text: /*
   * Copyright (c) 2016, Alliance for Open Media. All rights reserved
   *
   * This source code is subject to the terms of the BSD 2 Clause License and
   * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
   * was not distributed with this source code in the LICENSE file, you can
   * obtain it at www.aomedia.org/license/software. If the Alliance for Open
   * Media Patent License 1.0 was not distributed with this source code in the
   * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
   */
  
  #include <assert.h>
  
  #include "av1/common/av1_loopfilter.h"
  #include "av1/common/blockd.h"
  #include "av1/common/seg_common.h"
  #include "av1/common/quant_common.h"
  
  static const int seg_feature_data_signed[SEG_LVL_MAX] = { 1, 1, 1, 1, 1, 0, 0 };
  
  static const int seg_feature_data_max[SEG_LVL_MAX] = {
    MAXQ, MAX_LOOP_FILTER, MAX_LOOP_FILTER, MAX_LOOP_FILTER, MAX_LOOP_FILTER, 7, 0
  };
  
  // 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.
  
  void av1_clearall_segfeatures(struct segmentation *seg) {
    av1_zero(seg->feature_data);
    av1_zero(seg->feature_mask);
  }
  
  void av1_enable_segfeature(struct segmentation *seg, int segment_id,
                             SEG_LVL_FEATURES feature_id) {
    seg->feature_mask[segment_id] |= 1 << feature_id;
  }
  
  int av1_seg_feature_data_max(SEG_LVL_FEATURES feature_id) {
    return seg_feature_data_max[feature_id];
  }
  
  int av1_is_segfeature_signed(SEG_LVL_FEATURES feature_id) {
    return seg_feature_data_signed[feature_id];
  }
  
  // The 'seg_data' given for each segment can be either deltas (from the default
  // value chosen for the frame) or absolute values.
  //
  // Valid range for abs values is (0-127 for MB_LVL_ALT_Q), (0-63 for
  // SEGMENT_ALT_LF)
  // Valid range for delta values are (+/-127 for MB_LVL_ALT_Q), (+/-63 for
  // SEGMENT_ALT_LF)
  //
  // abs_delta = SEGMENT_DELTADATA (deltas) abs_delta = SEGMENT_ABSDATA (use
  // the absolute values given).
  
  void av1_set_segdata(struct segmentation *seg, int segment_id,
                       SEG_LVL_FEATURES feature_id, int seg_data) {
    if (seg_data < 0) {
      assert(seg_feature_data_signed[feature_id]);
      assert(-seg_data <= seg_feature_data_max[feature_id]);
    } else {
      assert(seg_data <= seg_feature_data_max[feature_id]);
    }
  
    seg->feature_data[segment_id][feature_id] = seg_data;
  }
  
  // TBD? Functions to read and write segment data with range / validity checking
  