[FFmpeg-user] Decombing via screening

[Mark Filipak]

In the command line below,
                I will eventually insert a screen maker --+
                                                          ¦
separatefields,scale=height=2*in_h:sws_flags=neighbor,--HERE--,tblend=normal[D]

but first, I need to persuade 'tblend' to accept the 2 frames made by 'separatefields' (and scaled 
by 'scale').
But as you can see in the next section (extracted from the log), though the 'height=2*in_h' 
directive works (i.e., the 1920x540 frames from 'separatefields' are scaled to 1920x1080), ffmpeg is 
not happy. Is it because the SARs don't match? How can I overcome that?
Thanks!

[Parsed_interleave_7 @ 00000282efb0a6c0] Parameters for input link input1 (size 1920x1080, SAR 2:1) 
do not match the corresponding output link parameters (1920x1080, SAR 1:1)
[Parsed_interleave_7 @ 00000282efb0a6c0] Failed to configure output pad on Parsed_interleave_7



ffmpeg -report -ss 0:00 -analyzeduration 5000000000 -probesize 5000000000 -i "M:\Test 
Videos\23.976p.mkv" -filter_complex 
"telecine=pattern=46,split[A][B],[A]select='not(eq(mod(n+1\,5)\,3))'[C],[B]select='bitor(eq(mod(n+1\,5)\,2)\,eq(mod(n+1\,5)\,3))',separatefields,scale=height=2*in_h:sws_flags=neighbor,tblend=normal[D],[C][D]interleave,datascope=size=1920x1080:x=45:y=340:mode=color2" 
-map 0 -c:v libx264 -crf 20 -an -sn "C:\AVOut\23.976p.5.MKV"

ffmpeg started on 2020-04-14 at 09:21:39
Report written to "REPORT.LOG"
Log level: 32
ffmpeg version git-2020-04-03-52523b6 Copyright (c) 2000-2020 the FFmpeg developers
   built with gcc 9.3.1 (GCC) 20200328
   configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls 
--enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype 
--enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg 
--enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libsrt 
--enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp 
--enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib 
--enable-gmp --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvo-amrwbenc 
--enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx 
--enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec 
--enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
   libavutil      56. 42.102 / 56. 42.102
   libavcodec     58. 77.101 / 58. 77.101
   libavformat    58. 42.100 / 58. 42.100
   libavdevice    58.  9.103 / 58.  9.103
   libavfilter     7. 77.101 /  7. 77.101
   libswscale      5.  6.101 /  5.  6.101
   libswresample   3.  6.100 /  3.  6.100
   libpostproc    55.  6.100 / 55.  6.100
Input #0, matroska,webm, from 'M:\Test Videos\23.976p.mkv':
   Metadata:
     encoder         : libebml v1.3.9 + libmatroska v1.5.2
     creation_time   : 2020-04-04T03:44:24.000000Z
   Duration: 00:00:10.01, start: 0.000000, bitrate: 544 kb/s
     Stream #0:0: Video: h264 (High), yuv420p(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 
23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
     Metadata:
       BPS-eng         : 538378
       DURATION-eng    : 00:00:10.010000000
       NUMBER_OF_FRAMES-eng: 240
       NUMBER_OF_BYTES-eng: 673646
       _STATISTICS_WRITING_APP-eng: mkvmerge v41.0.0 ('Smarra') 64-bit
       _STATISTICS_WRITING_DATE_UTC-eng: 2020-04-04 03:44:24
       _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
[Parsed_telecine_0 @ 00000282ecc69f00] Telecine pattern 46 yields up to 3 frames per frame, pts 
advance factor: 4/10
Stream mapping:
   Stream #0:0 (h264) -> telecine
   datascope -> Stream #0:0 (libx264)
Press [q] to stop, [?] for help
[Parsed_telecine_0 @ 00000282ec6f7600] Telecine pattern 46 yields up to 3 frames per frame, pts 
advance factor: 4/10
[Parsed_interleave_7 @ 00000282efb0a6c0] Parameters for input link input1 (size 1920x1080, SAR 2:1) 
do not match the corresponding output link parameters (1920x1080, SAR 1:1)
[Parsed_interleave_7 @ 00000282efb0a6c0] Failed to configure output pad on Parsed_interleave_7
Error reinitializing filters!
Failed to inject frame into filter network: Invalid argument
Error while processing the decoded data for stream #0:0
Conversion failed!