/*

 *  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 "vp9/common/vp9_common.h"

#include "vp9/common/vp9_pred_common.h"

#include "vp9/common/vp9_seg_common.h"

int vp9_compound_reference_allowed(const VP9_COMMON *cm) {

  int i;

  for (i = 1; i < REFS_PER_FRAME; ++i)

    if (cm->ref_frame_sign_bias[i + 1] != cm->ref_frame_sign_bias[1]) return 1;

  return 0;

}

void vp9_setup_compound_reference_mode(VP9_COMMON *cm) {

  if (cm->ref_frame_sign_bias[LAST_FRAME] ==

      cm->ref_frame_sign_bias[GOLDEN_FRAME]) {

    cm->comp_fixed_ref = ALTREF_FRAME;

    cm->comp_var_ref[0] = LAST_FRAME;

    cm->comp_var_ref[1] = GOLDEN_FRAME;

  } else if (cm->ref_frame_sign_bias[LAST_FRAME] ==

             cm->ref_frame_sign_bias[ALTREF_FRAME]) {

    cm->comp_fixed_ref = GOLDEN_FRAME;

    cm->comp_var_ref[0] = LAST_FRAME;

    cm->comp_var_ref[1] = ALTREF_FRAME;

  } else {

    cm->comp_fixed_ref = LAST_FRAME;

    cm->comp_var_ref[0] = GOLDEN_FRAME;

    cm->comp_var_ref[1] = ALTREF_FRAME;

  }

}

int vp9_get_reference_mode_context(const VP9_COMMON *cm,

                                   const MACROBLOCKD *xd) {

  int ctx;

  const MODE_INFO *const above_mi = xd->above_mi;

  const MODE_INFO *const left_mi = xd->left_mi;

  const int has_above = !!above_mi;

  const int has_left = !!left_mi;

  // Note:

  // The mode info data structure has a one element border above and to the

  // left of the entries corresponding to real macroblocks.

  // The prediction flags in these dummy entries are initialized to 0.

  if (has_above && has_left) {  // both edges available

    if (!has_second_ref(above_mi) && !has_second_ref(left_mi))

      // neither edge uses comp pred (0/1)

      ctx = (above_mi->ref_frame[0] == cm->comp_fixed_ref) ^

            (left_mi->ref_frame[0] == cm->comp_fixed_ref);

    else if (!has_second_ref(above_mi))

      // one of two edges uses comp pred (2/3)

      ctx = 2 + (above_mi->ref_frame[0] == cm->comp_fixed_ref ||

                 !is_inter_block(above_mi));

    else if (!has_second_ref(left_mi))

      // one of two edges uses comp pred (2/3)

      ctx = 2 + (left_mi->ref_frame[0] == cm->comp_fixed_ref ||

                 !is_inter_block(left_mi));

    else  // both edges use comp pred (4)

      ctx = 4;

  } else if (has_above || has_left) {  // one edge available

    const MODE_INFO *edge_mi = has_above ? above_mi : left_mi;

    if (!has_second_ref(edge_mi))

      // edge does not use comp pred (0/1)

      ctx = edge_mi->ref_frame[0] == cm->comp_fixed_ref;

    else

      // edge uses comp pred (3)

      ctx = 3;

  } else {  // no edges available (1)

    ctx = 1;

  }

  assert(ctx >= 0 && ctx < COMP_INTER_CONTEXTS);

  return ctx;

}

// Returns a context number for the given MB prediction signal

int vp9_get_pred_context_comp_ref_p(const VP9_COMMON *cm,

                                    const MACROBLOCKD *xd) {

  int pred_context;

  const MODE_INFO *const above_mi = xd->above_mi;

  const MODE_INFO *const left_mi = xd->left_mi;

  const int above_in_image = !!above_mi;

  const int left_in_image = !!left_mi;

  // Note:

  // The mode info data structure has a one element border above and to the

  // left of the entries corresponding to real macroblocks.

  // The prediction flags in these dummy entries are initialized to 0.

