$OpenBSD$
Unbreak build.

Index: encode/mpeg2vaenc.c
--- encode/mpeg2vaenc.c.orig
+++ encode/mpeg2vaenc.c
@@ -162,6 +162,7 @@ struct __bitstream {
 
 typedef struct __bitstream bitstream;
 
+#ifndef swap32
 static unsigned int 
 swap32(unsigned int val)
 {
@@ -172,6 +173,7 @@ swap32(unsigned int val)
             (pval[2] << 8)      |
             (pval[3] << 0));
 }
+#endif	// defined(swap32)
 
 static void
 bitstream_start(bitstream *bs)
