`--hls-prefer-native` on a live twitch.tv stream uses ffmpeg anyway, bypasses proxy

[Jw86Ht]

Make sure you are using the latest version: run youtube-dl --version and ensure your version is 2018.03.10. 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 Issues with outdated version will be rejected.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 2018.03.10

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

---

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:

Add the -v flag to your command line you run youtube-dl with (youtube-dl -v <your command line>), copy the whole output and insert it here. It should look similar to one below (replace it with your log inserted between triple ```):

$ ./youtube-dl -v -f 480p --hls-prefer-native --proxy socks5://127.0.0.1:9050/ https://www.twitch.tv/carlsagan42
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'-f', u'480p', u'--hls-prefer-native', u'--proxy', u'socks5://127.0.0.1:9050/', u'https://www.twitch.tv/carlsagan42']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2018.03.10
[debug] Git HEAD: d11691899
[debug] Python version 2.7.13 (CPython) - Linux-4.9.0-6-amd64-x86_64-with-debian-9.3
[debug] exe versions: ffmpeg 3.2.10-1, ffprobe 3.2.10-1, rtmpdump 2.4
[debug] Proxy map: {u'http': u'socks5://127.0.0.1:9050/', u'https': u'socks5://127.0.0.1:9050/'}
[twitch:stream] carlsagan42: Downloading stream JSON
[twitch:stream] carlsagan42: Downloading channel access token
[twitch:stream] carlsagan42: Downloading m3u8 information
[debug] Invoking downloader on u'https://video-weaver.fra02.hls.ttvnw.net/v1/playlist/Ct0Cojn-wSxhMMks9Vx5meXm9_glFtr1hh-lZHU5nCL2gkiPKoAKH6_5vZnzNNtmXu8lqtQi9Pb4m5l0N2FUby3E95lA4SFtWTXy2FBo_sSiaO9TSTL7MxEVScTjzyzK8QLWVKpu7bRuU-1KPSXbf5i0FmkoVK0dRHprt4ncfEN5UCQMry3eHD7OP2d6TpLZWjqkK76TipGU5Nhc6fhmmmT5n_SM3PWLxN14M0A-CO7-2YHlxTkCcsE_t18dEshuoXU53WHt8BNGVuEIG-aazWa6RbktHzYApS7yYYSPn-JxWdC9YumLL3lwdfvjGsgG041cjvLfAIInkHo4QOggZMdJbM2iCmYYjFep9P9JdU3XSRenytswvrSOA8CAaUjcPse8Y3-Q0OAI18nXgTonUK9Jmu7pbQmjp7xxmHij1HTQXWEGDa4WK2rrN58vQhrq92Kau5YFZIwhFQGzoijiABIQwCewrcVMde0tVoYAMxMBoBoMb6bZHixVpps31Dj5.m3u8'
[download] Destination: CarlSagan42 2018-03-10 19_50-27888787776.mp4
WARNING: ffmpeg does not support SOCKS proxies. Downloading is likely to fail. Consider adding --hls-prefer-native to your command.
[debug] ffmpeg command line: ffmpeg -y -loglevel verbose -headers 'Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip, deflate
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:59.0) Gecko/20100101 Firefox/59.0 (Chrome)
' -i 'https://video-weaver.fra02.hls.ttvnw.net/v1/playlist/Ct0Cojn-wSxhMMks9Vx5meXm9_glFtr1hh-lZHU5nCL2gkiPKoAKH6_5vZnzNNtmXu8lqtQi9Pb4m5l0N2FUby3E95lA4SFtWTXy2FBo_sSiaO9TSTL7MxEVScTjzyzK8QLWVKpu7bRuU-1KPSXbf5i0FmkoVK0dRHprt4ncfEN5UCQMry3eHD7OP2d6TpLZWjqkK76TipGU5Nhc6fhmmmT5n_SM3PWLxN14M0A-CO7-2YHlxTkCcsE_t18dEshuoXU53WHt8BNGVuEIG-aazWa6RbktHzYApS7yYYSPn-JxWdC9YumLL3lwdfvjGsgG041cjvLfAIInkHo4QOggZMdJbM2iCmYYjFep9P9JdU3XSRenytswvrSOA8CAaUjcPse8Y3-Q0OAI18nXgTonUK9Jmu7pbQmjp7xxmHij1HTQXWEGDa4WK2rrN58vQhrq92Kau5YFZIwhFQGzoijiABIQwCewrcVMde0tVoYAMxMBoBoMb6bZHixVpps31Dj5.m3u8' -c copy -f mp4 'file:CarlSagan42 2018-03-10 19_50-27888787776.mp4.part'
ffmpeg version 3.2.10-1~deb9u1 Copyright (c) 2000-2018 the FFmpeg developers
[then it proceeds to download]

---

Because the --hls-prefer-ffmpeg downloader doesn't support a SOCKS proxy (#10304), I tried using --hls-prefer-native. But youtube-dl used ffmpeg anyway, and even emitted a warning telling me to use an option I was already using:

WARNING: ffmpeg does not support SOCKS proxies. Downloading is likely to fail. Consider adding --hls-prefer-native to your command.

Although the stream starts to download, it's clear that it's ffmpeg doing the downloading, and I verified with tcpdump that the download was not obeying my --proxy option.

