[FFmpeg-user] Libx265 halves the quality when psy-rd is enabled for 444 input.

Aditya Dandavate adityadandavate04 at gmail.com
Sun Dec 31 05:32:50 EET 2023


I was testing libx265 encoder and I was that when psy-rd is enabled for 444
input, the quality is halved.

Here are my encoding settings:

# Video capture encoding settings
cap_soundcommand "ffmpeg -f s16le -ar %s -ac 2 -i - -c:a aac -profile:a 1
-q:a 2.0 -y temp_a.nut"
cap_videocommand "ffmpeg -f rawvideo -pix_fmt rgb24 -r %r -s %wx%h -i -
-c:v libx265 -crf 25 -preset medium -y temp_v.nut"
cap_muxcommand "ffmpeg -i temp_v.nut -i temp_a.nut -c copy -y %f"
cap_tempfile1 "temp_a.nut"
cap_tempfile2 "temp_v.nut"
cap_remove_tempfiles 1
cap_wipescreen 0
cap_fps 60

ffmpeg version 2023-12-18-git-be8a4f80b9-full_build-www.gyan.dev
Copyright (c) 2000-2023 the FFmpeg developers
  built with gcc 12.2.0 (Rev10, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static
--pkg-config=pkgconf --disable-w32threads --disable-autodetect
--enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2
--enable-gmp --enable-bzlib --enable-lzma --enable-libsnappy
--enable-zlib --enable-librist --enable-libsrt --enable-libssh
--enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca
--enable-sdl2 --enable-libaribb24 --enable-libaribcaption
--enable-libdav1d --enable-libdavs2 --enable-libuavs3d
--enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp
--enable-libx264 --enable-libx265 --enable-libxavs2 --enable-libxvid
--enable-libaom --enable-libjxl --enable-libopenjpeg --enable-libvpx
--enable-mediafoundation --enable-libass --enable-frei0r
--enable-libfreetype --enable-libfribidi --enable-libharfbuzz
--enable-liblensfun --enable-libvidstab --enable-libvmaf
--enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid
--enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-dxva2
--enable-d3d11va --enable-libvpl --enable-libshaderc --enable-vulkan
--enable-libplacebo --enable-opencl --enable-libcdio --enable-libgme
--enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb
--enable-libmp3lame --enable-libshine --enable-libtheora
--enable-libtwolame --enable-libvo-amrwbenc --enable-libcodec2
--enable-libilbc --enable-libgsm --enable-libopencore-amrnb
--enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa
--enable-libbs2b --enable-libflite --enable-libmysofa
--enable-librubberband --enable-libsoxr --enable-chromaprint
  libavutil      58. 34.100 / 58. 34.100
  libavcodec     60. 35.100 / 60. 35.100
  libavformat    60. 18.100 / 60. 18.100
  libavdevice    60.  4.100 / 60.  4.100
  libavfilter     9. 14.100 /  9. 14.100
  libswscale      7.  6.100 /  7.  6.100
  libswresample   4. 13.100 /  4. 13.100
  libpostproc    57.  4.100 / 57.  4.100
Input #0, rawvideo, from 'fd:':
  Duration: N/A, start: 0.000000, bitrate: 5308416 kb/s
  Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24,
2560x1440, 5308416 kb/s, 60 tbr, 60 tbn
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo (native) -> hevc (libx265))
x265 [info]: HEVC encoder version 3.5+113-8787af124
x265 [info]: build info [Windows][GCC 13.2.0][64 bit] 8bit+10bit+12bit
