If you use an external HDMI media player with frame rate matching you may have noticed that your TV goes black for a second or two before and after video playback. QMS is here to solve it.

QMS (Quick Media Switching) is designed to eliminate the 'HDMI bonk' (blackout) in specific instances. It is an optional feature under HDMI 2.1a, meaning that HDMI 2.1a devices can support it or not – it is up to the manufacturer. QMS was originally announced as part of HDMI 2.1 a few years ago but never made it into any TV products until it was revised under HDMI 2.1a.

- "Quick Media Switching for movies and video uses the HDMI VRR mechanism to eliminate the blackout period when an HDMI Source device switches its video mode. As long as the resolution remains the same and only the frame rate changes, QMS will instantly switch between frame rates," the HDMI organization explained.


 How QMS works. Illustration: HDMI organization 

As you know, the frame rate of most movies and series is 24 frames per second while TV programming can be in 25, 30, 50 or 60fps. In the future, high frame rate content will go beyond to 100, 120 or even higher frame rates. If your media player has frame rate matching (for example Apple TV 4K with 'Match Frame Rate'), the HDMI output mode will alternate based on what you are watching at any given time to ensure judder-free video playback. The TV must then change its refresh rate to match to avoid motion judder, i.e. 24, 50, 60, 120Hz etc. This change in refresh rate introduces a short black screen.

The situation outlined above is what QMS is designed to solve. Although QMS is based on HDMI 2.1's VRR system – and now officially called QMS-VRR – "QMS is a separate feature from VRR", Brad Bramy of the HDMI organization told FlatpanelsHD. In other words you cannot expect that any existing TVs with VRR automatically support QMS. It is possible to add QMS via a firmware update, as long as specific hardware requirements are met, but it is entirely up to the manufacturer.

In technical terms, QMS allows a source device to signal to the TV in advance what the upcoming frame rate will be via HDMI's Video Timing Extended Metadata (VTEM). QMS is meant for video playback – not gaming – so it is designed this way to enable the TV to still utilize its various video processing systems.

QMS works with any type of HDMI cable.


QMS in TVs and media players
Both the source device and the TV must support QMS to make it work. The player (source) must also have a match frame rate function to make it feasible in practice.

Apple TV 4K (2022) is the first media player to support QMS. LG is the first TV maker to have announced support and it will be supported in 2023 OLED and some 2023 LCD models. See the next section.

At the time of writing, no other TV makers have announced support but here is what some of them had to say when asked by FlatpanelsHD.

Sony:
- "QMS VRR will not be supported. The future plan is TBD. Sony will announce if something decided."

Philips:
- "No, but we have included in the scope for the (near) future."

LG:
- "At this time we are not announcing any plans to support QMS in older TVs."

Samsung: 
Samsung has not commented publicly on the matter but some of its 2023 models identify as QMS compatible to Apple TV 4K (2022). However, it does not work so it could be an error.

TCL: 
TCL will unveil its 2023 TV line-up next month and, naturally, we'll be on the case.


TVs with HDMI 2.1 QMS
The list below pulls data from FlatpanelsHD's TV Database and will be automatically updated as new TVs with QMS launch. You can bookmark the list for future reference. Click on any TV model to get more information in the TV Database where you can also compare models.