How to speed-up x264 2-pass encode?

[ben45]

Hello
How can i speed-up this x264 setting without (or minimum) quality loss? (megui)
program --level 4.1 --pass 2 --bitrate 940--stats ".stats" --threads 16 --deblock -1:-1 --keyint 240 --ref 5 --qpmin 10 --qpmax 51 --vbv-bufsize 25000 --vbv-maxrate 20000 --me umh --direct auto --trellis 2 --psy-rd 1.0:0.15 --output "output" "input"

[Atak_Snajpera]

reduce ref from 5 to 3

[ben45]

reduce ref from 5 to 3

This will not reduce quality?

[ben45]

Will using Temporal direct reduce quality?

[Atak_Snajpera]

everything reduces quality. Question is will you notice this small drop in picture quality?

[ben45]

everything reduces quality. Question is will you notice this small drop in picture quality?

Small like subme=7 and subme=9 difference?

[Atak_Snajpera]

yes.
if you want additional speed up you can also replace umh with hex.

[benwaggoner]

Hello
How can i speed-up this x264 setting without (or minimum) quality loss? (megui)
program --level 4.1 --pass 2 --bitrate 940--stats ".stats" --threads 16 --deblock -1:-1 --keyint 240 --ref 5 --qpmin 10 --qpmax 51 --vbv-bufsize 25000 --vbv-maxrate 20000 --me umh --direct auto --trellis 2 --psy-rd 1.0:0.15 --output "output" "input"
What hardware are you running on? Unless you have a lot of cores, 16 threads may be overkill, and the overhead of thread sync can cause it's own performance loss.

Going to level 4.0 with lower bufsize and maxrate will also reduce the peak bitrate, speeding up CABAC significantly. Are you doing 1080p? Seems unlikely with a 940 bitrate. I recommend using the lowest Level that supports your frame size and frame rate.

[kuchikirukia]

Going to level 4.0 with lower bufsize and maxrate will also reduce the peak bitrate, speeding up CABAC significantly. Are you doing 1080p? Seems unlikely with a 940 bitrate. I recommend using the lowest Level that supports your frame size and frame rate.

?


Unlimited/Autoguess (came out level 4): encoded 2696 frames, 8.71 fps, 4537.37 kb/s
Level 4: encoded 2696 frames, 8.68 fps, 4570.03 kb/s
Level 4 10k/10k vbv: encoded 2696 frames, 8.69 fps, 4570.03 kb/s

If you were to set it down further into bitrate starvation mode, I don't see how anyone would consider that an acceptable speed/quality tradeoff.