x265 [info]: using cpu capabilities: MMX2 SSE2Fast LZCNT SSSE3 SSE4.2
AVX FMA3 BMI2 AVX2
x265 [warning]: halving the quality when psy-rd is enabled for 444
input. Setting cbQpOffset = 6 and crQpOffset = 6
x265 [info]: Main 4:4:4 profile, Level-5 (Main tier)
x265 [info]: Thread pool created using 4 threads
x265 [info]: Slices                              : 1
x265 [info]: frame threads / pool features       : 2 / wpp(23 rows)
x265 [info]: Coding QT: max CU size, min CU size : 64 / 8
x265 [info]: Residual QT: max TU size, max depth : 32 / 1 inter / 1 intra
x265 [info]: ME / range / subpel / merge         : hex / 57 / 2 / 3
x265 [info]: Keyframe min / max / scenecut / bias  : 25 / 250 / 40 / 5.00
x265 [info]: Cb/Cr QP Offset                     : 6 / 6
x265 [info]: Lookahead / bframes / badapt        : 20 / 4 / 2
x265 [info]: b-pyramid / weightp / weightb       : 1 / 1 / 0
x265 [info]: References / ref-limit  cu / depth  : 3 / off / on
x265 [info]: AQ: mode / str / qg-size / cu-tree  : 2 / 1.0 / 32 / 1
x265 [info]: Rate Control / qCompress            : CRF-25.0 / 0.60
x265 [info]: tools: rd=3 psy-rd=2.00 early-skip rskip mode=1 signhide tmvp
x265 [info]: tools: b-intra strong-intra-smoothing lslices=8 deblock sao
Output #0, nut, to 'temp_v.nut':
  Metadata:
    encoder         : Lavf60.18.100
  Stream #0:0: Video: hevc (HEVC / 0x43564548), gbrp(pc,
gbr/unknown/unknown, progressive), 2560x1440, q=2-31, 60 fps, 61440
tbn
    Metadata:
      encoder         : Lavc60.35.100 libx265
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
frame=    0 fps=0.0 q=0.0 size=       0kB time=N/A bitrate=N/A speed=N/A
frame=    0 fps=0.0 q=0.0 size=       0kB time=N/A bitrate=N/A speed=N/A
frame=    0 fps=0.0 q=0.0 size=       0kB time=N/A bitrate=N/A speed=N/A
frame=    0 fps=0.0 q=0.0 size=       0kB time=N/A bitrate=N/A speed=N/A
frame=    0 fps=0.0 q=0.0 size=       0kB time=N/A bitrate=N/A speed=N/A
frame=    2 fps=0.6 q=31.6 size=     250kB time=00:00:00.00
bitrate=N/A speed=   0x
frame=    6 fps=1.7 q=36.0 size=     252kB time=00:00:00.06
bitrate=30979.8kbits/s speed=0.0184x
frame=    9 fps=2.2 q=35.9 size=     256kB time=00:00:00.11
bitrate=17975.5kbits/s speed=0.0281x
frame=   13 fps=2.8 q=36.0 size=     256kB time=00:00:00.18
bitrate=11439.0kbits/s speed=0.0394x
frame=   16 fps=3.1 q=27.2 size=     256kB time=00:00:00.23
bitrate=8987.8kbits/s speed=0.0451x
frame=   18 fps=3.2 q=35.3 size=     256kB time=00:00:00.26
bitrate=7864.3kbits/s speed=0.0468x
frame=   21 fps=3.4 q=34.0 size=     256kB time=00:00:00.31
bitrate=6622.6kbits/s speed=0.0511x
frame=   25 fps=3.7 q=35.0 size=     256kB time=00:00:00.38
bitrate=5470.8kbits/s speed=0.057x
frame=   31 fps=4.3 q=35.4 size=     256kB time=00:00:00.48
bitrate=4338.9kbits/s speed=0.0668x
frame=   32 fps=4.1 q=28.7 size=     256kB time=00:00:00.50
bitrate=4194.3kbits/s speed=0.0645x
frame=   33 fps=4.0 q=33.4 size=     256kB time=00:00:00.51
bitrate=4059.0kbits/s speed=0.0625x
frame=   34 fps=3.9 q=35.4 size=     256kB time=00:00:00.53
bitrate=3932.2kbits/s speed=0.0607x
frame=   37 fps=4.0 q=29.6 size=     256kB time=00:00:00.58
