Updates libvpx to enable the VP9 decoder.

This change enables VP9 decoder for all build configurations.

Checkout is from master branch(hash:12180c8329d56d72e8d4424b8fd82b1b2f8e846a).

Change-Id: Ieaba85d0bc54e1ecdf9596398dafa03c43182f8c

1 files changed, 520 insertions, 0 deletions

diff --git a/libvpx/vp9/common/vp9_pred_common.c b/libvpx/vp9/common/vp9_pred_common.c
new file mode 100644
index 0000000..17da4f2
--- /dev/null
+++ b/libvpx/vp9/common/vp9_pred_common.c
@@ -0,0 +1,520 @@
+
+/*
+ *  Copyright (c) 2012 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <limits.h>
+
+#include "vp9/common/vp9_common.h"
+#include "vp9/common/vp9_pred_common.h"
+#include "vp9/common/vp9_seg_common.h"
+#include "vp9/common/vp9_treecoder.h"
+
+// TBD prediction functions for various bitstream signals
+
+// Returns a context number for the given MB prediction signal
+unsigned char vp9_get_pred_context(const VP9_COMMON *const cm,
+                                   const MACROBLOCKD *const xd,
+                                   PRED_ID pred_id) {
+  int pred_context;
+  const MODE_INFO *const mi = xd->mode_info_context;
+  const MODE_INFO *const above_mi = mi - cm->mode_info_stride;
+  const MODE_INFO *const left_mi = mi - 1;
+  const int left_in_image = xd->left_available && left_mi->mbmi.mb_in_image;
+  const int above_in_image = xd->up_available && above_mi->mbmi.mb_in_image;
+  // Note:
+  // The mode info data structure has a one element border above and to the
+  // left of the entries correpsonding to real macroblocks.
+  // The prediction flags in these dummy entries are initialised to 0.
+  switch (pred_id) {
+    case PRED_SEG_ID:
+      pred_context = above_mi->mbmi.seg_id_predicted;
+      if (xd->left_available)
+        pred_context += left_mi->mbmi.seg_id_predicted;
+      break;
+
+    case PRED_MBSKIP:
+      pred_context = above_mi->mbmi.mb_skip_coeff;
+      if (xd->left_available)
+        pred_context += left_mi->mbmi.mb_skip_coeff;
+      break;
+
+    case PRED_SWITCHABLE_INTERP: {
+      // left
+      const int left_mv_pred = is_inter_mode(left_mi->mbmi.mode);
+      const int left_interp = left_in_image && left_mv_pred ?
+                    vp9_switchable_interp_map[left_mi->mbmi.interp_filter] :
+                    VP9_SWITCHABLE_FILTERS;
+
+      // above
+      const int above_mv_pred = is_inter_mode(above_mi->mbmi.mode);
+      const int above_interp = above_in_image && above_mv_pred ?
+                    vp9_switchable_interp_map[above_mi->mbmi.interp_filter] :
+                    VP9_SWITCHABLE_FILTERS;
+
+      assert(left_interp != -1);
+      assert(above_interp != -1);
+
+      if (left_interp == above_interp)
+        pred_context = left_interp;
+      else if (left_interp == VP9_SWITCHABLE_FILTERS &&
+               above_interp != VP9_SWITCHABLE_FILTERS)
+         pred_context = above_interp;
+      else if (left_interp != VP9_SWITCHABLE_FILTERS &&
+               above_interp == VP9_SWITCHABLE_FILTERS)
+        pred_context = left_interp;
+      else
+        pred_context = VP9_SWITCHABLE_FILTERS;
+
+      break;
+    }
+
+    case PRED_INTRA_INTER: {
+      if (above_in_image && left_in_image) {  // both edges available
+        if (left_mi->mbmi.ref_frame[0] == INTRA_FRAME &&
+            above_mi->mbmi.ref_frame[0] == INTRA_FRAME) {  // intra/intra (3)
+          pred_context = 3;
+        } else {  // intra/inter (1) or inter/inter (0)
+          pred_context = left_mi->mbmi.ref_frame[0] == INTRA_FRAME ||
+                         above_mi->mbmi.ref_frame[0] == INTRA_FRAME;
+        }