  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

    const int above_intra = !is_inter_block(above_mi);

    const int left_intra = !is_inter_block(left_mi);

    if (above_intra && left_intra) {  // intra/intra (2)

      pred_context = 2;

    } else if (above_intra || left_intra) {  // intra/inter

      const MODE_INFO *edge_mi = above_intra ? left_mi : above_mi;

      if (!has_second_ref(edge_mi))  // single pred (1/3)

        pred_context = 1 + 2 * (edge_mi->ref_frame[0] != cm->comp_var_ref[1]);

      else  // comp pred (1/3)

        pred_context =

            1 + 2 * (edge_mi->ref_frame[var_ref_idx] != cm->comp_var_ref[1]);

    } else {  // inter/inter

      const int l_sg = !has_second_ref(left_mi);

      const int a_sg = !has_second_ref(above_mi);

      const MV_REFERENCE_FRAME vrfa =

          a_sg ? above_mi->ref_frame[0] : above_mi->ref_frame[var_ref_idx];

      const MV_REFERENCE_FRAME vrfl =

          l_sg ? left_mi->ref_frame[0] : left_mi->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

        const MV_REFERENCE_FRAME vrfc = l_sg ? vrfa : vrfl;

        const 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_mi = above_in_image ? above_mi : left_mi;

    if (!is_inter_block(edge_mi)) {

      pred_context = 2;

    } else {

      if (has_second_ref(edge_mi))

        pred_context =

            4 * (edge_mi->ref_frame[var_ref_idx] != cm->comp_var_ref[1]);

      else

        pred_context = 3 * (edge_mi->ref_frame[0] != cm->comp_var_ref[1]);

    }

  } else {  // no edges available (2)

    pred_context = 2;

  }

  assert(pred_context >= 0 && pred_context < REF_CONTEXTS);

  return pred_context;

}

int vp9_get_pred_context_single_ref_p1(const MACROBLOCKD *xd) {

  int pred_context;

  const MODE_INFO *const above_mi = xd->above_mi;

  const MODE_INFO *const left_mi = xd->left_mi;

  const int has_above = !!above_mi;

  const int has_left = !!left_mi;

  // Note:

  // The mode info data structure has a one element border above and to the

  // left of the entries corresponding to real macroblocks.

  // The prediction flags in these dummy entries are initialized to 0.

  if (has_above && has_left) {  // both edges available

    const int above_intra = !is_inter_block(above_mi);

    const int left_intra = !is_inter_block(left_mi);

    if (above_intra && left_intra) {  // intra/intra

      pred_context = 2;

    } else if (above_intra || left_intra) {  // intra/inter or inter/intra

      const MODE_INFO *edge_mi = above_intra ? left_mi : above_mi;

      if (!has_second_ref(edge_mi))

        pred_context = 4 * (edge_mi->ref_frame[0] == LAST_FRAME);

      else

        pred_context = 1 + (edge_mi->ref_frame[0] == LAST_FRAME ||

                            edge_mi->ref_frame[1] == LAST_FRAME);

    } else {  // inter/inter

      const int above_has_second = has_second_ref(above_mi);

      const int left_has_second = has_second_ref(left_mi);

      const MV_REFERENCE_FRAME above0 = above_mi->ref_frame[0];

      const MV_REFERENCE_FRAME above1 = above_mi->ref_frame[1];

      const MV_REFERENCE_FRAME left0 = left_mi->ref_frame[0];

      const MV_REFERENCE_FRAME left1 = left_mi->ref_frame[1];

      if (above_has_second && left_has_second) {

        pred_context = 1 + (above0 == LAST_FRAME || above1 == LAST_FRAME ||

                            left0 == LAST_FRAME || left1 == LAST_FRAME);

      } else if (above_has_second || left_has_second) {

        const MV_REFERENCE_FRAME rfs = !above_has_second ? above0 : left0;

        const MV_REFERENCE_FRAME crf1 = above_has_second ? above0 : left0;

        const MV_REFERENCE_FRAME crf2 = above_has_second ? above1 : left1;

        if (rfs == LAST_FRAME)

          pred_context = 3 + (crf1 == LAST_FRAME || crf2 == LAST_FRAME);

        else

          pred_context = (crf1 == LAST_FRAME || crf2 == LAST_FRAME);

      } else {

        pred_context = 2 * (above0 == LAST_FRAME) + 2 * (left0 == LAST_FRAME);

      }

    }

  } else if (has_above || has_left) {  // one edge available

    const MODE_INFO *edge_mi = has_above ? above_mi : left_mi;

    if (!is_inter_block(edge_mi)) {  // intra

      pred_context = 2;

