ffmpeg 淡入淡出过滤器已安装但不起作用？

Question

我在运行 Apache 2.2.3 的 CentOS 5 服务器上运行 php 5.1.6

我安装了 ffmpeg 库，我的目标是将一组图像隐藏到幻灯片中，每个图像交换具有淡入/淡出效果。

命令 ffmpeg 说：

`FFmpeg version SVN-r26402, Copyright (c) 2000-2011 the FFmpeg developers
  built on Sep 12 2011 03:37:39 with gcc 4.1.2 20080704 (Red Hat 4.1.2-50)
  configuration:
  libavutil     50.36. 0 / 50.36. 0
  libavcore      0.16. 1 /  0.16. 1
  libavcodec    52.108. 0 / 52.108. 0
  libavformat   52.93. 0 / 52.93. 0
  libavdevice   52. 2. 3 / 52. 2. 3
  libavfilter    1.74. 0 /  1.74. 0
  libswscale     0.12. 0 /  0.12. 0
Hyper fast Audio and Video encoder
usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

Use -h to get full help or, even better, run 'man ffmpeg'

并且命令 ffmpeg -filters 打印：

FFmpeg version SVN-r26402, Copyright (c) 2000-2011 the FFmpeg developers
  built on Sep 12 2011 03:37:39 with gcc 4.1.2 20080704 (Red Hat 4.1.2-50)
  configuration:
  libavutil     50.36. 0 / 50.36. 0
  libavcore      0.16. 1 /  0.16. 1
  libavcodec    52.108. 0 / 52.108. 0
  libavformat   52.93. 0 / 52.93. 0
  libavdevice   52. 2. 3 / 52. 2. 3
  libavfilter    1.74. 0 /  1.74. 0
  libswscale     0.12. 0 /  0.12. 0
Filters:
anull            Pass the source unchanged to the output.
anullsrc         Null audio source, never return audio frames.
anullsink        Do absolutely nothing with the input audio.
copy             Copy the input video unchanged to the output.
crop             Crop the input video to width:height:x:y.
drawbox          Draw a colored box on the input video.
fifo             Buffer input images and send them when they are requested.
format           Convert the input video to one of the specified pixel formats.
gradfun          Debands video quickly using gradients.
hflip            Horizontally flip the input video.
noformat         Force libavfilter not to use any of the specified pixel formats for the input to the next filter.
null             Pass the source unchanged to the output.
overlay          Overlay a video source on top of the input.
pad              Pad input image to width:height[:x:y[:color]] (default x and y: 0, default color: black).
pixdesctest      Test pixel format definitions.
scale            Scale the input video to width:height size and/or convert the image format.
setdar           Set the frame display aspect ratio.
setpts           Set PTS for the output video frame.
setsar           Set the pixel sample aspect ratio.
settb            Set timebase for the output link.
slicify          Pass the images of input video on to next video filter as multiple slices.
transpose        Transpose input video.
unsharp          Sharpen or blur the input video.
vflip            Flip the input video vertically.
buffer           Buffer video frames, and make them accessible to the filterchain.
color            Provide an uniformly colored input, syntax is: [color[:size[:rate]]]
nullsrc          Null video source, never return images.
nullsink         Do absolutely nothing with the input video.`

首先，我的 ffmpeg 没有淡入淡出过滤器，因为它给出了错误

fade: filter not found

，所以我安装了创建 vf_fade.c 的补丁，并对 ffmpeg 中 libavfilters 目录的 Makefile 和 allfilters.c 文件进行了相应的更改。再次配置它，然后还运行命令“make”和“make install”重新启动服务器，但仍然显示相同的错误，

fade: filter not found

下一步我应该做什么？如果需要更多详细信息，请询问，我们将不胜感激所有帮助、想法和链接。

Answer 1

你真的需要 ffmpeg 吗？

听起来您只需使用 javascript 就可以实现相同的效果，甚至可能更好。看一下 jQuery 的 fading API 看看这是否足以完成您的任务想。