Learned about MCAP and protobuf. MCAP strings together protobuf messages which store data like videos and pose frames. Foxglove is a pretty cool tool to visualize MCAPs, which can be seen in the video–had to copy/paste code from claude to get the hand frames remapped into a different format to get it visualized. MCAP is used by Open100k for their egocentric data. I wonder why they decided to go with MCAP and not some other kind of organization. MCAP is also used by ROS2 systems to store data.