[FFmpeg-user] AVCintra100 encoding with horizontal blocking artefacts

Fri Dec 9 14:53:49 EET 2022

Hi,
I'm trying to encode AVC100 in UK (25i) but getting odd blocking artefacts, where the screen is banded in about 10 horizontal rows with random levels of brightness, which change on a sub-second basis, darker or lighter. I'm using the latest release build on a Windows 10 CPU.

Any ideas? Screenshot available if I can work out where to post it. (I guess I shouldn't attach it to this email?)

Many thanks in advance for any help or guidance on offer. Full uncut command line attached below.
Phil

C:\Users\zzzzzzzzz>ffmpeg -i C:\Users\zzzzzzzzzzzz\Downloads\testcard\PRIVATE\M4ROOT\CLIP\C6192.MP4 -y -vcodec libx264 -g 1 -pix_fmt yuv422p10le -r 25 -x264-params avcintra-class=100:interlaced=1 -strict unofficial testavcinterlaced3.mxf
ffmpeg version 5.1.2-full_build-www.gyan.dev Copyright (c) 2000-2022 the FFmpeg developers
  built with gcc 12.1.0 (Rev2, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static --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-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-liblensfun --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-d3d11va --enable-dxva2 --enable-libmfx --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-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      57. 28.100 / 57. 28.100
  libavcodec     59. 37.100 / 59. 37.100
  libavformat    59. 27.100 / 59. 27.100
  libavdevice    59.  7.100 / 59.  7.100
  libavfilter     8. 44.100 /  8. 44.100
  libswscale      6.  7.100 /  6.  7.100
  libswresample   4.  7.100 /  4.  7.100
  libpostproc    56.  6.100 / 56.  6.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 000002ab305c6900] st: 0 edit list: 1 Missing key frame while searching for timestamp: 1000
[mov,mp4,m4a,3gp,3g2,mj2 @ 000002ab305c6900] st: 0 edit list 1 Cannot find an index entry before timestamp: 1000.
Guessed Channel Layout for Input Stream #0.1 : stereo
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'C:\Users\barnettp\Downloads\testcard\PRIVATE\M4ROOT\CLIP\C6192.MP4':
  Metadata:
    major_brand     : XAVC
    minor_version   : 16785407
    compatible_brands: XAVCmp42iso2
    creation_time   : 2022-11-29T13:30:09.000000Z
  Duration: 00:00:12.96, start: 0.000000, bitrate: 62225 kb/s
  Stream #0:0[0x1](und): Video: h264 (High 4:2:2) (avc1 / 0x31637661), yuv422p10le(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 46909 kb/s, 50 fps, 50 tbr, 50k tbn (default)
    Metadata:
      creation_time   : 2022-11-29T13:30:09.000000Z
      handler_name    : Video Media Handler
      vendor_id       : [0][0][0][0]
      encoder         : AVC Coding
  Stream #0:1[0x2](und): Audio: pcm_s16be (twos / 0x736F7774), 48000 Hz, stereo, s16, 1536 kb/s (default)
    Metadata:
      creation_time   : 2022-11-29T13:30:09.000000Z
      handler_name    : Sound Media Handler
      vendor_id       : [0][0][0][0]
  Stream #0:2[0x3](und): Data: none (rtmd / 0x646D7472), 4505 kb/s (default)
    Metadata:
      creation_time   : 2022-11-29T13:30:09.000000Z
      handler_name    : Timed Metadata Media Handler
      timecode        : 00:25:17:38
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (pcm_s16be (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
[libx264 @ 000002ab3263e700] using SAR=1/1
[libx264 @ 000002ab3263e700] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 000002ab3263e700] profile High 4:2:2 Intra, level 4.1, 4:2:2, 10-bit
Output #0, mxf, to 'testavcinterlaced3.mxf':
  Metadata:
    major_brand     : XAVC
    minor_version   : 16785407
    compatible_brands: XAVCmp42iso2
    encoder         : Lavf59.27.100
  Stream #0:0(und): Video: h264, yuv422p10le(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 25 fps, 25 tbn (default)
    Metadata:
      creation_time   : 2022-11-29T13:30:09.000000Z
      handler_name    : Video Media Handler
      vendor_id       : [0][0][0][0]
      encoder         : Lavc59.37.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
  Stream #0:1(und): Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s (default)
    Metadata:
      creation_time   : 2022-11-29T13:30:09.000000Z
      handler_name    : Sound Media Handler
      vendor_id       : [0][0][0][0]
      encoder         : Lavc59.37.100 pcm_s16le
frame=  326 fps= 33 q=-1.0 Lsize=  182905kB time=00:00:13.04 bitrate=114904.8kbits/s dup=0 drop=322 speed=1.32x
video:181093kB audio:2430kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
[libx264 @ 000002ab3263e700] frame I:326   Avg QP:16.76  size:568832
[libx264 @ 000002ab3263e700] mb I  I16..4:  0.0% 100.0%  0.0%
[libx264 @ 000002ab3263e700] field mbs: intra: 0.0%
[libx264 @ 000002ab3263e700] 8x8 transform intra:100.0%
[libx264 @ 000002ab3263e700] coded y,uvDC,uvAC intra: 99.9% 100.0% 94.3%
[libx264 @ 000002ab3263e700] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 12% 14% 24%  7%  8%  8%  8%  9% 12%
[libx264 @ 000002ab3263e700] i8c dc,h,v,p: 53% 13% 19% 15%
[libx264 @ 000002ab3263e700] kb/s:113766.41

Phillip Barnett
Server Manager
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