问如何使用ffmpeg淡出视频的边缘？

EN

 ffmpeg -i movie.mov -b:v 700K -filter_complex "[0]split[v0][v1];[v0]format=yuva420p,geq=r=0:g=0:b=0:a=255*(Y/H),scale=w=1*iw:h=200[fg];[v1][fg]overlay=0:800:shortest=1" converted.mov

ffmpeg version 4.2.3 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9.3.1 (GCC) 20200523
  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-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-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'movie_014.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 0
    compatible_brands: qt
    creation_time   : 2020-12-10T04:36:09.000000Z
  Duration: 00:00:10.03, start: 0.000000, bitrate: 142307 kb/s
    Stream #0:0(und): Video: prores (XQ) (ap4x / 0x78347061), yuva444p12le(tv, bt709, progressive), 1000x1000, 142222 kb/s, SAR 1:1 DAR 1:1, 30 fps, 30 tbr, 30k tbn, 30k tbc (default)
    Metadata:
      creation_time   : 2020-12-10T04:36:09.000000Z
      handler_name    : Core Media Video
      encoder         : Apple ProRes 4444 XQ
File 'converted.mov' already exists. Overwrite ? [y/N] y
Stream mapping:
  Stream #0:0 (prores) -> split
  overlay -> Stream #0:0 (libx264)
Press [q] to stop, [?] for help
[swscaler @ 0000019691457fc0] No accelerated colorspace conversion found from yuva420p to gbrap.
[libx264 @ 000001968c30f5c0] using SAR=1/1
[libx264 @ 000001968c30f5c0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 000001968c30f5c0] profile High, level 3.2, 4:2:0, 8-bit
[libx264 @ 000001968c30f5c0] 264 - core 160 - H.264/MPEG-4 AVC codec - Copyleft 2003-2020 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 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=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1 bitrate=700 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mov, to 'converted.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 0
    compatible_brands: qt
    encoder         : Lavf58.29.100
    Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv420p, 1000x1000 [SAR 1:1 DAR 1:1], q=-1--1, 700 kb/s, 30 fps, 15360 tbn, 30 tbc (default)
    Metadata:
      encoder         : Lavc58.54.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/700000 buffer size: 0 vbv_delay: -1
frame=  301 fps= 22 q=-1.0 Lsize=     843kB time=00:00:09.93 bitrate= 695.3kbits/s speed=0.716x
video:839kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.515537%
[libx264 @ 000001968c30f5c0] frame I:2     Avg QP:24.02  size: 22224
[libx264 @ 000001968c30f5c0] frame P:76    Avg QP:24.00  size:  6595
[libx264 @ 000001968c30f5c0] frame B:223   Avg QP:27.38  size:  1402
[libx264 @ 000001968c30f5c0] consecutive B-frames:  1.0%  0.7%  0.0% 98.3%
[libx264 @ 000001968c30f5c0] mb I  I16..4: 36.6% 56.1%  7.4%
[libx264 @ 000001968c30f5c0] mb P  I16..4:  0.5%  1.4%  0.2%  P16..4: 16.0%  7.4%  3.6%  0.0%  0.0%    skip:70.9%
[libx264 @ 000001968c30f5c0] mb B  I16..4:  0.0%  0.0%  0.0%  B16..8: 18.7%  1.3%  0.1%  direct: 0.1%  skip:79.7%  L0:39.1% L1:58.3% BI: 2.6%
[libx264 @ 000001968c30f5c0] final ratefactor: 24.27
[libx264 @ 000001968c30f5c0] 8x8 transform intra:60.1% inter:78.0%
[libx264 @ 000001968c30f5c0] coded y,uvDC,uvAC intra: 30.9% 22.8% 8.2% inter: 3.7% 1.7% 0.0%
[libx264 @ 000001968c30f5c0] i16 v,h,dc,p: 65% 24%  4%  7%
[libx264 @ 000001968c30f5c0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 18% 16% 36%  4%  6%  7%  4%  5%  4%
[libx264 @ 000001968c30f5c0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 24% 12% 23%  7%  9%  8%  6%  8%  5%
[libx264 @ 000001968c30f5c0] i8c dc,h,v,p: 79% 10%  9%  2%
[libx264 @ 000001968c30f5c0] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 000001968c30f5c0] ref P L0: 66.4% 21.6%  9.5%  2.6%
[libx264 @ 000001968c30f5c0] ref B L0: 92.1%  6.8%  1.1%
[libx264 @ 000001968c30f5c0] ref B L1: 97.6%  2.4%
[libx264 @ 000001968c30f5c0] kb/s:684.29