The last official firmware for the Denon AVR-1912 (for most regions) was . If you see 1.22, you are fully updated. If you see 1.18 or lower, you have several updates pending.
Users reported issues where the video would flash on and off, or audio would cut out when switching inputs or pausing 3D content. Firmware updates addressed the EDID (Extended Display Identification Data) communication between the source (Blu-ray player/Game console), the receiver, and the TV, ensuring a stable signal. Denon Avr 1912 Firmware Update