[coder543]

Display Stream Compression (DSC) is fine. It is not a "diminished experience". DSC is visually lossless.

Instead, those docks use a technology called DisplayLink which has nothing to do with DSC. DisplayLink means that external monitors are basically "software" displays that are tremendously slower and often very limited in resolutions and frame rates. Having any DisplayLink display connected also breaks HDCP and can cause other problems.

[mrob]

The relevant standard is proprietary, but Wikipedia quotes it, confirming that "visually lossless" is marketing lies:

https://en.wikipedia.org/wiki/DisplayPort#Display_Stream_Com...

[coder543]

"Marketing lies" is unnecessarily inflammatory. I googled before posting to see if I could find anyone legitimately complaining about DSC, and it really seemed like pretty much everyone was happy with it.

There are always people like "audiophiles" who claim to be able to distinguish impossibly small differences, and there is perhaps a very small number of people with exceptional hearing who actually do... but 320kbps compressed audio is "audibly lossless" for most of the population. The exact same thing applies here, by all appearances. I'm sure there are mp3 test cases where the compression does something terrible, just like with DSC... that just isn't what people actually encounter day to day.

I can't see the second study linked which is on IEEE, but if you look at the fist one, Figure 4 shows that DSC was "visually lossless" in almost all test cases. Let me quote one thing from that study:

> As described above, the HDR content was selected to challenge the codecs, in spite of this both DSC 1.2a and VDC-M performed very well. This finding is consistent with previous series of experiments using SDR images.

So, this testing was done with samples that would challenge the codecs... and they still did great. It doesn't appear to be "marketing lies" at all. It appears to be a genuine attempt to describe a technology that enables new capabilities while dealing with the imperfect limitation in bandwidth of the available hardware.

Do you have some terrible personal experience with DSC to share? Did you do a blind test so that you weren't aware of whether DSC was enabled or not when making your judgments? Are you aware that almost all non-OLED monitors (especially high refresh rate) always have artifacts around motion, even without DSC?

I haven't personally had a chance to test out DSC other than perhaps some short experiences, which is why I based my initial comment on googling what other people experienced and how Wikipedia describes it. You pointed me to a study which seems to confirm that DSC is perfectly fine.

[mrob]

>in almost all test cases

Common sense suggests that "visually lossless" means no detectable difference by the naked eye ever, not in "almost all test cases". MP3 is a very old codec, and it's possible that there are still some "killer samples" that can be ABXed by skilled listeners with good equipment even when encoded by a modern version of LAME. A better example of something that could reasonably called "audibly lossless" might be something like Opus at 160kbps, for which I've seen no evidence of any successful ABX. But even that is is usually called "transparent", not "audibly lossless", so not only is "visually lossless" a lie, the name itself is propaganda.

[coder543]

> Common sense suggests that "visually lossless" means no detectable difference by the naked eye ever, not in "almost all test cases".

Common sense suggests no such thing. When you buy a bottle of “water”, it actually has a bunch of stuff in it that isn’t water. How dare they?! When someone says “I’ll be there in 15 minutes”, it is highly unlikely that they will show up in exactly 900 seconds. Such liars! Why are you even meeting them? When people say airplanes are “safe”, you might angrily point out how many people have died, not realizing that “safe” is relative to other things and not an absolute in that context. This is common across basically everything in life. “There are no absolutes.” If you think common sense is to automatically assume every statement that even looks remotely absolute is intended to be taken absolutely… that is not common. Short statements will come off as absolute, when they are just intended to be taken as approximate, but even absolutes are usually meant to be taken as slightly less than absolute.

“Visually lossless” is a description of the by far most common experience with DSC. They’re not describing it as truly lossless, so you know there is some loss occurring. It is natural to assume that in extraordinary circumstances, that loss might be noticeable side by side… but you don’t have a side by side when using a monitor most of the time, so the very lossy human vision system will happily ignore small imperfections.

> so not only is "visually lossless" a lie, the name itself is propaganda.

Your whole comment shows that you don’t understand how communication works. It is “visually lossless” as far as people are concerned. The study shows that! This is not at all what propaganda looks like.

When Apple labeled their iPhone screen a “retina screen” because people would no longer notice the pixels, I suppose you called that a “lie” as well because you could lean in really close or use a microscope? The retina display density achieved its stated goal.

There is literally no point in continuing this discussion when you take such an absolutist position and refuse to consider what alternative communications would look like. How about “99.9% visually lossless”? That would be even more confusing to people.

Communicating complicated concepts succinctly is a lossy process. Language is lossy. As they say, “all models are wrong, but some are useful.”

[mrob]

I understand perfectly that "visually lossless" was chosen to emotionally manipulate people by triggering positive associations with the word "lossless", despite not actually being lossless, or even transparent. Language is lossy, but that does not excuse corporations twisting it further in their attempts to exploit you.

[coder543]

Who is being exploited in this situation? I've never heard of anyone successfully selling a product because DSC is "visually lossless". It's a short explanation for a complicated technology, on the rare occasion that anyone googles DSC to try to understand what it is.

Your continued use of inflammatory and frankly incorrect language isn't helping your case. If this is "exploitative" marketing language that is "lying", you should file a case with some consumer protection body. You have also failed to demonstrate how you would communicate the overwhelming effectiveness of DSC that the study showed.