Nope, it isn't. Please stop spreading wrong information
I'll try. )
Also you should say "blocks" instead of "scenes", now with MB-Tree rate-control being used
I don't use mbtree for some reasons.
I guess you mean "CQP" (aka "constant quantizer").
I meant pq aka "picture quality".
And of course CQP cannot be equivalent to CRF/2-Pass. But CQP was never mentioned!
"The advantage of the CRF mode is that it suits the human
perception much better than the QP mode. For example it will raise the quantizers in "fast" scenes where the
loss won't be visible anyway and lower the quantizers in "slow" scenes. Therefore the CRF mode should
give the same subjective quality as QP mode, but it usually achieves a significant higher compression. It's
recommended to prefer CRF mode over QP mode, although CRF is a bit slower. When switching from QP to
CRF mode, you may want to slightly lower the quantizer. This should give approximately the same file size
as before, but better visual quality! Another important advantage of CRF mode is that it will benefit from
adaptive quantization, something that QP mode can't do."
So, CRF is much more subjectively closer to CQP than 2pass mode.
The good example of using crf + 2pass: I encode with CRF and try to get the file size not bigger than X. But it unfortunately become a bit larger. What to do? Start new encoding and loose time for 2 passes? Or I can use stats from CRF mode and make just 2nd pass. It's obvious.
So. The rule is - use CRF or CRF+2pass (when you missed).
Here's real HD comparision (Anger Management BD CEE AVC).
crop + spline36resize+
selectTotal=framecount()/50
selectrangeevery(selectTotal,50)
CRF:
Commandline for x264:
"C:\Programs - W7\x264_x64.2010-04-25\pipebuf.exe" "C:\Programs - W7\x264_x64.2010-04-25\avs2yuv.exe" Q:\HDProjects\anger\anger.avs - : "C:\Programs - W7\x264_x64.2010-04-25\x264_x64.exe"
--crf 17.50 --level 4.1 --ref 12 --no-fast-pskip --bframes 8 --weightp 2 --no-mbtree --b-pyramid normal --b-adapt 2 --deblock -3:-3 --subme 10 --trellis 2 --partitions all --me umh --merange 48 --thread-input --vbv-bufsize 62500 --vbv-maxrate 50000 --aq-mode 1 --aq-strength 0.8 --psy-rd 1.0:0 --ssim --output Q:\HDProjects\anger\anger-crf175-aq08-psy100-b8-1629-me48-2.mkv --frames 2505 --demuxer y4m --stdin y4m - : 4
x264 [info]: frame I:56 Avg QP:
17.33 size: 99584
x264 [info]: frame P:505 Avg QP:
18.70 size: 52507
x264 [info]: frame B:1944 Avg QP:
20.94 size: 25136
x264 [info]: consecutive B-frames: 1.9% 0.9% 3.8% 15.5% 22.0% 39.4% 9.1% 3.6% 3.7%
2-PASS:
Commandline for x264:
"C:\Programs - W7\x264_x64.2010-04-25\pipebuf.exe" "C:\Programs - W7\x264_x64.2010-04-25\avs2yuv.exe" Q:\HDProjects\anger\anger.avs - : "C:\Programs - W7\x264_x64.2010-04-25\x264_x64.exe"
--bitrate 6200 --pass 2 --stats Q:\HDProjects\anger\anger-crf175-aq08-psy100-b8-1629-me48-2pass.mkv.x264-stats --level 4.1 --ref 12 --no-fast-pskip --bframes 8 --slow-firstpass --weightp 2 --no-mbtree --b-pyramid normal --b-adapt 2 --direct auto --no-dct-decimate --deblock -3:-3 --subme 10 --trellis 2 --partitions all --me umh --merange 48 --thread-input --vbv-bufsize 62500 --vbv-maxrate 50000 --aq-mode 1 --aq-strength 0.8 --psy-rd 1.0:0 --ssim --output Q:\HDProjects\anger\anger-crf175-aq08-psy100-b8-1629-me48-2pass.mkv --frames 2505 --demuxer y4m --stdin y4m - : 4
x264 [info]: frame I:56 Avg QP:
17.66 size:102710
x264 [info]: frame P:505 Avg QP:
21.39 size: 45379
x264 [info]: frame B:1944 Avg QP:
21.11 size: 26195
x264 [info]: consecutive B-frames: 1.9% 0.9% 3.8% 15.5% 22.0% 39.4% 9.1% 3.6% 3.7%
CRF - 2-PASS:
As you can see CRF gives more bitrate for static scenes than 2-PASS. And don't waste it - look at first mega leap on bitrate viewer screen.
And look at quants )