Merge "Adds high bitdepth convolve, interpred & scaling"
diff --git a/vp9/common/x86/vp9_loopfilter_intrin_sse2.c b/vp9/common/x86/vp9_loopfilter_intrin_sse2.c
index 448ad5a..de2394b 100644
--- a/vp9/common/x86/vp9_loopfilter_intrin_sse2.c
+++ b/vp9/common/x86/vp9_loopfilter_intrin_sse2.c
@@ -12,6 +12,10 @@
 #include "vp9/common/vp9_loopfilter.h"
 #include "vpx_ports/emmintrin_compat.h"
 
+static INLINE __m128i abs_diff(__m128i a, __m128i b) {
+  return _mm_or_si128(_mm_subs_epu8(a, b), _mm_subs_epu8(b, a));
+}
+
 static void mb_lpf_horizontal_edge_w_sse2_8(unsigned char *s,
                                             int p,
                                             const unsigned char *_blimit,
@@ -46,15 +50,12 @@
 
   {
     __m128i abs_p1q1, abs_p0q0, abs_q1q0, fe, ff, work;
-    abs_p1p0 = _mm_or_si128(_mm_subs_epu8(q1p1, q0p0),
-                            _mm_subs_epu8(q0p0, q1p1));
+    abs_p1p0 = abs_diff(q1p1, q0p0);
     abs_q1q0 =  _mm_srli_si128(abs_p1p0, 8);
     fe = _mm_set1_epi8(0xfe);
     ff = _mm_cmpeq_epi8(abs_p1p0, abs_p1p0);
-    abs_p0q0 = _mm_or_si128(_mm_subs_epu8(q0p0, p0q0),
-                            _mm_subs_epu8(p0q0, q0p0));
-    abs_p1q1 = _mm_or_si128(_mm_subs_epu8(q1p1, p1q1),
-                            _mm_subs_epu8(p1q1, q1p1));
+    abs_p0q0 = abs_diff(q0p0, p0q0);
+    abs_p1q1 = abs_diff(q1p1, p1q1);
     flat = _mm_max_epu8(abs_p1p0, abs_q1q0);
     hev = _mm_subs_epu8(flat, thresh);
     hev = _mm_xor_si128(_mm_cmpeq_epi8(hev, zero), ff);
@@ -68,10 +69,8 @@
     // mask |= (abs(p1 - p0) > limit) * -1;
     // mask |= (abs(q1 - q0) > limit) * -1;
 
-    work = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(q2p2, q1p1),
-                                     _mm_subs_epu8(q1p1, q2p2)),
-                        _mm_or_si128(_mm_subs_epu8(q3p3, q2p2),
-                                     _mm_subs_epu8(q2p2, q3p3)));
+    work = _mm_max_epu8(abs_diff(q2p2, q1p1),
+                        abs_diff(q3p3, q2p2));
     mask = _mm_max_epu8(work, mask);
     mask = _mm_max_epu8(mask, _mm_srli_si128(mask, 8));
     mask = _mm_subs_epu8(mask, limit);
@@ -125,10 +124,7 @@
 
     {
       __m128i work;
-      flat = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(q2p2, q0p0),
-                                       _mm_subs_epu8(q0p0, q2p2)),
-                          _mm_or_si128(_mm_subs_epu8(q3p3, q0p0),
-                                       _mm_subs_epu8(q0p0, q3p3)));
+      flat = _mm_max_epu8(abs_diff(q2p2, q0p0), abs_diff(q3p3, q0p0));
       flat = _mm_max_epu8(abs_p1p0, flat);
       flat = _mm_max_epu8(flat, _mm_srli_si128(flat, 8));
       flat = _mm_subs_epu8(flat, one);
@@ -142,21 +138,12 @@
       q6p6 = _mm_loadl_epi64((__m128i *)(s - 7 * p));
       q6p6 = _mm_castps_si128(_mm_loadh_pi(_mm_castsi128_ps(q6p6),
                                            (__m64 *)(s + 6 * p)));
-
-      flat2 = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(q4p4, q0p0),
-                                        _mm_subs_epu8(q0p0, q4p4)),
-                           _mm_or_si128(_mm_subs_epu8(q5p5, q0p0),
-                                        _mm_subs_epu8(q0p0, q5p5)));
+      flat2 = _mm_max_epu8(abs_diff(q4p4, q0p0), abs_diff(q5p5, q0p0));
 
       q7p7 = _mm_loadl_epi64((__m128i *)(s - 8 * p));
       q7p7 = _mm_castps_si128(_mm_loadh_pi(_mm_castsi128_ps(q7p7),
                                            (__m64 *)(s + 7 * p)));
-
-      work = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(q6p6, q0p0),
-                                       _mm_subs_epu8(q0p0, q6p6)),
-                          _mm_or_si128(_mm_subs_epu8(q7p7, q0p0),
-                                       _mm_subs_epu8(q0p0, q7p7)));
-
+      work = _mm_max_epu8(abs_diff(q6p6, q0p0), abs_diff(q7p7, q0p0));
       flat2 = _mm_max_epu8(work, flat2);
       flat2 = _mm_max_epu8(flat2, _mm_srli_si128(flat2, 8));
       flat2 = _mm_subs_epu8(flat2, one);
@@ -364,20 +351,34 @@
   }
 }
 
+static INLINE __m128i filter_add2_sub2(__m128i total, __m128i a1, __m128i a2,
+                                       __m128i s1, __m128i s2) {
+  total = _mm_add_epi16(a1, total);
+  total = _mm_add_epi16(_mm_sub_epi16(total, _mm_add_epi16(s1, s2)), a2);
+  return total;
+}
+
+static INLINE __m128i filter8_mask(__m128i flat, __m128i other_filt,
+                                   __m128i f8_lo, __m128i f8_hi) {
+  const __m128i f8 = _mm_packus_epi16(_mm_srli_epi16(f8_lo, 3),
+                                      _mm_srli_epi16(f8_hi, 3));
+  const __m128i result = _mm_and_si128(flat, f8);
+  return _mm_or_si128(_mm_andnot_si128(flat, other_filt), result);
+}
+
+static INLINE __m128i filter16_mask(__m128i flat, __m128i other_filt,
+                                    __m128i f_lo, __m128i f_hi) {
+  const __m128i f = _mm_packus_epi16(_mm_srli_epi16(f_lo, 4),
+                                     _mm_srli_epi16(f_hi, 4));
+  const __m128i result = _mm_and_si128(flat, f);
+  return _mm_or_si128(_mm_andnot_si128(flat, other_filt), result);
+}
+
 static void mb_lpf_horizontal_edge_w_sse2_16(unsigned char *s,
                                              int p,
                                              const unsigned char *_blimit,
                                              const unsigned char *_limit,
                                              const unsigned char *_thresh) {
-  DECLARE_ALIGNED_ARRAY(16, unsigned char, flat2_op, 7 * 16);
-  DECLARE_ALIGNED_ARRAY(16, unsigned char, flat2_oq, 7 * 16);
-
-  DECLARE_ALIGNED_ARRAY(16, unsigned char, flat_op, 3 * 16);
-  DECLARE_ALIGNED_ARRAY(16, unsigned char, flat_oq, 3 * 16);
-
-  DECLARE_ALIGNED_ARRAY(16, unsigned char, ap, 8 * 16);
-  DECLARE_ALIGNED_ARRAY(16, unsigned char, aq, 8 * 16);
-
   const __m128i zero = _mm_set1_epi16(0);
   const __m128i one = _mm_set1_epi8(1);
   const __m128i blimit = _mm_load_si128((const __m128i *)_blimit);
@@ -387,8 +388,14 @@
   __m128i p7, p6, p5;
   __m128i p4, p3, p2, p1, p0, q0, q1, q2, q3, q4;
   __m128i q5, q6, q7;
-  int i = 0;
 
+  __m128i op2, op1, op0, oq0, oq1, oq2;
+
+  __m128i max_abs_p1p0q1q0;
+
+  p7 = _mm_loadu_si128((__m128i *)(s - 8 * p));
+  p6 = _mm_loadu_si128((__m128i *)(s - 7 * p));
+  p5 = _mm_loadu_si128((__m128i *)(s - 6 * p));
   p4 = _mm_loadu_si128((__m128i *)(s - 5 * p));
   p3 = _mm_loadu_si128((__m128i *)(s - 4 * p));
   p2 = _mm_loadu_si128((__m128i *)(s - 3 * p));
@@ -399,58 +406,59 @@
   q2 = _mm_loadu_si128((__m128i *)(s + 2 * p));
   q3 = _mm_loadu_si128((__m128i *)(s + 3 * p));
   q4 = _mm_loadu_si128((__m128i *)(s + 4 * p));
-
-  _mm_store_si128((__m128i *)&ap[4 * 16], p4);
-  _mm_store_si128((__m128i *)&ap[3 * 16], p3);
-  _mm_store_si128((__m128i *)&ap[2 * 16], p2);
-  _mm_store_si128((__m128i *)&ap[1 * 16], p1);
-  _mm_store_si128((__m128i *)&ap[0 * 16], p0);
-  _mm_store_si128((__m128i *)&aq[4 * 16], q4);
-  _mm_store_si128((__m128i *)&aq[3 * 16], q3);
-  _mm_store_si128((__m128i *)&aq[2 * 16], q2);
-  _mm_store_si128((__m128i *)&aq[1 * 16], q1);
-  _mm_store_si128((__m128i *)&aq[0 * 16], q0);
-
+  q5 = _mm_loadu_si128((__m128i *)(s + 5 * p));
+  q6 = _mm_loadu_si128((__m128i *)(s + 6 * p));
+  q7 = _mm_loadu_si128((__m128i *)(s + 7 * p));
 
