用 ffmpeg 对视频进行转码，分割等操作

参考

• 关于ffmpeg的总结
• ffmpeg 的官网
• ffmpeg 百度百科基本用法

实战

• 转码: ffmpeg -i a.mp4 b.avi (将a.mp4 转码为b.avi)
• 当视频不含声音时: ffmpeg -i a.mp4 -vcodec copy -an a.avi
• 截取视频: ffmpeg -i a.mp4 -ss 5 -t 10 b.avi (从第5秒开始，截取10秒视频)

• 将图片序列合成视频

  ffmpeg -f image2 -i image%d.jpg video.avi
  上面的命令会把当前目录下的图片（名字如：image1.jpg. image2.jpg. 等…）合并成video.avi

• 将视频分解成图片序列

  ffmpeg -i video.avi image%d.jpg
  上面的命令会生成image1.jpg. image2.jpg. …
  ffmpeg -i video.avi -vframes 100 picture/people%5d.png
  上面的命令会在picture 目录下生成people00001.png, people00002.png …peopel00100.png

查看视频信息

• ffmpeg -i a.avi

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from ‘a.mp4’:
  Metadata:
  major_brand : mp42
  minor_version : 0
  compatible_brands: mp42isom
  Duration: 01:00:08.98, start: 0.000000, bitrate: 4133 kb/s
  Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420
  p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 4089 kb/s, 24.96 fps, 25
  tbr, 90k tbn, 50 tbc (default)
  Stream #0:1(und): Audio: none (wxh1 / 0x31687877), 8000 Hz, 1 ch
  annels, 40 kb/s (default)

• ffprobe -i a.avi

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from ‘../video3.mp4’:
  Metadata:
  major_brand : mp42
  minor_version : 0
  compatible_brands: mp42isom
  Duration: 01:00:08.98, start: 0.000000, bitrate: 4133 kb/s
  Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420
  p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 4089 kb/s, 24.96 fps, 25
  tbr, 90k tbn, 50 tbc (default)
  Stream #0:1(und): Audio: none (wxh1 / 0x31687877), 8000 Hz, 1 ch
  annels, 40 kb/s (default)