Psychovisual Enhancement Yes or No

[cornetet]

If I understand this Psychovisual Enhancement thing, it puts more data in the area of the screen where the Human eye is most likely to to watching the action.

So is this enhancement worth it? Do I choose this effect based on the TYPE of movie I'm watching (i.e. a fast-paced Action/Adventure versus a slow-paced Drama)

Need to know everyone's opinions out there....

[DJ Bobo]

IMHO it's useless.
Was asked before, and got into a war with some other board users :D

[Stampede]

I don't like it persionally. What I recommend is that you take a 60 second trim from your movie and compress it with the bitrate and AVS script you were planning to use for the movie. Make one compressed copy with PE and one without. Then compare not only by playing back at full motion but also open two virtualdub windows and compare individual frames side by side. This should help you decide which works best for you.

[OvERaCiD23]

in the few tests i've done, i saw no improvement (or change rather) in video quality. compressibility tests remained the same as well. i don't see a point to them, seems like it's just another thing that could f*** up your encoding for no real reason. i've just stuck with b-frames and have been happy, which i believe is the consenus of a majority of the people on the board.

[Stigma]

Basicly psychovisual does not ADD more data to fast parts of the move, rather it tries to save bits whereever it thinks that you wont notice. the 2 major points are in very high-speed movements, where your eye can only see a blur anyway, and where there are extremely dark or extremely light scenes (because the human eye has difficluty seeing details in those cases).

But back to your question, is it worth it? Well, you wont notice PE effects unless you are either actively searching for it, or you are extremely sensitive to seeing "errors" in the move. On a full movie it can often save you up towards 15-25MB, wich will then be automaticly be used somewhere else (to make the rest look better then usual).

So do a test movie, check it for yourself... if you dont notice anything bad, then feel free to use it. The reason why PE is often hated areound these boards is mostly because there are very many talented perfectionists here wich wont settle or anything less than 100% ^_^

One last thing: do NOT use strong psychovisuals as default in your encoding. it often causes large artifacts one or more places in the movie. i recomend "light" myself, wich has never given me trouble. Thats usually a good tradeoff if you need to pump up the general bitrate for the encode.

Thats my 2 cents =)
-Stigma

[jggimi]

I've used PE in "light" mode quite a bit, and, once in a while, in "medium" mode. I've never used "heavy".

I've found, for me, that scenes with water -- ocean, or underwater -- are significantly improved when using "medium" PE on the encoding. Because more bits are made available for those scenes, you see less obvious "macroblocks in motion" that appear with lower bitrates. This is because PE provides additional bits for those scenes. If I've got content with lots of water, I'll usually set PE to "medium".

I've found that I can not really tell the difference between "light" PE and none. It might be due to my eyes, of course. And because I can't tell, I leave "light" PE as my default, in the hope that more bits are used where they are needed.

[JohnMK]

I might be wrong, but I think I have the theory right. If I understand PE correctly, it would seem to be of little benefit to me since I always choose a resolution that gets me about 60% or more quality, and I always adjust RC avg. value to about half the total number of frames. It would seem PE might make a movie of 55% or less value look like a movie of a few percent better. So if you're a 55%-er, maybe it helps. If you're like me though, PE seems of very little value indeed.

I always leave it turned off; I've never done any comparison to see if it improves visual quality or not, but the consensus here and elsewhere is rather neutral, so I really don't care. :-/