Q>I selected global "Generate MP4 thumbnails" & "Generate JPEG thumbnails" but when I try to `http://<my server>:8081/<app>/<stream>/thumbnail.mp4` I get a "Not Found" error and I don't know how to access the jpeg image to use.
A< Please make sure you have "Generate MP4 thumbnails" & "Generate JPEG thumbnails" enabled for <app> too if you have particular settings for this <app>. Global settings are applied only if you don't have settings for your application(<app> in your example).
Please also note that "thumbnail.mp4" requests are available without transcoder license as Nimble doesn't have to decoder and encoder video stream. But "thumbnail.jpg" and "dvr_thumbnail.jpg" required decoding and encoding and hence you need https://softvelum.com/transcoder/ to get .jpg thumbnails
A couple questions:
Q>1. How should I be trying to retrieve thumbnails for live streams?
A< Please see details above.
Q>2. Is there somewhere on the filesystem I can view where these are stored on the Nimble Streamer server?
A< Good question. Nimble use RAM memory to generate and store thumbnails for performance reason so you cannot access them through filesystem. There is nothing in a filesystem at all.
Q>3. If I want to access the mp4 thumbnails over https is that possible?
A< Yes you can access mp4 thumbnails via https. All you need is to setup https https://blog.wmspanel.com/2014/12/ssl-hls-mpeg-dash-icecast-https-support.html
if you have hls/dash streams available via https, you will be able to get thumbnails via https too as the same delivery method is used in both cases.