ffmpeg 图片背景透明 水印左上角

ffmpeg实现图片背景透明
ffmpeg -i input.png -vf crop=200:100:10:10,chromakey=#FFFFFF:0.1:0.1 transparent.png
ffprobe -i transparent.png
ffprobe version 4.4.2-1 Copyright (c) 2007-2021 the FFmpeg developers
Input #0, png_pipe, from 'transparent_1.png':
  Duration: N/A, bitrate: N/A
  Stream #0:0: Video: png, rgb24(pc), 200x100 [SAR 1:1 DAR 337:375], 25 fps, 25 tbr, 25 tbn, 25 tbc

ffprobe -i input.mp4
ffprobe version 4.4.2-1 Copyright (c) 2007-2021 the FFmpeg developers
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.76.100
  Duration: 00:01:05.00, start: 0.000000, bitrate: 670 kb/s
  Stream #0:0(und): Video: h264 (High 4:4:4 Predictive) (avc1 / 0x31637661), yuv444p, 400x400, 533 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
    Metadata:
      handler_name    : VideoHandler
      vendor_id       : [0][0][0][0]
  Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      vendor_id       : [0][0][0][0]
将透明背景图片以水印的方式在视频左上角呈现。
ffmpeg -i input.mp4 -i transparent_0.png -filter_complex overlay transparent_0.mp4