Is Divx 5.02 much slower than 5.01?

[at0mic8oy]

A few days ago...i updated my codecs on my computer with Nimo Codec Pack v5 build 8....previously i had an older version of the same pack and i had divx 5.01 pro installed....nimo would update to divx 5.02 pro...

before i installed the codec pack i could encode up to 2 different mpeg2 videos to divx 5.xx at 75fps each at the same time.....now i'm getting 15fps on a single uncompressed avi -> Divx 5.02 90% quality based encode.

i'm a bit frustrated at such a huge drop in encoding performance, and i'd greatly appreciate it if someone could shed some light at to what could cause this.

i have a Dual Athlon MP 1800+ machine with a 80 gig IDE RAID 0 array to encode video on...but it's now encoding as slow as my 900mhz Athlon Thunderbird.

[sherpya]

Originally posted by at0mic8oy

before i installed the codec pack i could encode up to 2 different mpeg2 videos to divx 5.xx at 75fps each at the same time

i have a Dual Athlon MP 1800+ machine with a 80 gig IDE RAID 0 array to encode video on...but it's now encoding as slow as my 900mhz Athlon Thunderbird.
75 fps??? Have you stolen your pc from nasa?
I think a home pc can't encode divx at 75fps even if a dual athlon (encode process uses mainly one cpu)
However 75 to 15 seems a bit strange you must use same input file to make comparations...
Still using same compresssion parameters?

[manono]

Hi-

You encode at a low enough resolution and you can get those kinds of speeds. But that doesn't answer the question, and I don't know the answer, although perhaps someone else might.

[Acaila]

The drop from 75 to 15 fps can't possibly be because of the codec update (in fact 5.02 should be slightly faster than 5.01 because they fixed a slowdown bug). You should look more closely at things like filters and the programs you encode with.

@manono:
Welcome to the team, it's great to have you on board :)

[at0mic8oy]

sorry...very stupid of me...75fps was mpeg2 to divx 5...15fps is uncompressed avi to divx 5....but i never thought the format should make that much difference....i'm trying to encode full 720x480 DV video to divx 5...the results come out nice...but the speed drop has kinda freaked me out....

could it be the difference in input format that made the speed drop that much?

[Acaila]

AFAIK the input format shouldn't make much of a difference (in fact the MPEG2 video needs to be decoded as well, so one would expect it to be slower than an uncompressed source). Are you using more filters for the uncompressed AVI, or maybe you're using VDub in full processing mode?

[khp]

With an raw uncompressed source, disk speed will quickly become the limiting factor.

You did'nt mention your source resolution. But if we assume 720*576 24bit rgb. 15 fps corrosponds to 18 MB per second. If you are using the same disk for both source and destination, even a striped raid will be pushing the limits.

[at0mic8oy]

I am encoding virtual dub in full processing mode.....but i did that for the mpegs also....

the source and destination are the same disk...it's 2 ATA 100 seagate baracudas striped as raid 0....i have a 3 disk raid 5 ultra160 scsi array...but it has never seemed any faster than the IDEs.

All i've ever used in the past as been gordian knot...but virtual dub is very handy for DV editing so i have been trying to just use it....ino it only uses a single processor which sucks...but it still seems like it should be faster....any suggestions for alternatives that can encode using SMP?

i'd be happy to get about 30fps...i think the machine should be fast enuf to do realtime divx encoding at a pretty good quality...

[Acaila]

GordianKnot also uses VirtualDub, however it sets it to fast recompress mode. This helps A LOT! Full processing will do colorspace conversions (regardsless of anything else you tell it to do) which can easily drop your speed by 3/4.

Use fast recompress in VDub and set whatever filters you want to use in Avisynth, that way you'll be cruising again. It may not be fully SMP capable, but it's pretty close. I get 80-90% cpu load on my encodes.

And yes, that system should be quite enough for real time DivX encoding, even twice real-time :)

[at0mic8oy]

thanx sooooo much for the replies....

Originally posted by Acaila
GordianKnot also uses VirtualDub, however it sets it to fast recompress mode. This helps A LOT! Full processing will do colorspace conversions (regardsless of anything else you tell it to do) which can easily drop your speed by 3/4.


i'll try that...i never had before because i figured it'd reduce the quality.

Originally posted by Acaila

Use fast recompress in VDub and set whatever filters you want to use in Avisynth, that way you'll be cruising again. It may not be fully SMP capable, but it's pretty close. I get 80-90% cpu load on my encodes.


i've encoded alot of stuff with simple quality based settings in the codec and simple apps like gordian knot and xmpeg...but never messed with avisynth...can you link me to some docs on how to set the filters in avisynth?

[Acaila]

i'll try that...i never had before because i figured it'd reduce the quality.Actually using Full Processing reduces the quality if the source isn't in RGB, the only time you'll want to use this is when you want to use filters that don't work in YUY2 colorspace (as Avisynth does). Fast Recompress keeps the source's colorspace and is thus always the better setting.

can you link me to some docs on how to set the filters in avisynth?Sure,

The Avisynth Q&A (http://forum.doom9.org/showthread.php?s=&threadid=25002) contains a lot of useful info, among other things a list of where to find certain filters that aren't included in the main peogram.
The Sourceforge (http://sourceforge.net/projects/avisynth2/) page for Avisynth is where you can find the latest version, which also has detailed documentation about how to use filters.

NB. GKnot also uses Avisynth, you can look there for an example of how a full script looks like.

[REIGN_]

Yoy mentioned 15 fps when doing a divx avi. With a dual Athlon Mp system is really bad. Because i have a 700 mhz pentium III and i get 17 fps standard with avisynth 2.0.5 (great) and MPEGdecoder (even greater). I hope you will find the way because your system can do a lot of things and make them fast