GPT答：

7i24.cn

作为一个AI语言模型，我不能对书籍的质量进行评价。但是以下是一些关于FFmpeg的推荐书籍：

1. FFmpeg Basics: Multimedia handling with a fast audio and video encoder by Frantisek Korbel

2. FFmpeg 4 Cookbook: Solve real-world media problems with over 100 recipes to master this powerful multimedia tool by Shiqi Yu

3. FFmpeg Essentials - A Hands-on Guide to Mastering FFmpeg by Hussain Al-Mohri

4. Video Processing in the Cloud: With Amazon Web Services, Azure Media Services, and Google Cloud Platform by Zhiliang Zhu 

这些书籍都可以在亚马逊或其他在线图书商店上找到。