Extract stream segments for YouTube

[vkay94]

• I carefully read the contribution guidelines and agree to them.
• I have tested the API against NewPipe.
• I agree to create a pull request for NewPipe as soon as possible to make it compatible with the changed API.

This PR extracts the stream segments data provided by YouTube and makes them accessible inside StreamInfo. Other services which don't support this data return an empty list when trying getting them. This also applies to streams in YouTube which aren't divided by the uploader.

Video chapters of a longer stream (desktop version)

The added data class StreamSegment contains the following data:

• String title: Title of the chapter set by the uploader
• int startTimeSeconds: Starting point of the chapter in seconds
• String url: Direct link to the segment (...?t=)
• String previewUrl: Url to the image at the start position

Test against NewPipe

Demo video in NewPipe's player: https://streamable.com/e/3e27wa
Debug app: app-debug-segments-20201212.zip

[TobiGr]

thank you!

[opusforlife2]

Nice! Maybe there is a way to integrate this into the background player as well.

[vkay94]

I've updated the commits by using has() and explicit ParsingException throwing if the text and start time aren't valid. I did some testing with a sample video on my Account by trying various scenarios (unordered timestamps, empty titles, unavailable thumbnails at the beginning) and how the ytInitialData is formatted in those cases.

I'll update the test apk shortly.

[TobiGr]

Thanks. That looks better now!