关于 ffmpeg ‘UINT64_C’ was not declared in this scope 的错误

ffmpeg 默认是用C文件来编译的，如果某个CPP文件想引用ffmpeg中的某些函数或者头文件，有可能出现

‘UINT64_C’ was not declared in this scope的错误

情形大概如下

The same issue i'm getting here when compiling chromium with ffmpeg from svn:

In file included from /usr/include/libavutil/avutil.h:81:0,

from /usr/include/libavcodec/avcodec.h:30,                

 from out/Release/obj.target/geni/ffmpeg_stubs.cc:16:

/usr/include/libavutil/common.h: In function 'int32_t av_clipl_int32(int64_t)':

/usr/include/libavutil/common.h:154:47: error: 'UINT64_C' was not declared in this scope

make: *** [out/Release/obj.target/geni/ffmpeg_stubs.o] Error 1

方法1.

可以 在cpp文件中加入

extern "C"{

#ifdef __cplusplus
 #define __STDC_CONSTANT_MACROS
 #ifdef _STDINT_H
  #undef _STDINT_H
 #endif
 # include <stdint.h>
#endif

}

来解决

已可以在 Android.mk 中添加

LOCAL_CFLAGS += -D__STDC_CONSTANT_MACROS=1