[多媒体] OpenMax / DirectShow / FFmpeg

• OpenMax is an API specification
• DirectShow is an API specification and an implementation of that API
• FFmpeg provides libraries, and libraries are implementations of API specifications

参考：I'd like to know the relations among openmax, directshow and ffmpeg - Stack Overflowhttps://stackoverflow.com/questions/69959931/id-like-to-know-the-relations-among-openmax-directshow-and-ffmpeg