+      } else if (above_in_image || left_in_image) {  // one edge available
+        const MODE_INFO *edge = above_in_image ? above_mi : left_mi;
+
+        // inter: 0, intra: 2
+        pred_context = 2 * (edge->mbmi.ref_frame[0] == INTRA_FRAME);
+      } else {
+        pred_context = 0;
+      }
+      assert(pred_context >= 0 && pred_context < INTRA_INTER_CONTEXTS);
+      break;
+    }
+
+    case PRED_COMP_INTER_INTER: {
+      if (above_in_image && left_in_image) {  // both edges available
+        if (above_mi->mbmi.ref_frame[1] <= INTRA_FRAME &&
+            left_mi->mbmi.ref_frame[1] <= INTRA_FRAME) {
+          // neither edge uses comp pred (0/1)
+          pred_context = ((above_mi->mbmi.ref_frame[0] == cm->comp_fixed_ref) ^
+                          (left_mi->mbmi.ref_frame[0] == cm->comp_fixed_ref));
+        } else if (above_mi->mbmi.ref_frame[1] <= INTRA_FRAME) {
+          // one of two edges uses comp pred (2/3)
+          pred_context = 2 +
+              (above_mi->mbmi.ref_frame[0] == cm->comp_fixed_ref ||
+               above_mi->mbmi.ref_frame[0] == INTRA_FRAME);
+        } else if (left_mi->mbmi.ref_frame[1] <= INTRA_FRAME) {
+          // one of two edges uses comp pred (2/3)
+          pred_context = 2 +
+              (left_mi->mbmi.ref_frame[0] == cm->comp_fixed_ref ||
+               left_mi->mbmi.ref_frame[0] == INTRA_FRAME);
+        } else {  // both edges use comp pred (4)
+          pred_context = 4;
+        }
+      } else if (above_in_image || left_in_image) {  // one edge available
+        const MODE_INFO *edge = above_in_image ? above_mi : left_mi;
+
+        if (edge->mbmi.ref_frame[1] <= INTRA_FRAME) {
+          // edge does not use comp pred (0/1)
+          pred_context = edge->mbmi.ref_frame[0] == cm->comp_fixed_ref;
+        } else {  // edge uses comp pred (3)
+          pred_context = 3;
+        }
+      } else {  // no edges available (1)
+        pred_context = 1;
+      }
+      assert(pred_context >= 0 && pred_context < COMP_INTER_CONTEXTS);
+      break;
+    }
+
+    case PRED_COMP_REF_P: {
+      const int fix_ref_idx = cm->ref_frame_sign_bias[cm->comp_fixed_ref];
+      const int var_ref_idx = !fix_ref_idx;
+
+      if (above_in_image && left_in_image) {  // both edges available
+        if (above_mi->mbmi.ref_frame[0] == INTRA_FRAME &&
+            left_mi->mbmi.ref_frame[0] == INTRA_FRAME) {  // intra/intra (2)
+          pred_context = 2;
+        } else if (above_mi->mbmi.ref_frame[0] == INTRA_FRAME ||
+                   left_mi->mbmi.ref_frame[0] == INTRA_FRAME) {  // intra/inter
+          const MODE_INFO *edge = above_mi->mbmi.ref_frame[0] == INTRA_FRAME ?
+                                  left_mi : above_mi;
+
+          if (edge->mbmi.ref_frame[1] <= INTRA_FRAME) {  // single pred (1/3)
+            pred_context = 1 +
+                2 * edge->mbmi.ref_frame[0] != cm->comp_var_ref[1];
+          } else {  // comp pred (1/3)
+            pred_context = 1 +
+                2 * edge->mbmi.ref_frame[var_ref_idx] != cm->comp_var_ref[1];
+          }
+        } else {  // inter/inter
+          int l_sg = left_mi->mbmi.ref_frame[1] <= INTRA_FRAME;
+          int a_sg = above_mi->mbmi.ref_frame[1] <= INTRA_FRAME;
+          MV_REFERENCE_FRAME vrfa = a_sg ? above_mi->mbmi.ref_frame[0] :
+              above_mi->mbmi.ref_frame[var_ref_idx];
+          MV_REFERENCE_FRAME vrfl = l_sg ? left_mi->mbmi.ref_frame[0] :
+              left_mi->mbmi.ref_frame[var_ref_idx];
+
+          if (vrfa == vrfl && cm->comp_var_ref[1] == vrfa) {
+            pred_context = 0;
+          } else if (l_sg && a_sg) {  // single/single