   {
-    const __m128i abs_p1p0 = _mm_or_si128(_mm_subs_epu8(p1, p0),
-                                          _mm_subs_epu8(p0, p1));
-    const __m128i abs_q1q0 = _mm_or_si128(_mm_subs_epu8(q1, q0),
-                                          _mm_subs_epu8(q0, q1));
+    const __m128i abs_p1p0 = abs_diff(p1, p0);
+    const __m128i abs_q1q0 = abs_diff(q1, q0);
     const __m128i fe = _mm_set1_epi8(0xfe);
-    const __m128i ff = _mm_cmpeq_epi8(abs_p1p0, abs_p1p0);
-    __m128i abs_p0q0 = _mm_or_si128(_mm_subs_epu8(p0, q0),
-                                    _mm_subs_epu8(q0, p0));
-    __m128i abs_p1q1 = _mm_or_si128(_mm_subs_epu8(p1, q1),
-                                    _mm_subs_epu8(q1, p1));
+    const __m128i ff = _mm_cmpeq_epi8(zero, zero);
+    __m128i abs_p0q0 = abs_diff(p0, q0);
+    __m128i abs_p1q1 = abs_diff(p1, q1);
     __m128i work;
-    flat = _mm_max_epu8(abs_p1p0, abs_q1q0);
-    hev = _mm_subs_epu8(flat, thresh);
-    hev = _mm_xor_si128(_mm_cmpeq_epi8(hev, zero), ff);
+    max_abs_p1p0q1q0 = _mm_max_epu8(abs_p1p0, abs_q1q0);
 
     abs_p0q0 =_mm_adds_epu8(abs_p0q0, abs_p0q0);
     abs_p1q1 = _mm_srli_epi16(_mm_and_si128(abs_p1q1, fe), 1);
     mask = _mm_subs_epu8(_mm_adds_epu8(abs_p0q0, abs_p1q1), blimit);
     mask = _mm_xor_si128(_mm_cmpeq_epi8(mask, zero), ff);
     // mask |= (abs(p0 - q0) * 2 + abs(p1 - q1) / 2  > blimit) * -1;
-    mask = _mm_max_epu8(flat, mask);
+    mask = _mm_max_epu8(max_abs_p1p0q1q0, mask);
     // mask |= (abs(p1 - p0) > limit) * -1;
     // mask |= (abs(q1 - q0) > limit) * -1;
-    work = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(p2, p1),
-                                     _mm_subs_epu8(p1, p2)),
-                         _mm_or_si128(_mm_subs_epu8(p3, p2),
-                                      _mm_subs_epu8(p2, p3)));
+    work = _mm_max_epu8(abs_diff(p2, p1), abs_diff(p3, p2));
     mask = _mm_max_epu8(work, mask);
-    work = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(q2, q1),
-                                     _mm_subs_epu8(q1, q2)),
-                         _mm_or_si128(_mm_subs_epu8(q3, q2),
-                                      _mm_subs_epu8(q2, q3)));
+    work = _mm_max_epu8(abs_diff(q2, q1), abs_diff(q3, q2));
     mask = _mm_max_epu8(work, mask);
     mask = _mm_subs_epu8(mask, limit);
     mask = _mm_cmpeq_epi8(mask, zero);
   }
 
-  // lp filter
+  {
+    __m128i work;
+    work = _mm_max_epu8(abs_diff(p2, p0), abs_diff(q2, q0));
+    flat = _mm_max_epu8(work, max_abs_p1p0q1q0);
+    work = _mm_max_epu8(abs_diff(p3, p0), abs_diff(q3, q0));
+    flat = _mm_max_epu8(work, flat);
+    work = _mm_max_epu8(abs_diff(p4, p0), abs_diff(q4, q0));
+    flat = _mm_subs_epu8(flat, one);
+    flat = _mm_cmpeq_epi8(flat, zero);
+    flat = _mm_and_si128(flat, mask);
+    flat2 = _mm_max_epu8(abs_diff(p5, p0), abs_diff(q5, q0));
+    flat2 = _mm_max_epu8(work, flat2);
+    work = _mm_max_epu8(abs_diff(p6, p0), abs_diff(q6, q0));
+    flat2 = _mm_max_epu8(work, flat2);
+    work = _mm_max_epu8(abs_diff(p7, p0), abs_diff(q7, q0));
+    flat2 = _mm_max_epu8(work, flat2);
+    flat2 = _mm_subs_epu8(flat2, one);
+    flat2 = _mm_cmpeq_epi8(flat2, zero);
+    flat2 = _mm_and_si128(flat2, flat);  // flat2 & flat & mask
+  }
+
+  // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // filter4
   {
     const __m128i t4 = _mm_set1_epi8(4);
     const __m128i t3 = _mm_set1_epi8(3);
@@ -459,23 +467,27 @@
     const __m128i t1f = _mm_set1_epi8(0x1f);
     const __m128i t1 = _mm_set1_epi8(0x1);
     const __m128i t7f = _mm_set1_epi8(0x7f);
+    const __m128i ff = _mm_cmpeq_epi8(t4, t4);
 
-    __m128i ps1 = _mm_xor_si128(p1, t80);
-    __m128i ps0 = _mm_xor_si128(p0, t80);
-    __m128i qs0 = _mm_xor_si128(q0, t80);
-    __m128i qs1 = _mm_xor_si128(q1, t80);
     __m128i filt;
     __m128i work_a;
     __m128i filter1, filter2;
 
-    filt = _mm_and_si128(_mm_subs_epi8(ps1, qs1), hev);
-    work_a = _mm_subs_epi8(qs0, ps0);
+    op1 = _mm_xor_si128(p1, t80);
+    op0 = _mm_xor_si128(p0, t80);
+    oq0 = _mm_xor_si128(q0, t80);
+    oq1 = _mm_xor_si128(q1, t80);
+
+    hev = _mm_subs_epu8(max_abs_p1p0q1q0, thresh);
+    hev = _mm_xor_si128(_mm_cmpeq_epi8(hev, zero), ff);
+    filt = _mm_and_si128(_mm_subs_epi8(op1, oq1), hev);
+
+    work_a = _mm_subs_epi8(oq0, op0);
     filt = _mm_adds_epi8(filt, work_a);
     filt = _mm_adds_epi8(filt, work_a);
     filt = _mm_adds_epi8(filt, work_a);
     // (vp9_filter + 3 * (qs0 - ps0)) & mask
     filt = _mm_and_si128(filt, mask);
-
     filter1 = _mm_adds_epi8(filt, t4);
     filter2 = _mm_adds_epi8(filt, t3);
 
@@ -485,7 +497,7 @@
     work_a = _mm_and_si128(work_a, te0);
     filter1 = _mm_and_si128(filter1, t1f);
     filter1 = _mm_or_si128(filter1, work_a);
-    qs0 = _mm_xor_si128(_mm_subs_epi8(qs0, filter1), t80);
+    oq0 = _mm_xor_si128(_mm_subs_epi8(oq0, filter1), t80);
 
     // Filter2 >> 3
     work_a = _mm_cmpgt_epi8(zero, filter2);
@@ -493,7 +505,7 @@
     work_a = _mm_and_si128(work_a, te0);
     filter2 = _mm_and_si128(filter2, t1f);
     filter2 = _mm_or_si128(filter2, work_a);
-    ps0 = _mm_xor_si128(_mm_adds_epi8(ps0, filter2), t80);
+    op0 = _mm_xor_si128(_mm_adds_epi8(op0, filter2), t80);
 
     // filt >> 1
     filt = _mm_adds_epi8(filter1, t1);
@@ -503,345 +515,195 @@
     filt = _mm_and_si128(filt, t7f);
     filt = _mm_or_si128(filt, work_a);
     filt = _mm_andnot_si128(hev, filt);
-    ps1 = _mm_xor_si128(_mm_adds_epi8(ps1, filt), t80);
-    qs1 = _mm_xor_si128(_mm_subs_epi8(qs1, filt), t80);
+    op1 = _mm_xor_si128(_mm_adds_epi8(op1, filt), t80);
+    oq1 = _mm_xor_si128(_mm_subs_epi8(oq1, filt), t80);
     // loopfilter done
 
+    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    // filter8
     {
-      __m128i work;
-      work = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(p2, p0),
-                                       _mm_subs_epu8(p0, p2)),
-                           _mm_or_si128(_mm_subs_epu8(q2, q0),
-                                        _mm_subs_epu8(q0, q2)));
-      flat = _mm_max_epu8(work, flat);
-      work = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(p3, p0),
-                                       _mm_subs_epu8(p0, p3)),
-                           _mm_or_si128(_mm_subs_epu8(q3, q0),
-                                        _mm_subs_epu8(q0, q3)));
-      flat = _mm_max_epu8(work, flat);
-      work = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(p4, p0),
-                                       _mm_subs_epu8(p0, p4)),
-                           _mm_or_si128(_mm_subs_epu8(q4, q0),
-                                        _mm_subs_epu8(q0, q4)));
-      flat = _mm_subs_epu8(flat, one);
-      flat = _mm_cmpeq_epi8(flat, zero);
-      flat = _mm_and_si128(flat, mask);
+      const __m128i four = _mm_set1_epi16(4);
+      const __m128i p3_lo = _mm_unpacklo_epi8(p3, zero);
+      const __m128i p2_lo = _mm_unpacklo_epi8(p2, zero);
+      const __m128i p1_lo = _mm_unpacklo_epi8(p1, zero);
+      const __m128i p0_lo = _mm_unpacklo_epi8(p0, zero);
+      const __m128i q0_lo = _mm_unpacklo_epi8(q0, zero);
+      const __m128i q1_lo = _mm_unpacklo_epi8(q1, zero);
+      const __m128i q2_lo = _mm_unpacklo_epi8(q2, zero);
+      const __m128i q3_lo = _mm_unpacklo_epi8(q3, zero);
 
-      p5 = _mm_loadu_si128((__m128i *)(s - 6 * p));
-      q5 = _mm_loadu_si128((__m128i *)(s + 5 * p));
-      flat2 = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(p5, p0),
-                                       _mm_subs_epu8(p0, p5)),
-                           _mm_or_si128(_mm_subs_epu8(q5, q0),
-                                        _mm_subs_epu8(q0, q5)));
-      _mm_store_si128((__m128i *)&ap[5 * 16], p5);
-      _mm_store_si128((__m128i *)&aq[5 * 16], q5);
-      flat2 = _mm_max_epu8(work, flat2);
-      p6 = _mm_loadu_si128((__m128i *)(s - 7 * p));
-      q6 = _mm_loadu_si128((__m128i *)(s + 6 * p));
-      work = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(p6, p0),
-                                       _mm_subs_epu8(p0, p6)),
-                           _mm_or_si128(_mm_subs_epu8(q6, q0),
-                                        _mm_subs_epu8(q0, q6)));
-      _mm_store_si128((__m128i *)&ap[6 * 16], p6);
-      _mm_store_si128((__m128i *)&aq[6 * 16], q6);
-      flat2 = _mm_max_epu8(work, flat2);
+      const __m128i p3_hi = _mm_unpackhi_epi8(p3, zero);
+      const __m128i p2_hi = _mm_unpackhi_epi8(p2, zero);
+      const __m128i p1_hi = _mm_unpackhi_epi8(p1, zero);
+      const __m128i p0_hi = _mm_unpackhi_epi8(p0, zero);
+      const __m128i q0_hi = _mm_unpackhi_epi8(q0, zero);
+      const __m128i q1_hi = _mm_unpackhi_epi8(q1, zero);
+      const __m128i q2_hi = _mm_unpackhi_epi8(q2, zero);
+      const __m128i q3_hi = _mm_unpackhi_epi8(q3, zero);
+      __m128i f8_lo, f8_hi;
 
