4K to x264 settings

[hatenooobs]

I would like to encode with Megui from a 4K source to 1080p x264. But have very pale colors, what do I have to change in the settings?


Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format-Profil : High@L4.1
Format-Einstellungen : CABAC / 5 Ref Frames
Format-Einstellungen für CABAC : Ja
Format-Einstellungen für RefFrames : 5 frames
Codec-ID : V_MPEG4/ISO/AVC
Dauer : 2 h 3 min
Bitrate : 2 516 kb/s
Breite : 1 280 Pixel
Höhe : 688 Pixel
Bildseitenverhältnis : 1,85:1
Ursprüngliches Bildseitenverhältnis : 1,85:1
Modus der Bildwiederholungsrate : konstant
Bildwiederholungsrate : 23,976 (24000/1001) FPS
ColorSpace : YUV
ChromaSubsampling/String : 4:2:0
BitDepth/String : 8 bits
Scantyp : progressiv
Bits/(Pixel*Frame) : 0.119
Stream-Größe : 2,17 GiB (51%)
verwendete Encoder-Bibliothek : x264 core 148 r2708 86b7198
Kodierungseinstellungen : cabac=1 / ref=5 / deblock=1:-1:-1 / analyse=0x3:0x113 / me=umh / subme=8 / psy=1 / psy_rd=1.00:0.15 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-3 / threads=21 / lookahead_threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=2 / 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=62500 / vbv_bufsize=78125 / crf_max=0.0 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=1:1.00
Default : Ja
Forced : Nein
colour_range : Limited
colour_primaries : BT.2020
transfer_characteristics : PQ
matrix_coefficients : BT.2020 non-constant

[sneaker]

Your source is HDR? x264 doesn't support signalling the required parameters. You could add them on the container level using mkvtoolnix but not all players will support this.

My recommendation:
A. If you want to keep HDR only encode to HEVC/H.265
B. If you don't want to keep you need to do a HDR->SDR conversion (tone mapping). AFAIK MeGUI doesn't have this feature (short of integrating your own AviSynth conversion).

There are solutions for HDR->SDR tone mapping for ffmpeg and VapourSynth. (I think RipBot integrates the ffmpeg solution.)
https://forum.doom9.org/showthread.php?p=1827927
https://forum.doom9.org/showthread.php?t=174415
https://github.com/ifb/vapoursynth-tonemap

[KarMa]

Going to guess it has something to do with your BT.2020 source not being converted to BT.709 when you downsize the resolution. So you have a 1080p BT.2020 video being displayed as BT.709. My experience with BT.2020 is not much but maybe in avisynth put

Dither_convert_yuv_to_rgb(matrix="2020")
Dither_convert_rgb_to_yuv(matrix="709")

[Cornucopia]

Dither is a poor/LCD way to tonemap HDR.

Scott

[KarMa]

Dither is a poor/LCD way to tonemap HDR.

Scott

Do we even know for sure it's HDR?

Can also use the below if you don't want 16-bit dither.

converttorgb(matrix = "Rec2020" )
converttoyv12(matrix = "Rec709" )

Requires avisynth+

[_Al_]

If he is starting with this, I'd recommend ffmpeg (perhaps easier setup) or Vapoursynth (just video, audio would need to be treated separately), but not Avisynth.

[hydra3333]

or nvencc (possibly piped from ffmpeg) if she/he has an nvidia card https://github.com/rigaya/NVEnc ?

just right-click and translate the githib page and check the English NVEncC_Options.en.md