bitrate=3595.1kbits/s speed=0.0628x
frame=   39 fps=4.0 q=29.5 size=     256kB time=00:00:00.61
bitrate=3400.8kbits/s speed=0.0628x
frame=   40 fps=3.9 q=29.7 size=     512kB time=00:00:00.63
bitrate=6622.6kbits/s speed=0.0613x
frame=   43 fps=4.0 q=29.8 size=     512kB time=00:00:00.68
bitrate=6138.0kbits/s speed=0.063x
frame=   45 fps=4.0 q=30.2 size=     512kB time=00:00:00.71
bitrate=5852.5kbits/s speed=0.0631x
frame=   47 fps=4.0 q=30.0 size=     512kB time=00:00:00.75
bitrate=5592.4kbits/s speed=0.0632x
frame=   49 fps=4.0 q=30.0 size=     512kB time=00:00:00.78
bitrate=5354.4kbits/s speed=0.0632x
frame=   50 fps=3.9 q=30.8 size=     512kB time=00:00:00.80
bitrate=5242.9kbits/s speed=0.062x
frame=   52 fps=3.9 q=30.7 size=     768kB time=00:00:00.83
bitrate=7549.8kbits/s speed=0.0621x
frame=   54 fps=3.9 q=30.7 size=     768kB time=00:00:00.86
bitrate=7259.4kbits/s speed=0.0622x
frame=   55 fps=3.8 q=31.0 size=     768kB time=00:00:00.88
bitrate=7122.4kbits/s speed=0.0611x
frame=   57 fps=3.8 q=30.8 size=     768kB time=00:00:00.91
bitrate=6863.4kbits/s speed=0.0612x
frame=   60 fps=3.9 q=30.8 size=    1024kB time=00:00:00.96
bitrate=8677.9kbits/s speed=0.0624x
frame=   62 fps=3.9 q=30.8 size=    1024kB time=00:00:01.00
bitrate=8388.6kbits/s speed=0.0625x
frame=   64 fps=3.9 q=30.9 size=    1024kB time=00:00:01.03
bitrate=8118.0kbits/s speed=0.0625x
frame=   66 fps=3.9 q=30.7 size=    1024kB time=00:00:01.06
bitrate=7864.3kbits/s speed=0.0626x
frame=   67 fps=3.8 q=30.7 size=    1024kB time=00:00:01.08
bitrate=7743.3kbits/s speed=0.0617x
frame=   69 fps=3.8 q=30.0 size=    1024kB time=00:00:01.11
bitrate=7512.2kbits/s speed=0.0618x
frame=   71 fps=3.8 q=30.4 size=    1280kB time=00:00:01.15
bitrate=9118.1kbits/s speed=0.0619x
frame=   72 fps=3.8 q=30.5 size=    1280kB time=00:00:01.16
bitrate=8987.8kbits/s speed=0.0611x
frame=   75 fps=3.8 q=29.7 size=    1280kB time=00:00:01.21
bitrate=8618.4kbits/s speed=0.062x
frame=   77 fps=3.8 q=29.8 size=    1280kB time=00:00:01.25
bitrate=8388.6kbits/s speed=0.0621x
frame=   79 fps=3.8 q=29.5 size=    1280kB time=00:00:01.28
bitrate=8170.7kbits/s speed=0.0622x
frame=   81 fps=3.8 q=29.0 size=    1536kB time=00:00:01.31
bitrate=9556.6kbits/s speed=0.0622x
frame=   83 fps=3.8 q=27.9 size=    1536kB time=00:00:01.35
bitrate=9320.7kbits/s speed=0.0623x
frame=   85 fps=3.8 q=33.8 size=    1536kB time=00:00:01.38
bitrate=9096.1kbits/s speed=0.0623x
frame=   88 fps=3.9 q=34.1 size=    1792kB time=00:00:01.43
bitrate=10241.9kbits/s speed=0.0631x
frame=   94 fps=4.0 q=36.0 size=    1792kB time=00:00:01.53
bitrate=9574.0kbits/s speed=0.066x
frame=  100 fps=4.2 q=36.0 size=    1792kB time=00:00:01.63
bitrate=8987.8kbits/s speed=0.0688x
frame=  104 fps=4.3 q=36.0 size=    1792kB time=00:00:01.70
bitrate=8635.3kbits/s speed=0.0701x
frame=  109 fps=4.4 q=35.9 size=    1792kB time=00:00:01.78
bitrate=8231.8kbits/s speed=0.072x
frame=  111 fps=4.4 q=34.1 size=    1792kB time=00:00:01.81
bitrate=8080.8kbits/s speed=0.0719x
frame=  115 fps=4.5 q=27.2 size=    1792kB time=00:00:01.88
bitrate=7794.7kbits/s speed=0.073x
