| From: James Knott via talk <talk@gtalug.org> | | On 2023-06-19 14:47, D. Hugh Redelmeier via talk wrote: | > One silly wast of bandwidth is blanking intervals. That mattered for CRTs | > since steering the electron beam took time. It should not matter for | > LCDs. | | That doesn't make sense, especially when you consider how the digital system | works, with things like I, P and B frames. | https://en.wikipedia.org/wiki/Video_compression_picture_types Just because it no longer makes sense (I called it silly) doesn't make it go away. But it may be vestigial. I don't yet know how to control it on my Linux desktops. Is such compression part of what HDMI carries? For computer monitors? Almost all compression used in video is lossy -- not what I want for a computer monitor (My obsolete desktop monitor is a TV set. To get to 4k with HDMI 1.4 (or was it 1.2?), it uses 4:2:2 chroma sub-sampling, a kind of compression. This is looked down upon, to say the least.) ATSC has compression. MPEG-n have compression. H.264 and H.265 have compression. VP9 has compression. Each is lossy. But I don't think that they are what flows over HDMI. (There is compression coming for DisplayPort and HDMI standards to support 8k (DSC: Display Stream Compression). It is claimed to be "Visually lossless" but I imagine that it isn't always lossless for computer monitor use. <https://en.wikipedia.org/wiki/Display_Stream_Compression> ) | As you mentioned blanking intervals are a relic of analog TV, dating back | before WW2. There is absolutely no need for them with digital TV. Except varous things exploited them. Like whacking on GPU registers only during blanking intervals to avoid tearing.