+            if ((vrfa == cm->comp_fixed_ref && vrfl == cm->comp_var_ref[0]) ||
+                (vrfl == cm->comp_fixed_ref && vrfa == cm->comp_var_ref[0])) {
+              pred_context = 4;
+            } else if (vrfa == vrfl) {
+              pred_context = 3;
+            } else {
+              pred_context = 1;
+            }
+          } else if (l_sg || a_sg) {  // single/comp
+            MV_REFERENCE_FRAME vrfc = l_sg ? vrfa : vrfl;
+            MV_REFERENCE_FRAME rfs = a_sg ? vrfa : vrfl;
+
+            if (vrfc == cm->comp_var_ref[1] && rfs != cm->comp_var_ref[1]) {
+              pred_context = 1;
+            } else if (rfs == cm->comp_var_ref[1] &&
+                       vrfc != cm->comp_var_ref[1]) {
+              pred_context = 2;
+            } else {
+              pred_context = 4;
+            }
+          } else if (vrfa == vrfl) {  // comp/comp
+            pred_context = 4;
+          } else {
+            pred_context = 2;
+          }
+        }
+      } else if (above_in_image || left_in_image) {  // one edge available
+        const MODE_INFO *edge = above_in_image ? above_mi : left_mi;
+
+        if (edge->mbmi.ref_frame[0] == INTRA_FRAME) {
+          pred_context = 2;
+        } else if (edge->mbmi.ref_frame[1] > INTRA_FRAME) {
+          pred_context =
+              4 * edge->mbmi.ref_frame[var_ref_idx] != cm->comp_var_ref[1];
+        } else {
+          pred_context = 3 * edge->mbmi.ref_frame[0] != cm->comp_var_ref[1];
+        }
+      } else {  // no edges available (2)
+        pred_context = 2;
+      }
+      assert(pred_context >= 0 && pred_context < REF_CONTEXTS);
+      break;
+    }
+
+    case PRED_SINGLE_REF_P1: {
+      if (above_in_image && left_in_image) {  // both edges available
+        if (above_mi->mbmi.ref_frame[0] == INTRA_FRAME &&
+            left_mi->mbmi.ref_frame[0] == INTRA_FRAME) {
+          pred_context = 2;
+        } else if (above_mi->mbmi.ref_frame[0] == INTRA_FRAME ||
+                   left_mi->mbmi.ref_frame[0] == INTRA_FRAME) {
+          const MODE_INFO *edge = above_mi->mbmi.ref_frame[0] == INTRA_FRAME ?
+                                  left_mi : above_mi;
+
+          if (edge->mbmi.ref_frame[1] <= INTRA_FRAME) {
+            pred_context = 4 * (edge->mbmi.ref_frame[0] == LAST_FRAME);
+          } else {
+            pred_context = 1 + (edge->mbmi.ref_frame[0] == LAST_FRAME ||
+                                edge->mbmi.ref_frame[1] == LAST_FRAME);
+          }
+        } else if (above_mi->mbmi.ref_frame[1] <= INTRA_FRAME &&
+                   left_mi->mbmi.ref_frame[1] <= INTRA_FRAME) {
+          pred_context = 2 * (above_mi->mbmi.ref_frame[0] == LAST_FRAME) +
+                         2 * (left_mi->mbmi.ref_frame[0] == LAST_FRAME);
+        } else if (above_mi->mbmi.ref_frame[1] > INTRA_FRAME &&
+                   left_mi->mbmi.ref_frame[1] > INTRA_FRAME) {
+          pred_context = 1 + (above_mi->mbmi.ref_frame[0] == LAST_FRAME ||
+                              above_mi->mbmi.ref_frame[1] == LAST_FRAME ||
+                              left_mi->mbmi.ref_frame[0] == LAST_FRAME ||
+                              left_mi->mbmi.ref_frame[1] == LAST_FRAME);
+        } else {
+          MV_REFERENCE_FRAME rfs = above_mi->mbmi.ref_frame[1] <= INTRA_FRAME ?
+              above_mi->mbmi.ref_frame[0] : left_mi->mbmi.ref_frame[0];
+          MV_REFERENCE_FRAME crf1 = above_mi->mbmi.ref_frame[1] > INTRA_FRAME ?
+              above_mi->mbmi.ref_frame[0] : left_mi->mbmi.ref_frame[0];
+          MV_REFERENCE_FRAME crf2 = above_mi->mbmi.ref_frame[1] > INTRA_FRAME ?
