download only audio from youtube video using youtube-dl in python script

问题

There\'s a few posts on downloading audio from YouTube using youtube-dl, but none of them are concrete or too helpful. I\'m wondering what the best way to do it from a Python script is.

For example, here\'s the README example for downloading videos:

import youtube_dl

ydl_opts = {}
with youtube_dl.YoutubeDL(ydl_opts) as ydl:
    ydl.download([\'http://www.youtube.com/watch?v=BaW_jenozKc\'])

Obviously if you just care about the audio, you\'d rather not download the whole video...

The youtube-dl source is only so helpful (ie, not very).

Any suggestions how to script this?

回答1:

Read on in the developer instructions for an amended example:

from __future__ import unicode_literals
import youtube_dl


ydl_opts = {
    'format': 'bestaudio/best',
    'postprocessors': [{
        'key': 'FFmpegExtractAudio',
        'preferredcodec': 'mp3',
        'preferredquality': '192',
    }],
}
with youtube_dl.YoutubeDL(ydl_opts) as ydl:
    ydl.download(['http://www.youtube.com/watch?v=BaW_jenozKc'])

This will download an audio file if possible/supported. If the file is not mp3 already, the downloaded file be converted to mp3 using ffmpeg or avconv. For more information, refer to the format and postprocessors documentation entries in a current version of youtube-dl.

回答2:

Use postprocessors argument. The list of all the available postprocessors can be found here.

If you want to pass additional ffmpeg or avconv options, which are not included in youtube-dl library (like audio bitrate - -ar <BR> in ffmpeg), add postprocessor_args as a list.

You can also prefer ffmpeg over avconv setting prefer_ffmpeg to True.

And to keep both original and converted audio file set 'keepvideo' to True.

For example:

from __future__ import unicode_literals
import youtube_dl

ydl_opts = {
    'format': 'bestaudio/best',
    'postprocessors': [{
        'key': 'FFmpegExtractAudio',
        'preferredcodec': 'wav',
        'preferredquality': '192'
    }],
    'postprocessor_args': [
        '-ar', '16000'
    ],
    'prefer_ffmpeg': True,
    'keepvideo': True
}

with youtube_dl.YoutubeDL(ydl_opts) as ydl:
    ydl.download(['http://www.youtube.com/watch?v=BaW_jenozKc'])

The list of all the available options is in the documentation. You can read ffmpeg posprocessor's code here.

And a less complex example is in their GitHub README.

来源：https://stackoverflow.com/questions/27473526/download-only-audio-from-youtube-video-using-youtube-dl-in-python-script

标签

python

audio

youtube

youtube-dl