Comments on my Divx settings ???

**Satan Claus** · 21 Jul 2004, 11:19 AM

"Hi there, I have an 8 minute, 720 x 480 DV file that is roughly 1 gig in size.

I used Divx pro 5.0.2 codec to encode with VIRTUALDUB and with the following settings:

1 pass
780 kbps
Bi-directional encoding
source interlaced:all frames are interlaced
Max keyframe interval: 250 frames
Max quantizer: 4
Min quantizer: 2
RC averaging/reaction period: 2000 frames/10 frames
Rate control: 20
Performance quality: slowest

Quality is GREAT, but I think this is a big file size. File takes about 15 to 20 mins to encode and resulting file size is 180 MB. Audio compression accounts for 7 megs.

Any suggestions on how I could SPEED up the encoding process AND REDUCE file size?

(will reducing the resolution down from 720 x 480 to 640 x 480 help?)"

First of all, to speed up the process all u can do is to upgrade your machine, (if your compressing at 12 fps aprox. then u must be running a 2.0 MHz machine with 256 RAM?). Anyhow, thatÂ´s a very good speed. The other thing you can do is to change the performance quality to "fastest" but the compression would be less heavy and the final file would be even bigger.

Second, about the size, for a high quality 720 x 480 pixels 8 minutes video, 170 Mbs is not bad. Of course, reducing the size down to 640 x 480, will save u quite some Mbs but you should maintain the aspect ratio (640 x 428 aprox.).
Also, reduce the RC averaging/reaction period (this is one of the main parameters to control both quality and size of your video).
My final recomendation to u, is that u should play with all the parameters until u get to learn what exactly they do and how the change the final compressed video.

Hope this helps u...
Satan Claus.

**anonymez** · 22 Jul 2004, 11:41 AM

you need to do a little research man

first of all, if you want high quality divx video, try getting the latest version (5.2). second, do not use single-pass encoding. use 2 pass or multi-pass. Both passes should have exactly the same settings, except the first pass should be done on "standard" and last on "slowest"... those settings have been found to give best quality to speed ratio.

and satan claus, reducing the resolution does not affect the file size, but may give a clearer picture.

but that is only if you want to use divx... if you want great speed with great quality, go for xvid...

good luck

**Satan Claus** · 22 Jul 2004, 12:47 PM

u gotta be ****ting me if u tell me that a 720 x 480 pxs video uses the same amount of space as a 640 x 428 video....
second, divx 5.2 is a piece of crap, it looses some feature on every version... not to be able to control the quantizers sucks ass and the quality u so speak about goes to **** when you use 12 units quantizers with low bitrate....
i would not wasted time answering if i hadnÂ´t tested the **** out divx 5.2...
everything after the 5.05 version is crap..
iÂ´ve also heard that xvid was better and i have the codec but no matter what specs i use, the size keeps comming smaller with divx, donÂ´t know why...

Satan Claus

**anonymez** · 23 Jul 2004, 11:12 AM

yup, decreasing/increasing resolution does not affect the file size, but affects how many bits each pixel will get... essentially, you will get a higher quality image as the resolution decreases as each pixel be allocated more data

for example, if you encode a dvd (720x576) to say divx at the same resolution at 800kbit/s, it will look crap compared to a divx at a lower resolution (say 624x???)

I have encoded with all versions of divx from 5.02 to 5.2, and i really have not noticed any change except for the encoding speed. I myself, as i said, use xvid... beats divx in quality and dramatically in speed, but you gotta know what you're doing... check out the dvd--->xvid guide at http://www.divx-digest.com... i get best results with gordian knot.

any encodes i do with divx is purely for testing.

good luck