In order to reproduce the problem, you'll need to find a stream that's currently online, otherwise you'll just get the error ERROR: <user> is offline. Sorry I don't know of any streams that are always available, but you can just choose one from the front page of https://twitch.tv/.

I tried without the --proxy option too: it still uses ffmpeg, though without the warning about not supporting a SOCKS proxy.

I tried uninstalling ffmpeg and repeating the command. When I do this, I get an error about an m3u8 download requiring ffmpeg or avconv. Here is the output log when ffmpeg is uninstalled:

$ ./youtube-dl -v -f 480p --hls-prefer-native --proxy socks5://127.0.0.1:9050/ https://www.twitch.tv/carlsagan42
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'-f', u'480p', u'--hls-prefer-native', u'--proxy', u'socks5://127.0.0.1:9050/', u'https://www.twitch.tv/carlsagan42']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2018.03.10
[debug] Git HEAD: d11691899
[debug] Python version 2.7.13 (CPython) - Linux-4.9.0-6-amd64-x86_64-with-debian-9.3
[debug] exe versions: rtmpdump 2.4
[debug] Proxy map: {u'http': u'socks5://127.0.0.1:9050/', u'https': u'socks5://127.0.0.1:9050/'}
[twitch:stream] carlsagan42: Downloading stream JSON
[twitch:stream] carlsagan42: Downloading channel access token
[twitch:stream] carlsagan42: Downloading m3u8 information
[debug] Invoking downloader on u'https://video-weaver.fra02.hls.ttvnw.net/v1/playlist/Ct0CN0Os0dJgqPUxm_h00xUjsaoWUI9SdZai0eVokpV3bXcb_G2Zb0N-j1nCEN3x8AUi3VX7W3OcSIkRKWmByTdAwod4RrOfQ-kbt4iX_u_9JBW7pYV8GCivcft7dv8Rez12zQNv8Vozs6kNc0jQRT3wO-I60oCHrh-SeL7ff8KZL5r-U-C62ODeLMqF1wz7eG1v_puFIEqZ2ZkU2rV-gVeo-x9b5SOra4DCIe_QZjxPEozR_cC1oacdUNDLDjqZlBYcUrFX86qi33NmV4q6zecB2G9dTrRZ7MNVc0IHupxc00zJFKOHVfxprJiXGXUiBGw_mWY5L9VAsDdAWDFFbYrfi2WoO8wdyB2-1LTt0jbrVbjqp1p9WNktVLY2gdAVx2naDLHMFw04W421xv6fffq0TgxuENgiZP2ew8u5scqUq9vNwNdRqGjN3hB1cQyYwJqjY7AQE3vsOGXK52RbSRIQ7DI_aJzTdnKiylmAq_Mj0RoMNtXmnKGd0XgyXvxU.m3u8'
[download] Destination: CarlSagan42 2018-03-10 19_52-27888787776.mp4
ERROR: m3u8 download detected but ffmpeg or avconv could not be found. Please install one.
  File "./youtube-dl", line 6, in <module>
    youtube_dl.main()
  File "/home/user/youtube-dl/youtube_dl/__init__.py", line 471, in main
    _real_main(argv)
  File "/home/user/youtube-dl/youtube_dl/__init__.py", line 461, in _real_main
    retcode = ydl.download(all_urls)
  File "/home/user/youtube-dl/youtube_dl/YoutubeDL.py", line 1989, in download
    url, force_generic_extractor=self.params.get('force_generic_extractor', False))
  File "/home/user/youtube-dl/youtube_dl/YoutubeDL.py", line 796, in extract_info
    return self.process_ie_result(ie_result, download, extra_info)
  File "/home/user/youtube-dl/youtube_dl/YoutubeDL.py", line 850, in process_ie_result
    return self.process_video_result(ie_result, download=download)
  File "/home/user/youtube-dl/youtube_dl/YoutubeDL.py", line 1623, in process_video_result
    self.process_info(new_info)
  File "/home/user/youtube-dl/youtube_dl/YoutubeDL.py", line 1896, in process_info
    success = dl(filename, info_dict)
  File "/home/user/youtube-dl/youtube_dl/YoutubeDL.py", line 1835, in dl
    return fd.download(name, info)
  File "/home/user/youtube-dl/youtube_dl/downloader/common.py", line 364, in download
    return self.real_download(filename, info_dict)
  File "/home/user/youtube-dl/youtube_dl/downloader/external.py", line 33, in real_download
    retval = self._call_downloader(tmpfilename, info_dict)
  File "/home/user/youtube-dl/youtube_dl/downloader/external.py", line 209, in _call_downloader
    self.report_error('m3u8 download detected but ffmpeg or avconv could not be found. Please install one.')
  File "/home/user/youtube-dl/youtube_dl/downloader/common.py", line 166, in report_error
    self.ydl.report_error(*args, **kargs)
  File "/home/user/youtube-dl/youtube_dl/YoutubeDL.py", line 613, in report_error
    self.trouble(error_message, tb)
  File "/home/user/youtube-dl/youtube_dl/YoutubeDL.py", line 575, in trouble
    tb_data = traceback.format_list(traceback.extract_stack())

[dstftw]

hls native does not support live streams.