    } else {  // inter

      if (!has_second_ref(edge_mi))

        pred_context = 4 * (edge_mi->ref_frame[0] == LAST_FRAME);

      else

        pred_context = 1 + (edge_mi->ref_frame[0] == LAST_FRAME ||

                            edge_mi->ref_frame[1] == LAST_FRAME);

    }

  } else {  // no edges available

    pred_context = 2;

  }

  assert(pred_context >= 0 && pred_context < REF_CONTEXTS);

  return pred_context;

}

int vp9_get_pred_context_single_ref_p2(const MACROBLOCKD *xd) {

  int pred_context;

  const MODE_INFO *const above_mi = xd->above_mi;

  const MODE_INFO *const left_mi = xd->left_mi;

  const int has_above = !!above_mi;

  const int has_left = !!left_mi;

  // Note:

  // The mode info data structure has a one element border above and to the

  // left of the entries corresponding to real macroblocks.

  // The prediction flags in these dummy entries are initialized to 0.

  if (has_above && has_left) {  // both edges available

    const int above_intra = !is_inter_block(above_mi);

    const int left_intra = !is_inter_block(left_mi);

    if (above_intra && left_intra) {  // intra/intra

      pred_context = 2;

    } else if (above_intra || left_intra) {  // intra/inter or inter/intra

      const MODE_INFO *edge_mi = above_intra ? left_mi : above_mi;

      if (!has_second_ref(edge_mi)) {

        if (edge_mi->ref_frame[0] == LAST_FRAME)

          pred_context = 3;

        else

          pred_context = 4 * (edge_mi->ref_frame[0] == GOLDEN_FRAME);

      } else {

        pred_context = 1 + 2 * (edge_mi->ref_frame[0] == GOLDEN_FRAME ||

                                edge_mi->ref_frame[1] == GOLDEN_FRAME);

      }

    } else {  // inter/inter

      const int above_has_second = has_second_ref(above_mi);

      const int left_has_second = has_second_ref(left_mi);

      const MV_REFERENCE_FRAME above0 = above_mi->ref_frame[0];

      const MV_REFERENCE_FRAME above1 = above_mi->ref_frame[1];

      const MV_REFERENCE_FRAME left0 = left_mi->ref_frame[0];

      const MV_REFERENCE_FRAME left1 = left_mi->ref_frame[1];

      if (above_has_second && left_has_second) {

        if (above0 == left0 && above1 == left1)

          pred_context =

              3 * (above0 == GOLDEN_FRAME || above1 == GOLDEN_FRAME ||

                   left0 == GOLDEN_FRAME || left1 == GOLDEN_FRAME);

        else

          pred_context = 2;

      } else if (above_has_second || left_has_second) {

        const MV_REFERENCE_FRAME rfs = !above_has_second ? above0 : left0;

        const MV_REFERENCE_FRAME crf1 = above_has_second ? above0 : left0;

        const MV_REFERENCE_FRAME crf2 = above_has_second ? above1 : left1;

        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 (above0 == LAST_FRAME && left0 == LAST_FRAME) {

          pred_context = 3;

        } else if (above0 == LAST_FRAME || left0 == LAST_FRAME) {

          const MV_REFERENCE_FRAME edge0 =

              (above0 == LAST_FRAME) ? left0 : above0;

          pred_context = 4 * (edge0 == GOLDEN_FRAME);

        } else {

          pred_context =

              2 * (above0 == GOLDEN_FRAME) + 2 * (left0 == GOLDEN_FRAME);

        }

      }

    }

  } else if (has_above || has_left) {  // one edge available

    const MODE_INFO *edge_mi = has_above ? above_mi : left_mi;

    if (!is_inter_block(edge_mi) ||

        (edge_mi->ref_frame[0] == LAST_FRAME && !has_second_ref(edge_mi)))

      pred_context = 2;

    else if (!has_second_ref(edge_mi))

      pred_context = 4 * (edge_mi->ref_frame[0] == GOLDEN_FRAME);

    else

      pred_context = 3 * (edge_mi->ref_frame[0] == GOLDEN_FRAME ||

                          edge_mi->ref_frame[1] == GOLDEN_FRAME);

  } else {  // no edges available (2)

    pred_context = 2;

  }

  assert(pred_context >= 0 && pred_context < REF_CONTEXTS);

  return pred_context;

}