frame=  118 fps=4.5 q=27.3 size=    1792kB time=00:00:01.93
bitrate=7593.1kbits/s speed=0.0734x
frame=  119 fps=4.4 q=35.8 size=    1792kB time=00:00:01.95
bitrate=7528.2kbits/s speed=0.0726x
frame=  120 fps=4.4 q=27.5 size=    1792kB time=00:00:01.96
bitrate=7464.4kbits/s speed=0.0718x
frame=  122 fps=4.4 q=35.3 size=    1792kB time=00:00:02.00
bitrate=7340.0kbits/s speed=0.0717x
frame=  125 fps=4.4 q=34.5 size=    1792kB time=00:00:02.05
bitrate=7161.0kbits/s speed=0.0722x
frame=  129 fps=4.5 q=28.4 size=    2048kB time=00:00:02.11
bitrate=7926.2kbits/s speed=0.0731x
frame=  130 fps=4.4 q=34.6 size=    2048kB time=00:00:02.13
bitrate=7864.3kbits/s speed=0.0724x
frame=  133 fps=4.4 q=33.6 size=    2048kB time=00:00:02.18
bitrate=7684.2kbits/s speed=0.0728x
frame=  135 fps=4.4 q=34.6 size=    2048kB time=00:00:02.21
bitrate=7568.7kbits/s speed=0.0727x
frame=  137 fps=4.4 q=29.8 size=    2048kB time=00:00:02.25
bitrate=7456.5kbits/s speed=0.0726x
frame=  139 fps=4.4 q=29.9 size=    2048kB time=00:00:02.28
bitrate=7347.7kbits/s speed=0.0724x
frame=  140 fps=4.4 q=30.1 size=    2048kB time=00:00:02.30
bitrate=7294.4kbits/s speed=0.0718x
frame=  142 fps=4.4 q=29.9 size=    2048kB time=00:00:02.33
bitrate=7190.2kbits/s speed=0.0717x
frame=  144 fps=4.4 q=30.0 size=    2304kB time=00:00:02.36
bitrate=7975.1kbits/s speed=0.0716x
frame=  146 fps=4.3 q=30.0 size=    2304kB time=00:00:02.40
bitrate=7864.3kbits/s speed=0.0715x
frame=  148 fps=4.3 q=29.8 size=    2304kB time=00:00:02.43
bitrate=7756.6kbits/s speed=0.0714x
frame=  150 fps=4.3 q=30.4 size=    2304kB time=00:00:02.46
bitrate=7651.8kbits/s speed=0.0713x
frame=  152 fps=4.3 q=30.1 size=    2304kB time=00:00:02.50
bitrate=7549.7kbits/s speed=0.0712x
frame=  153 fps=4.3 q=30.1 size=    2304kB time=00:00:02.51
bitrate=7499.7kbits/s speed=0.0706x
frame=  155 fps=4.3 q=30.1 size=    2560kB time=00:00:02.55
bitrate=8224.1kbits/s speed=0.0705x
frame=  156 fps=4.3 q=30.1 size=    2560kB time=00:00:02.56
bitrate=8170.7kbits/s speed=0.07x
frame=  158 fps=4.2 q=29.9 size=    2560kB time=00:00:02.60
bitrate=8066.0kbits/s speed=0.0699x
frame=  160 fps=4.2 q=30.3 size=    2560kB time=00:00:02.63
bitrate=7963.9kbits/s speed=0.0699x
frame=  162 fps=4.2 q=29.6 size=    2560kB time=00:00:02.66
bitrate=7864.3kbits/s speed=0.0698x
frame=  165 fps=4.3 q=27.6 size=    2560kB time=00:00:02.71
bitrate=7719.6kbits/s speed=0.0701x
frame=  167 fps=4.3 q=32.5 size=    2560kB time=00:00:02.75
bitrate=7626.0kbits/s speed=0.0701x
frame=  170 fps=4.3 q=33.4 size=    2816kB time=00:00:02.80
bitrate=8238.8kbits/s speed=0.0704x
frame=  172 fps=4.3 q=28.8 size=    2816kB time=00:00:02.83
bitrate=8141.9kbits/s speed=0.0703x
frame=  174 fps=4.3 q=29.9 size=    2816kB time=00:00:02.86
bitrate=8047.2kbits/s speed=0.0703x
frame=  176 fps=4.3 q=29.9 size=    2816kB time=00:00:02.90
bitrate=7954.7kbits/s speed=0.0702x
frame=  178 fps=4.3 q=30.1 size=    2816kB time=00:00:02.93
bitrate=7864.3kbits/s speed=0.0701x
frame=  179 fps=4.2 q=30.0 size=    2816kB time=00:00:02.95
bitrate=7819.9kbits/s speed=0.0697x
frame=  181 fps=4.2 q=29.9 size=    2816kB time=00:00:02.98
