Merge "Adjust gm parameter computation to avoid mismatch" into nextgenv2

vp10/common/mv.h

@@ -50,26 +50,29 @@ typedef struct mv32 {
 //
 // The ABS parameters are used to create an upper and lower bound
 // for each parameter. In other words, after a parameter is integerized
-// it is clamped between -(1 << ABS_XXX_BITS) and (1 << ABS_XXX_BITS)
+// it is clamped between -(1 << ABS_XXX_BITS) and (1 << ABS_XXX_BITS).
 //
-// XXX_PREC_DIFF and XXX_DECODE_FACTOR are computed once here to
+// XXX_PREC_DIFF, XXX_ENCODE_FACTOR and XXX_DECODE_FACTOR
-// prevent repetetive computation on the decoder side. These are
+// are computed once here to prevent repetitive
+// computation on the decoder side. These are
 // to allow the global motion parameters to be encoded in a lower
 // precision than the warped model precision. This means that they
 // need to be changed to warped precision when they are decoded.
 //
 // XX_MIN, XX_MAX are also computed to avoid repeated computation
 
-#define GM_TRANS_PREC_BITS        3
+#define GM_TRANS_PREC_BITS      5
 #define GM_TRANS_PREC_DIFF      (WARPEDMODEL_PREC_BITS - GM_TRANS_PREC_BITS)
 #define GM_TRANS_DECODE_FACTOR  (1 << GM_TRANS_PREC_DIFF)
+#define GM_TRANS_ENCODE_FACTOR  (1 / (GM_TRANS_DECODE_FACTOR))
 
 #define GM_ALPHA_PREC_BITS      5
 #define GM_ALPHA_PREC_DIFF      (WARPEDMODEL_PREC_BITS - GM_ALPHA_PREC_BITS)
 #define GM_ALPHA_DECODE_FACTOR  (1 << GM_ALPHA_PREC_DIFF)
+#define GM_ALPHA_ENCODE_FACTOR  (1 / (GM_ALPHA_DECODE_FACTOR))
 
-#define GM_ABS_ALPHA_BITS         5
+#define GM_ABS_ALPHA_BITS       8
-#define GM_ABS_TRANS_BITS         5
+#define GM_ABS_TRANS_BITS       8
 
 #define GM_TRANS_MAX            (1 << GM_ABS_TRANS_BITS)
 #define GM_ALPHA_MAX            (1 << GM_ABS_ALPHA_BITS)

vp10/decoder/decodeframe.c

@@ -3473,6 +3473,7 @@ static void read_global_motion_params(Global_Motion_Params *params,
       params->motion_params.wmmat[5] =
           vp10_read_primitive_symmetric(r, GM_ABS_ALPHA_BITS) *
           GM_ALPHA_DECODE_FACTOR;
+      // fallthrough intended
     case GLOBAL_ROTZOOM:
       params->motion_params.wmmat[2] =
           (vp10_read_primitive_symmetric(r, GM_ABS_ALPHA_BITS) *
@@ -3480,6 +3481,7 @@ static void read_global_motion_params(Global_Motion_Params *params,
       params->motion_params.wmmat[3] =
           vp10_read_primitive_symmetric(r, GM_ABS_ALPHA_BITS) *
           GM_ALPHA_DECODE_FACTOR;
+      // fallthrough intended
     case GLOBAL_TRANSLATION:
       params->motion_params.wmmat[0] =
           vp10_read_primitive_symmetric(r, GM_ABS_TRANS_BITS) *

