Tweaking mpeg2dec3.DEF for speed in D2S w/Avisynth 2.5x permanent, something, increase, decent

andy

I remembered something I promised D2S I would post about: A slight but decent speed increase can be had from tweaking Mpeg2dec3 (used with AviSynth 2.51 D2S installations) by specifying idct=2 for AMD/P3 or idct=5 for P4.

You can do this two ways. Edit the AVS script by checking edit script in the frameserver tab and hand edit like this: mpeg2source (quot;stuff.d2vquot;,idct=2) #or idct=5 for P4
OR for permanent use:

Mpeg2dec3 allows presets to be made by entries in the mpeg2dec3.DEF file. It is placed in the same dir with mpeg2dec3.DLL and is just a notepad file with one line: idct=2 (or 5)   

There were a lot of other settings in the original DEF file, but I found I had to remove all them to get the same speed increase as the hand edit line above. I assume some of the other settings invoked functions that slowed things down.  

Hey, I never took the time to test what most of them did except to note we need to study this as some of them could be very useful to us. Maybe somebody else will study them and post results here. Also, somebody post some timing differences with and without idct=x if they have the time (Markrb since you are doing timings now?).

Here is the original DEF file:

d2v=quot;your default project file here.d2vquot;
cpu=0
idct=2
iPP=false
moderate_h=20
moderate_v=40
showQ=false
fastMC=false
cpu2=quot;quot;

will report back my findings

wow, i am really impressed by this tweak, it enhanced my encoding speed about 0.2, pretty nice

thx to DDog for posting this nifty little tweak

eternal, glad it helped. Hey, P4, P3 or AMD? NTSC or PAL? 4:3 or 16:9?

Just curious as .2 speed increase is a little more than I get.

source was pal, 16:9 and i am on an amd...
i'll do some more testing on a friends p4, post results later

regards

eternal

I tried it on an AMD and I didn't get any change.  I tried both in the avs file and in a seperate .DEF file.

I will do further testing.

Mark

pretty strange, i did 2 encodings so far on my amd, on the second try i could even get about .22...

as said before i'll do some more testing

@ markrb: same here  

i just dont get any seed improve
and made by editing the script and also by using the def file .

Odd

Must make more tests

For testing just do the hand edit. I know that works (for me). Forget the DEF file for now as I am not sure about that.

well, i did the hand edit aswell as a part of the video encoding, works fine. just tried that tweak on my friends p4 but unfortunately there wasn't any noticeable speed enhancement.

seems like as if this won't work on all systems, huh?

regards

eternal

Mark do you really need a faster system?  
I'm jealous enough with your current speed, please don't report any faster speeds

is this also supesed to work on avi2svcd ? i only get quot; invalid argument error quot; in wmp ...

I´ve tried this tweak on my p4 celeron 1.7 but dont see any higher speed. Just wonder if I am doing it right?
Ive been trying both editing after dvd2avi and as part of encoding.
And the only DEF file I have is the one in my VFAP map?
Here is my AVS part of my log:

---AVS Begin---
Import(quot;C:\Program\DVD2SVCD\Movie\RESAMP~1.AVSquot;)
LoadPlugin(quot;C:\Program\DVD2SVCD\AVISYN~1.5PL\Mpeg2dec\MPEG2D~1.DLLquot;)
LoadPlugin(quot;C:\Program\DVD2SVCD\AVISYN~1.5PL\AVISYN~2.DLLquot;)
mpeg2source(quot;C:\Program\DVD2SVCD\Movie\DVD2AV~1.D2Vquot;,idct=5)
LoadPlugin(quot;C:\Program\DVD2SVCD\Avisynth2.5 Plugins\SimpleResize\SimpleResize.dllquot;)
ConvertToYUY2().SimpleResize(480,576)
ConvertToYUY2()
AvisynthSubtitler(quot;C:\Program\DVD2SVCD\Movie\subs\quot;,quot;permsubs.txtquot;)
ResampleAudio(44100)
----AVS End----

i don't get it either, tested the tweak on a friends jiuhb, exatly same processor as mine, even with the same stepping, on the same windows xp, with the same dvd2svcd version etc., but he didn't get any speed increase. i am wondering whats going on, maybe any of you got an idea?

regards

eternal

Heck, I don't know either. I did some tests here showthread.ph...0amp;pagenumber=2
(About four up from the end)
It seemed to show a clear speed dif although they were short tests. They were also re creatable. Maybe it is more evident on my old TBird? Dunno.

hm, thats really strange, seems like it depends on some special thing which we didnt find yet. fact is, the tweak works on several systems very fine, but on others there isn't any speed change, neither increase nor decrease. i tested it on 3 system, one was nearly the same as mine, the other one was a friends p4, on my system i could get a .2 cce increase, on the p4 and on the other jiuhb athlon there wasn't any change noticeable. i set up dvd2svcd exactly like i did on my tests, even with the same dvds as source. maybe we'll find out sometime whats going on here.

regards

eternal