libvpx: Add VP9 decoder.

source/libvpx/vp9/common/vp9_seg_common.c

+/*
+ *  Copyright (c) 2010 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 <assert.h>
+#include "vp9/common/vp9_blockd.h"
+#include "vp9/common/vp9_seg_common.h"
+
+static const int segfeaturedata_signed[SEG_LVL_MAX] = { 1, 1, 0, 0, 0, 0 };
+static const int seg_feature_data_max[SEG_LVL_MAX] =
+                 { MAXQ, 63, 0xf, MB_MODE_COUNT - 1, 255, TX_SIZE_MAX - 1};
+
+// These functions provide access to new segment level features.
+// Eventually these function may be "optimized out" but for the moment,
+// the coding mechanism is still subject to change so these provide a
+// convenient single point of change.
+
+int vp9_segfeature_active(const MACROBLOCKD *xd,
+                          int segment_id,
+                          SEG_LVL_FEATURES feature_id) {
+  // Return true if mask bit set and segmentation enabled.
+  return (xd->segmentation_enabled &&
+          (xd->segment_feature_mask[segment_id] &
+           (0x01 << feature_id)));
+}
+
+void vp9_clearall_segfeatures(MACROBLOCKD *xd) {
+  vpx_memset(xd->segment_feature_data, 0, sizeof(xd->segment_feature_data));
+  vpx_memset(xd->segment_feature_mask, 0, sizeof(xd->segment_feature_mask));
+}
+
+void vp9_enable_segfeature(MACROBLOCKD *xd,
+                           int segment_id,
+                           SEG_LVL_FEATURES feature_id) {
+  xd->segment_feature_mask[segment_id] |= (0x01 << feature_id);
+}
+
+void vp9_disable_segfeature(MACROBLOCKD *xd,
+                            int segment_id,
+                            SEG_LVL_FEATURES feature_id) {
+  xd->segment_feature_mask[segment_id] &= ~(1 << feature_id);
+}
+
+int vp9_seg_feature_data_max(SEG_LVL_FEATURES feature_id) {
+  return seg_feature_data_max[feature_id];
+}
+
+int vp9_is_segfeature_signed(SEG_LVL_FEATURES feature_id) {
+  return (segfeaturedata_signed[feature_id]);
+}
+
+void vp9_clear_segdata(MACROBLOCKD *xd,
+                       int segment_id,
+                       SEG_LVL_FEATURES feature_id) {
+  xd->segment_feature_data[segment_id][feature_id] = 0;
+}
+
+void vp9_set_segdata(MACROBLOCKD *xd,
+                     int segment_id,
+                     SEG_LVL_FEATURES feature_id,
+                     int seg_data) {
+  assert(seg_data <= seg_feature_data_max[feature_id]);
+  if (seg_data < 0) {
+    assert(segfeaturedata_signed[feature_id]);
+    assert(-seg_data <= seg_feature_data_max[feature_id]);
+  }
+
+  xd->segment_feature_data[segment_id][feature_id] = seg_data;
+}
+
+int vp9_get_segdata(const MACROBLOCKD *xd,
+                    int segment_id,
+                    SEG_LVL_FEATURES feature_id) {
+  return xd->segment_feature_data[segment_id][feature_id];
+}
+
+void vp9_clear_segref(MACROBLOCKD *xd, int segment_id) {
+  xd->segment_feature_data[segment_id][SEG_LVL_REF_FRAME] = 0;
+}
+
+void vp9_set_segref(MACROBLOCKD *xd,
+                    int segment_id,
+                    MV_REFERENCE_FRAME ref_frame) {
+  xd->segment_feature_data[segment_id][SEG_LVL_REF_FRAME] |=
+    (1 << ref_frame);
+}
+
+int vp9_check_segref(const MACROBLOCKD *xd,
+                     int segment_id,
+                     MV_REFERENCE_FRAME ref_frame) {
+  return (xd->segment_feature_data[segment_id][SEG_LVL_REF_FRAME] &
+          (1 << ref_frame)) ? 1 : 0;
+}
+
+int vp9_check_segref_inter(MACROBLOCKD *xd, int segment_id) {
+  return (xd->segment_feature_data[segment_id][SEG_LVL_REF_FRAME] &
+          ~(1 << INTRA_FRAME)) ? 1 : 0;
+}
+
+int vp9_get_seg_tx_type(MACROBLOCKD *xd, int segment_id) {
+  if (vp9_segfeature_active(xd, segment_id, SEG_LVL_TRANSFORM))
+    return vp9_get_segdata(xd, segment_id, SEG_LVL_TRANSFORM);
+  else
+    return TX_4X4;
+}
+// TBD? Functions to read and write segment data with range / validity checking