My .NET client application needs to upload a video for which the title, description and custom thumbnail are not available at upload time. This metadata becomes available to my application at an indeterminate time after upload begins.
When this metadata becomes available to my application, would it be possible for me to update the video even if the initial upload is still in progress? It seems as though it would be possible if I had the video ID. However, (as far as I can tell) the video ID is not made available to me until after the video is uploaded.
As of now, there's no mentioned way to do this!
A possible solution is to set the video to being "unlisted" or "private"
and then, after the upload finishes, push your information with a second request (update request).
YouTube could probably handle change requests during uploads, but as you mentioned, there's no way to receive the videoID prior to upload end.