Isn't it always true on x86_64 that you have sse? +#ifdef ARCH_X86_64 + if (gCpuCaps.hasSSE) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + { + dct64_MMX_func = dct64_sse; + mp_msg(MSGT_DECAUDIO,MSGL_V,"mp3lib: using SSE optimized decore!\n"); + } + else +#endif