what does xywh mean in vtt file

Question

what do these lines: #xywh=0,0,160,90 means in vtt file for thumbnails ?

WEBVTT 00:00.000 --> 00:05.000
/assets/thumbnails.jpg#xywh=0,0,160,90

00:05.000 --> 00:10.000
/assets/preview2.jpg#xywh=160,0,320,90

00:10.000 --> 00:15.000
/assets/preview3.jpg#xywh=0,90,160,180

00:15.000 --> 00:20.000
/assets/preview4.jpg#xywh=160,90,320,180

Thanks.

Answer 1

I found out these are coordinates of each individual thumbnail in the sprite image.

https://www.webtvsolutions.com/support.php?s=ws_webtv_docs&d=clips_video_thumbnails&lang=en