FFmpegを使えば
 次のコマンドでサイド・バイ・サイドの比較ビデオを作成できる：

```bash
ffmpeg -i input1.mp4 -i input2.mp4 -filter_complex "[0:v][1:v]hstack=inputs=2[v]" -map "[v]" output.mp4
```
Using FFmpeg, you can
 create a side-by-side comparison video with the following command:

```bash
ffmpeg -i input1.mp4 -i input2.mp4 -filter_complex "[0:v][1:v]hstack=inputs=2[v]" -map "[v]" output.mp4
```