ffmpeg 无法生成缩略图

Question

在 Windows 中使用 ffmpeg 制作缩略图我用:

./ffmpeg -i 1.mp4 -ss 00:00:01 -f image2 1.jpg

或者:

./ffmpeg -ss 00:00:01 -i 1.mp4 -f image2 1.jpg

但是没有人可以生成缩略图，它显示:

ffmpeg -i input.mp4 -ss 1 -frames:v 1 output.jpg
ffmpeg version N-91013-g8007a86363 Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 7.3.1 (GCC) 20180406
  configuration: 
  libavutil      56. 18.100 / 56. 18.100
  libavcodec     58. 19.101 / 58. 19.101
  libavformat    58. 13.102 / 58. 13.102
  libavdevice    58.  4.100 / 58.  4.100
  libavfilter     7. 21.100 /  7. 21.100
  libswscale      5.  2.100 /  5.  2.100
  libswresample   3.  2.100 /  3.  2.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 1
    compatible_brands: isom
    creation_time   : 2017-01-11T08:30:55.000000Z
    encoder         : My MP4Box GUI 0.6.0.6 <http://my-mp4box-gui.zymichost.com>
  Duration: 00:03:27.93, start: 0.000000, bitrate: 9345 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 2560x1440 [SAR 1:1 DAR 16:9], 9216 kb/s, 30 fps, 30 tbr, 90k tbn, 60 tbc (default)
    Metadata:
      creation_time   : 2016-10-14T14:16:02.000000Z
      handler_name    : videoplayback.mp4
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 125 kb/s (default)
    Metadata:
      creation_time   : 2017-01-11T08:30:56.000000Z
      handler_name    : videoplayback (1).m4a
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> mjpeg (native))
Press [q] to stop, [?] for help
[swscaler @ 0x55ad99ffe1c0] deprecated pixel format used, make sure you did set range correctly
Output #0, image2, to 'output.jpg':
  Metadata:
    major_brand     : isom
    minor_version   : 1
    compatible_brands: isom
    encoder         : Lavf58.13.102
    Stream #0:0(und): Video: mjpeg, yuvj420p(pc), 2560x1440 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 30 fps, 30 tbn, 30 tbc (default)
    Metadata:
      creation_time   : 2016-10-14T14:16:02.000000Z
      handler_name    : videoplayback.mp4
      encoder         : Lavc58.19.101 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)

我发现编码器的视频是

 My MP4Box GUI 0.6.0.6 <http://my-mp4box-gui.zymichost.com>

ffmpeg无法生成缩略图。以及如何生成缩略图？

Answer 1

ffmpeg -i input.flv -vf fps=1 out%d.png
通过这个，可以创建特定帧的图像。