Fixes #9275 These video segments look like ads and they don't appear in the web player.
[utils] imporove parse_duration to handle more formats
Both GDCVault and GPUTechConf uses the service of DigitalSpeaking.
Fixes #9248
The old API results in URLs with HTTP 403 from time to time. Hopefully fixes #9219.
It now uses generic onionstudios embed
Since there doesn't seem to be any indication, it stops when there aren't new videos in the webpage.
In r'pl=\d+&play=\d+' pages, several metadata items are missing Closes #9222.
[downloader/external] enable piping for FFmpegFD(closes #2124)
Now the webpage says there are 24 songs.
It now uses brightcove
It's strange that the date is changed. Anyway, new data matches what the webpage says.