[ffbuild/common.mak:81: libavformat/adtsenc.o] Error 1

./libavcodec/x86/mathops.h:125: Error: operand type mismatch for `shr'
make: *** [ffbuild/common.mak:81: libavformat/adtsenc.o] Error 1
更改编译代码方式：
cd FFmpeg-n5.1.2/libavcodec/x86/
vim mathops.h
定位到125
先删除125至最后一行，然后添加新的内容

// avoid +32 for shift optimization (gcc should do that ...)
#define NEG_SSR32 NEG_SSR32
static inline int32_t NEG_SSR32( int32_t a, int8_t s){
if (__builtin_constant_p(s))
  __asm__ ("sarl %1, %0\n\t"
    : "+r" (a)
    : "i" (-s & 0x1F)
);
else
  __asm__ ("sarl %1, %0\n\t"
    : "+r" (a)
    : "c" ((uint8_t)(-s))
);
  return a;
}
#define NEG_USR32 NEG_USR32
static inline uint32_t NEG_USR32(uint32_t a, int8_t s){
if (__builtin_constant_p(s))
  __asm__ ("shrl %1, %0\n\t"
    : "+r" (a)
    : "i" (-s & 0x1F)
);
else
  __asm__ ("shrl %1, %0\n\t"
    : "+r" (a)
    : "c" ((uint8_t)(-s))
);
return a;
}
#endif /* HAVE_INLINE_ASM */
#endif /* AVCODEC_X86_MATHOPS_H */

cd ../../
make clean
make -j4
make install