commit 5dfa9300840a481a3f35fb9ad50e2b4ac83a6dea
author Debargha Mukherjee <debargha@google.com> Fri Feb 10 05:00:08 2017 -0800
committer Debargha Mukherjee <debargha@google.com> Fri Feb 17 22:02:59 2017 +0000
tree ed9d390de58dafa106a495ee144cc6d7cc63f524
parent 15dbc1a1495f57840e608911814ab0fdddd4ced9

Support trapezoidal models for global motion

Adds functinoality for least-squares, RANSAC as well as encoding and
decoding with new constrained homographies that warp blocks to horizontal
and/or vertical trapezoids. This is for future experimentation. None
of the models are actually enabled in the code.

Change-Id: I1936018c6b11587d6fd83c3a2c63548cb641b33f

av1/encoder/bitstream.c

diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index 8331e8a..e454200 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -4495,10 +4495,16 @@
                   &global_motion_types_encodings[type]);
   switch (type) {
     case HOMOGRAPHY:
-      aom_write_primitive_symmetric(
-          w, (params->wmmat[6] >> GM_ROW3HOMO_PREC_DIFF), GM_ABS_ROW3HOMO_BITS);
-      aom_write_primitive_symmetric(
-          w, (params->wmmat[7] >> GM_ROW3HOMO_PREC_DIFF), GM_ABS_ROW3HOMO_BITS);
+    case HORTRAPEZOID:
+    case VERTRAPEZOID:
+      if (type != HORTRAPEZOID)
+        aom_write_primitive_symmetric(
+            w, (params->wmmat[6] >> GM_ROW3HOMO_PREC_DIFF),
+            GM_ABS_ROW3HOMO_BITS);
+      if (type != VERTRAPEZOID)
+        aom_write_primitive_symmetric(
+            w, (params->wmmat[7] >> GM_ROW3HOMO_PREC_DIFF),
+            GM_ABS_ROW3HOMO_BITS);
     // fallthrough intended
     case AFFINE:
     case ROTZOOM:
@@ -4506,11 +4512,13 @@
           w,
           (params->wmmat[2] >> GM_ALPHA_PREC_DIFF) - (1 << GM_ALPHA_PREC_BITS),
           GM_ABS_ALPHA_BITS);
-      aom_write_primitive_symmetric(w, (params->wmmat[3] >> GM_ALPHA_PREC_DIFF),
-                                    GM_ABS_ALPHA_BITS);
-      if (type == AFFINE || type == HOMOGRAPHY) {
+      if (type != VERTRAPEZOID)
         aom_write_primitive_symmetric(
-            w, (params->wmmat[4] >> GM_ALPHA_PREC_DIFF), GM_ABS_ALPHA_BITS);
+            w, (params->wmmat[3] >> GM_ALPHA_PREC_DIFF), GM_ABS_ALPHA_BITS);
+      if (type >= AFFINE) {
+        if (type != HORTRAPEZOID)
+          aom_write_primitive_symmetric(
+              w, (params->wmmat[4] >> GM_ALPHA_PREC_DIFF), GM_ABS_ALPHA_BITS);
         aom_write_primitive_symmetric(w,
                                       (params->wmmat[5] >> GM_ALPHA_PREC_DIFF) -
                                           (1 << GM_ALPHA_PREC_BITS),