How is a track's 30sec defined that's obtained from preview_url (Spotify Web API)?

问题

I am interested to use an audio raw dataset provided by Spotify Web API in Python. I wonder if the audio sample follows any rules to define the 30sec provided by the preview_url.

preview_url | string | A link to a 30 second preview (MP3 format) of the track. Can be null

Is the 30sec of the track extracted from:

1. The first 30 sec?
2. The track after 1 minute?
3. The track between 1-3mins?
4. A random part of the track?

回答1:

Spotify analyses every track and then is able to tell where different parts of the song begin and end.

I suppose that what you hear in the 30s preview is a guess that Spotify makes of what the refrain/main part of the songs is.

Therefore you can't generally say which part is chosen because that is determined by an AI for each song respectively.

来源：https://stackoverflow.com/questions/64979102/how-is-a-tracks-30sec-defined-thats-obtained-from-preview-url-spotify-web-api