Downloading captions using Youtube v3 API

Question

While attempting to download captions for a video (not owned by me) using OAuth 2.0 authorization, I am receiving a 403 Forbidden error which states "The permissions associated with the request are not sufficient to download the caption track. The request might not be properly authorized, or the video order might not have enabled third-party contributions for this caption." On further research, I have found other people also faced the same issue as this, and have not been able to download captions unless the video was uploaded from their own account.

Is there still no possible way of downloading a caption track from a video? How exactly do sites like keepsubs(dot)com, manage to do this then?

Answer 1

Captions: download documentation

Authorization

This request requires authorization with at least one of the following scopes (read more about authentication and authorization).

Scope https://www.googleapis.com/auth/youtube.force-ssl https://www.googleapis.com/auth/youtubepartner

The owner of the video will have to authenticate your application using Oauth2 with one of those scopes.

Answer 2

The V3 API doesn't allow this. You would have to make a request to youtube, load the javascript, turn subtitles on, then look for the https://www.youtube.com/api/timedtext request.

It uses a signature, key, and some other items in the query string that the request will fail without. You can make the request to the timedtext endpoint from the server using any http requestor.

Other thoughts: You might be able to get that request to be loaded automatically by having subtitles automatically turned on in the query string somehow. This would make your life a lot easier.

You could also try to replicate how they create the key and signature, and then just create it yourself. I bet it uses the video id in some manner.