diff -r -u -x '*.o' mythtv-0.19/libs/libmythmpeg2/cpu_accel.c edited-mythtv-0.19/libs/libmythmpeg2/cpu_accel.c
--- mythtv-0.19/libs/libmythmpeg2/cpu_accel.c	2005-07-05 22:35:21.000000000 -0400
+++ edited-mythtv-0.19/libs/libmythmpeg2/cpu_accel.c	2006-02-19 17:06:03.299472861 -0500
@@ -212,7 +212,9 @@
 
     accel = 0;
 #ifdef ACCEL_DETECT
-#if defined (ARCH_X86) || defined (ARCH_PPC) || defined (ARCH_ALPHA) || defined (ARCH_SPARC)
+#if defined (ARCH_X86_64)
+    accel = MPEG2_ACCEL_X86_MMX|MPEG2_ACCEL_X86_MMXEXT;
+#elif defined (ARCH_X86) || defined (ARCH_PPC) || defined (ARCH_ALPHA) || defined (ARCH_SPARC)
     accel = arch_accel ();
 #endif
 #endif
diff -r -u -x '*.o' mythtv-0.19/libs/libmythsoundtouch/cpu_detect_x86_gcc.cpp edited-mythtv-0.19/libs/libmythsoundtouch/cpu_detect_x86_gcc.cpp
--- mythtv-0.19/libs/libmythsoundtouch/cpu_detect_x86_gcc.cpp	2005-01-24 01:42:19.000000000 -0500
+++ edited-mythtv-0.19/libs/libmythsoundtouch/cpu_detect_x86_gcc.cpp	2006-02-20 15:15:41.059353880 -0500
@@ -72,7 +72,15 @@
 /// Checks which instruction set extensions are supported by the CPU.
 uint detectCPUextensions(void)
 {
-#ifndef __i386__
+#if defined(__SSE2__)
+    // If compiled for x86_64 or an -march that has SSE2.
+    // The cpu detect code here currently doesn't work on x86_64,
+    // but x86_64 always has these instructions:
+    return SUPPORT_SSE2|SUPPORT_SSE|SUPPORT_MMX;
+#elif defined(__SSE__)
+    // If compiled for -march supporting SSE.
+    return SUPPORT_SSE|SUPPORT_MMX;
+#elif ! defined(MMX)
     return 0; // always disable extensions on non-x86 platforms.
 #else
     uint res = 0;