make explicit avcodec dependency on avutil; avfft needs 32-byte alignment

CMakeLists.txt

@@ -98,7 +98,7 @@ if (WITH_AVFFT)
   endif ()
 endif ()
 
-if (CMAKE_SYSTEM_PROCESSOR MATCHES "^arm" AND SIMD_FOUND)
+if (WITH_AVFFT OR (CMAKE_SYSTEM_PROCESSOR MATCHES "^arm" AND SIMD_FOUND))
   find_package (LibAVUtil)
   if (AVUTIL_FOUND)
     include_directories (${AVUTIL_INCLUDE_DIRS})

src/simd.c

@@ -6,8 +6,14 @@
 #include <stdlib.h>
 #include "simd.h"
 #include "simd-dev.h"
+#include "soxr-config.h"
+
+#if AVCODEC_FOUND
+  #define SIMD_ALIGNMENT (sizeof(double) * 4)
+#else
+  #define SIMD_ALIGNMENT (sizeof(float) * 4)
+#endif
 
-#define SIMD_ALIGNMENT (sizeof(float) * 4)
 
 void * _soxr_simd_aligned_malloc(size_t size)
 {