Why AVC looks better than 10-bit HEVC with same CRF

[vash1]

Hello,

I am a newbie to video encoding.

I've tried to encode 2 min sample from Bluray source with CRF 18 and slow preset using both codecs: HEVC (H.265 10 bit) and AVC (H.264).

The encoding was done with HandBrake Version 1.1.2 (2018-09)


Using the same CRF 18, AVC looks better to me than 10-bit HEVC compared to the source.
HEVC encode looks a bit blurred compared to AVC. So I am trying to figure out why is it so.


As far as I know, CRF values differ for HEVC and AVC. HEVC CRF 18 ~ AVC CRF 16.

So I don't understand why 10-bit HEVC looks not so sharp as AVC. Or maybe I need to tweak some other encoding parameters?

Thanks!

________________

Attaching Bluray source, x265, x264 screenshots and MediaInfo for both encoded files below


x264

General
Unique ID : 254846919266459289744895003014519459266 (0xBFB9BB36CE21C91B665F452F39960DC2)
Complete name : The.Wailing.2016.BDRemux.1080p_2min - x264 CRF 18 slow.mkv
Format : Matroska
Format version : Version 4 / Version 2
File size : 86.6 MiB
Duration : 2mn 0s
Overall bit rate : 6 014 Kbps
Movie name : The.Wailing.2016.BDRemux.1080p_by_vedigo
Encoded date : UTC 2018-11-09T08:41:54Z
Writing application : HandBrake 1.1.2 2018090500
Writing library : Lavf57.7.2 / Lavf57.7.2

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L4
Format settings, CABAC : Yes
Format settings, ReFrames : 5 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 2mn 0s
Bit rate : 5 895 Kbps
Width : 1 920 pixels
Height : 804 pixels
Display aspect ratio : 2.40:1
Frame rate mode : Constant
Frame rate : 24.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.159
Stream size : 84.8 MiB (98%)
Writing library : x264 core 155 r2901 7d0ff22
Encoding settings : cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x1:0x111 / me=hex / subme=8 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=12 / lookahead_threads=2 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=240 / keyint_min=24 / scenecut=40 / intra_refresh=0 / rc_lookahead=50 / rc=crf / mbtree=1 / crf=18.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / vbv_maxrate=20000 / vbv_bufsize=25000 / crf_max=0.0 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=1:1.00
Default : Yes
Forced : No
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709

x265

General
Unique ID : 56058483865459205996801490659679413297 (0x2A2C78A53D20908DFA277A83072C2431)
Complete name : The.Wailing.2016.BDRemux.1080p_2min - x265 CRF 18 slow.mkv
Format : Matroska
Format version : Version 4 / Version 2
File size : 77.3 MiB
Duration : 2mn 0s
Overall bit rate : 5 373 Kbps
Encoded date : UTC 2018-11-09T08:47:21Z
Writing application : HandBrake 1.1.2 2018090500
Writing library : Lavf57.7.2 / Lavf57.7.2