-      p7 = _mm_loadu_si128((__m128i *)(s - 8 * p));
-      q7 = _mm_loadu_si128((__m128i *)(s + 7 * p));
-      work = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(p7, p0),
-                                       _mm_subs_epu8(p0, p7)),
-                           _mm_or_si128(_mm_subs_epu8(q7, q0),
-                                        _mm_subs_epu8(q0, q7)));
-      _mm_store_si128((__m128i *)&ap[7 * 16], p7);
-      _mm_store_si128((__m128i *)&aq[7 * 16], q7);
-      flat2 = _mm_max_epu8(work, flat2);
-      flat2 = _mm_subs_epu8(flat2, one);
-      flat2 = _mm_cmpeq_epi8(flat2, zero);
-      flat2 = _mm_and_si128(flat2, flat);  // flat2 & flat & mask
+      f8_lo = _mm_add_epi16(_mm_add_epi16(p3_lo, four),
+                            _mm_add_epi16(p3_lo, p2_lo));
+      f8_lo = _mm_add_epi16(_mm_add_epi16(p3_lo, f8_lo),
+                            _mm_add_epi16(p2_lo, p1_lo));
+      f8_lo = _mm_add_epi16(_mm_add_epi16(p0_lo, q0_lo), f8_lo);
+
+      f8_hi = _mm_add_epi16(_mm_add_epi16(p3_hi, four),
+                            _mm_add_epi16(p3_hi, p2_hi));
+      f8_hi = _mm_add_epi16(_mm_add_epi16(p3_hi, f8_hi),
+                            _mm_add_epi16(p2_hi, p1_hi));
+      f8_hi = _mm_add_epi16(_mm_add_epi16(p0_hi, q0_hi), f8_hi);
+
+      op2 = filter8_mask(flat, p2, f8_lo, f8_hi);
+
+      f8_lo = filter_add2_sub2(f8_lo, q1_lo, p1_lo, p2_lo, p3_lo);
+      f8_hi = filter_add2_sub2(f8_hi, q1_hi, p1_hi, p2_hi, p3_hi);
+      op1 = filter8_mask(flat, op1, f8_lo, f8_hi);
+
+      f8_lo = filter_add2_sub2(f8_lo, q2_lo, p0_lo, p1_lo, p3_lo);
+      f8_hi = filter_add2_sub2(f8_hi, q2_hi, p0_hi, p1_hi, p3_hi);
+      op0 = filter8_mask(flat, op0, f8_lo, f8_hi);
+
+      f8_lo = filter_add2_sub2(f8_lo, q3_lo, q0_lo, p0_lo, p3_lo);
+      f8_hi = filter_add2_sub2(f8_hi, q3_hi, q0_hi, p0_hi, p3_hi);
+      oq0 = filter8_mask(flat, oq0, f8_lo, f8_hi);
+
+      f8_lo = filter_add2_sub2(f8_lo, q3_lo, q1_lo, q0_lo, p2_lo);
+      f8_hi = filter_add2_sub2(f8_hi, q3_hi, q1_hi, q0_hi, p2_hi);
+      oq1 = filter8_mask(flat, oq1, f8_lo, f8_hi);
+
+      f8_lo = filter_add2_sub2(f8_lo, q3_lo, q2_lo, q1_lo, p1_lo);
+      f8_hi = filter_add2_sub2(f8_hi, q3_hi, q2_hi, q1_hi, p1_hi);
+      oq2 = filter8_mask(flat, q2, f8_lo, f8_hi);
     }
 
     // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-    // flat and wide flat calculations
+    // wide flat calculations
     {
       const __m128i eight = _mm_set1_epi16(8);
-      const __m128i four = _mm_set1_epi16(4);
-      __m128i temp_flat2 = flat2;
-      unsigned char *src = s;
-      int i = 0;
-      do {
-        __m128i workp_shft;
-        __m128i a, b, c;
+      const __m128i p7_lo = _mm_unpacklo_epi8(p7, zero);
+      const __m128i p6_lo = _mm_unpacklo_epi8(p6, zero);
+      const __m128i p5_lo = _mm_unpacklo_epi8(p5, zero);
+      const __m128i p4_lo = _mm_unpacklo_epi8(p4, zero);
+      const __m128i p3_lo = _mm_unpacklo_epi8(p3, zero);
+      const __m128i p2_lo = _mm_unpacklo_epi8(p2, zero);
+      const __m128i p1_lo = _mm_unpacklo_epi8(p1, zero);
+      const __m128i p0_lo = _mm_unpacklo_epi8(p0, zero);
+      const __m128i q0_lo = _mm_unpacklo_epi8(q0, zero);
+      const __m128i q1_lo = _mm_unpacklo_epi8(q1, zero);
+      const __m128i q2_lo = _mm_unpacklo_epi8(q2, zero);
+      const __m128i q3_lo = _mm_unpacklo_epi8(q3, zero);
+      const __m128i q4_lo = _mm_unpacklo_epi8(q4, zero);
+      const __m128i q5_lo = _mm_unpacklo_epi8(q5, zero);
+      const __m128i q6_lo = _mm_unpacklo_epi8(q6, zero);
+      const __m128i q7_lo = _mm_unpacklo_epi8(q7, zero);
 
-        unsigned int off = i * 8;
-        p7 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&ap[7 * 16] + off)),
-                               zero);
-        p6 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&ap[6 * 16] + off)),
-                               zero);
-        p5 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&ap[5 * 16] + off)),
-                               zero);
-        p4 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&ap[4 * 16] + off)),
-                               zero);
-        p3 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&ap[3 * 16] + off)),
-                               zero);
-        p2 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&ap[2 * 16] + off)),
-                               zero);
-        p1 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&ap[1 * 16] + off)),
-                               zero);
-        p0 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&ap[0 * 16] + off)),
-                               zero);
-        q0 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&aq[0 * 16] + off)),
-                               zero);
-        q1 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&aq[1 * 16] + off)),
-                               zero);
-        q2 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&aq[2 * 16] + off)),
-                               zero);
-        q3 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&aq[3 * 16] + off)),
-                               zero);
-        q4 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&aq[4 * 16] + off)),
-                               zero);
-        q5 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&aq[5 * 16] + off)),
-                               zero);
-        q6 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&aq[6 * 16] + off)),
-                               zero);
-        q7 = _mm_unpacklo_epi8(_mm_loadl_epi64((__m128i *)(&aq[7 * 16] + off)),
-                               zero);
+      const __m128i p7_hi = _mm_unpackhi_epi8(p7, zero);
+      const __m128i p6_hi = _mm_unpackhi_epi8(p6, zero);
+      const __m128i p5_hi = _mm_unpackhi_epi8(p5, zero);
+      const __m128i p4_hi = _mm_unpackhi_epi8(p4, zero);
+      const __m128i p3_hi = _mm_unpackhi_epi8(p3, zero);
+      const __m128i p2_hi = _mm_unpackhi_epi8(p2, zero);
+      const __m128i p1_hi = _mm_unpackhi_epi8(p1, zero);
+      const __m128i p0_hi = _mm_unpackhi_epi8(p0, zero);
+      const __m128i q0_hi = _mm_unpackhi_epi8(q0, zero);
+      const __m128i q1_hi = _mm_unpackhi_epi8(q1, zero);
+      const __m128i q2_hi = _mm_unpackhi_epi8(q2, zero);
+      const __m128i q3_hi = _mm_unpackhi_epi8(q3, zero);
+      const __m128i q4_hi = _mm_unpackhi_epi8(q4, zero);
+      const __m128i q5_hi = _mm_unpackhi_epi8(q5, zero);
+      const __m128i q6_hi = _mm_unpackhi_epi8(q6, zero);
+      const __m128i q7_hi = _mm_unpackhi_epi8(q7, zero);
 
-        c = _mm_sub_epi16(_mm_slli_epi16(p7, 3), p7);  // p7 * 7
-        c = _mm_add_epi16(_mm_slli_epi16(p6, 1), _mm_add_epi16(p4, c));
+      __m128i f_lo;
+      __m128i f_hi;
 
-        b = _mm_add_epi16(_mm_add_epi16(p3, four), _mm_add_epi16(p3, p2));
-        a = _mm_add_epi16(p3, _mm_add_epi16(p2, p1));
-        a = _mm_add_epi16(_mm_add_epi16(p0, q0), a);
+      f_lo = _mm_sub_epi16(_mm_slli_epi16(p7_lo, 3), p7_lo);  // p7 * 7
+      f_lo = _mm_add_epi16(_mm_slli_epi16(p6_lo, 1),
+                           _mm_add_epi16(p4_lo, f_lo));
+      f_lo = _mm_add_epi16(_mm_add_epi16(p3_lo, f_lo),
+                           _mm_add_epi16(p2_lo, p1_lo));
+      f_lo = _mm_add_epi16(_mm_add_epi16(p0_lo, q0_lo), f_lo);
+      f_lo = _mm_add_epi16(_mm_add_epi16(p5_lo, eight), f_lo);
 
