2 Questions using aria2c in python

[TA40]

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Make sure you are using the latest version: run youtube-dl --version and ensure your version is 2019.03.09. If it's not, read this FAQ entry and update. Issues with outdated version will be rejected.

• I've verified and I assure that I'm running youtube-dl 2019.03.09

Before submitting an issue make sure you have:

• At least skimmed through the README, most notably the FAQ and BUGS sections
• Searched the bugtracker for similar issues including closed ones
• Checked that provided video/audio/playlist URLs (if any) are alive and playable in a browser

What is the purpose of your issue?

• Bug report (encountered problems with youtube-dl)
• Site support request (request for adding support for a new site)
• Feature request (request for a new functionality)
• Question
• Other

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If the purpose of this issue is a bug report, site support request or you are not completely sure provide the full verbose output as follows:

[debug] Encodings: locale cp1252, fs utf-8, out utf-8, pref cp1252
[debug] youtube-dl version 2019.03.09
[debug] Python version 3.6.4 (CPython) - Windows-10-10.0.17763-SP0
[debug] exe versions: ffmpeg 3.4.2
[debug] Proxy map: {}
[youtube] DLzxrzFCyOs: Downloading webpage
[youtube] DLzxrzFCyOs: Downloading video info webpage
[youtube] {18} signature length 42.41, html5 player vflkyt12p
[youtube] {271} signature length 42.41, html5 player vflkyt12p
[youtube] {137} signature length 42.41, html5 player vflkyt12p
[youtube] {248} signature length 42.41, html5 player vflkyt12p
[youtube] {136} signature length 42.41, html5 player vflkyt12p
[youtube] {247} signature length 42.41, html5 player vflkyt12p
[youtube] {135} signature length 42.41, html5 player vflkyt12p
[youtube] {244} signature length 42.41, html5 player vflkyt12p
[youtube] {134} signature length 42.41, html5 player vflkyt12p
[youtube] {243} signature length 42.41, html5 player vflkyt12p
[youtube] {133} signature length 42.41, html5 player vflkyt12p
[youtube] {242} signature length 42.41, html5 player vflkyt12p
[youtube] {160} signature length 42.41, html5 player vflkyt12p
[youtube] {278} signature length 42.41, html5 player vflkyt12p
[youtube] {140} signature length 42.41, html5 player vflkyt12p
[youtube] {171} signature length 42.41, html5 player vflkyt12p
[youtube] {249} signature length 42.41, html5 player vflkyt12p
[youtube] {250} signature length 42.41, html5 player vflkyt12p
[youtube] {251} signature length 42.41, html5 player vflkyt12p
[debug] Default format spec: bestvideo+bestaudio/best
[debug] Invoking downloader on 'https://r2---sn-4g5e6nsk.googlevideo.com/videoplayback?lmt=1538219388413002&dur=212.579&txp=5532432&itag=271&clen=88019015&gir=yes&fvip=2&sparams=aitags%2Cclen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Ckeepalive%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Crequiressl%2Csource%2Cexpire&requiressl=yes&source=youtube&aitags=133%2C134%2C135%2C136%2C137%2C160%2C242%2C243%2C244%2C247%2C248%2C271%2C278&mv=m&mt=1552535616&ms=au%2Conr&pl=16&keepalive=yes&id=o-AD37HiS6Wta-Q-vceNFTu7Jg5HmlTkKI876F0HtWEAj9&ipbits=0&mn=sn-4g5e6nsk%2Csn-h0jeener&mm=31%2C26&ip=176.198.183.108&initcwndbps=1548750&c=WEB&expire=1552557338&ei=udCJXO3vO8a_gQeA8bbQCA&key=yt6&mime=video%2Fwebm&signature=3B28054F94099C4551264ADCA2A5CF12EF0D5A56.05D567FFE576E7FDABD4A9213728EA89E50CB6DA&ratebypass=yes'
[download] Destination: Rick Astley - Never Gonna Give You Up [HQ]-DLzxrzFCyOs.f271.webm
Traceback (most recent call last):
  File "testen.py", line 12, in <module>
    down.download(["https://www.youtube.com/watch?v=DLzxrzFCyOs"])
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\lib\site-packages\youtube_dl\YoutubeDL.py", line 2006, in download
    url, force_generic_extractor=self.params.get('force_generic_extractor', False))
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\lib\site-packages\youtube_dl\YoutubeDL.py", line 805, in extract_info
    return self.process_ie_result(ie_result, download, extra_info)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\lib\site-packages\youtube_dl\YoutubeDL.py", line 859, in process_ie_result
    return self.process_video_result(ie_result, download=download)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\lib\site-packages\youtube_dl\YoutubeDL.py", line 1640, in process_video_result
    self.process_info(new_info)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\lib\site-packages\youtube_dl\YoutubeDL.py", line 1907, in process_info
    partial_success = dl(fname, new_info)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\lib\site-packages\youtube_dl\YoutubeDL.py", line 1852, in dl
    return fd.download(name, info)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\lib\site-packages\youtube_dl\downloader\common.py", line 364, in download
    return self.real_download(filename, info_dict)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\lib\site-packages\youtube_dl\downloader\external.py", line 35, in real_download
    retval = self._call_downloader(tmpfilename, info_dict)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\lib\site-packages\youtube_dl\downloader\external.py", line 101, in _call_downloader
    cmd = [encodeArgument(a) for a in self._make_cmd(tmpfilename, info_dict)]
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\lib\site-packages\youtube_dl\downloader\external.py", line 187, in _make_cmd
    '--min-split-size', '1M', '--max-connection-per-server', '4'])
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\lib\site-packages\youtube_dl\downloader\external.py", line 97, in _configuration_args
    return cli_configuration_args(self.params, 'external_downloader_args', default)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\lib\site-packages\youtube_dl\utils.py", line 2923, in cli_configuration_args
    assert isinstance(ex_args, list)
AssertionError

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If the purpose of this issue is a site support request please provide all kinds of example URLs support for which should be included (replace following example URLs by yours):

• URL I used: https://www.youtube.com/watch?v=DLzxrzFCyOs

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Description of your issue, suggested solution and other information

First of all, this is the simple python code:

# -*- coding: utf-8 -*-
import os
import youtube_dl
cwd = os.getcwd()

download_opts = {
'external_downloader':"aria2c",
'external_downloader_args':"-x 16 -s 16 -k 1M",
'verbose':True,
}
with youtube_dl.YoutubeDL(download_opts) as down:
	down.download(["https://www.youtube.com/watch?v=DLzxrzFCyOs"])

So, my questions are:

1. How do I set the path for aria2c? I don't want the aria2c.exe inside the folder where the script is, it should be in an subfolder called "bin".
   I tried 'external_downloader':"bin\\aria2c", or 'external_downloader':cwd+"\\bin\\aria2c", but either it ignored it or it gave me an error.

2. How do I specify the external_downloader_args? It works when aria2c is in the same folder as the .py script and I delete the line 'external_downloader_args':"-x 16 -s 16 -k 1M", but with it, it just outputs the error above.

This question was asked, but you said we should open a new Issue with reproducable environment, so I attached a .zip if needed. It just contains the script, a .bat file, aria2c and an empty "bin" folder ^^ test.zip
#15337 (comment)

Thanks!

[ealgase]

You should put the aria2c binary in a folder in your PATH.

[dstftw]

As for 2, external_downloader_args must be a list not string as clearly stated in option's description.