bitrate=7732.5kbits/s speed=0.0696x
frame=  183 fps=4.2 q=30.0 size=    2816kB time=00:00:03.01
bitrate=7647.1kbits/s speed=0.0695x
frame=  184 fps=4.2 q=30.4 size=    2816kB time=00:00:03.03
bitrate=7605.1kbits/s speed=0.0691x
frame=  186 fps=4.2 q=30.2 size=    3072kB time=00:00:03.06
bitrate=8206.2kbits/s speed=0.0691x
frame=  187 fps=4.2 q=30.3 size=    3072kB time=00:00:03.08
bitrate=8161.9kbits/s speed=0.0686x
frame=  189 fps=4.2 q=30.2 size=    3072kB time=00:00:03.11
bitrate=8074.6kbits/s speed=0.0686x
frame=  190 fps=4.1 q=30.3 size=    3072kB time=00:00:03.13
bitrate=8031.6kbits/s speed=0.0682x
frame=  191 fps=4.1 q=30.3 size=    3072kB time=00:00:03.15
bitrate=7989.2kbits/s speed=0.0678x
frame=  193 fps=4.1 q=29.8 size=    3328kB time=00:00:03.18
bitrate=8564.3kbits/s speed=0.0678x
frame=  195 fps=4.1 q=30.2 size=    3328kB time=00:00:03.21
bitrate=8475.5kbits/s speed=0.0677x
frame=  197 fps=4.1 q=29.5 size=    3328kB time=00:00:03.25
bitrate=8388.6kbits/s speed=0.0677x
frame=  199 fps=4.1 q=28.6 size=    3328kB time=00:00:03.28
bitrate=8303.4kbits/s speed=0.0676x
frame=  200 fps=4.1 q=28.1 size=    3328kB time=00:00:03.30
bitrate=8261.5kbits/s speed=0.0673x
frame=  202 fps=4.1 q=27.4 size=    3584kB time=00:00:03.33
bitrate=8808.0kbits/s speed=0.0673x
frame=  205 fps=4.1 q=33.6 size=    3584kB time=00:00:03.38
bitrate=8677.9kbits/s speed=0.0676x
frame=  209 fps=4.1 q=27.1 size=    3584kB time=00:00:03.45
bitrate=8510.2kbits/s speed=0.0682x
frame=  212 fps=4.1 q=35.9 size=    3584kB time=00:00:03.50
bitrate=8388.6kbits/s speed=0.0685x
frame=  217 fps=4.2 q=36.0 size=    3840kB time=00:00:03.58
bitrate=8778.8kbits/s speed=0.0694x
frame=  219 fps=4.2 q=27.4 size=    3840kB time=00:00:03.61
bitrate=8697.9kbits/s speed=0.0694x
frame=  221 fps=4.2 q=35.9 size=    3840kB time=00:00:03.65
bitrate=8618.4kbits/s speed=0.0693x
frame=  223 fps=4.2 q=36.1 size=    3840kB time=00:00:03.68
bitrate=8540.4kbits/s speed=0.0693x
frame=  227 fps=4.2 q=35.2 size=    3840kB time=00:00:03.75
bitrate=8388.6kbits/s speed=0.0698x
frame=  231 fps=4.3 q=35.7 size=    3840kB time=00:00:03.81
bitrate=8242.1kbits/s speed=0.0704x
frame=  234 fps=4.3 q=28.7 size=    3840kB time=00:00:03.86
bitrate=8135.5kbits/s speed=0.0707x
frame=  238 fps=4.3 q=28.7 size=    3840kB time=00:00:03.93
bitrate=7997.6kbits/s speed=0.0712x
frame=  241 fps=4.3 q=33.5 size=    3840kB time=00:00:03.98
bitrate=7897.2kbits/s speed=0.0715x
frame=  241 fps=4.3 q=33.5 size=    3840kB time=00:00:03.98
bitrate=7897.2kbits/s speed=0.0708x
frame=  241 fps=4.2 q=33.5 size=    3840kB time=00:00:03.98
bitrate=7897.2kbits/s speed=0.0701x
frame=  245 fps=4.3 q=34.7 size=    3840kB time=00:00:04.05
bitrate=7767.2kbits/s speed=0.0707x
frame=  247 fps=4.3 q=30.3 size=    3840kB time=00:00:04.08
bitrate=7703.8kbits/s speed=0.0706x
frame=  249 fps=4.3 q=30.3 size=    4096kB time=00:00:04.11
bitrate=8150.9kbits/s speed=0.0706x
frame=  249 fps=4.2 q=30.3 size=    4096kB time=00:00:04.11
bitrate=8150.9kbits/s speed=0.07x
frame=  251 fps=4.2 q=27.0 size=    4096kB time=00:00:04.15
bitrate=8085.4kbits/s speed=0.0699x