+              above_mi->mbmi.ref_frame[1] : left_mi->mbmi.ref_frame[1];
+
+          if (rfs == LAST_FRAME) {
+            pred_context = 3 + (crf1 == LAST_FRAME || crf2 == LAST_FRAME);
+          } else {
+            pred_context = crf1 == LAST_FRAME || crf2 == LAST_FRAME;
+          }
+        }
+      } else if (above_in_image || left_in_image) {  // one edge available
+        const MODE_INFO *edge = above_in_image ? above_mi : left_mi;
+
+        if (edge->mbmi.ref_frame[0] == INTRA_FRAME) {
+          pred_context = 2;
+        } else if (edge->mbmi.ref_frame[1] <= INTRA_FRAME) {
+          pred_context = 4 * (edge->mbmi.ref_frame[0] == LAST_FRAME);
+        } else {
+          pred_context = 1 + (edge->mbmi.ref_frame[0] == LAST_FRAME ||
+                              edge->mbmi.ref_frame[1] == LAST_FRAME);
+        }
+      } else {  // no edges available (2)
+        pred_context = 2;
+      }
+      assert(pred_context >= 0 && pred_context < REF_CONTEXTS);
+      break;
+    }
+
+    case PRED_SINGLE_REF_P2: {
+      if (above_in_image && left_in_image) {  // both edges available
+        if (above_mi->mbmi.ref_frame[0] == INTRA_FRAME &&
+            left_mi->mbmi.ref_frame[0] == INTRA_FRAME) {
+          pred_context = 2;
+        } else if (above_mi->mbmi.ref_frame[0] == INTRA_FRAME ||
+                   left_mi->mbmi.ref_frame[0] == INTRA_FRAME) {
+          const MODE_INFO *edge = above_mi->mbmi.ref_frame[0] == INTRA_FRAME ?
+                                  left_mi : above_mi;
+
+          if (edge->mbmi.ref_frame[1] <= INTRA_FRAME) {
+            if (edge->mbmi.ref_frame[0] == LAST_FRAME) {
+              pred_context = 3;
+            } else {
+              pred_context = 4 * (edge->mbmi.ref_frame[0] == GOLDEN_FRAME);
+            }
+          } else {
+            pred_context = 1 + 2 * (edge->mbmi.ref_frame[0] == GOLDEN_FRAME ||
+                                    edge->mbmi.ref_frame[1] == GOLDEN_FRAME);
+          }
+        } else if (above_mi->mbmi.ref_frame[1] <= INTRA_FRAME &&
+                   left_mi->mbmi.ref_frame[1] <= INTRA_FRAME) {
+          if (above_mi->mbmi.ref_frame[0] == LAST_FRAME &&
+              left_mi->mbmi.ref_frame[0] == LAST_FRAME) {
+            pred_context = 3;
+          } else if (above_mi->mbmi.ref_frame[0] == LAST_FRAME ||
+                     left_mi->mbmi.ref_frame[0] == LAST_FRAME) {
+            const MODE_INFO *edge = above_mi->mbmi.ref_frame[0] == LAST_FRAME ?
+                                    left_mi : above_mi;
+
+            pred_context = 4 * (edge->mbmi.ref_frame[0] == GOLDEN_FRAME);
+          } else {
+            pred_context = 2 * (above_mi->mbmi.ref_frame[0] == GOLDEN_FRAME) +
+                           2 * (left_mi->mbmi.ref_frame[0] == GOLDEN_FRAME);
+          }
+        } else if (above_mi->mbmi.ref_frame[1] > INTRA_FRAME &&
+                   left_mi->mbmi.ref_frame[1] > INTRA_FRAME) {
+          if (above_mi->mbmi.ref_frame[0] == left_mi->mbmi.ref_frame[0] &&
+              above_mi->mbmi.ref_frame[1] == left_mi->mbmi.ref_frame[1]) {
+            pred_context = 3 * (above_mi->mbmi.ref_frame[0] == GOLDEN_FRAME ||
+                                above_mi->mbmi.ref_frame[1] == GOLDEN_FRAME ||
+                                left_mi->mbmi.ref_frame[0] == GOLDEN_FRAME ||
+                                left_mi->mbmi.ref_frame[1] == GOLDEN_FRAME);
+          } else {
+            pred_context = 2;
+          }
+        } else {
+          MV_REFERENCE_FRAME rfs = above_mi->mbmi.ref_frame[1] <= INTRA_FRAME ?
