Fixing Washed Out HDR Streaming From Hyper-V To LG OLED65C8PUA

Hey guys! Today, we're diving deep into an issue reported by a user experiencing washed-out colors when streaming in HDR to their LG OLED65C8PUA from a Hyper-V virtual machine. This is a pretty specific setup, but the troubleshooting steps and insights can be valuable for anyone dealing with similar streaming problems. Let's get started!

Understanding the Problem: Washed Out HDR

When dealing with washed-out HDR, it's crucial to pinpoint the root cause. The user, mariotaku, is running Sunshine on a Windows 11 Pro Hyper-V virtual machine and streaming to their LG OLED65C8PUA using Moonlight. The key issue is that the colors appear washed out during streaming, and there's no HDR notification when the stream begins. This indicates that the HDR signal isn't being properly transmitted or interpreted by the TV. Understanding the intricacies of HDR streaming is essential to resolving this issue. High Dynamic Range (HDR) enhances the color and contrast in video content, providing a more vibrant and realistic picture. When HDR isn't correctly implemented, the image can appear dull and washed out, lacking the intended visual impact. In mariotaku's setup, the problem manifests specifically when streaming from a Hyper-V virtual machine to the LG C8 OLED TV. This setup involves several layers of technology, including the virtual machine, the streaming software (Sunshine and Moonlight), and the TV's display capabilities. Each of these layers could potentially introduce issues that lead to the washed-out color problem. For instance, the virtual machine's configuration might not be correctly set up to handle HDR output, or the streaming software might not be properly encoding and transmitting the HDR signal. Alternatively, the TV might not be correctly interpreting the signal it receives, or there could be compatibility issues between the various components in the setup. To effectively troubleshoot this issue, it’s essential to consider each component in the streaming pipeline and identify where the HDR signal is being lost or misinterpreted. This often involves checking settings, configurations, and compatibility between the different devices and software involved. By systematically investigating each potential point of failure, we can narrow down the cause and implement the appropriate solutions to restore the intended HDR experience. This is particularly important in a complex setup like this, where multiple factors could be contributing to the problem.

The Setup: A Tech Deep Dive

Let's break down mariotaku's setup. They're running Sunshine on a Windows 11 Pro Hyper-V virtual machine. Hyper-V GPU partitioning is in use, along with VB-CABLE Virtual Audio. The host machine is a beast: AMD 7950X3D, Nvidia GeForce RTX 4090, and 64GB of RAM. This thing should handle streaming like a champ! The host is wired to the router, and the LG OLED65C8PUA is connected via a USB to Ethernet adapter. This is a high-performance setup, which makes the washed-out colors even more puzzling. When dealing with streaming setups like this, the devil is often in the details. Hyper-V GPU partitioning, for instance, allows a virtual machine to directly access the host's GPU, which is crucial for gaming and streaming. However, if the partitioning isn't configured correctly, it can lead to performance issues or, in this case, problems with HDR output. Similarly, VB-CABLE Virtual Audio is used to route audio between applications, but misconfiguration can sometimes interfere with other system processes. The wired Ethernet connections on both the host and the TV are good choices, as they minimize latency and provide a stable connection. However, the USB to Ethernet adapter on the TV could be a potential bottleneck or source of compatibility issues. While USB Ethernet adapters can provide a network connection, they might not always offer the same performance or reliability as a built-in Ethernet port. The high-end specifications of the host machine (AMD 7950X3D, Nvidia GeForce RTX 4090, 64GB RAM) indicate that the hardware itself is unlikely to be the problem. This points to software configuration, compatibility issues, or driver-related problems as more likely causes. Given the complexity of the setup, it’s important to systematically check each component to ensure it’s functioning correctly and configured optimally. This includes verifying the Hyper-V settings, the Sunshine and Moonlight configurations, the audio routing setup, and the network connections. By methodically examining each aspect, we can identify the source of the washed-out HDR and implement the necessary fixes.

