webm | video | 1080p | - | - | |
| 171 | webm | audio | - | 128k | - | |
| 218 | webm | video | 480p | - | - | |
| 219 | webm | video | 144p | - | - | |
| 242 | webm | video | 240p | - | - | |
| 243 | webm | video | 360p | - | - | |
| 244 | webm | video | 480p | - | - | |
| 245 | webm | video | 480p | - | - | |
| 246 | webm | video | 480p | - | - | |
| 247 | webm | video | 720p | - | - | |
| 248 | webm | video | 1080p | - | - | |
| 249 | webm | audio | - | 50k | - | |
| 250 | webm | audio | - | 70k | - | |
| 251 | webm | audio | - | 160k | - | |
| 264 | mp4 | video | 1440p | - | - | |
| 266 | mp4 | video | 2160p60 | - | - | |
| 271 | webm | video | 1440p | - | - | |
| 272 | webm | video | 4320p | - | - | |
| 278 | webm | video | 144p | - | - | |
| 298 | mp4 | video | 720p60 | - | - | |
| 299 | mp4 | video | 1080p60 | - | - | |
| 302 | webm | video | 720p60 | - | - | |
| 303 | webm | video | 1080p60 | - | - | |
| 308 | webm | video | 1440p60 | - | - | |
| 313 | webm | video | 2160p | - | - | |
| 315 | webm | video | 2160p60 | - | - | |
| 330 | webm | video | 144p60 | - | hdr | |
| 331 | webm | video | 240p60 | - | hdr | |
| 332 | webm | video | 360p60 | - | hdr | |
| 333 | webm | video | 480p60 | - | hdr | |
| 334 | webm | video | 720p60 | - | hdr | |
| 335 | webm | video | 1080p60 | - | hdr | |
| 336 | webm | video | 1440p60 | - | hdr | |
| 337 | webm | video | 2160p60 | - | hdr | |
| 394 | mp4 | video | 144p | - | - | |
| 395 | mp4 | video | 240p | - | - | |
| 396 | mp4 | video | 360p | - | - | |
| 397 | mp4 | video | 480p | - | - | |
| 398 | mp4 | video | 720p | - | - | |
| 399 | mp4 | video | 1080p | - | - | |
| 400 | mp4 | video | 1440p | - | - | |
| 401 | mp4 | video | 2160p | - | - | |
| 402 | mp4 | video | 2880p | - | - | |
关于网络
- 因为需要避免西方资本主义思想毒害，网络经常请求不稳定
- 常见的错误会有以下两种：
HTTPErrorURLError- 使用Pycharm的同学还会遇到
ConnectionResetError
- 前两种错误需要引入
from urllib.error import HTTPError, URLError - 然后通过where循环，try…except… 来重复请求
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| yt = None
while True:
try:
yt = YouTube(url)
break
except HTTPError:
self.logger.error("请求出错一次：HTTPError")
continue
except URLError:
self.logger.error("请求出错一次：URLError")
continue
streams = yt.streams.filter(subtype='mp4').all()
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下载视频
- 当确认了符合条件的视频后，可通过
download 的方式直接下载
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| from pytube import YouTube
yt=YouTube('http://youtube.com/watch?v=9bZkp7q19f0')
mp4=yt.streams.first()
mp4.download(output_path, filename, filename_prefix)
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- 其中
download 会接受3个参数：output_path ：视频输出路径；filename ：视频输出名称，默认为视频的标题，该名称不需要扩展名；filename_prefix ：视频名称前缀，这里主要是区分音频和视频，因为音频和视频下载后名称相同，格式相同，前者会被后者覆盖掉。可以增加前缀来进行区分，比如音频为“audio_FilmTitle.mp4”、视频为“video_FilmTitle.mp4”
音视频合并