vp10/encoder/bitstream.c

@@ -3200,19 +3200,29 @@ static void write_global_motion_params(Global_Motion_Params *params,
     case GLOBAL_ZERO:
       break;
     case GLOBAL_AFFINE:
-      vp10_write_primitive_symmetric(w, params->motion_params.wmmat[4],
+      vp10_write_primitive_symmetric(w, (params->motion_params.wmmat[4] *
+                                     GM_ALPHA_ENCODE_FACTOR) -
+                                     (1 << GM_ALPHA_PREC_BITS),
                                      GM_ABS_ALPHA_BITS);
-      vp10_write_primitive_symmetric(w, params->motion_params.wmmat[5],
+      vp10_write_primitive_symmetric(w, params->motion_params.wmmat[5] *
+                                     GM_ALPHA_ENCODE_FACTOR,
                                      GM_ABS_ALPHA_BITS);
+      // fallthrough intended
     case GLOBAL_ROTZOOM:
-      vp10_write_primitive_symmetric(w, params->motion_params.wmmat[2],
+      vp10_write_primitive_symmetric(w, (params->motion_params.wmmat[2] *
+                                     GM_ALPHA_ENCODE_FACTOR) -
+                                     (1 << GM_ALPHA_PREC_BITS),
                                      GM_ABS_ALPHA_BITS);
-      vp10_write_primitive_symmetric(w, params->motion_params.wmmat[3],
+      vp10_write_primitive_symmetric(w, params->motion_params.wmmat[3] *
+                                     GM_ALPHA_ENCODE_FACTOR,
                                      GM_ABS_ALPHA_BITS);
+      // fallthrough intended
     case GLOBAL_TRANSLATION:
-      vp10_write_primitive_symmetric(w, params->motion_params.wmmat[0],
+      vp10_write_primitive_symmetric(w, params->motion_params.wmmat[0] *
+                                     GM_TRANS_ENCODE_FACTOR,
                                      GM_ABS_TRANS_BITS);
-      vp10_write_primitive_symmetric(w, params->motion_params.wmmat[1],
+      vp10_write_primitive_symmetric(w, params->motion_params.wmmat[1] *
+                                     GM_TRANS_ENCODE_FACTOR,
                                      GM_ABS_TRANS_BITS);
       break;
     default:

vp10/encoder/encodeframe.c

@@ -4549,18 +4549,20 @@ static void convert_to_params(double *H, TransformationType type,
                                               (1 << GM_TRANS_PREC_BITS) + 0.5);
   model->motion_params.wmmat[0] =
       clamp(model->motion_params.wmmat[0],
-            GM_TRANS_MIN, GM_TRANS_MAX);
+            GM_TRANS_MIN, GM_TRANS_MAX) *
+            GM_TRANS_DECODE_FACTOR;
   model->motion_params.wmmat[1] =
       clamp(model->motion_params.wmmat[1],
-            GM_TRANS_MIN, GM_TRANS_MAX);
+            GM_TRANS_MIN, GM_TRANS_MAX) *
+            GM_TRANS_DECODE_FACTOR;
 
   for (i = 2; i < n_params; ++i) {
     model->motion_params.wmmat[i] =
         (int) floor(H[i] *
-                    (1 << GM_ALPHA_PREC_BITS) + 0.5) -
+                    (1 << GM_ALPHA_PREC_BITS) + 0.5);
-                    (!(i & 1) * (1 << GM_ALPHA_PREC_BITS));
     model->motion_params.wmmat[i] = clamp(model->motion_params.wmmat[i],
-                                          GM_ALPHA_MIN, GM_ALPHA_MAX);
+                                          GM_ALPHA_MIN, GM_ALPHA_MAX) *
+                                          GM_ALPHA_DECODE_FACTOR;
     alpha_present |= (model->motion_params.wmmat[i] != 0);
   }
 
@@ -4579,6 +4581,7 @@ static void convert_model_to_params(double *H, TransformationType type,
   if (type > HOMOGRAPHY)
       convert_to_params(H, type, model);
   model->gmtype = get_gmtype(model);
+  model->motion_params.wmtype = gm_to_trans_type(model->gmtype);
 }
 #endif  // CONFIG_GLOBAL_MOTION
 
@@ -4610,7 +4613,7 @@ static void encode_frame_internal(VP10_COMP *cpi) {
     int frame;
     double H[9] = {0, 0, 0, 0, 0, 0, 0, 0, 1};
     for (frame = LAST_FRAME; frame <= ALTREF_FRAME; ++frame)
-      convert_model_to_params(H, ROTZOOM, &cm->global_motion[frame]);
+      convert_model_to_params(H, AFFINE, &cm->global_motion[frame]);
   }
 #endif  // CONFIG_GLOBAL_MOTION