我希望按照接受的答案中描述的方式完成这个问题。
但是，上述命令在 ffmpeg 版本 4.2.2 中不再起作用。
我已经更新命令以使用新格式应用多个过滤器（逗号分隔），但收到警告“输出文件为空，未编码任何内容”并且没有输出。
$ ffmpeg -ss 3 -i input.mp4 -vf "select=gt(scene\,0.4), fps=fps=1/100" -frames:v 5 -vsync vfr out%02d.jpg
ffmpeg version 4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
built with Apple clang version 11.0.0 (clang-1100.0.33.16)
configuration: --prefix=/usr/local/Cellar/ffmpeg/4.2.2 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags='-I/Library/Java/JavaVirtualMachines/adoptopenjdk-13.0.1.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/adoptopenjdk-13.0.1.jdk/Contents/Home/include/darwin -fno-stack-check' --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libmp3lame --enable-libopus --enable-librubberband --enable-libsnappy --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
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
libavresample 4. 0. 0 / 4. 0. 0
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 'test.mp4':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: mp42mp41isomavc1
creation_time : 2017-01-14T09:24:55.000000Z
Duration: 00:01:16.25, start: 0.000000, bitrate: 12030 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 2560x1440 [SAR 1:1 DAR 16:9], 11775 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
Metadata:
creation_time : 2017-01-14T09:24:55.000000Z
handler_name : L-SMASH Video Handler
encoder : AVC Coding
Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 256 kb/s (default)
Metadata:
creation_time : 2017-01-14T09:24:55.000000Z
handler_name : L-SMASH Audio Handler
Stream mapping:
Stream #0:0 -> #0:0 (h264 (native) -> mjpeg (native))
Press [q] to stop, [?] for help
[swscaler @ 0x1191ca000] deprecated pixel format used, make sure you did set range correctly
[mjpeg @ 0x7fd4e6806200] bitrate tolerance 4000000 too small for bitrate 200000, overriding
Output #0, image2, to 'out%02d.jpg':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: mp42mp41isomavc1
encoder : Lavf58.29.100
Stream #0:0(und): Video: mjpeg, yuvj444p(pc), 2560x1440 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 0.01 fps, 0.01 tbn, 0.01 tbc (default)
Metadata:
creation_time : 2017-01-14T09:24:55.000000Z
handler_name : L-SMASH Video Handler
encoder : Lavc58.54.100 mjpeg
Side data:
cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
frame= 0 fps=0.0 q=0.0 Lsize=N/A time=00:00:00.00 bitrate=N/A speed= 0x
video:0kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
Output file is empty, nothing was encoded (check -ss / -t / -frames parameters if used)