-        _mm_storel_epi64((__m128i *)&flat_op[2 * 16 + i * 8],
-                         _mm_packus_epi16(_mm_srli_epi16(_mm_add_epi16(a, b), 3)
-                                          , b));
+      f_hi = _mm_sub_epi16(_mm_slli_epi16(p7_hi, 3), p7_hi);  // p7 * 7
+      f_hi = _mm_add_epi16(_mm_slli_epi16(p6_hi, 1),
+                           _mm_add_epi16(p4_hi, f_hi));
+      f_hi = _mm_add_epi16(_mm_add_epi16(p3_hi, f_hi),
+                           _mm_add_epi16(p2_hi, p1_hi));
+      f_hi = _mm_add_epi16(_mm_add_epi16(p0_hi, q0_hi), f_hi);
+      f_hi = _mm_add_epi16(_mm_add_epi16(p5_hi, eight), f_hi);
 
-        c = _mm_add_epi16(_mm_add_epi16(p5, eight), c);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_op[6 * 16 + i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
+      p6 = filter16_mask(flat2, p6, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s - 7 * p), p6);
 
-        a = _mm_add_epi16(q1, a);
-        b = _mm_add_epi16(_mm_sub_epi16(b, _mm_add_epi16(p3, p2)), p1);
-        _mm_storel_epi64((__m128i *)&flat_op[1 * 16 + i * 8],
-                         _mm_packus_epi16(_mm_srli_epi16(_mm_add_epi16(a, b), 3)
-                                          , b));
+      f_lo = filter_add2_sub2(f_lo, q1_lo, p5_lo, p6_lo, p7_lo);
+      f_hi = filter_add2_sub2(f_hi, q1_hi, p5_hi, p6_hi, p7_hi);
+      p5 = filter16_mask(flat2, p5, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s - 6 * p), p5);
 
-        c = _mm_add_epi16(_mm_sub_epi16(c, _mm_add_epi16(p7, p6)), p5);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_op[5 * 16 + i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
+      f_lo = filter_add2_sub2(f_lo, q2_lo, p4_lo, p5_lo, p7_lo);
+      f_hi = filter_add2_sub2(f_hi, q2_hi, p4_hi, p5_hi, p7_hi);
+      p4 = filter16_mask(flat2, p4, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s - 5 * p), p4);
 
-        a = _mm_add_epi16(q2, a);
-        b = _mm_add_epi16(_mm_sub_epi16(b, _mm_add_epi16(p3, p1)), p0);
-        _mm_storel_epi64((__m128i *)&flat_op[i * 8],
-                         _mm_packus_epi16(_mm_srli_epi16(_mm_add_epi16(a, b), 3)
-                                          , b));
+      f_lo = filter_add2_sub2(f_lo, q3_lo, p3_lo, p4_lo, p7_lo);
+      f_hi = filter_add2_sub2(f_hi, q3_hi, p3_hi, p4_hi, p7_hi);
+      p3 = filter16_mask(flat2, p3, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s - 4 * p), p3);
 
-        c = _mm_add_epi16(_mm_sub_epi16(c, _mm_add_epi16(p7, p5)), p4);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_op[4 * 16 + i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
+      f_lo = filter_add2_sub2(f_lo, q4_lo, p2_lo, p3_lo, p7_lo);
+      f_hi = filter_add2_sub2(f_hi, q4_hi, p2_hi, p3_hi, p7_hi);
+      op2 = filter16_mask(flat2, op2, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s - 3 * p), op2);
 
-        a = _mm_add_epi16(q3, a);
-        b = _mm_add_epi16(_mm_sub_epi16(b, _mm_add_epi16(p3, p0)), q0);
-        _mm_storel_epi64((__m128i *)&flat_oq[i * 8],
-                         _mm_packus_epi16(_mm_srli_epi16(_mm_add_epi16(a, b), 3)
-                                          , b));
+      f_lo = filter_add2_sub2(f_lo, q5_lo, p1_lo, p2_lo, p7_lo);
+      f_hi = filter_add2_sub2(f_hi, q5_hi, p1_hi, p2_hi, p7_hi);
+      op1 = filter16_mask(flat2, op1, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s - 2 * p), op1);
 
-        c = _mm_add_epi16(_mm_sub_epi16(c, _mm_add_epi16(p7, p4)), p3);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_op[3 * 16 + i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
+      f_lo = filter_add2_sub2(f_lo, q6_lo, p0_lo, p1_lo, p7_lo);
+      f_hi = filter_add2_sub2(f_hi, q6_hi, p0_hi, p1_hi, p7_hi);
+      op0 = filter16_mask(flat2, op0, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s - 1 * p), op0);
 
-        b = _mm_add_epi16(q3, b);
-        b = _mm_add_epi16(_mm_sub_epi16(b, _mm_add_epi16(p2, q0)), q1);
-        _mm_storel_epi64((__m128i *)&flat_oq[16 + i * 8],
-                         _mm_packus_epi16(_mm_srli_epi16(_mm_add_epi16(a, b), 3)
-                                          , b));
+      f_lo = filter_add2_sub2(f_lo, q7_lo, q0_lo, p0_lo, p7_lo);
+      f_hi = filter_add2_sub2(f_hi, q7_hi, q0_hi, p0_hi, p7_hi);
+      oq0 = filter16_mask(flat2, oq0, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s - 0 * p), oq0);
 
-        c = _mm_add_epi16(q4, c);
-        c = _mm_add_epi16(_mm_sub_epi16(c, _mm_add_epi16(p7, p3)), p2);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_op[2 * 16 + i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
+      f_lo = filter_add2_sub2(f_lo, q7_lo, q1_lo, p6_lo, q0_lo);
+      f_hi = filter_add2_sub2(f_hi, q7_hi, q1_hi, p6_hi, q0_hi);
+      oq1 = filter16_mask(flat2, oq1, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s + 1 * p), oq1);
 
-        b = _mm_add_epi16(q3, b);
-        b = _mm_add_epi16(_mm_sub_epi16(b, _mm_add_epi16(p1, q1)), q2);
-        _mm_storel_epi64((__m128i *)&flat_oq[2 * 16 + i * 8],
-                         _mm_packus_epi16(_mm_srli_epi16(_mm_add_epi16(a, b), 3)
-                                          , b));
-        a = _mm_add_epi16(q5, a);
-        c = _mm_add_epi16(_mm_sub_epi16(c, _mm_add_epi16(p7, p2)), p1);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_op[16 + i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
+      f_lo = filter_add2_sub2(f_lo, q7_lo, q2_lo, p5_lo, q1_lo);
+      f_hi = filter_add2_sub2(f_hi, q7_hi, q2_hi, p5_hi, q1_hi);
+      oq2 = filter16_mask(flat2, oq2, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s + 2 * p), oq2);
 
-        a = _mm_add_epi16(q6, a);
-        c = _mm_add_epi16(_mm_sub_epi16(c, _mm_add_epi16(p7, p1)), p0);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_op[i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
+      f_lo = filter_add2_sub2(f_lo, q7_lo, q3_lo, p4_lo, q2_lo);
+      f_hi = filter_add2_sub2(f_hi, q7_hi, q3_hi, p4_hi, q2_hi);
+      q3 = filter16_mask(flat2, q3, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s + 3 * p), q3);
 
-        a = _mm_add_epi16(q7, a);
-        c = _mm_add_epi16(_mm_sub_epi16(c, _mm_add_epi16(p7, p0)), q0);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_oq[i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
+      f_lo = filter_add2_sub2(f_lo, q7_lo, q4_lo, p3_lo, q3_lo);
+      f_hi = filter_add2_sub2(f_hi, q7_hi, q4_hi, p3_hi, q3_hi);
+      q4 = filter16_mask(flat2, q4, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s + 4 * p), q4);
 
-        a = _mm_add_epi16(q7, a);
-        c = _mm_add_epi16(_mm_sub_epi16(c, _mm_add_epi16(p6, q0)), q1);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_oq[16 + i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
+      f_lo = filter_add2_sub2(f_lo, q7_lo, q5_lo, p2_lo, q4_lo);
+      f_hi = filter_add2_sub2(f_hi, q7_hi, q5_hi, p2_hi, q4_hi);
+      q5 = filter16_mask(flat2, q5, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s + 5 * p), q5);
 
