我一直在尝试使用FFmpeg旋转视频。我正在处理竖屏模式下拍摄的iPhone视频。我知道如何使用MediaInfo(非常好的库)确定当前旋转角度,但现在我遇到了FFmpeg的问题。
根据我所读的,你需要使用vfilter选项。根据我所看到的,它应该是这个样子:
ffmpeg -vfilters "rotate=90" -i input.mp4 output.mp4
然而,我无法使它正常工作。首先,-vfilters不再存在了,现在改为-vf。其次,我遇到了以下错误:
No such filter: 'rotate'
Error opening filters!
据我所知,我拥有一个 FFmpeg 的全选项构建版本。运行 ffmpeg -filters 显示如下内容:Filters:
anull Pass the source unchanged to the output.
aspect Set the frame aspect ratio.
crop Crop the input video to x:y:width:height.
fifo Buffer input images and send them when they are requested.
format Convert the input video to one of the specified pixel formats.
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.
pad Pad input image to width:height[:x:y[:color]] (default x and y:
0, default color: black).
pixdesctest Test pixel format definitions.
pixelaspect Set the pixel aspect ratio.
scale Scale the input video to width:height size and/or convert the i
mage format.
slicify Pass the images of input video on to next video filter as multi
ple slices.
unsharp Sharpen or blur the input video.
vflip Flip the input video vertically.
buffer Buffer video frames, and make them accessible to the filterchai
n.
color Provide an uniformly colored input, syntax is: [color[:size[:ra
te]]]
nullsrc Null video source, never return images.
nullsink Do absolutely nothing with the input video.
虽然拥有vflip和hflip选项很好,但它们并不能满足我的需求。我需要能够旋转视频至少90度的功能。如果还有270度的选项,那就更好了。旋转选项去哪里了?