| 1 | | = `-vframes` 操作选项 = |
| 2 | | |
| 3 | | 从视频中输出一帧生成文件: |
| 4 | | |
| 5 | | {{{ |
| 6 | | ffmpeg -i input.flv -ss 00:00:14.435 -vframes 1 out.png |
| 7 | | }}} |
| 8 | | |
| 9 | | 这个例子将会 [[Seeking|seek]] 到时间进度条位置在 0h:0m:14sec:435msec 处并输出一帧 (`-vframes 1`) 输出生成一个 PNG 文件. |
| 10 | | |
| 11 | | = `fps` 视频 filter = |
| 12 | | |
| 13 | | 每一秒输出一帧图像为图片, 图片命名为 `out1.png`, `out2.png`, `out3.png`,依次顺序输出. |
| 14 | | |
| 15 | | {{{ |
| 16 | | ffmpeg -i input.flv -vf fps=1 out%d.png |
| 17 | | }}} |
| 18 | | |
| 19 | | 每一分钟截一次图, 命名 `img001.jpg`, `img002.jpg`, `img003.jpg`, 依次顺序递增. 例子中的 `%03d` 为用来规定每个输出图片的序数将格式化使用3位数. |
| 20 | | |
| 21 | | {{{ |
| 22 | | ffmpeg -i myvideo.avi -vf fps=1/60 img%03d.jpg |
| 23 | | }}} |
| 24 | | |
| 25 | | 每十分钟输出一张图片: |
| 26 | | |
| 27 | | {{{ |
| 28 | | ffmpeg -i test.flv -vf fps=1/600 thumb%04d.bmp |
| 29 | | }}} |
| 30 | | |
| 31 | | = `select` 视频 filter = |
| 32 | | |
| 33 | | 每个I帧生成一张图片: |
| 34 | | |
| 35 | | {{{ |
| 36 | | ffmpeg -i input.flv -vf "select='eq(pict_type,PICT_TYPE_I)'" -vsync vfr thumb%04d.png |
| 37 | | }}} |
| 38 | | |
| 39 | | === 更多参考帮助 === |
| 40 | | |
| 41 | | * [[Create a video slideshow from images]] |
| 42 | | * [https://ffmpeg.org/ffmpeg-filters.html#fps fps video filter documentation] |
| 43 | | * [https://ffmpeg.org/ffmpeg-filters.html#select_002c-aselect select filter documentation] |
| 44 | | * [http://superuser.com/questions/538112/meaningful-thumbnails-for-a-video-using-ffmpeg] |