The Culprit: Software and Protocols

The user is streaming their desktop from the Hyper-V virtual machine to the LG C8 using ndl-webos4. This is where things get interesting. The washed-out colors appear with this setting, and no HDR notification pops up. Switching HDR on or off in Windows makes no difference. The gaming experience is decent, with an average 12ms decoder latency at 1440p (120Hz), which is pretty good. However, NetCast produces the same washed-out colors and similar performance. The crucial observation here is that using smp-webos4 seems to fix the colors, but the decoder latency skyrockets to 1800ms at 1440p (120Hz), making it unplayable. An HDR notification does appear with smp-webos4, confirming that HDR is being recognized. This suggests that the issue isn’t necessarily with the underlying hardware but rather with the specific streaming protocols and their implementation. The ndl-webos4 protocol might not be correctly handling HDR transmission in this particular setup, leading to the washed-out colors. The fact that HDR doesn't trigger a notification further supports this, indicating that the signal isn't being properly recognized. On the other hand, smp-webos4 seems capable of delivering HDR, as evidenced by the HDR notification and the correct colors. However, the massive increase in decoder latency makes this option unusable for real-time applications like gaming. This latency issue could be due to the way smp-webos4 encodes and decodes the video stream, or it might be related to compatibility issues with the hardware or software components in the setup. The fact that NetCast also produces washed-out colors suggests that there might be a common underlying problem affecting multiple streaming protocols. This could be related to how the virtual machine handles HDR output, how the streaming software encodes the video, or how the TV interprets the incoming signal. To resolve this, we need to delve deeper into the technical specifications of each protocol and identify the differences that might be causing these issues. This could involve analyzing the encoding methods, the color spaces used, the HDR metadata transmission, and other relevant factors. By understanding these details, we can potentially tweak the settings or configurations to optimize performance and ensure correct HDR transmission.

Reproduction Steps and Expected Behavior

Mariotaku outlined the reproduction steps: start Moonlight on the C8, select the computer, select Desktop, and the stream starts with washed-out colors. The expected behavior is to stream using ndl-webos4 without washed-out colors. This clear set of steps helps us understand exactly how the issue arises. The simplicity of the reproduction steps highlights that the problem likely lies in the initial handshake and setup of the streaming session. The fact that the washed-out colors appear consistently when following these steps suggests that it's not a random occurrence but a systematic issue related to how the streaming protocol is initialized. The expected behavior, streaming with ndl-webos4 without washed-out colors, is the key benchmark we're aiming for. This indicates that the user believes ndl-webos4 should be capable of delivering HDR content correctly, which is a reasonable expectation given its design purpose. To achieve this goal, we need to focus on understanding why ndl-webos4 is failing to properly transmit HDR in this specific setup. This could involve examining the initialization process, the video encoding parameters, the HDR metadata handling, and any other factors that might affect color reproduction. By comparing the behavior of ndl-webos4 with smp-webos4 (which does produce correct colors but with unacceptably high latency), we might be able to identify the crucial differences that lead to the washed-out effect. Additionally, considering the other components in the setup, such as the Hyper-V virtual machine, the GPU partitioning, and the network connection, is essential. It's possible that the issue is not solely within the streaming protocol itself but also related to the interaction between the protocol and these other elements. By systematically investigating each aspect of the setup and the streaming process, we can pinpoint the exact cause and implement the necessary solutions to achieve the desired outcome of clear, vibrant HDR streaming.

Troubleshooting Time: Let's Fix This!

Okay, guys, let's get our hands dirty and troubleshoot this issue. Here’s a breakdown of potential solutions and steps we can take:

1. Check HDR Settings:

   • Windows HDR: Even though the user mentioned that toggling HDR in Windows doesn't affect the stream, it's worth double-checking. Ensure HDR is enabled in Windows display settings for the virtual machine. Sometimes, a simple toggle can kick things into gear. Ensuring that HDR settings in Windows are correctly configured is a fundamental step in troubleshooting HDR issues. Even though the user has already tried toggling HDR on and off, it's crucial to verify that the settings are indeed being applied within the virtual machine environment. This involves checking the display settings within the virtual machine to ensure that HDR is enabled, and that the correct display is selected for HDR output. Sometimes, virtual environments can introduce complexities in how display settings are applied, so it's important to rule out any misconfigurations. One common issue is that the virtual machine might not be correctly detecting the HDR capabilities of the physical display, leading it to default to a standard dynamic range (SDR) output. This can be caused by driver issues, incorrect virtualization settings, or limitations in the way the GPU is partitioned within the Hyper-V environment. To address this, you might need to update the display drivers within the virtual machine, ensure that the GPU partitioning is configured to fully expose the GPU's capabilities to the virtual environment, and potentially adjust the virtual machine's settings to explicitly enable HDR support. Furthermore, it's worth checking whether the HDR settings are being overridden by any other applications or configurations within the virtual machine. Some games or media players, for instance, might have their own HDR settings that can conflict with the system-wide settings. By thoroughly investigating the HDR settings within the virtual machine, we can ensure that the virtual environment is properly configured to output HDR content, which is essential for achieving the desired visual quality in the streamed content. This step sets the foundation for further troubleshooting and helps to eliminate potential software-related causes of the washed-out color issue.

2. Sunshine Configuration:

   • HDR Encoding: Dig into Sunshine's settings. Is HDR encoding enabled? Are there specific settings related to color space or HDR metadata that might be causing issues? Ensuring proper Sunshine configuration is critical for successful HDR streaming. Sunshine acts as the bridge between the host machine's video output and the streaming client, so its settings directly influence how the video is encoded and transmitted. One of the first things to check is whether HDR encoding is explicitly enabled within Sunshine. This setting might be labeled as