Select a component to see open bugs in that component:
For issues with Adobe's Shockwave Flash plugin (.swf .flv). info
Open source H.264 encoder/decoder freely offered by openh264.org which Firefox uses to offer H.264 to its users. These bugs are against the plugin itself, not bugs in Firefox. Bugs in Firefox should be filed under Core::WebRTC or Core::Video/Audio, depending on the use case.
For issues with a plugin which doesn't have a specific component
Bugs relating to telemetry pings that collect data about libraries injected into Firefox