frame=  252 fps=4.2 q=29.4 size=    4352kB time=00:00:04.16
bitrate=8556.4kbits/s speed=0.0696x
frame=  253 fps=4.2 q=29.7 size=    4352kB time=00:00:04.18
bitrate=8522.3kbits/s speed=0.0693x
frame=  255 fps=4.2 q=29.8 size=    4352kB time=00:00:04.21
bitrate=8454.9kbits/s speed=0.0692x
frame=  257 fps=4.2 q=29.6 size=    4352kB time=00:00:04.25
bitrate=8388.6kbits/s speed=0.0692x
frame=  260 fps=4.2 q=29.8 size=    4608kB time=00:00:04.30
bitrate=8778.8kbits/s speed=0.0694x
frame=  262 fps=4.2 q=30.2 size=    4608kB time=00:00:04.33
bitrate=8711.2kbits/s speed=0.0694x
frame=  264 fps=4.2 q=30.4 size=    4608kB time=00:00:04.36
bitrate=8644.7kbits/s speed=0.0693x
frame=  265 fps=4.2 q=30.2 size=    4608kB time=00:00:04.38
bitrate=8611.9kbits/s speed=0.069x
frame=  267 fps=4.2 q=30.0 size=    4608kB time=00:00:04.41
bitrate=8546.9kbits/s speed=0.069x
frame=  269 fps=4.2 q=30.1 size=    4864kB time=00:00:04.45
bitrate=8954.1kbits/s speed=0.069x
frame=  271 fps=4.2 q=30.0 size=    4864kB time=00:00:04.48
bitrate=8887.6kbits/s speed=0.0689x
frame=  273 fps=4.2 q=30.5 size=    4864kB time=00:00:04.51
bitrate=8822.0kbits/s speed=0.0689x
frame=  275 fps=4.2 q=29.4 size=    4864kB time=00:00:04.55
bitrate=8757.3kbits/s speed=0.0689x
frame=  276 fps=4.1 q=30.4 size=    4864kB time=00:00:04.56
bitrate=8725.4kbits/s speed=0.0686x
frame=  279 fps=4.2 q=32.3 size=    4864kB time=00:00:04.61
bitrate=8630.9kbits/s speed=0.0688x
frame=  280 fps=4.1 q=30.6 size=    4864kB time=00:00:04.63
bitrate=8599.8kbits/s speed=0.0685x
frame=  281 fps=4.1 q=30.5 size=    4864kB time=00:00:04.65
bitrate=8569.0kbits/s speed=0.0683x
frame=  282 fps=4.1 q=29.2 size=    5120kB time=00:00:04.66
bitrate=8987.8kbits/s speed=0.068x
frame=  288 fps=4.2 q=36.0 size=    5120kB time=00:00:04.76
bitrate=8799.2kbits/s speed=0.0689x
[out#0/nut @ 0000022c5b21d680] video:5242kB audio:0kB subtitle:0kB
other streams:0kB global headers:2kB muxing overhead: 0.149640%
frame=  290 fps=4.2 q=36.1 Lsize=    5250kB time=00:00:04.80
bitrate=8959.3kbits/s speed=0.0694x
x265 [info]: frame I:      2, Avg QP:25.94  kb/s: 118883.52
x265 [info]: frame P:    173, Avg QP:29.64  kb/s: 12860.30
x265 [info]: frame B:    115, Avg QP:34.99  kb/s: 984.95
x265 [info]: Weighted P-Frames: Y:2.3% UV:2.3%

encoded 290 frames in 69.16s (4.19 fps), 8882.30 kb/s, Avg QP:31.74

I stopped the encoding right away.

Last time, I encoded the Video Capture in Lossless audio and video codecs
(ffv1 and flac) and stored them in .mkv container.

While encoding with the previous lossless video in libx265, and in aac
audio, I had got VMAF score of around 72 for 1080p CRF=28 -preset medium.

But, when I encoded the same video in CRF 23 and libx264, preset medium,
aac audio, I got VMAF score of around 96!

The libx265 ffmpeg encoding settings say that CRF of 28 for libx265 should
be same of CRF=23 of libx264, but I am getting very low VMAF scores, at
CRF=28, ffmpeg.

I think, psy-rd is the main reason for decrease in video quality.

How to fix this issue ? Can anyone please help me ?


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