Higher ratetol on first pass + other advanced x264 musings

cvk_b · Post by **cvk_b** » Sat May 12, 2007 8:02 am

I am using a modified palmrest crf/abr combo script— encoding for iPod.

First pass (CRF):
x264b30
CRF (0.74)
width 640
turbo options

Second pass (ABR):
stats file from first pass ignoring bitrate
x264b30
width 640
bitrate 1500
qcomp=0
ratetol=0.67 (rhester, from irc logs, curb bitrate spikes iPod can't handle)
+more x264 options to force compatibility and push quality

My question is: Could I be making better use of my first pass?

This post at doom9 suggests that a higher ratetol on the first pass is better. If you are using different options for each pass, what & why?

jbrjake · Post by **jbrjake** » Sat May 12, 2007 1:38 pm

What set of turbo options are you using currently, and what are the other x264 options you're using in the 2nd pass?

cvk_b · Post by **cvk_b** » Sat May 12, 2007 5:24 pm

jbrjake wrote:What set of turbo options are you using currently, and what are the other x264 options you're using in the 2nd pass?

1st) only the turbo options from palmrest itself

Code: Select all

TURBO="subme=1:me=dia:trellis=0:analyse=none"

2nd)

Code: Select all

subme=7:me=umh:me-range=36:subq=6:no-fast-pskip:trellis=1:analyse=all:filter=-2,0

plus iPod stuff

Code: Select all

bitrate=1500:qcomp=0:ratetol=0.67:cabac=0:level=30:bframes=0:8x8dct=0

cbud · Post by **cbud** » Fri May 18, 2007 3:13 pm

Does anybody have a rate tolerance value for the Apple TV?

Cavalicious · Post by **Cavalicious** » Wed May 23, 2007 1:43 pm

cbud wrote:Does anybody have a rate tolerance value for the Apple TV?

3000 seems to be the sweet spot for me. Keep it under 5000. A setting of 5000 is hit or miss, due to flux. 4500 is a safe max, BUT, I notice very little from 3000 to 4500.

rhester · Post by **rhester** » Wed May 23, 2007 3:17 pm

I would advise against the use of ratetol on the final pass in order to constrain maximum rates. Please see my latest posts on the Apple TV forum for details.

Rodney