+              above_mi->mbmi.ref_frame[0] : left_mi->mbmi.ref_frame[0];
+          MV_REFERENCE_FRAME crf1 = above_mi->mbmi.ref_frame[1] > INTRA_FRAME ?
+              above_mi->mbmi.ref_frame[0] : left_mi->mbmi.ref_frame[0];
+          MV_REFERENCE_FRAME crf2 = above_mi->mbmi.ref_frame[1] > INTRA_FRAME ?
+              above_mi->mbmi.ref_frame[1] : left_mi->mbmi.ref_frame[1];
+
+          if (rfs == GOLDEN_FRAME) {
+            pred_context = 3 + (crf1 == GOLDEN_FRAME || crf2 == GOLDEN_FRAME);
+          } else if (rfs == ALTREF_FRAME) {
+            pred_context = crf1 == GOLDEN_FRAME || crf2 == GOLDEN_FRAME;
+          } else {
+            pred_context =
+                1 + 2 * (crf1 == GOLDEN_FRAME || crf2 == GOLDEN_FRAME);
+          }
+        }
+      } else if (above_in_image || left_in_image) {  // one edge available
+        const MODE_INFO *edge = above_in_image ? above_mi : left_mi;
+
+        if (edge->mbmi.ref_frame[0] == INTRA_FRAME ||
+            (edge->mbmi.ref_frame[0] == LAST_FRAME &&
+             edge->mbmi.ref_frame[1] <= INTRA_FRAME)) {
+          pred_context = 2;
+        } else if (edge->mbmi.ref_frame[1] <= INTRA_FRAME) {
+          pred_context = 4 * (edge->mbmi.ref_frame[0] == GOLDEN_FRAME);
+        } else {
+          pred_context = 3 * (edge->mbmi.ref_frame[0] == GOLDEN_FRAME ||
+                              edge->mbmi.ref_frame[1] == GOLDEN_FRAME);
+        }
+      } else {  // no edges available (2)
+        pred_context = 2;
+      }
+      assert(pred_context >= 0 && pred_context < REF_CONTEXTS);
+      break;
+    }
+
+    case PRED_TX_SIZE: {
+      int above_context, left_context;
+      int max_tx_size;
+      if (mi->mbmi.sb_type < BLOCK_SIZE_SB8X8)
+        max_tx_size = TX_4X4;
+      else if (mi->mbmi.sb_type < BLOCK_SIZE_MB16X16)
+        max_tx_size = TX_8X8;
+      else if (mi->mbmi.sb_type < BLOCK_SIZE_SB32X32)
+        max_tx_size = TX_16X16;
+      else
+        max_tx_size = TX_32X32;
+      above_context = left_context = max_tx_size;
+      if (above_in_image) {
+        above_context = (above_mi->mbmi.mb_skip_coeff ?
+                         max_tx_size : above_mi->mbmi.txfm_size);
+      }
+      if (left_in_image) {
+        left_context = (left_mi->mbmi.mb_skip_coeff ?
+                        max_tx_size : left_mi->mbmi.txfm_size);
+      }
+      if (!left_in_image) {
+        left_context = above_context;
+      }
+      if (!above_in_image) {
+        above_context = left_context;
+      }
+      pred_context = (above_context + left_context > max_tx_size);
+      break;
+    }
+
+    default:
+      assert(0);
+      pred_context = 0;  // *** add error trap code.
+      break;
+  }
+
+  return pred_context;
+}
+
+// This function returns a context probability for coding a given
+// prediction signal
+vp9_prob vp9_get_pred_prob(const VP9_COMMON *const cm,
+                          const MACROBLOCKD *const xd,
+                          PRED_ID pred_id) {
+  const int pred_context = vp9_get_pred_context(cm, xd, pred_id);
+
+  switch (pred_id) {
+    case PRED_SEG_ID:
+      return cm->segment_pred_probs[pred_context];
+    case PRED_MBSKIP:
+      return cm->fc.mbskip_probs[pred_context];
+    case PRED_INTRA_INTER:
+      return cm->fc.intra_inter_prob[pred_context];
+    case PRED_COMP_INTER_INTER:
+      return cm->fc.comp_inter_prob[pred_context];
+    case PRED_COMP_REF_P:
+      return cm->fc.comp_ref_prob[pred_context];
+    case PRED_SINGLE_REF_P1:
+      return cm->fc.single_ref_prob[pred_context][0];
+    case PRED_SINGLE_REF_P2:
+      return cm->fc.single_ref_prob[pred_context][1];
+    default:
+      assert(0);
+      return 128;  // *** add error trap code.