-        a = _mm_add_epi16(q7, a);
-        c = _mm_add_epi16(_mm_sub_epi16(c, _mm_add_epi16(p5, q1)), q2);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_oq[2 * 16 + i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
-
-        a = _mm_add_epi16(q7, a);
-        c = _mm_add_epi16(_mm_sub_epi16(c, _mm_add_epi16(p4, q2)), q3);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_oq[3 * 16 + i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
-
-        a = _mm_add_epi16(q7, a);
-        c = _mm_add_epi16(_mm_sub_epi16(c, _mm_add_epi16(p3, q3)), q4);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_oq[4 * 16 + i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
-
-        a = _mm_add_epi16(q7, a);
-        c = _mm_add_epi16(_mm_sub_epi16(c, _mm_add_epi16(p2, q4)), q5);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_oq[5 * 16 + i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
-
-        a = _mm_add_epi16(q7, a);
-        c = _mm_add_epi16(_mm_sub_epi16(c, _mm_add_epi16(p1, q5)), q6);
-        workp_shft = _mm_srli_epi16(_mm_add_epi16(a, c), 4);
-        _mm_storel_epi64((__m128i *)&flat2_oq[6 * 16 + i * 8],
-                         _mm_packus_epi16(workp_shft, workp_shft));
-
-        temp_flat2 = _mm_srli_si128(temp_flat2, 8);
-        src += 8;
-      } while (++i < 2);
+      f_lo = filter_add2_sub2(f_lo, q7_lo, q6_lo, p1_lo, q5_lo);
+      f_hi = filter_add2_sub2(f_hi, q7_hi, q6_hi, p1_hi, q5_hi);
+      q6 = filter16_mask(flat2, q6, f_lo, f_hi);
+      _mm_storeu_si128((__m128i *)(s + 6 * p), q6);
     }
     // wide flat
     // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-    work_a = _mm_load_si128((__m128i *)&ap[2 * 16]);
-    p2 = _mm_load_si128((__m128i *)&flat_op[2 * 16]);
-    work_a = _mm_andnot_si128(flat, work_a);
-    p2 = _mm_and_si128(flat, p2);
-    p2 = _mm_or_si128(work_a, p2);
-    _mm_store_si128((__m128i *)&flat_op[2 * 16], p2);
-
-    p1 = _mm_load_si128((__m128i *)&flat_op[1 * 16]);
-    work_a = _mm_andnot_si128(flat, ps1);
-    p1 = _mm_and_si128(flat, p1);
-    p1 = _mm_or_si128(work_a, p1);
-    _mm_store_si128((__m128i *)&flat_op[1 * 16], p1);
-
-    p0 = _mm_load_si128((__m128i *)&flat_op[0]);
-    work_a = _mm_andnot_si128(flat, ps0);
-    p0 = _mm_and_si128(flat, p0);
-    p0 = _mm_or_si128(work_a, p0);
-    _mm_store_si128((__m128i *)&flat_op[0], p0);
-
-    q0 = _mm_load_si128((__m128i *)&flat_oq[0]);
-    work_a = _mm_andnot_si128(flat, qs0);
-    q0 = _mm_and_si128(flat, q0);
-    q0 = _mm_or_si128(work_a, q0);
-    _mm_store_si128((__m128i *)&flat_oq[0], q0);
-
-    q1 = _mm_load_si128((__m128i *)&flat_oq[1 * 16]);
-    work_a = _mm_andnot_si128(flat, qs1);
-    q1 = _mm_and_si128(flat, q1);
-    q1 = _mm_or_si128(work_a, q1);
-    _mm_store_si128((__m128i *)&flat_oq[1 * 16], q1);
-
-    work_a = _mm_load_si128((__m128i *)&aq[2 * 16]);
-    q2 = _mm_load_si128((__m128i *)&flat_oq[2 * 16]);
-    work_a = _mm_andnot_si128(flat, work_a);
-    q2 = _mm_and_si128(flat, q2);
-    q2 = _mm_or_si128(work_a, q2);
-    _mm_store_si128((__m128i *)&flat_oq[2 * 16], q2);
-
-    // write out op6 - op3
-    {
-      unsigned char *dst = (s - 7 * p);
-      for (i = 6; i > 2; i--) {
-        __m128i flat2_output;
-        work_a = _mm_load_si128((__m128i *)&ap[i * 16]);
-        flat2_output = _mm_load_si128((__m128i *)&flat2_op[i * 16]);
-        work_a = _mm_andnot_si128(flat2, work_a);
-        flat2_output = _mm_and_si128(flat2, flat2_output);
-        work_a = _mm_or_si128(work_a, flat2_output);
-        _mm_storeu_si128((__m128i *)dst, work_a);
-        dst += p;
-      }
-    }
-
-    work_a = _mm_load_si128((__m128i *)&flat_op[2 * 16]);
-    p2 = _mm_load_si128((__m128i *)&flat2_op[2 * 16]);
-    work_a = _mm_andnot_si128(flat2, work_a);
-    p2 = _mm_and_si128(flat2, p2);
-    p2 = _mm_or_si128(work_a, p2);
-    _mm_storeu_si128((__m128i *)(s - 3 * p), p2);
-
-    work_a = _mm_load_si128((__m128i *)&flat_op[1 * 16]);
-    p1 = _mm_load_si128((__m128i *)&flat2_op[1 * 16]);
-    work_a = _mm_andnot_si128(flat2, work_a);
-    p1 = _mm_and_si128(flat2, p1);
-    p1 = _mm_or_si128(work_a, p1);
-    _mm_storeu_si128((__m128i *)(s - 2 * p), p1);
-
-    work_a = _mm_load_si128((__m128i *)&flat_op[0]);
-    p0 = _mm_load_si128((__m128i *)&flat2_op[0]);
-    work_a = _mm_andnot_si128(flat2, work_a);
-    p0 = _mm_and_si128(flat2, p0);
-    p0 = _mm_or_si128(work_a, p0);
-    _mm_storeu_si128((__m128i *)(s - 1 * p), p0);
-
-    work_a = _mm_load_si128((__m128i *)&flat_oq[0]);
-    q0 = _mm_load_si128((__m128i *)&flat2_oq[0]);
-    work_a = _mm_andnot_si128(flat2, work_a);
-    q0 = _mm_and_si128(flat2, q0);
-    q0 = _mm_or_si128(work_a, q0);
-    _mm_storeu_si128((__m128i *)(s - 0 * p), q0);
-
-    work_a = _mm_load_si128((__m128i *)&flat_oq[1 * 16]);
-    q1 = _mm_load_si128((__m128i *)&flat2_oq[16]);
-    work_a = _mm_andnot_si128(flat2, work_a);
-    q1 = _mm_and_si128(flat2, q1);
-    q1 = _mm_or_si128(work_a, q1);
-    _mm_storeu_si128((__m128i *)(s + 1 * p), q1);
-
-    work_a = _mm_load_si128((__m128i *)&flat_oq[2 * 16]);
-    q2 = _mm_load_si128((__m128i *)&flat2_oq[2 * 16]);
-    work_a = _mm_andnot_si128(flat2, work_a);
-    q2 = _mm_and_si128(flat2, q2);
-    q2 = _mm_or_si128(work_a, q2);
-    _mm_storeu_si128((__m128i *)(s + 2 * p), q2);
-
-    // write out oq3 - oq7
-    {
-      unsigned char *dst = (s + 3 * p);
-      for (i = 3; i < 7; i++) {
-        __m128i flat2_output;
-        work_a = _mm_load_si128((__m128i *)&aq[i * 16]);
-        flat2_output = _mm_load_si128((__m128i *)&flat2_oq[i * 16]);
-        work_a = _mm_andnot_si128(flat2, work_a);
-        flat2_output = _mm_and_si128(flat2, flat2_output);
-        work_a = _mm_or_si128(work_a, flat2_output);
-        _mm_storeu_si128((__m128i *)dst, work_a);
-        dst += p;
-      }
-    }
   }
 }
 
@@ -893,14 +755,11 @@
     const __m128i fe = _mm_set1_epi8(0xfe);
     const __m128i ff = _mm_cmpeq_epi8(fe, fe);
     __m128i abs_p1q1, abs_p0q0, abs_q1q0, abs_p1p0, work;
-    abs_p1p0 = _mm_or_si128(_mm_subs_epu8(q1p1, q0p0),
-                            _mm_subs_epu8(q0p0, q1p1));
+    abs_p1p0 = abs_diff(q1p1, q0p0);
     abs_q1q0 =  _mm_srli_si128(abs_p1p0, 8);
 
-    abs_p0q0 = _mm_or_si128(_mm_subs_epu8(q0p0, p0q0),
-                            _mm_subs_epu8(p0q0, q0p0));
-    abs_p1q1 = _mm_or_si128(_mm_subs_epu8(q1p1, p1q1),
-                            _mm_subs_epu8(p1q1, q1p1));
+    abs_p0q0 = abs_diff(q0p0, p0q0);
+    abs_p1q1 = abs_diff(q1p1, p1q1);
     flat = _mm_max_epu8(abs_p1p0, abs_q1q0);
     hev = _mm_subs_epu8(flat, thresh);
     hev = _mm_xor_si128(_mm_cmpeq_epi8(hev, zero), ff);
@@ -914,10 +773,8 @@
     // mask |= (abs(p1 - p0) > limit) * -1;
     // mask |= (abs(q1 - q0) > limit) * -1;
 
-    work = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(q2p2, q1p1),
-                                     _mm_subs_epu8(q1p1, q2p2)),
-                        _mm_or_si128(_mm_subs_epu8(q3p3, q2p2),
-                                     _mm_subs_epu8(q2p2, q3p3)));
+    work = _mm_max_epu8(abs_diff(q2p2, q1p1),
+                        abs_diff(q3p3, q2p2));
     mask = _mm_max_epu8(work, mask);
     mask = _mm_max_epu8(mask, _mm_srli_si128(mask, 8));
     mask = _mm_subs_epu8(mask, limit);
@@ -925,10 +782,8 @@
 
     // flat_mask4
 
-    flat = _mm_max_epu8(_mm_or_si128(_mm_subs_epu8(q2p2, q0p0),
-                                     _mm_subs_epu8(q0p0, q2p2)),
-                        _mm_or_si128(_mm_subs_epu8(q3p3, q0p0),
-                                     _mm_subs_epu8(q0p0, q3p3)));
+    flat = _mm_max_epu8(abs_diff(q2p2, q0p0),
+                        abs_diff(q3p3, q0p0));
     flat = _mm_max_epu8(abs_p1p0, flat);
     flat = _mm_max_epu8(flat, _mm_srli_si128(flat, 8));
     flat = _mm_subs_epu8(flat, one);
diff --git a/vp9/encoder/vp9_firstpass.c b/vp9/encoder/vp9_firstpass.c
index df82be5..e9b5aa2 100644
--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -35,26 +35,28 @@
 #include "vp9/encoder/vp9_rd.h"
 #include "vp9/encoder/vp9_variance.h"
 
-#define OUTPUT_FPF 0
+#define OUTPUT_FPF          0
+#define ARF_STATS_OUTPUT    0
 
-#define IIFACTOR   12.5
-#define IIKFACTOR1 12.5
-#define IIKFACTOR2 15.0
-#define RMAX       512.0
-#define GF_RMAX    96.0
-#define ERR_DIVISOR   150.0
-#define MIN_DECAY_FACTOR 0.1
-#define SVC_FACTOR_PT_LOW 0.45
-#define FACTOR_PT_LOW 0.5
-#define FACTOR_PT_HIGH 0.9
-
-#define KF_MB_INTRA_MIN 150
-#define GF_MB_INTRA_MIN 100
+#define BOOST_FACTOR        12.5
+#define ERR_DIVISOR         100.0
+#define FACTOR_PT_LOW       0.5
+#define FACTOR_PT_HIGH      0.9
+#define FIRST_PASS_Q        10.0
+#define GF_MAX_BOOST        96.0
+#define INTRA_MODE_PENALTY  1024
+#define KF_MAX_BOOST        128.0
+#define MIN_DECAY_FACTOR    0.01
+#define MIN_GF_INTERVAL     4
+#define MIN_KF_BOOST        300
+#define NEW_MV_MODE_PENALTY 32
+#define SVC_FACTOR_PT_LOW   0.45
 
 #define DOUBLE_DIVIDE_CHECK(x) ((x) < 0 ? (x) - 0.000001 : (x) + 0.000001)
 
