we are also looking for a bitmovin service that can generate caption files and thumbnails from assets, which can then be loaded onto the player.
While I can’t help with the thumbnails, I can certainly help with the caption side of things. I work for AI Media (Bitmovin Valued Partner and global captioning solutions provider). We have a automated captioning product called Lexi Recorded that uses ASR (automated speech recognition) to create caption files.
Feel free to shoot me a message on here or via our website to discuss.