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View Full Version : job command line had chroma-qp-offset -2 but mediainfo returns offset at -4


sub24ox7
18th April 2010, 17:55
I am using x264 core 93 r1538 bd72d46 with MEGUI, I looked in the logs and found and my first pass commandline job is" --level 4.1 --pass 1 --bitrate 15500 --stats "D:\demux\LOGS\log.stats" --deblock -3:-3 --bframes 9 --b-adapt 2 --b-pyramid strict --ref 6 --chroma-qp-offset -2 --vbv-bufsize 50000 --vbv-maxrate 50000 --ratetol 2.0 --qcomp 0.7 --merange 64 --me umh --direct auto --subme 9 --trellis 2 --psnr --ssim --sar 1:1 --output NUL "D:\demux\Tombstone.avs" "
Second Pass command line job "--level 4.1 --pass 2 --bitrate 15500 --stats "D:\demux\LOGS\log.stats" --deblock -3:-3 --bframes 9 --b-adapt 2 --b-pyramid strict --ref 6 --chroma-qp-offset -2 --vbv-bufsize 50000 --vbv-maxrate 50000 --ratetol 2.0 --qcomp 0.7 --merange 64 --me umh --direct auto --subme 9 --trellis 2 --psnr --ssim --sar 1:1 --output "D:\demux\Tombstone.264" "D:\demux\Tombstone.avs" "

I used Chroma offset at -2 and the command line job reflects that also used rclookahead at 60. Mediainfo returns Chroma offset at -4 and rc lookahead at 40.

Here is the what Mediainfo returns for encoder settings
Encoding settings : cabac=1 / ref=6 / deblock=1:-3:-3 / analyse=0x3:0x113 / me=umh / subme=9 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=64 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-4 / threads=12 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / constrained_intra=0 / bframes=9 / b_pyramid=1 / b_adapt=2 / b_bias=0 / direct=3 / wpredb=1 / wpredp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=2pass / mbtree=1 / bitrate=15500 / ratetol=2.0 / qcomp=0.70 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / vbv_maxrate=50000 / vbv_bufsize=50000 / ip_ratio=1.40 / aq=1:1.00 / nal_hrd=none

So I guess what I am asking is whether anyone else has had this experience and whether I am doing something wrong and what I can do to fix it.

J_Darnley
18th April 2010, 18:40
psy-rd and psy-trellis change the chroma qp offset by -1 when <= 0.25 and -2 when not

sub24ox7
18th April 2010, 21:11
Thanks that explains that:) what about the rclookahead though?

J_Darnley
18th April 2010, 21:19
What about it? Neither command line specifies an option that will alter the rc_lookahead value so the default value of 40 is used.