Expression: public_stream != nullptr

Microsoft Visual C++ Runtime Library
---------------------------
Debug Assertion Failed!


Program: D:\project\c++\ffmpeg_3.4-64\ffmpeg_02\x64\Debug\ffmpeg_02.exe
File: minkernel\crts\ucrt\src\appcrt\stdio\feoferr.cpp
Line: 17


Expression: public_stream != nullptr


For information on how your program can cause an assertion
failure, see the Visual C++ documentation on asserts.

(Press Retry to debug the application)

其实就是ffmpeg的空指针异常，这里是说数据流为空，原因有文件不存在、流为空等等