ref: ac4dc510275a843724bd040a7aef2e02bd65e8eb
dir: /vp9/common/vp9_pred_common.c/
/*
* 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_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;
}