I submitted the following patch to libdv-devel@lists.sourceforge.net, and it is currently pending acceptance.

Subject: [libdv-dev] [PATCH] Fix reorder_block() zigzag on non-x86

The reorder_block() zigzag behaves incorrectly in the !ARCH_X86 &&
!ARCH_X86_64 case.  The current code fails to take into account the
effects of _dv_prepare_reorder_tables(), which changes the indexes
contained in the reorder_88[] and reorder_248[] arrays.

---

Restore older, known good, reorder_block() inner loop.

 encode.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff -ru libdv-0.104-orig/libdv/encode.c libdv-0.104-fixed/libdv/encode.c
--- libdv-0.104-orig/libdv/encode.c     2004-11-16 21:36:30.000000000 -0600
+++ libdv-0.104-fixed/libdv/encode.c    2006-03-07 14:07:22.000000000 -0600
@@ -512,10 +512,9 @@
        _dv_reorder_block_mmx_x86_64(bl->coeffs, reorder);
        emms();
 #else
-       for (i = 0; i < 64; i++) {
-         //            *(unsigned short*) ((char*) zigzag +
reorder[i])=bl->coeffs[i];
-         zigzag[reorder[i] - 1] = bl->coeffs[i];
-       }
+       for (i = 0; i < 64; i++)
+         *(unsigned short*) ((char*) zigzag + reorder[i])=bl->coeffs[i];
+
        memcpy(bl->coeffs, zigzag, 64 * sizeof(dv_coeff_t));
 #endif
 }