[Mentar]

Well, that's been very interesting and - kinda enlightening to me. I've got to admit that I'm a little bit puzzled, but I guess I shouldn't be too surprised either.

So, to sum it all up: Over the last 24 hours I've talked to alot of encoders about this issue which I considered intriguing (because it touched down on some research I've been doing ~1 month ago on my vacation), namely visual impression of above-SD resolutions, and their use for "HD" encodes. What does matter, what doesn't matter much, what works and what doesn't.

Initially I experimented alot with DVD sources (720x480 - the defined "SD" resolution), particularly with Elfen Lied R2, one of the cleanest and best transfers I've seen so far. I remembered the fullscreen impression of Hayate of Gotoku (the first show I worked on that deserved a "HD" label with MY understanding of the word), and I wondered if I could somehow recreate this with the Elfen Lied DVD source, now armed with x264.

The results were sobering. Even though the source seemed fine, I was unable to recreate a comparable level of sharpness. Consequently, I did some upscale experiments, but again, to no satisfactory end. I really tried, and I know a thing or two about handling DVD sources, but it all came down to one bitter truth: The source itself might have been "clean", but it didn't really fully utilize the full resolution. Most background details were in itself blobs of multiple pixels, there were no real clarity and 1-pixel-width structures. Attempts to sharpen without creating halos (the normal bane of too much sharpening) were made again and again, but - nope.

The _best_ (subjective!) results were reached with a combination of supersampling to 1.5x source resolution, sharpening, mild linedarkening, mild antialiasing, downsizing, and finally (key) slight _linethinning_ (originally, only to warp away sharpening halos a bit). Initially, I couldn't understand that, really. Why did linethinning have such an impact on the visual impression?

Eventually I understood - it was because my eye was drawn to contrasts - not background details - , and fullscreen playback of the usual sd-linewidth of ~3-5 pixels, the resulting lines looked "fat" and not realistic, especially in conjunction with mild residual halos giving it an "embossed" look. By thinning the lines, one didn't gain details or anything, but the resulting visual impression was more pleasing.

So I began looking for sources which had "finer" structures. And there they were - 1280x720 captures of HD-mastered material. Here, filtering could be done quite differently: Just to clean up the lines, doing some very mild line removal and sometimes line mending (mild antialiasing). So the background details were multi-pixel blobs and not really sharp? SO WHAT. That's not where the eye was looking.

And this is why HD-mastered raws aired in SD (case 2) are still way superior to what you get as SD DVD sources: They are much more detailed, SD or not. See the bell tree I used for my initial screenshot. You simply DO NOT GET structures this fine on common SD sources. Therefore, having even those "crippled" HD versions resized back up either by capper or (even better) by stations BY FAR surpasses what's well-known as normal SD. Because what really counts is the quality of the original material, the airing res is much less important. Upscaling back to HD res can be done cleanly, and it will still result in a balanced frame. The background structures will be harmed, but the visual impression of a sharp HD pic is salvageable. SD sources differ from other SDs already, and scaled-down HD material is most definitely NOT "normal" SD. See Kimikiss raws as a prime example of what I'm talking about.

So, to wrap it up, we need to agree to disagree. Type 2 cases _absolutely_ deserve a HD resolution release in my opinion. Here, going SD is in fact generally harmful, because the lines tend to be thinned too much, leaving a strange look of unstructured color plains. Whether you call them HD (I do and consider it justified), MHD (we can tag them "Middle HD" instead of the Mentar pun) - I don't care. They're an important and fairly large class of sources which deserve proper handling.

So far, every single encoder I've talked to who has compared the mkv with the avi agreed that the result is very obvious (and no, Nich, it has nothing to do with the sharpness advantage of h264 - I've made so many tests that I could puke them out). On the other hand, all those encoders criticizing this decision I talked to had one thing in common: They hadn't even bothered to have a look at what they were talking about. Some of them even with a flabbergasting aura of pride, because they just KNEW that they were right. They had to be.

Feedback for these MHD releases has been overwhelmingly positive. I'll definitely continue doing them, and many other groups do the same thing. I'd invite the naysayers to find a calm minute when nobody is watching them, to download MHD and SD releases, and to try to make honest assessments of the difference. And if anyone of them succeeds at what I failed at (making SDs look like MHDs without scaling to their resolutions), please gimme a holler.

Peace.