Archimago explores various aspects of HDMI functionality, focusing on color and power delivery. The post investigates the practical impact of YCbCr 4:2:0 chroma subsampling versus 4:2:2 and RGB, finding minimal visual differences in real-world content despite theoretical bandwidth advantages. It also delves into Dolby Vision's use of Metadata Enhanced Layer (MEL) and Full Enhanced Layer (FEL), clarifying their bandwidth requirements and potential cable compatibility issues. Finally, the post touches on +5V injection over HDMI and its role in powering devices like Chromecast, emphasizing the importance of proper cable support for this feature.
This video demonstrates building a "faux infinity mirror" effect around a TV screen using recycled materials. The creator utilizes a broken LCD monitor, extracting its backlight and diffuser panel. These are then combined with a one-way mirror film applied to a picture frame and strategically placed LED strips to create the illusion of depth and infinite reflections behind the TV. The project highlights a resourceful way to enhance a standard television's aesthetic using readily available, discarded electronics.
HN commenters largely praised the ingenuity and DIY spirit of the project, with several expressing admiration for the creator's resourcefulness in using recycled materials. Some discussed the technical aspects, questioning the actual contrast ratio achieved and pointing out that "infinity contrast" is a misnomer as true black is impossible without individually controllable pixels like OLED. Others debated the practicality and image quality compared to commercially available projectors, noting potential issues with brightness and resolution. A few users shared similar DIY projection projects they had undertaken or considered. Overall, the sentiment was positive, viewing the project as a fun experiment even if not a practical replacement for a standard TV.
While current technology allows for the creation and display of 3D images (specifically "cross-view" autostereograms) using just a standard camera and screen, it's not widely utilized. The author argues this is a missed opportunity. Cross-view images, generated by slightly offsetting two perspectives of the same scene, create a 3D effect visible by crossing your eyes or using the parallel viewing method. This technique is simple, accessible, and doesn't require special glasses or hardware beyond what most people already possess, making it a viable and readily available format for sharing 3D experiences.
Hacker News users generally agree with the premise that cross-view autostereoscopic displays are a compelling, albeit niche, technology. Several commenters share personal experiences with the Nintendo 3DS and other similar devices, praising the effect and lamenting the lack of wider adoption. Some discuss the technical challenges of implementing this technology, including resolution limitations and the "sweet spot" viewing angle. Others point out that VR/AR headsets offer a more immersive 3D experience, though some argue cross-view offers a more casual and accessible alternative. A few express hope for future advancements and broader integration in consumer electronics like laptops and phones. Finally, some commenters mention lenticular printing and other forms of autostereoscopic displays as interesting alternatives.
TCL is betting on "NXTPAPER" screen technology, which aims to mimic the look and feel of paper for a more comfortable reading experience. This technology utilizes multiple layers of reflective material to enhance contrast and reduce blue light, creating a display that appears brighter in sunlight than typical LCDs while maintaining low power consumption. While not e-ink, NXTPAPER 2.0 boasts improved color gamut and refresh rates, making it suitable for not just e-readers, but also tablets and potentially laptops. TCL aims to expand this technology across its product lines, offering a paper-like alternative to traditional screens.
Hacker News commenters discuss TCL's NxtPaper display technology, generally expressing skepticism about its widespread adoption. Some doubt the claimed power savings, especially given the backlight required for color displays. Others question the "paper-like" feel and wonder if it truly offers advantages over existing e-ink or LCD technologies for typical use cases. A few commenters express interest, particularly for niche applications like e-readers or note-taking, but overall the sentiment is cautious, awaiting real-world reviews and comparisons to determine if the technology lives up to its promises. Some also discuss the history of similar display technologies and their ultimate lack of success.
Summary of Comments ( 4 )
https://news.ycombinator.com/item?id=43497398
HN users generally agree with the author's points about HDMI cable quality not significantly impacting picture quality with properly functioning cables, even at high bandwidths. Some commenters add further nuance, explaining that cable quality matters more with longer cable runs and higher resolutions/refresh rates, where signal degradation becomes more likely. Others point out real-world issues like bad connectors or manufacturing defects being more common culprits for HDMI problems than the cable itself. A few users shared personal experiences with long HDMI cable runs and offered advice about reliable brands or using active cables/repeaters for those situations. The discussion also touches upon the confusion surrounding HDMI marketing and versioning, with some users suggesting the article could be clearer for non-technical readers.
The Hacker News post "HDMI Musings: YCbCr color subsampling, Dolby Vision MEL/FEL, and and5V injection" linking to an Archimago blog post has generated a modest discussion with several insightful comments.
One commenter highlights the common misconception that HDMI cables matter beyond basic functionality and certification. They point out that the signal is digital and either works or doesn't, unlike analog signals where cable quality can significantly impact the result. They emphasize that expensive HDMI cables often offer no real benefit beyond marketing hype, and consumers should be wary of inflated prices for features that provide no practical improvement. They suggest looking for certified cables that meet the required specifications at a reasonable price.
Another commenter delves into the complexities of chroma subsampling, explaining how it reduces bandwidth by exploiting the human eye's lower sensitivity to color detail compared to luminance. They detail the different types of subsampling, such as 4:4:4 (no subsampling), 4:2:2 (reduced horizontal chroma resolution), and 4:2:0 (reduced horizontal and vertical chroma resolution), and their implications for image quality. They also touch on the potential benefits of subsampling, such as reduced bandwidth requirements and file sizes, particularly relevant for high-resolution video.
A further comment discusses the challenges of dealing with different video formats and standards within a single HDMI connection, especially concerning HDR and Dolby Vision. The commenter expresses frustration with the lack of clear and consistent information regarding the capabilities of different devices and cables, making it difficult for consumers to ensure compatibility and optimal performance. They highlight the confusion arising from various HDR implementations and the need for better communication and standardization within the industry.
The discussion also touches upon the practical considerations of HDMI cable selection. One commenter mentions their experience with longer HDMI cables, emphasizing the importance of certified, high-quality cables for reliable signal transmission over longer distances. They advise against cheap, uncertified cables, which may not meet the required specifications and could lead to signal degradation or intermittent connectivity issues.
Another user focuses on the 5V injection aspect, explaining its purpose in powering active HDMI cables or other connected devices. They discuss the potential issues that can arise if the 5V supply is insufficient, such as signal loss or malfunctioning equipment. They suggest checking the power requirements of connected devices and ensuring that the HDMI source can provide adequate power.
Finally, one commenter links to another resource that provides further information on HDMI specifications and cable testing, offering a helpful reference for those seeking a deeper understanding of the topic.
In summary, the comments provide valuable insights into various aspects of HDMI technology, including cable quality, chroma subsampling, HDR compatibility, and 5V power injection. They also highlight the challenges and frustrations faced by consumers navigating the complexities of HDMI standards and the need for better information and standardization within the industry.