-#define MIN_KF_BOOST        300
-#define MIN_GF_INTERVAL     4
+#if ARF_STATS_OUTPUT
+unsigned int arf_count = 0;
+#endif
 
 static void swap_yv12(YV12_BUFFER_CONFIG *a, YV12_BUFFER_CONFIG *b) {
   YV12_BUFFER_CONFIG temp = *a;
@@ -299,7 +301,7 @@
   int num00, tmp_err, n;
   const BLOCK_SIZE bsize = xd->mi[0]->mbmi.sb_type;
   vp9_variance_fn_ptr_t v_fn_ptr = cpi->fn_ptr[bsize];
-  const int new_mv_mode_penalty = 256;
+  const int new_mv_mode_penalty = NEW_MV_MODE_PENALTY;
 
   int step_param = 3;
   int further_steps = (MAX_MVSEARCH_STEPS - 1) - step_param;
@@ -364,7 +366,7 @@
   int i;
 
   for (i = 0; i < QINDEX_RANGE; ++i)
-    if (vp9_convert_qindex_to_q(i, bit_depth) >= 30.0)
+    if (vp9_convert_qindex_to_q(i, bit_depth) >= FIRST_PASS_Q)
       break;
 
   if (i == QINDEX_RANGE)
@@ -414,7 +416,7 @@
   int mvcount = 0;
   int intercount = 0;
   int second_ref_count = 0;
-  int intrapenalty = 256;
+  const int intrapenalty = INTRA_MODE_PENALTY;
   int neutral_count = 0;
   int new_mv_count = 0;
   int sum_in_vectors = 0;
@@ -830,12 +832,18 @@
   vp9_clear_system_state();
   {
     FIRSTPASS_STATS fps;
+    // The minimum error here insures some bit alocation to frames even
+    // in static regions. The allocation per MB declines for larger formats
+    // where the typical "real" energy per MB also falls.
+    // Initial estimate here uses sqrt(mbs) to define the min_err, where the
+    // number of mbs is propotional to image area.
+    const double min_err = 200 * sqrt(cm->MBs);
 
     fps.frame = cm->current_video_frame;
     fps.spatial_layer_id = cpi->svc.spatial_layer_id;
-    fps.intra_error = (double)(intra_error >> 8);
-    fps.coded_error = (double)(coded_error >> 8);
-    fps.sr_coded_error = (double)(sr_coded_error >> 8);
+    fps.coded_error = (double)(coded_error >> 8) + min_err;
+    fps.sr_coded_error = (double)(sr_coded_error >> 8) + min_err;
+    fps.intra_error = (double)(intra_error >> 8) + min_err;
     fps.count = 1.0;
     fps.pcnt_inter = (double)intercount / cm->MBs;
     fps.pcnt_second_ref = (double)second_ref_count / cm->MBs;
@@ -1033,17 +1041,6 @@
                              10000000.0);
   }
 
-  // Calculate a minimum intra value to be used in determining the IIratio
-  // scores used in the second pass. We have this minimum to make sure
-  // that clips that are static but "low complexity" in the intra domain
-  // are still boosted appropriately for KF/GF/ARF.
-  if (!is_two_pass_svc) {
-    // We don't know the number of MBs for each layer at this point.
-    // So we will do it later.
-    twopass->kf_intra_err_min = KF_MB_INTRA_MIN * cpi->common.MBs;
-    twopass->gf_intra_err_min = GF_MB_INTRA_MIN * cpi->common.MBs;
-  }
-
   // This variable monitors how far behind the second ref update is lagging.
   twopass->sr_update_lag = 1;
 
@@ -1067,34 +1064,58 @@
 
   // Reset the vbr bits off target counter
   cpi->rc.vbr_bits_off_target = 0;
+
+  // Static sequence monitor variables.
+  twopass->kf_zeromotion_pct = 100;
+  twopass->last_kfgroup_zeromotion_pct = 100;
+}
+
+#define SR_DIFF_PART 0.0015
+#define MOTION_AMP_PART 0.003
+#define INTRA_PART 0.005
+#define DEFAULT_DECAY_LIMIT 0.75
+#define LOW_SR_DIFF_TRHESH 0.1
+#define SR_DIFF_MAX 128.0
+
+static double get_sr_decay_rate(const VP9_COMMON *cm,
+                                const FIRSTPASS_STATS *frame) {
+  double sr_diff = (frame->sr_coded_error - frame->coded_error) / cm->MBs;
+  double sr_decay = 1.0;
+  const double motion_amplitude_factor =
+    frame->pcnt_motion * ((frame->mvc_abs + frame->mvr_abs) / 2);
+  const double pcnt_intra = 100 * (1.0 - frame->pcnt_inter);
+
+  if ((sr_diff > LOW_SR_DIFF_TRHESH)) {
+    sr_diff = MIN(sr_diff, SR_DIFF_MAX);
+    sr_decay = 1.0 - (SR_DIFF_PART * sr_diff) -
+               (MOTION_AMP_PART * motion_amplitude_factor) -
+               (INTRA_PART * pcnt_intra);
+  }
+  return MAX(sr_decay, MIN(DEFAULT_DECAY_LIMIT, frame->pcnt_inter));
 }
 
 // This function gives an estimate of how badly we believe the prediction
 // quality is decaying from frame to frame.
-static double get_prediction_decay_rate(const VP9_COMMON *cm,
-                                        const FIRSTPASS_STATS *next_frame) {
-  // Look at the observed drop in prediction quality between the last frame
-  // and the GF buffer (which contains an older frame).
-  const double mb_sr_err_diff = (next_frame->sr_coded_error -
-                                     next_frame->coded_error) / cm->MBs;
-  const double second_ref_decay = mb_sr_err_diff <= 512.0
-      ? fclamp(pow(1.0 - (mb_sr_err_diff / 512.0), 0.5), 0.85, 1.0)
-      : 0.85;
-
-  return MIN(second_ref_decay, next_frame->pcnt_inter);
-}
-
-// This function gives an estimate of how badly we believe the prediction
-// quality is decaying from frame to frame.
-static double get_zero_motion_factor(const FIRSTPASS_STATS *frame) {
-  const double sr_ratio = frame->coded_error /
-                          DOUBLE_DIVIDE_CHECK(frame->sr_coded_error);
+static double get_zero_motion_factor(const VP9_COMMON *cm,
+                                     const FIRSTPASS_STATS *frame) {
   const double zero_motion_pct = frame->pcnt_inter -
                                  frame->pcnt_motion;
-
-  return MIN(sr_ratio, zero_motion_pct);
+  double sr_decay = get_sr_decay_rate(cm, frame);
+  return MIN(sr_decay, zero_motion_pct);
 }
 
+#define ZM_POWER_FACTOR 0.75
+
+static double get_prediction_decay_rate(const VP9_COMMON *cm,
+                                        const FIRSTPASS_STATS *next_frame) {
+  const double sr_decay_rate = get_sr_decay_rate(cm, next_frame);
+  const double zero_motion_factor =
+    (0.95 * pow((next_frame->pcnt_inter - next_frame->pcnt_motion),
+                ZM_POWER_FACTOR));
+
+  return MAX(zero_motion_factor,
+             (sr_decay_rate + ((1.0 - sr_decay_rate) * zero_motion_factor)));
+}
 
 // Function to test for a condition where a complex transition is followed
 // by a static section. For example in slide shows where there is a fade
@@ -1172,19 +1193,17 @@
   }
 }
 
-// Calculate a baseline boost number for the current frame.
-static double calc_frame_boost(const TWO_PASS *twopass,
+#define BASELINE_ERR_PER_MB 1000.0
+static double calc_frame_boost(VP9_COMP *cpi,
                                const FIRSTPASS_STATS *this_frame,
-                               double this_frame_mv_in_out) {
+                               double this_frame_mv_in_out,
+                               double max_boost) {
   double frame_boost;
 
-  // Underlying boost factor is based on inter intra error ratio.
-  if (this_frame->intra_error > twopass->gf_intra_err_min)
-    frame_boost = (IIFACTOR * this_frame->intra_error /
-                   DOUBLE_DIVIDE_CHECK(this_frame->coded_error));
-  else
-    frame_boost = (IIFACTOR * twopass->gf_intra_err_min /
-                   DOUBLE_DIVIDE_CHECK(this_frame->coded_error));
+  // Underlying boost factor is based on inter error ratio.
+  frame_boost = (BASELINE_ERR_PER_MB * cpi->common.MBs) /
+                DOUBLE_DIVIDE_CHECK(this_frame->coded_error);
+  frame_boost = frame_boost * BOOST_FACTOR;
 
   // Increase boost for frames where new data coming into frame (e.g. zoom out).
   // Slightly reduce boost if there is a net balance of motion out of the frame
@@ -1195,7 +1214,7 @@
   else
     frame_boost += frame_boost * (this_frame_mv_in_out / 2.0);
 
-  return MIN(frame_boost, GF_RMAX);
+  return MIN(frame_boost, max_boost);
 }
 
 static int calc_arf_boost(VP9_COMP *cpi, int offset,
@@ -1236,8 +1255,9 @@
                           ? MIN_DECAY_FACTOR : decay_accumulator;
     }
 
-    boost_score += decay_accumulator * calc_frame_boost(twopass, this_frame,
-                                                        this_frame_mv_in_out);
+    boost_score += decay_accumulator * calc_frame_boost(cpi, this_frame,
+                                                        this_frame_mv_in_out,
+                                                        GF_MAX_BOOST);
   }
 
   *f_boost = (int)boost_score;
@@ -1274,8 +1294,9 @@
                               ? MIN_DECAY_FACTOR : decay_accumulator;
     }
 
-    boost_score += decay_accumulator * calc_frame_boost(twopass, this_frame,
-                                                        this_frame_mv_in_out);
+    boost_score += decay_accumulator * calc_frame_boost(cpi, this_frame,
+                                                        this_frame_mv_in_out,
+                                                        GF_MAX_BOOST);
   }
   *b_boost = (int)boost_score;
 
@@ -1585,7 +1606,7 @@
     gf_group_err -= gf_first_frame_err;
 
   // Motion breakout threshold for loop below depends on image size.
-  mv_ratio_accumulator_thresh = (cpi->common.width + cpi->common.height) / 10.0;
+  mv_ratio_accumulator_thresh = (cpi->common.width + cpi->common.height) / 4.0;
 
