Very long 2nd pass encode times

[gkar]

I have been trying out the XVid codec (1.1.0-30122005) & have noticed unacceptable 2nd pass times -up to 7 hours for a 2.5GB encoded video file.

My settings are:

Advanced Simple@L5
MPEG Quantization
QPixel, GMC,
B-VOP 2: 1.50: 1.0
Packed Bitstream
Level & Aspect Ratio tabs default

Zones: User Defined
6-Ultra High
VHQ Mode: 1-Decision Mode
Chroma Motion
Turbo
Other: 0: 300
Trellis
Default Quantization

The encode times are 2-3 times longer than the DivX 5.1.1
What settings should I alter to drop the times down to an acceptable level? Thanks.

My PC is an AMD 2200Athlon
512mb DDR400 RAM
WinXP Home w SP2 & updates

[iNFO-DVD]

2.2 CPU & 7 hours 2nd pass, little hard to tell whether this is 'normal' with those settings or not without knowing how long the movie is (duration) and what resolution you converting it at?

Do you definately need to use MPEG quant? H.263 is quicker if it's speed you are after, gmc? qpel? all take up time.

[foxyshadis]

GMC and QPel is probably were some of the slowdown comes from. Did you have those options enabled in Divx? (I forget if 5.1.1 had Qpel.) Also, why no upgrades to 5.2.1? It has some important bugfixes. (And 6.x is much better still, but it's $5 to upgrade.)

Lastly, same avisynth script? Or if you were doing it through divx converter/dr divx before, what are you using now?

(Different matrices aren't really any faster, except that it typically results in smaller sizes, and lower bitrates are slightly faster. At 2.5G per movie, h.263 would ruin it.)

[iNFO-DVD]

At 2.5G per movie, h.263 would ruin it.Not if the movie was 6 hours long :)

[Koepi]

Disable GMC. DivX only has (useless) 1-warp-point GMC, whee XviD uses (only little efficient) 3-warp-point GMC. Which takes up _plenty_ of time.

Cheers
Koepi

[sysKin]

Yup, GMC probably halved your 2nd pass speed.

[gkar]

WOW. Thanks for the response, friends. :thanks:

Let me reinterate some of the info to confirm in my own mind.

Disable GMC -what does it do, in terms of quality, bearing in mind I am only re-encoding normal DL 4.5GB DVDs? Would the difference be distinquishable to the average eye on playback via a 480p projector (X1)?

Also, QPel? What's it for? Please no mathematical definitions :D


Not if the movie was 6 hours long
The movie is 2hr 38min 15sec

...and what resolution you converting it at?

672x272-464 depending on aspect ratio

I use Gordian Knot 0.35 for my movie encodes.

Do you definately need to use MPEG quant?
As I understand it, MPEG is recommended for 2-3CD rips. I base my file size by GK's 70% compressibility test.

Also, for single pass encode from SDTV capture (Hauppauge 150MCE) off VHF/UHF ariel would the default settings be the most practical? :thanks:

[iNFO-DVD]

I'm sorry, but in my own personal opinion a lot of the options you are choosing for a movie that will be shown an a projector are just not needed if you want to gain some speed.

[gkar]

I'm sorry, but in my own personal opinion a lot of the options you are choosing for a movie that will be shown an a projector are just not needed if you want to gain some speed.

Any chance on expounding a bit? I would try settings from anyone with sound knowledge on the subject. It's how we learn. I won't hold it against you, honestly http://bestsmileys.com/expressions/9.gif

[gkar]

On the flip side, I'm doing an encode from a captured show & the video rendering rate is up 3x compared with DivX5.1.1 http://bestsmileys.com/thumbs/2.gif

[iNFO-DVD]

The point I was trying to make was why do an encoder with settings that will greatly reduce the speed if after the conversion and you watch the movie you'll not see the benefits of that extra time taken.

As for XVID settings there's a link on Doom9 that goes here:
http://ronald.vslcatena.nl/docs/xvidfaq.html
and another link to a more updated guide:
http://www.divx-digest.com/articles/xvid_setup.html

To be honest the best thing to do is read some information and guides and just do some tests. Try some really intense options and again some more conservative speedier options, note the encoding times, watch the results.

[gkar]

The point I was trying to make was why do an encoder with settings that will greatly reduce the speed if after the conversion and you watch the movie you'll not see the benefits of that extra time taken.


I appreciate that. However, I am attempting to think about playback in the future. I won't always have my present equip & want good viewing with my next generation of HT gear.

To close out this thread: I changed min. quants to 2 & diabled GMC. A 2.03 hour movie 2nd passed in around two & half hours. It must have been due mainly to GMC. I can't notice any difference. Thanks to all.