NHK World audio on demand broken

[an-nhk-world-fan]

Checklist

• I'm reporting a broken site support
• I've verified that I'm running youtube-dl version 2020.03.08
• I've checked that all provided URLs are alive and playable in a browser
• I've checked that all URLs and arguments with special characters are properly quoted or escaped
• I've searched the bugtracker for similar issues including closed ones

Verbose log

Issue 1:

D:\>youtube-dl -v https://www3.nhk.or.jp/nhkworld/en/ondemand/audio/bosai-20200212-1/
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', 'https://www3.nhk.or.jp/nhkworld/en/ondemand/a
udio/bosai-20200212-1/']
[debug] Encodings: locale cp1252, fs mbcs, out cp850, pref cp1252
[debug] youtube-dl version 2020.03.08
[debug] Python version 3.4.4 (CPython) - Windows-7-6.1.7601-SP1
[debug] exe versions: rtmpdump 2.3
[debug] Proxy map: {}
[NhkVod] bosai-20200212-1: Downloading JSON metadata
[NhkVod] bosai-20200212-1: Downloading m3u8 information
[debug] Default format spec: best/bestvideo+bestaudio
[debug] Invoking downloader on 'rtmp://flv.nhk.or.jp/ondemand/mp4:flv/nhkworld/e
n/rod/audio/bosai-20200212-1/audios/pPFMHeYa7s0XCVChycUFRWzbLtKZ4Ema.m4a'
[download] Destination: BOSAI, Measures for Saving Your Life - Disaster Preventi
on for Residents of Japan from Overseas (Part 1) - Chinese and Brazilians-bosai-
20200212-1-en.flv
[debug] rtmpdump command line: rtmpdump --verbose -r "rtmp://flv.nhk.or.jp/ondem
and/mp4:flv/nhkworld/en/rod/audio/bosai-20200212-1/audios/pPFMHeYa7s0XCVChycUFRW
zbLtKZ4Ema.m4a" -o "BOSAI, Measures for Saving Your Life - Disaster Prevention f
or Residents of Japan from Overseas (Part 1) - Chinese and Brazilians-bosai-2020
0212-1-en.flv.part" --resume --skip 1
[rtmpdump] RTMPDump v2.3
[rtmpdump] (c) 2010 Andrej Stepanchuk, Howard Chu, The Flvstreamer Team; license
: GPL
[rtmpdump] DEBUG: Parsing...
[rtmpdump] DEBUG: Parsed protocol: 0
[rtmpdump] DEBUG: Parsed host    : flv.nhk.or.jp
[rtmpdump] DEBUG: Parsed app     : ondemand
[rtmpdump] DEBUG: Number of skipped key frames for resume: 1
[rtmpdump] DEBUG: Protocol : RTMP
[rtmpdump] DEBUG: Hostname : flv.nhk.or.jp
[rtmpdump] DEBUG: Port     : 1935
[rtmpdump] DEBUG: Playpath : mp4:flv/nhkworld/en/rod/audio/bosai-20200212-1/audi
os/pPFMHeYa7s0XCVChycUFRWzbLtKZ4Ema.m4a
[rtmpdump] DEBUG: tcUrl    : rtmp://flv.nhk.or.jp:1935/ondemand
[rtmpdump] DEBUG: app      : ondemand
[rtmpdump] DEBUG: live     : no
[rtmpdump] DEBUG: timeout  : 30 sec
[rtmpdump] DEBUG: Failed to get last keyframe.
[rtmpdump] DEBUG: Closing connection.
[rtmpdump] Downloaded 0 bytes
[rtmpdump] RTMPDump v2.3
[rtmpdump] (c) 2010 Andrej Stepanchuk, Howard Chu, The Flvstreamer Team; license
: GPL
[rtmpdump] DEBUG: Parsing...
[rtmpdump] DEBUG: Parsed protocol: 0
[rtmpdump] DEBUG: Parsed host    : flv.nhk.or.jp
[rtmpdump] DEBUG: Parsed app     : ondemand
[rtmpdump] DEBUG: Number of skipped key frames for resume: 1
[rtmpdump] DEBUG: Number of skipped key frames for resume: 1
[rtmpdump] DEBUG: Protocol : RTMP
[rtmpdump] DEBUG: Hostname : flv.nhk.or.jp
[rtmpdump] DEBUG: Port     : 1935
[rtmpdump] DEBUG: Playpath : mp4:flv/nhkworld/en/rod/audio/bosai-20200212-1/audi
os/pPFMHeYa7s0XCVChycUFRWzbLtKZ4Ema.m4a
[rtmpdump] DEBUG: tcUrl    : rtmp://flv.nhk.or.jp:1935/ondemand
[rtmpdump] DEBUG: app      : ondemand
[rtmpdump] DEBUG: live     : no
[rtmpdump] DEBUG: timeout  : 30 sec
[rtmpdump] DEBUG: Failed to get last keyframe.
[rtmpdump] DEBUG: Closing connection.


ERROR: rtmpdump exited with code 1
  File "__main__.py", line 19, in <module>
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\__init__.py", line 474, in main
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\__init__.py", line 464, in _real_main
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\YoutubeDL.py", line 2019, in download
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\YoutubeDL.py", line 808, in extract_info
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\YoutubeDL.py", line 863, in process_ie_result
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\YoutubeDL.py", line 1644, in process_video_result
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\YoutubeDL.py", line 1926, in process_info
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\YoutubeDL.py", line 1865, in dl
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\downloader\common.py", line 366, in download
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\downloader\rtmp.py", line 213, in real_download
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\downloader\common.py", line 165, in report_error
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\YoutubeDL.py", line 625, in report_error
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\YoutubeDL.py", line 587, in trouble

Issue 2 with "j_art" URLs specifically:

D:\>youtube-dl -v https://www3.nhk.or.jp/nhkworld/en/ondemand/audio/j_art-20150903-1/
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', 'https://www3.nhk.or.jp/nhkworld/en/ondemand/a
udio/j_art-20150903-1/']
[debug] Encodings: locale cp1252, fs mbcs, out cp850, pref cp1252
[debug] youtube-dl version 2020.03.08
[debug] Python version 3.4.4 (CPython) - Windows-7-6.1.7601-SP1
[debug] exe versions: rtmpdump 2.3
[debug] Proxy map: {}
[generic] j_art-20150903-1: Requesting header
WARNING: Falling back on generic information extractor.
[generic] j_art-20150903-1: Downloading webpage
[generic] j_art-20150903-1: Extracting information
ERROR: Unsupported URL: https://www3.nhk.or.jp/nhkworld/en/ondemand/audio/j_art-
20150903-1/
Traceback (most recent call last):
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\YoutubeDL.py", line 797, in extract_info
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\extractor\common.py", line 530, in extract
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp378onz
6j\build\youtube_dl\extractor\generic.py", line 3351, in _real_extract
youtube_dl.utils.UnsupportedError: Unsupported URL: https://www3.nhk.or.jp/nhkwo
rld/en/ondemand/audio/j_art-20150903-1/

Description

There seems to be two issues with NHK World audio on demand:

1. Downloads fail with ERROR: rtmpdump exited with code 1
2. The Magic of Japanese Masterpieces error as unsupported URLs. Perhaps it's because there is an underscore in the URLs?