   // Work out a maximum interval for the GF group.
   // If the image appears almost completely static we can extend beyond this.
@@ -1629,11 +1650,13 @@
     if (!flash_detected) {
       last_loop_decay_rate = loop_decay_rate;
       loop_decay_rate = get_prediction_decay_rate(&cpi->common, &next_frame);
+
       decay_accumulator = decay_accumulator * loop_decay_rate;
 
       // Monitor for static sections.
-      zero_motion_accumulator = MIN(zero_motion_accumulator,
-                                    get_zero_motion_factor(&next_frame));
+      zero_motion_accumulator =
+        MIN(zero_motion_accumulator,
+            get_zero_motion_factor(&cpi->common, &next_frame));
 
       // Break clause to detect very still sections after motion. For example,
       // a static image after a fade or other transition.
@@ -1645,8 +1668,9 @@
     }
 
     // Calculate a boost number for this frame.
-    boost_score += decay_accumulator * calc_frame_boost(twopass, &next_frame,
-                                                        this_frame_mv_in_out);
+    boost_score += decay_accumulator * calc_frame_boost(cpi, &next_frame,
+                                                        this_frame_mv_in_out,
+                                                        GF_MAX_BOOST);
 
     // Break out conditions.
     if (
@@ -1655,38 +1679,21 @@
       (
         // Don't break out with a very short interval.
         (i > MIN_GF_INTERVAL) &&
-        ((boost_score > 125.0) || (next_frame.pcnt_inter < 0.75)) &&
         (!flash_detected) &&
         ((mv_ratio_accumulator > mv_ratio_accumulator_thresh) ||
          (abs_mv_in_out_accumulator > 3.0) ||
          (mv_in_out_accumulator < -2.0) ||
-         ((boost_score - old_boost_score) < IIFACTOR)))) {
+         ((boost_score - old_boost_score) < BOOST_FACTOR)))) {
       boost_score = old_boost_score;
       break;
     }
 
     *this_frame = next_frame;
-
     old_boost_score = boost_score;
   }
 
   twopass->gf_zeromotion_pct = (int)(zero_motion_accumulator * 1000.0);
 
-  // Don't allow a gf too near the next kf.
-  if ((rc->frames_to_key - i) < MIN_GF_INTERVAL) {
-    while (i < (rc->frames_to_key + !rc->next_key_frame_forced)) {
-      ++i;
-
-      if (EOF == input_stats(twopass, this_frame))
-        break;
-
-      if (i < rc->frames_to_key) {
-        mod_frame_err = calculate_modified_err(twopass, oxcf, this_frame);
-        gf_group_err += mod_frame_err;
-      }
-    }
-  }
-
   // Set the interval until the next gf.
   if (cpi->common.frame_type == KEY_FRAME || rc->source_alt_ref_active)
     rc->baseline_gf_interval = i - 1;
@@ -1713,10 +1720,7 @@
   // Should we use the alternate reference frame.
   if (allow_alt_ref &&
       (i < cpi->oxcf.lag_in_frames) &&
-      (i >= MIN_GF_INTERVAL) &&
-      // For real scene cuts (not forced kfs) don't allow arf very near kf.
-      (rc->next_key_frame_forced ||
-      (i <= (rc->frames_to_key - MIN_GF_INTERVAL)))) {
+      (i >= MIN_GF_INTERVAL)) {
     // Calculate the boost for alt ref.
     rc->gfu_boost = calc_arf_boost(cpi, 0, (i - 1), (i - 1), &f_boost,
                                    &b_boost);
@@ -1727,7 +1731,7 @@
       (cpi->multi_arf_allowed && (rc->baseline_gf_interval >= 6) &&
       (zero_motion_accumulator < 0.995)) ? 1 : 0;
   } else {
-    rc->gfu_boost = (int)boost_score;
+    rc->gfu_boost = MAX((int)boost_score, 125);
     rc->source_alt_ref_pending = 0;
   }
 
@@ -1782,6 +1786,9 @@
   }
 }
 
+// TODO(PGW) Re-examine the use of II ration in this code in the light of#
+// changes elsewhere
+#define KF_II_MAX 128.0
 static int test_candidate_kf(TWO_PASS *twopass,
                              const FIRSTPASS_STATS *last_frame,
                              const FIRSTPASS_STATS *this_frame,
@@ -1811,11 +1818,11 @@
 
     // Examine how well the key frame predicts subsequent frames.
     for (i = 0; i < 16; ++i) {
-      double next_iiratio = (IIKFACTOR1 * local_next_frame.intra_error /
+      double next_iiratio = (BOOST_FACTOR * local_next_frame.intra_error /
                              DOUBLE_DIVIDE_CHECK(local_next_frame.coded_error));
 
-      if (next_iiratio > RMAX)
-        next_iiratio = RMAX;
+      if (next_iiratio > KF_II_MAX)
+        next_iiratio = KF_II_MAX;
 
       // Cumulative effect of decay in prediction quality.
       if (local_next_frame.pcnt_inter > 0.85)
@@ -1870,7 +1877,9 @@
   FIRSTPASS_STATS next_frame;
   FIRSTPASS_STATS last_frame;
   int kf_bits = 0;
+  int loop_decay_counter = 0;
   double decay_accumulator = 1.0;
+  double av_decay_accumulator = 0.0;
   double zero_motion_accumulator = 1.0;
   double boost_score = 0.0;
   double kf_mod_err = 0.0;
@@ -2024,42 +2033,38 @@
   // Reset the first pass file position.
   reset_fpf_position(twopass, start_position);
 
-  // Scan through the kf group collating various stats used to deteermine
+  // Scan through the kf group collating various stats used to determine
   // how many bits to spend on it.
   decay_accumulator = 1.0;
   boost_score = 0.0;
-  for (i = 0; i < rc->frames_to_key; ++i) {
+  for (i = 0; i < (rc->frames_to_key - 1); ++i) {
     if (EOF == input_stats(twopass, &next_frame))
       break;
 
     // Monitor for static sections.
-    zero_motion_accumulator =MIN(zero_motion_accumulator,
-                                 get_zero_motion_factor(&next_frame));
+    zero_motion_accumulator =
+      MIN(zero_motion_accumulator,
+          get_zero_motion_factor(&cpi->common, &next_frame));
 
-    // For the first few frames collect data to decide kf boost.
-    if (i <= (rc->max_gf_interval * 2)) {
-      double r;
-      if (next_frame.intra_error > twopass->kf_intra_err_min)
-        r = (IIKFACTOR2 * next_frame.intra_error /
-             DOUBLE_DIVIDE_CHECK(next_frame.coded_error));
-      else
-        r = (IIKFACTOR2 * twopass->kf_intra_err_min /
-             DOUBLE_DIVIDE_CHECK(next_frame.coded_error));
-
-      if (r > RMAX)
-        r = RMAX;
+    // Not all frames in the group are necessarily used in calculating boost.
+    if ((i <= rc->max_gf_interval) ||
+        ((i <= (rc->max_gf_interval * 4)) && (decay_accumulator > 0.5))) {
+      const double frame_boost =
+        calc_frame_boost(cpi, this_frame, 0, KF_MAX_BOOST);
 
       // How fast is prediction quality decaying.
       if (!detect_flash(twopass, 0)) {
-        const double loop_decay_rate = get_prediction_decay_rate(&cpi->common,
-                                                                 &next_frame);
+        const double loop_decay_rate =
+          get_prediction_decay_rate(&cpi->common, &next_frame);
         decay_accumulator *= loop_decay_rate;
         decay_accumulator = MAX(decay_accumulator, MIN_DECAY_FACTOR);
+        av_decay_accumulator += decay_accumulator;
+        ++loop_decay_counter;
       }
-
-      boost_score += (decay_accumulator * r);
+      boost_score += (decay_accumulator * frame_boost);
     }
   }
+  av_decay_accumulator /= (double)loop_decay_counter;
 
   reset_fpf_position(twopass, start_position);
 
@@ -2071,14 +2076,12 @@
       calculate_section_intra_ratio(start_position, twopass->stats_in_end,
                                     rc->frames_to_key);
 
+  // Apply various clamps for min and max boost
+  rc->kf_boost = (int)(av_decay_accumulator * boost_score);
+  rc->kf_boost = MAX(rc->kf_boost, (rc->frames_to_key * 3));
+  rc->kf_boost = MAX(rc->kf_boost, MIN_KF_BOOST);
+
   // Work out how many bits to allocate for the key frame itself.
-  rc->kf_boost = (int)boost_score;
-
-  if (rc->kf_boost  < (rc->frames_to_key * 3))
-    rc->kf_boost  = (rc->frames_to_key * 3);
-  if (rc->kf_boost   < MIN_KF_BOOST)
-    rc->kf_boost = MIN_KF_BOOST;
-
   kf_bits = calculate_boost_bits((rc->frames_to_key - 1),
                                   rc->kf_boost, twopass->kf_group_bits);
 
@@ -2216,11 +2219,6 @@
 
   vp9_clear_system_state();
 
-  if (lc != NULL && twopass->kf_intra_err_min == 0) {
-    twopass->kf_intra_err_min = KF_MB_INTRA_MIN * cpi->common.MBs;
-    twopass->gf_intra_err_min = GF_MB_INTRA_MIN * cpi->common.MBs;
-  }
-
   if (cpi->oxcf.rc_mode == VPX_Q) {
     twopass->active_worst_quality = cpi->oxcf.cq_level;
   } else if (cm->current_video_frame == 0 ||
@@ -2286,6 +2284,18 @@
     rc->frames_till_gf_update_due = rc->baseline_gf_interval;
     if (lc != NULL)
       cpi->refresh_golden_frame = 1;
+
+#if ARF_STATS_OUTPUT
+    {
+      FILE *fpfile;
+      fpfile = fopen("arf.stt", "a");
+      ++arf_count;
+      fprintf(fpfile, "%10d %10d %10d %10ld\n",
+              cm->current_video_frame, rc->kf_boost, arf_count, rc->gfu_boost);
+
+      fclose(fpfile);
+    }
+#endif
   }
 
   configure_buffer_updates(cpi);
@@ -2325,6 +2335,7 @@
   if (cpi->common.frame_type != KEY_FRAME &&
       !vp9_is_upper_layer_key_frame(cpi)) {
     twopass->kf_group_bits -= bits_used;
+    twopass->last_kfgroup_zeromotion_pct = twopass->kf_zeromotion_pct;
   }
   twopass->kf_group_bits = MAX(twopass->kf_group_bits, 0);
 
diff --git a/vp9/encoder/vp9_firstpass.h b/vp9/encoder/vp9_firstpass.h
index aaa6b03..0b82d32 100644
--- a/vp9/encoder/vp9_firstpass.h
+++ b/vp9/encoder/vp9_firstpass.h
@@ -93,8 +93,6 @@
   double modified_error_min;
   double modified_error_max;
   double modified_error_left;
-  double kf_intra_err_min;
-  double gf_intra_err_min;
 
