after-effects - Android/ios中的app，特效视频合成，原理是怎么做的？应该有用第三方的工具的吧？

Question

我最近发现一款app，叫彩视（绝对不是帮他们打广告，而是我接到需求说要抄他们...其实我也很无语），这个app安卓和ios都有。

他们能把照片放到特效视频中，做成跟电子相册似得，但是效果比以前的电子相册丰富多了，看着就像是用after effect做出来一样。
（比如照片的轮廓会根据背景视频的不同而自动修改，有把轮廓改成不规则波浪的（如果熟悉after effect，这个效果就像里面的遮罩一样）；还有的，照片还能立体旋转（如果熟悉after effect，这个效果就像里面开了3d，然后绕着y轴自转一样，有立体感））

我能想到的方法，就是下载after effect的模板，然后用Android和ios的程序解析它，然后把照片放进模板中，然后渲染模板。但是问题是，after effect的模板要怎样解析...？

所以我认为应该有别的模板，可以使用Android和ios的程序来调用并解析的，请问有人知道吗？手机端的特效视频合成工具，开不开源都行

Answer 1

The idea of ​​doing special effects on a video screen is generally as follows:

• Decode the video into a frame of image A
• Then use the algorithm to generate the image B with special effects frame by frame in chronological order
• Image B, compressed into video after video encoding.

If you need to implement similar functions, although there are only three steps above, it is not recommended that you implement it from beginning to end. Considering the time cost, it is not worth it. I recommend a well-known open source project VLC Player, which supports iOS, Android. Baofengyingyin uses its decoding library. VLC has made its own internal core video encoding and decoding part into a library MobileVLCKit. They also have a video editing tool VLMC, check it out, you should have what you want.

Answer 2

The app you mentioned is almost the same as Meipai. It synthesizes pictures into videos, adds mv special effects and filters to synthesize videos again. In fact, it mainly uses ffmpeg plus image processing. I will tell you two libraries, GPUImage-android ffmpeg4android, I also want to make an app like this, but my personal abilities are limited. There is a buddy on github who made a similar app https://github.com/motianhuo/VCameraDemo. You can take a look

Answer 3

I don’t know about Android, but iOS’s coreImage has something for video processing

Answer 4

I am also encountering this problem and I can’t figure out how to achieve the effect similar to the after effect