+  }
+}
+
+// This function returns a context probability ptr for coding a given
+// prediction signal
+const vp9_prob *vp9_get_pred_probs(const VP9_COMMON *const cm,
+                                   const MACROBLOCKD *const xd,
+                                   PRED_ID pred_id) {
+  const MODE_INFO *const mi = xd->mode_info_context;
+  const int pred_context = vp9_get_pred_context(cm, xd, pred_id);
+
+  switch (pred_id) {
+    case PRED_SWITCHABLE_INTERP:
+      return &cm->fc.switchable_interp_prob[pred_context][0];
+
+    case PRED_TX_SIZE:
+      if (mi->mbmi.sb_type < BLOCK_SIZE_MB16X16)
+        return cm->fc.tx_probs_8x8p[pred_context];
+      else if (mi->mbmi.sb_type < BLOCK_SIZE_SB32X32)
+        return cm->fc.tx_probs_16x16p[pred_context];
+      else
+        return cm->fc.tx_probs_32x32p[pred_context];
+
+    default:
+      assert(0);
+      return NULL;  // *** add error trap code.
+  }
+}
+
+// This function returns the status of the given prediction signal.
+// I.e. is the predicted value for the given signal correct.
+unsigned char vp9_get_pred_flag(const MACROBLOCKD *const xd,
+                                PRED_ID pred_id) {
+  switch (pred_id) {
+    case PRED_SEG_ID:
+      return xd->mode_info_context->mbmi.seg_id_predicted;
+    case PRED_MBSKIP:
+      return xd->mode_info_context->mbmi.mb_skip_coeff;
+    default:
+      assert(0);
+      return 0;  // *** add error trap code.
+  }
+}
+
+// This function sets the status of the given prediction signal.
+// I.e. is the predicted value for the given signal correct.
+void vp9_set_pred_flag(MACROBLOCKD *const xd,
+                       PRED_ID pred_id,
+                       unsigned char pred_flag) {
+  const int mis = xd->mode_info_stride;
+  BLOCK_SIZE_TYPE bsize = xd->mode_info_context->mbmi.sb_type;
+  const int bh = 1 << mi_height_log2(bsize);
+  const int bw = 1 << mi_width_log2(bsize);
+#define sub(a, b) (b) < 0 ? (a) + (b) : (a)
+  const int x_mis = sub(bw, xd->mb_to_right_edge >> (3 + LOG2_MI_SIZE));
+  const int y_mis = sub(bh, xd->mb_to_bottom_edge >> (3 + LOG2_MI_SIZE));
+#undef sub
+  int x, y;
+
+  switch (pred_id) {
+    case PRED_SEG_ID:
+      for (y = 0; y < y_mis; y++) {
+        for (x = 0; x < x_mis; x++) {
+          xd->mode_info_context[y * mis + x].mbmi.seg_id_predicted = pred_flag;
+        }
+      }
+      break;
+
+    case PRED_MBSKIP:
+      for (y = 0; y < y_mis; y++) {
+        for (x = 0; x < x_mis; x++) {
+          xd->mode_info_context[y * mis + x].mbmi.mb_skip_coeff = pred_flag;
+        }
+      }
+      break;
+
+    default:
+      assert(0);
+      // *** add error trap code.
+      break;
+  }
+}
+
+
+// The following contain the guts of the prediction code used to
+// peredict various bitstream signals.
+
+// Macroblock segment id prediction function
+int vp9_get_pred_mi_segid(VP9_COMMON *cm, BLOCK_SIZE_TYPE sb_type,
+                          int mi_row, int mi_col) {
+  const int mi_index = mi_row * cm->mi_cols + mi_col;
+  const int bw = 1 << mi_width_log2(sb_type);
+  const int bh = 1 << mi_height_log2(sb_type);
+  const int ymis = MIN(cm->mi_rows - mi_row, bh);
+  const int xmis = MIN(cm->mi_cols - mi_col, bw);
+  int segment_id = INT_MAX;
+  int x, y;
+
+  for (y = 0; y < ymis; y++) {
+    for (x = 0; x < xmis; x++) {
+      const int index = mi_index + (y * cm->mi_cols + x);
+      segment_id = MIN(segment_id, cm->last_frame_seg_map[index]);
+    }
+  }
+  return segment_id;
+}