 #if CONFIG_FP_MB_STATS
   uint8_t *frame_mb_stats_buf;
@@ -110,6 +108,7 @@
   int sr_update_lag;
 
   int kf_zeromotion_pct;
+  int last_kfgroup_zeromotion_pct;
   int gf_zeromotion_pct;
 
   int active_worst_quality;
diff --git a/vp9/encoder/vp9_ratectrl.c b/vp9/encoder/vp9_ratectrl.c
index 94c0b64..9b6c773 100644
--- a/vp9/encoder/vp9_ratectrl.c
+++ b/vp9/encoder/vp9_ratectrl.c
@@ -126,10 +126,10 @@
   int i;
   for (i = 0; i < QINDEX_RANGE; i++) {
     const double maxq = vp9_convert_qindex_to_q(i, bit_depth);
-    kf_low_m[i] = get_minq_index(maxq, 0.000001, -0.0004, 0.125, bit_depth);
-    kf_high_m[i] = get_minq_index(maxq, 0.000002, -0.0012, 0.50, bit_depth);
+    kf_low_m[i] = get_minq_index(maxq, 0.000001, -0.0004, 0.150, bit_depth);
+    kf_high_m[i] = get_minq_index(maxq, 0.0000021, -0.00125, 0.55, bit_depth);
     arfgf_low[i] = get_minq_index(maxq, 0.0000015, -0.0009, 0.30, bit_depth);
-    arfgf_high[i] = get_minq_index(maxq, 0.0000021, -0.00125, 0.50, bit_depth);
+    arfgf_high[i] = get_minq_index(maxq, 0.0000021, -0.00125, 0.55, bit_depth);
     inter[i] = get_minq_index(maxq, 0.00000271, -0.00113, 0.90, bit_depth);
     rtc[i] = get_minq_index(maxq, 0.00000271, -0.00113, 0.70, bit_depth);
   }
@@ -175,7 +175,7 @@
                        double correction_factor,
                        vpx_bit_depth_t bit_depth) {
   const double q = vp9_convert_qindex_to_q(qindex, bit_depth);
-  int enumerator = frame_type == KEY_FRAME ? 3300000 : 2250000;
+  int enumerator = frame_type == KEY_FRAME ? 2700000 : 1800000;
 
   // q based adjustment to baseline enumerator
   enumerator += (int)(enumerator * q) >> 12;
@@ -610,7 +610,7 @@
 
   if (frame_is_intra_only(cm)) {
     active_best_quality = rc->best_quality;
-    // Handle the special case for key frames forced when we have75 reached
+    // Handle the special case for key frames forced when we have reached
     // the maximum key frame interval. Here force the Q to a range
     // based on the ambient Q to reduce the risk of popping.
     if (rc->this_key_frame_forced) {
@@ -880,6 +880,7 @@
   return q;
 }
 
+#define STATIC_MOTION_THRESH 95
 static int rc_pick_q_and_bounds_two_pass(const VP9_COMP *cpi,
                                          int *bottom_index,
                                          int *top_index) {
@@ -894,16 +895,31 @@
   ASSIGN_MINQ_TABLE(cm->bit_depth, inter_minq);
 
   if (frame_is_intra_only(cm) || vp9_is_upper_layer_key_frame(cpi)) {
-    // Handle the special case for key frames forced when we have75 reached
+    // Handle the special case for key frames forced when we have reached
     // the maximum key frame interval. Here force the Q to a range
     // based on the ambient Q to reduce the risk of popping.
     if (rc->this_key_frame_forced) {
-      int qindex = rc->last_boosted_qindex;
-      double last_boosted_q = vp9_convert_qindex_to_q(qindex, cm->bit_depth);
-      int delta_qindex = vp9_compute_qdelta(rc, last_boosted_q,
-                                            last_boosted_q * 0.75,
-                                            cm->bit_depth);
-      active_best_quality = MAX(qindex + delta_qindex, rc->best_quality);
+      double last_boosted_q;
+      int delta_qindex;
+      int qindex;
+
+      if (cpi->twopass.last_kfgroup_zeromotion_pct >= STATIC_MOTION_THRESH) {
+        qindex = MIN(rc->last_kf_qindex, rc->last_boosted_qindex);
+        active_best_quality = qindex;
+        last_boosted_q = vp9_convert_qindex_to_q(qindex, cm->bit_depth);
+        delta_qindex = vp9_compute_qdelta(rc, last_boosted_q,
+                                              last_boosted_q * 1.25,
+                                              cm->bit_depth);
+        active_worst_quality = MIN(qindex + delta_qindex, active_worst_quality);
+
+      } else {
+        qindex = rc->last_boosted_qindex;
+        last_boosted_q = vp9_convert_qindex_to_q(qindex, cm->bit_depth);
+        delta_qindex = vp9_compute_qdelta(rc, last_boosted_q,
+                                              last_boosted_q * 0.75,
+                                              cm->bit_depth);
+        active_best_quality = MAX(qindex + delta_qindex, rc->best_quality);
+      }
     } else {
       // Not forced keyframe.
       double q_adj_factor = 1.0;
@@ -972,18 +988,12 @@
     }
   }
 
-  // Clip the active best and worst quality values to limits.
-  active_best_quality = clamp(active_best_quality,
-                              rc->best_quality, rc->worst_quality);
-  active_worst_quality = clamp(active_worst_quality,
-                               active_best_quality, rc->worst_quality);
-
-  *top_index = active_worst_quality;
-  *bottom_index = active_best_quality;
-
 #if LIMIT_QRANGE_FOR_ALTREF_AND_KEY
   vp9_clear_system_state();
-  {
+  // Static forced key frames Q restrictions dealt with elsewhere.
+  if (!((frame_is_intra_only(cm) || vp9_is_upper_layer_key_frame(cpi))) ||
+      !rc->this_key_frame_forced ||
+      (cpi->twopass.last_kfgroup_zeromotion_pct < STATIC_MOTION_THRESH)) {
     const GF_GROUP *const gf_group = &cpi->twopass.gf_group;
     const double rate_factor_deltas[RATE_FACTOR_LEVELS] = {
       1.00,  // INTER_NORMAL
@@ -997,27 +1007,43 @@
     int qdelta = vp9_compute_qdelta_by_rate(&cpi->rc, cm->frame_type,
                                             active_worst_quality, rate_factor,
                                             cm->bit_depth);
-    *top_index = active_worst_quality + qdelta;
-    *top_index = (*top_index > *bottom_index) ? *top_index : *bottom_index;
+    active_worst_quality = active_worst_quality + qdelta;
+    active_worst_quality = MAX(active_worst_quality, active_best_quality);
   }
 #endif
 
+  // Clip the active best and worst quality values to limits.
+  active_best_quality = clamp(active_best_quality,
+                              rc->best_quality, rc->worst_quality);
+  active_worst_quality = clamp(active_worst_quality,
+                               active_best_quality, rc->worst_quality);
+
   if (oxcf->rc_mode == VPX_Q) {
     q = active_best_quality;
   // Special case code to try and match quality with forced key frames.
-  } else if ((cm->frame_type == KEY_FRAME) && rc->this_key_frame_forced) {
-    q = rc->last_boosted_qindex;
+  } else if ((frame_is_intra_only(cm) || vp9_is_upper_layer_key_frame(cpi)) &&
+             rc->this_key_frame_forced) {
+    // If static since last kf use better of last boosted and last kf q.
+    if (cpi->twopass.last_kfgroup_zeromotion_pct >= STATIC_MOTION_THRESH) {
+      q = MIN(rc->last_kf_qindex, rc->last_boosted_qindex);
+    } else {
+      q = rc->last_boosted_qindex;
+    }
   } else {
     q = vp9_rc_regulate_q(cpi, rc->this_frame_target,
                           active_best_quality, active_worst_quality);
-    if (q > *top_index) {
+    if (q > active_worst_quality) {
       // Special case when we are targeting the max allowed rate.
       if (rc->this_frame_target >= rc->max_frame_bandwidth)
-        *top_index = q;
+        active_worst_quality = q;
       else
-        q = *top_index;
+        q = active_worst_quality;
     }
   }
+  clamp(q, active_best_quality, active_worst_quality);
+
+  *top_index = active_worst_quality;
+  *bottom_index = active_best_quality;
 
   assert(*top_index <= rc->worst_quality &&
          *top_index >= rc->best_quality);
@@ -1161,11 +1187,12 @@
   // better than that already stored.
   // This is used to help set quality in forced key frames to reduce popping
   if ((qindex < rc->last_boosted_qindex) ||
-      ((cpi->static_mb_pct < 100) &&
-       ((cm->frame_type == KEY_FRAME) || cpi->refresh_alt_ref_frame ||
+      (((cm->frame_type == KEY_FRAME) || cpi->refresh_alt_ref_frame ||
         (cpi->refresh_golden_frame && !rc->is_src_frame_alt_ref)))) {
     rc->last_boosted_qindex = qindex;
   }
+  if (cm->frame_type == KEY_FRAME)
+    rc->last_kf_qindex = qindex;
 
   update_buffer_level(cpi, rc->projected_frame_size);
 
diff --git a/vp9/encoder/vp9_ratectrl.h b/vp9/encoder/vp9_ratectrl.h
index 2ced8e6..edfb9fc 100644
--- a/vp9/encoder/vp9_ratectrl.h
+++ b/vp9/encoder/vp9_ratectrl.h
@@ -42,6 +42,7 @@
   int sb64_target_rate;
   int last_q[FRAME_TYPES];         // Separate values for Intra/Inter
   int last_boosted_qindex;         // Last boosted GF/KF/ARF q
+  int last_kf_qindex;              // Q index of the last key frame coded.
 
   int gfu_boost;
   int last_boost;