I personally never encountered JPEGs or MP3s which were totally unreadable due to the being encoded by ancient software versions, but the metadata in common media formats is a total mess. Cameras and encoders are writing all sorts of obscure proprietary tags, or even things like X-Ray (STALKER Shadow of Chernobyl game engine) keeping gameplay-relevant binary metadata in OGG Vorbis comments. Which is even technically compliant with the standard I think, but that won't help you much.