E.S.A.
Цитата:
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А как же тогда официальная документация? Рекламная утка? Или этот парень как и я, субъективист
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Я уже давал тебе ссылку на этот форум, там в соответствующем топе (чё-то он у меня пока не открыается) ребята задались целью субъективно оценить качество кодирования с новым 5.1. Короче вот:
my test results of divx5.1
Just wanna share some observations about new codec.
First setup: movie source can be considered as a bit noisy (well, I'd say considerably noisy if it wasn't for old b&w movies comparing to which the source seems to be quite clean ). So in other words not ideal (like most of non-recent movies actually). 608x336 resolution which gave me ~67% of comp test with bitrate ~950kbps. So while it's still quite challenging for the codec it will be able to produce nice results. (if it was more than 80% then comprasion of different codecs/modes is pretty much useless).
I was comparing three encodes:
- 4 passes with 5.05
- 4 passes with 5.1 (normal speed)
- 4 passes with 5.1 (3 passes on normal, last on slowest)
In all cases no pro options were used (i.e. no b-frames indeed), and no PSY as well. (oh and lanczos resize was used, so pretty sharp picture was expected)
First I have to say that 5.05 performed worse that other two encodes in almost every single aspect. Having said that - I have to admit one thing: if you look at the edges of objects in all three encodes - they are absolutely identical (in both slow and high motion scenes). Which means actually that even when viewing video very close to your eyes most ppl will not be able to tell the difference between those three encodes.
Lets go and do the science now What was different and why 5.05 lost? Texture! I have to say staight away that everything that I'm gonna describe below is only visible when doing frame-by-frame comprasion. So 5.05 had fewer detais, more blocks and in general feels like less sharp. So lets move to divx5.1 and see if it's worth using slow/slowest modes of it.
First type of scenes I was looking at was non in-focus scenes (i.e. high motion, special effects etc.) Slowest mode performed well here as I was expecting. Picture looks more smooth and almost don't have any blocks whatsoever. Normal mode gave me slightly visible blocks mostly on such objects like fog, explosion etc. So far so good.
Now I was looking at steady in-focus shots to see how much details codec left in both cases. This came out as somplete surprise to me! Normal mode had significally more details resolved on the picture that slowest mode! (and this actually you will be able to see quite often when watching video as you have time to observe the details of the shot). So in fact slowest mode acted more like PSY (i.e. essentially noise removal filter). May be they have some kind of PSY always enabled in slowest mode...
Anyway imho steady shots are more important (coz they are more visible) and normal mode of divx5 is somewhat closer to what XviD users used to have. And of course when you consider the speed of slowest mode - it don't really see the point of using it at all.
So to sum up:
- Is it worth upgrading to 5.1? Yes, at least for the speed (I forgot to mention that 5.1 normal was faster than 5.05 simply because MV feature is finally working properly).
- Is it worth using slow/slowest mode of 5.1? No. Not only it's slow, but the result are not that great, sometimes even worse than normal mode.
All above is my personal opinion based one one concrete example. Others may have different observations