In-loop deblocking vs Avisynth deblock() filter

[hkl8324]

Someone in the forum said something I dont quite understand...
He said disabling the in-loop deblocking in x.264 and instead using the Avisynth deblock() filter will speed up the encoding.

I can understand that, but

Isnt blocking a bad consequence of insufficient bits allocated to edge, moving scene...?

From what I know is that deblock() filter deblocks the SOURCE, and the in-loop deblock of x.264 deblcoks the encoded materials. (or am I wrong?)

Why the avisynth filter can replace the in-loop one?

[Sagittaire]

Well it's simply totaly false ... lol

1) Avisynth deblocking is pre-process filter only for the source. It's useless if source is really good like DVD source.

2) Inloop is an encoding process for H264. It's usefull only for high quantisation level

[berrinam]

2) Inloop is an encoding process for H264. It's usefull only for high quantisation levelAh, just a slight clarification here: inloop is more useful at higher quantisation levels, but you shouldn't ever turn it off, because it will turn of automatically anyway when it's not needed (an over-simplification, I know, but let's not go there now)

[check]

When you apply normal deblocking / post-processing, it's done at the very end of all the decoding and so on and that's it.

The inloop deblocker in h264 gives better results because it can see the original image when the video is being encoded and therefore knows the best way to reproduce it more accurately. Other funky maths happens and the end result is that for sources that need deblocking, using the h264 inloop is far more efficient than disabling it and applying an external deblocker.

[Manao]

The inloop deblocker in h264 gives better results because it can see the original image when the video is being encoded and therefore knows the best way to reproduce it more accuratelyNo. The inloop deblocker is better because it is inloop : it deblocks the encoded picture before using it as reference, which means you don't motion compensate a blocky picture, but a deblocked one. Out of loop deblocker deblocks during the decoding only, and only shows the deblocked picture ( but use the blocked picture for motion compensation, since the encoder also used the blocked picture and both encoder / decoder must use the same picture )

[CruNcher]

@hkl8324

sorry but if you referencing to what i said you have to read it again i said:


after that use deblock() you can disable the inloop deblocker then and save processing time @ decoding alot of processing time

i didn't say it replaces the inloop deblocking of X264 as Manao said it can't but it's a alternative for blocky source if you want to save processing power @ decoding and don't want to use uber high filter settings that cause bluring in the end.

[hkl8324]

@CruNcher

Sorry, I miscomprehended your statment:p

:stupid:

Anyway, thanks for the explanations.

[Revgen]

but you shouldn't ever turn it off, because it will turn of automatically anyway when it's not needed

I've had better experiences (and faster speed) leaving it off at high bitrates. The video looks sharper and any blocking is hardly noticeable. But to each his own.