Video
ID : 1
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Main 10@L4@Main
Codec ID : V_MPEGH/ISO/HEVC
Duration : 2mn 0s
Bit rate : 5 266 Kbps
Width : 1 920 pixels
Height : 804 pixels
Display aspect ratio : 2.40:1
Frame rate mode : Constant
Frame rate : 24.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 10 bits
Bits/(Pixel*Frame) : 0.142
Stream size : 75.8 MiB (98%)
Writing library : x265 2.6:[Mac OS X][clang 9.1.0][64 bit] 10bit
Encoding settings : cpuid=1173503 / frame-threads=3 / wpp / no-pmode / no-pme / no-psnr / no-ssim / log-level=2 / input-csp=1 / input-res=1920x804 / interlace=0 / total-frames=0 / level-idc=0 / high-tier=1 / uhd-bd=0 / ref=4 / no-allow-non-conformance / no-repeat-headers / annexb / no-aud / no-hrd / info / hash=0 / no-temporal-layers / open-gop / min-keyint=24 / keyint=240 / bframes=4 / b-adapt=2 / b-pyramid / bframe-bias=0 / rc-lookahead=25 / lookahead-slices=4 / scenecut=40 / no-intra-refresh / ctu=64 / min-cu-size=8 / rect / no-amp / max-tu-size=32 / tu-inter-depth=1 / tu-intra-depth=1 / limit-tu=0 / rdoq-level=2 / dynamic-rd=0.00 / no-ssim-rd / signhide / no-tskip / nr-intra=0 / nr-inter=0 / no-constrained-intra / strong-intra-smoothing / max-merge=3 / limit-refs=3 / limit-modes / me=3 / subme=3 / merange=57 / temporal-mvp / weightp / no-weightb / no-analyze-src-pics / deblock=0:0 / sao / no-sao-non-deblock / rd=4 / no-early-skip / rskip / no-fast-intra / no-tskip-fast / no-cu-lossless / no-b-intra / no-splitrd-skip / rdpenalty=0 / psy-rd=2.00 / psy-rdoq=1.00 / no-rd-refine / analysis-reuse-mode=0 / no-lossless / cbqpoffs=0 / crqpoffs=0 / rc=crf / crf=18.0 / qcomp=0.60 / qpstep=4 / stats-write=0 / stats-read=0 / ipratio=1.40 / pbratio=1.30 / aq-mode=1 / aq-strength=1.00 / cutree / zone-count=0 / no-strict-cbr / qg-size=32 / no-rc-grain / qpmax=69 / qpmin=0 / no-const-vbv / sar=1 / overscan=0 / videoformat=5 / range=0 / colorprim=1 / transfer=1 / colormatrix=1 / chromaloc=0 / display-window=0 / max-cll=0,0 / min-luma=0 / max-luma=1023 / log2-max-poc-lsb=8 / vui-timing-info / vui-hrd-info / slices=1 / no-opt-qp-pps / no-opt-ref-list-length-pps / no-multi-pass-opt-rps / scenecut-bias=0.05 / no-opt-cu-delta-qp / no-aq-motion / no-hdr / no-hdr-opt / no-dhdr10-opt / analysis-reuse-level=5 / scale-factor=0 / refine-intra=0 / refine-inter=0 / refine-mv=0 / no-limit-sao / ctu-info=0 / no-lowpass-dct / refine-mv-type=0 / copy-pic=1
Default : Yes
Forced : No
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709

[poisondeathray]

It's not the same frame ;

Also no frame type - eg. maybe you're comparing a higher quality IDR frame to a low quality b-frame etc..

x264 uses 12% more bitrate according to your mediainfo report (not comparable; usually +/-1% deviation is acceptable, but 12% is significant)

sao tends to oversmooth for x265 . Many people disable it if it's not simple cartoon, or simple source, or intended lower bitrate target . Also people tend to use lower deblock (negative) and higher psy-rd , psy-rdoq settings for BD film sources

Also something wrong with either your screenshot method, up/down bitdepth conversion method, or encoding - there is a green hue shift for the x265 screenshot

[hello_hello]

Blurring seems to be a common x265 complaint. It might be better for 4k but for 1080p or lower I'd stick with x264.

It's been said (I haven't tested it myself as I only use x264) the psycho-visual options help with the blurring, although for a given CFR value they'd probably increase the bitrate. https://forum.videohelp.com/threads/390036-Can-the-smoothness-or-blurred-look-of-x265-...ed#post2527784

[vash1]

Thanks, poisondeathray and hello_hello.

no-sao fixed the issue

I captured the screenshots in VLC with 'Jump To second' method, so frames could be shuffled. What's the proper way or tool to get a specific frame?

I saw lots of encodes with deblock=-3:-3, so will keep that in mind as well. Not sure trough how high should be psy-rd and psy-rdoq settings.

[hello_hello]

MPC-HC's "Navigate/Go To" menu lets you specify a frame number to jump to, and/or it shows the current frame number.

[vash1]

MPC-HC's "Navigate/Go To" menu lets you specify a frame number to jump to, and/or it shows the current frame number.

I am on Mac. I believe there are jump-to-frame plugins for VLC. Will google for one.