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Known Issues & Limitations
H.264 (AVC) on Samsung Tizen TVs is generally limited to 1080p because it is a legacy and less-efficient codec compared to H.265 (HEVC) or AV1. While the H.264 standard technically supports 4K at Level 5.1 and above, most Samsung TV hardware decoders are capped at H.264 Level 4.1 or 4.2 to maximize efficiency. This limitation exists due to the high bitrate requirements of H.264 at higher resolutions such as 4K, which can exceed the TV’s internal memory bandwidth and cause playback instability. Consequently, manufacturers prioritize dedicated hardware resources for modern codecs that handle UHD data more efficiently.
Switch from H.264 to a high-efficiency codec such as HEVC or AV1 (requires a supported host GPU). These modern codecs are specifically designed to stream high-resolution content with much lower bitrates while remaining compatible with the TV’s dedicated hardware decoders.
You may have encountered video stuttering or “clunky” frames while streaming, despite the FPS stats reporting the correct value. This happens due to a display synchronization issue at the Tizen system level, where TVs may fail to initialize the maximum display refresh rate, resulting in frame skipping. On the other hand, the Moonlight app simply renders within whatever refresh rate configuration the TV provides to the application. This behavior is tied to how Tizen OS handles refresh rates at the system/application level and is not something that can be controlled or caused by Moonlight itself.
Based on user reports, the only reliable workaround is to switch to an external HDMI source (e.g., gaming console) before launching Moonlight. Powering on a device on the HDMI port appears to force the TV to reinitialize its display refresh rate, after which Moonlight runs smoothly. Be aware that simply switching to the HDMI input without powering on the console does not fix it, and the issue returns after the TV is powered off, since the state resets.
With Tizen 9.0, Samsung introduced platform-level changes to the Game Mode pipeline that appear to have unintended side effects, making Ultra Low Latency unstable for WASM-based internal applications, such as Moonlight. As a result, the TV fails to properly activate Game Mode during streaming, even when Game Mode (Ultra Low Latency) is enabled in Moonlight’s settings.
These changes can lead to various streaming issues, including video freezing on the first rendered frame, black screens, corrupted output at higher resolutions, instability at higher frame rates or bitrates, video codecs failing to initialize correctly, choppy or crackling audio, and other unpredictable behavior. For clarification, these issues are not caused by Moonlight, but are the result of breaking changes introduced by the Samsung Tizen platform.
Due to the inconsistent behavior of Game Mode on Tizen 9.0, there are currently two alternative solutions, neither of which guarantees a perfect experience across all affected TVs.
To attempt enabling Game Mode at the Tizen platform-level, you can apply the Game Mode metadata as described in Samsung’s documentation. To do this, after importing the Moonlight widget into Tizen Studio, open the config.xml file, switch to the Source tab, and add the following line inside the <widget> element (preferably alongside other metadata):
<tizen:metadata key="http://samsung.com/tv/metadata/use.game.mode" value="true"/>Save the changes and proceed with installing the application on your TV by following the installation guide.
Once installed, leave Game Mode disabled in Moonlight’s settings to use Low Latency instead of Ultra Low Latency, as this combination may allow Game Mode to activate while avoiding some of the issues that occur when using Ultra Low Latency.
Warning
Game Mode metadata is considered experimental and may cause unstable performance, black screen, resolution corruption, forced HDR activation (preventing HDR changes from Moonlight’s settings), or behave differently depending on the TV model and firmware. Some users report that it works successfully, while others continue to experience the known issues mentioned above.
If you experience issues with Game Mode metadata, the safest option is to avoid using it, and keep Game Mode disabled in Moonlight’s settings to use Low Latency. While this results in slightly higher latency compared to Ultra Low Latency, it still avoids several streaming issues that occur specifically when Game Mode is enabled.
Tip
It’s highly recommended to disable TV post-processing features such as Picture Clarity, Contrast Enhancer, and other video enhancements from Picture Settings in the TV menu to further reduce latency when Low Latency is active.