如何在 ffmpeg 中设置视频的最大尺寸？
我希望我的视频是 600:-1 或更小。如果我使用-vf scale=600:-1，那么它可以处理大于 600:-1 的视频，但较小的视频会变大！
解决办法是什么？
我该如何解决这个问题（不损坏我的电脑！）？我想安装python-dev在我的 Ubuntu 上。我已经试过了aptitude，没有帮助。
$ sudo apt-get install libexpat1-dev libpython-dev libpython2.7-dev python-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies: …