I'm doing something pretty similar right now for internal meetings and I use a process like: transcribe meeting with utterance timestamps, extract keyframes from video along with timestamps, request segmented summary from LLM along with rough timestamps for transitions, add keyframe analysis (mainly for slides).
gpt-4o, claude sonnet 3.5, llama 3.1 405b instruct, llama 3.1 70b instruct all do a pretty stunning job of this IMO. Each department still reviews and edits the final result before sending it out, but I'm so far quite impressed with what we get from the default output even for 1-2hr conversations.
I'd argue the key feature for us is also still providing a simple, intuitive UI for non technical users to manage the final result, edit, polish and send it out.