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View Full Version : Faster Syntax for IVTC with Decomb?

Kedirekin
5th February 2002, 01:01
Couldn't decide which of the forums to post this to, so this forum wins.

I 'grew up' (so to speak) on Decomb 1.82. When I changed to Decomb 1.91, it seemed that encoding slowed down, so I just performed a little testing. Here are my results (all speeds after 10 minutes of encoding, to give things a chance to stabalize).

With the following AviSynth script:

LoadPlugin("E:\RIPPIN~1\DVD2SV~3\SIMPLE~1\SIMPLE~1.DLL")
LoadPlugin("E:\RIPPIN~1\DVD2SV~3\Invers~1\Donald~1\Decomb.dll")
LoadPlugin("E:\RIPPIN~1\DVD2SV~3\MPEG2Dec\mpeg2dec.dll")
mpeg2source("E:\DVDCOP~1\STARGA~3\DVD2AVI_PROJECT_FILE.d2v")
Telecide
Decimate
TemporalSmoother(3,1)
SimpleResize(480,360)
AddBorders(0,60,0,60)
ResampleAudio(44100)

my CCE speed was 0.347 rt.

With the following:

LoadPlugin("E:\RIPPIN~1\DVD2SV~3\SIMPLE~1\SIMPLE~1.DLL")
LoadPlugin("E:\RIPPIN~1\DVD2SV~3\Invers~1\Donald~1\Decomb.dll")
LoadPlugin("E:\RIPPIN~1\DVD2SV~3\MPEG2Dec\mpeg2dec.dll")
mpeg2source("E:\DVDCOP~1\STARGA~3\DVD2AVI_PROJECT_FILE.d2v")
Telecide(false,false,false)
Decimate
FieldDeinterlace
TemporalSmoother(3,1)
SimpleResize(480,360)
AddBorders(0,60,0,60)
ResampleAudio(44100)

my CCE speed was 0.451 rt.

I assume the second syntax is faster because post-processing is taken out of Telecide and moved after Decimate, so it only has to process 4 out of every 5 frames.

Unfortunately, I do not know if my results are universal. So, this post serves double duty: 1) to let people know, and (optionally) 2) to ask people to confirm.

TIA
trbarry
6th February 2002, 17:51
I just noticed an interesting post by Donal Graft in the Decomb thread on the Avisynth forum that may apply:

I'll tell you about the null parentheses issue here because it is very important and very interesting. If you have a script like this where the parentheses are omitted:

Telecide
Decimate

...you can speed it up by as much as 25% simply by changing it to:

Telecide()
Decimate()

Apparently there is a quirk in Avisynth's parameter processing that causes it to waste large amounts of time in the first case. This works with previous versions as well. Believe me, I was blown away when I discovered this!


- Tom
dvd2svcd
6th February 2002, 18:04
I have just confirmed Donald Graft's statement. Incredible, who should have known.


LoadPlugin("D:\MULTIM~1\SIMPLE~1\SIMPLE~1.DLL")
LoadPlugin("D:\MULTIM~1\MPEG2Dec\mpeg2dec.dll")
LoadPlugin("D:\MULTIM~1\INVERS~1\DONALD~1\decomb.dll")
mpeg2source("D:\MULTIM~1\Movie\DVD2AV~1.D2V")
Telecide
Decimate(5)
SimpleResize(480,360)
AddBorders(0,60,0,60)
ResampleAudio(44100)
Speed in CCE 0.397


LoadPlugin("D:\MULTIM~1\SIMPLE~1\SIMPLE~1.DLL")
LoadPlugin("D:\MULTIM~1\MPEG2Dec\mpeg2dec.dll")
LoadPlugin("D:\MULTIM~1\INVERS~1\DONALD~1\decomb.dll")
mpeg2source("D:\MULTIM~1\Movie\DVD2AV~1.D2V")
Telecide() #The () really speeds things up
Decimate(5)
SimpleResize(480,360)
AddBorders(0,60,0,60)
ResampleAudio(44100)
Speed in CCE 0.543


I will make the changes in the next build.
mrbass
7th February 2002, 05:51
This is great 25% speed increase. Can anyone tell me using the quicker way Telecide() the average decrease percentage in encoding speed? The same for using IVTC Wizard? For me IIRC it was about 60% slower for IVTC Wizard. We need to add this info to the newbie faq SPEED section.

ResampleAudio(44100)
slightly off topic...but when in dvd2svcd's history was this removed? It used to be in there to avoid CCE crashes back in August / September IIRC.
dvd2svcd
7th February 2002, 08:53
ResampleAudio(44100)
slightly off topic...but when in dvd2svcd's history was this removed? It used to be in there to avoid CCE crashes back in August / September IIRC.


It has been reenabled in build 3.