[YandexMusic] downloads music in High Quality (320 Kbit/s)

[smusatov]

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• [x] Searched the bugtracker for similar pull requests
• [x] Read adding new extractor tutorial
• [x] Read youtube-dl coding conventions and adjusted the code to meet them
• [x] Covered the code with tests (note that PRs without tests will be REJECTED)
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What is the purpose of your pull request?

• [ ] Bug fix
• [x] Improvement
• [ ] New extractor
• [ ] New feature

---

Description of your pull request and other information

Improved the Yandex Music extractor: if cookies with authorization from a premium account are specified, then the extracted URL refers to High Quality (320 kbps)

[dirkf]

As we can't easily test this enhancement, please post logs showing this working: ideally one showing what happens with the existing code and one showing what happens with the PR code.

[ursval]

May I suggest test case? High quality in terms of Yandex means lower mp3 compression and higher bitrate. So, these are steps to prove that after this improvement downloaded file has higher quality:

1. Download some modern file
2. Run spectrum analyzer on it. For example, Audacity. Menus: Analyze -> Plot Spectrum
3. Compare maximum frequency It is typical for higher-rate compression to cut higher-rate frequencies So, we can tell that audio analyzed on firs image has higher compression rate that second one (see "cursor" field for edge frequency value).

I think, this proof is quite sufficient.

Experiment can be reproduced on song https://music.yandex.ru/album/1891713/track/17190963

[dirkf]

Or just run ffprobe or mediainfo on the audio file.

[unkernet]

I think this should be accepted.

Without this patch:

python3 -m youtube_dl -F --cookies ~/music.yandex.ru_cookies.txt https://music.yandex.ru/album/1891713/track/17190963
[yandexmusic:track] 17190963: Downloading track JSON
[yandexmusic:track] 17190963: Downloading track location url JSON
[yandexmusic:track] 17190963: Downloading track location JSON
[info] Available formats for 17190963:
format code  extension  resolution note
0            mp3        unknown    mp3  @192k, 0.00B

With this patch:

python3 -m youtube_dl -F --cookies ~/music.yandex.ru_cookies.txt https://music.yandex.ru/album/1891713/track/17190963 
[yandexmusic:track] 17190963: Downloading track JSON
[yandexmusic:track] 17190963: Downloading track location url JSON
[yandexmusic:track] 17190963: Downloading track location JSON
[info] Available formats for 17190963:
format code  extension  resolution note
0            mp3        unknown    mp3  @320k, 0.00B

With patch, without cookies

python3 -m youtube_dl -F https://music.yandex.ru/album/1891713/track/17190963
[yandexmusic:track] 17190963: Downloading track JSON
[yandexmusic:track] 17190963: Downloading track location url JSON
[yandexmusic:track] 17190963: Downloading track location JSON
[info] Available formats for 17190963:
format code  extension  resolution note
0            mp3        unknown    mp3  @128k, 0.00B

ffprobe

ffprobe -i "The Doors - People Are Strange-17190963.mp3" 
Input #0, mp3, from 'The Doors - People Are Strange-17190963.mp3':
  Duration: 00:02:12.73, start: 0.000000, bitrate: 320 kb/s
  Stream #0:0: Audio: mp3, 44100 Hz, stereo, fltp, 320 kb/s