View Full Version : Sanity check - DivX 5.1 - 3 pass settings


munkyboy
21st September 2003, 19:02
from the Divx support site
http://support.divx.com/cgi-bin/divx.cfg/php/enduser/std_adp.php?p_sid=GPUEokTg&p_lva=&p_faqid=228&p_created=1063142256&p_sp=cF9zcmNoPSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MjQmcF9wcm9kX2x2bDE9MiZwX3BhZ2U9MQ**&p_li=


A performance tip:
Do all but your last pass in Standard mode with the MV file enabled. Then, disable the MV file (this is imporant) and switch to Slow or Slowest mode for your final pass. If you use Psycho-vis then you can also disable it until your second-last pass as long as you disable the MV file at this point (e.g. if you're doing 4 passes, turn on PV and turn off MV in pass 3).


so, my interpretation of this means a 3 pass encode should go something like this:

1st pass:
Mode: Standard
Psycho Vis: Off
Log File: write
MV: Off

2nd pass:
Mode: Standard
Psycho Vis: On
Log File: write & read
MV: Off

3rd pass:
Mode: Slow/Slowest
Psycho Vis: On
Log File: read
MV: Off

Seeing as how MV should be off in the second to last pass, I disable it for all passes... I can only see it being used in a 4 pass situation for the 2nd pass.

btw, I've been lurking on the board for a long time. I hope to be contributing what I can back to the encoding community. :)

munky

bira
21st September 2003, 22:25
"(e.g. if you're doing 4 passes, turn on PV and turn off MV in pass 3)."

I don't understand how this is possible.

Anyway, wouldn't it be wiser to do something like that?

1st pass:
Mode: Standard
Psycho Vis: Off
Log File: write
MV: ON

nth -1 pass: (be it the second pass or the nth -1 pass)
Mode: Standard
Psycho Vis: Off
Log File: write & read
MV: ON

last pass: (e.g the nth pass)
Mode: Slow/Slowest
Psycho Vis: On
Log File: read
MV: Off

chris25frfr
22nd September 2003, 03:00
i saw this tip few days ago and i'm very interrested by the answer .

but i think bira is right . not sure

anyone else ??

thanks Munky :cool:

Sumster
22nd September 2003, 06:20
@Bira,

You can't have PV off for the N-1 pass.... PV changes the compressibility of the movie.

I would just keep PV on for all passes (therefore, keeping the compressibility constant, and not making sudden changes on the RC algorithm).

I use....

1st pass - PV ON, WRITE MV, STANDARD

Between 1 and N passes - PV ON, WRITE&READ MV, STANDARD (use the MV speed increase here).

Last pass - PV ON, NO MV, SLOWEST (can't re-use MV when changing the quality setting).

If you wished, you could DISABLE PV for all but the last TWO passes (ie. N-1 pass much have it on along with the last). However, I would assume that distributing bits with PV OFF, and then suddenly having PV ON would screw things up. Probably best to keep things as consistent as possible.

-Sumster