/media/libvpx/vp8/encoder/encodemv.c
http://github.com/zpao/v8monkey · C · 417 lines · 274 code · 90 blank · 53 comment · 30 complexity · c01c71c128a618707c33a5d2568ce2df MD5 · raw file
- /*
- * 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 "vp8/common/common.h"
- #include "encodemv.h"
- #include "vp8/common/entropymode.h"
- #include "vp8/common/systemdependent.h"
- #include <math.h>
- #ifdef ENTROPY_STATS
- extern unsigned int active_section;
- #endif
- static void encode_mvcomponent(
- vp8_writer *const w,
- const int v,
- const struct mv_context *mvc
- )
- {
- const vp8_prob *p = mvc->prob;
- const int x = v < 0 ? -v : v;
- if (x < mvnum_short) // Small
- {
- vp8_write(w, 0, p [mvpis_short]);
- vp8_treed_write(w, vp8_small_mvtree, p + MVPshort, x, 3);
- if (!x)
- return; // no sign bit
- }
- else // Large
- {
- int i = 0;
- vp8_write(w, 1, p [mvpis_short]);
- do
- vp8_write(w, (x >> i) & 1, p [MVPbits + i]);
- while (++i < 3);
- i = mvlong_width - 1; /* Skip bit 3, which is sometimes implicit */
- do
- vp8_write(w, (x >> i) & 1, p [MVPbits + i]);
- while (--i > 3);
- if (x & 0xFFF0)
- vp8_write(w, (x >> 3) & 1, p [MVPbits + 3]);
- }
- vp8_write(w, v < 0, p [MVPsign]);
- }
- #if 0
- static int max_mv_r = 0;
- static int max_mv_c = 0;
- #endif
- void vp8_encode_motion_vector(vp8_writer *w, const MV *mv, const MV_CONTEXT *mvc)
- {
- #if 0
- {
- if (abs(mv->row >> 1) > max_mv_r)
- {
- FILE *f = fopen("maxmv.stt", "a");
- max_mv_r = abs(mv->row >> 1);
- fprintf(f, "New Mv Row Max %6d\n", (mv->row >> 1));
- if ((abs(mv->row) / 2) != max_mv_r)
- fprintf(f, "MV Row conversion error %6d\n", abs(mv->row) / 2);
- fclose(f);
- }
- if (abs(mv->col >> 1) > max_mv_c)
- {
- FILE *f = fopen("maxmv.stt", "a");
- fprintf(f, "New Mv Col Max %6d\n", (mv->col >> 1));
- max_mv_c = abs(mv->col >> 1);
- fclose(f);
- }
- }
- #endif
- encode_mvcomponent(w, mv->row >> 1, &mvc[0]);
- encode_mvcomponent(w, mv->col >> 1, &mvc[1]);
- }
- static unsigned int cost_mvcomponent(const int v, const struct mv_context *mvc)
- {
- const vp8_prob *p = mvc->prob;
- const int x = v; //v<0? -v:v;
- unsigned int cost;
- if (x < mvnum_short)
- {
- cost = vp8_cost_zero(p [mvpis_short])
- + vp8_treed_cost(vp8_small_mvtree, p + MVPshort, x, 3);
- if (!x)
- return cost;
- }
- else
- {
- int i = 0;
- cost = vp8_cost_one(p [mvpis_short]);
- do
- cost += vp8_cost_bit(p [MVPbits + i], (x >> i) & 1);
- while (++i < 3);
- i = mvlong_width - 1; /* Skip bit 3, which is sometimes implicit */
- do
- cost += vp8_cost_bit(p [MVPbits + i], (x >> i) & 1);
- while (--i > 3);
- if (x & 0xFFF0)
- cost += vp8_cost_bit(p [MVPbits + 3], (x >> 3) & 1);
- }
- return cost; // + vp8_cost_bit( p [MVPsign], v < 0);
- }
- void vp8_build_component_cost_table(int *mvcost[2], const MV_CONTEXT *mvc, int mvc_flag[2])
- {
- int i = 1; //-mv_max;
- unsigned int cost0 = 0;
- unsigned int cost1 = 0;
- vp8_clear_system_state();
- i = 1;
- if (mvc_flag[0])
- {
- mvcost [0] [0] = cost_mvcomponent(0, &mvc[0]);
- do
- {
- //mvcost [0] [i] = cost_mvcomponent( i, &mvc[0]);
- cost0 = cost_mvcomponent(i, &mvc[0]);
- mvcost [0] [i] = cost0 + vp8_cost_zero(mvc[0].prob[MVPsign]);
- mvcost [0] [-i] = cost0 + vp8_cost_one(mvc[0].prob[MVPsign]);
- }
- while (++i <= mv_max);
- }
- i = 1;
- if (mvc_flag[1])
- {
- mvcost [1] [0] = cost_mvcomponent(0, &mvc[1]);
- do
- {
- //mvcost [1] [i] = cost_mvcomponent( i, mvc[1]);
- cost1 = cost_mvcomponent(i, &mvc[1]);
- mvcost [1] [i] = cost1 + vp8_cost_zero(mvc[1].prob[MVPsign]);
- mvcost [1] [-i] = cost1 + vp8_cost_one(mvc[1].prob[MVPsign]);
- }
- while (++i <= mv_max);
- }
- }
- // Motion vector probability table update depends on benefit.
- // Small correction allows for the fact that an update to an MV probability
- // may have benefit in subsequent frames as well as the current one.
- #define MV_PROB_UPDATE_CORRECTION -1
- __inline static void calc_prob(vp8_prob *p, const unsigned int ct[2])
- {
- const unsigned int tot = ct[0] + ct[1];
- if (tot)
- {
- const vp8_prob x = ((ct[0] * 255) / tot) & -2;
- *p = x ? x : 1;
- }
- }
- static void update(
- vp8_writer *const w,
- const unsigned int ct[2],
- vp8_prob *const cur_p,
- const vp8_prob new_p,
- const vp8_prob update_p,
- int *updated
- )
- {
- const int cur_b = vp8_cost_branch(ct, *cur_p);
- const int new_b = vp8_cost_branch(ct, new_p);
- const int cost = 7 + MV_PROB_UPDATE_CORRECTION + ((vp8_cost_one(update_p) - vp8_cost_zero(update_p) + 128) >> 8);
- if (cur_b - new_b > cost)
- {
- *cur_p = new_p;
- vp8_write(w, 1, update_p);
- vp8_write_literal(w, new_p >> 1, 7);
- *updated = 1;
- }
- else
- vp8_write(w, 0, update_p);
- }
- static void write_component_probs(
- vp8_writer *const w,
- struct mv_context *cur_mvc,
- const struct mv_context *default_mvc_,
- const struct mv_context *update_mvc,
- const unsigned int events [MVvals],
- unsigned int rc,
- int *updated
- )
- {
- vp8_prob *Pcur = cur_mvc->prob;
- const vp8_prob *default_mvc = default_mvc_->prob;
- const vp8_prob *Pupdate = update_mvc->prob;
- unsigned int is_short_ct[2], sign_ct[2];
- unsigned int bit_ct [mvlong_width] [2];
- unsigned int short_ct [mvnum_short];
- unsigned int short_bct [mvnum_short-1] [2];
- vp8_prob Pnew [MVPcount];
- (void) rc;
- vp8_copy_array(Pnew, default_mvc, MVPcount);
- vp8_zero(is_short_ct)
- vp8_zero(sign_ct)
- vp8_zero(bit_ct)
- vp8_zero(short_ct)
- vp8_zero(short_bct)
- //j=0
- {
- const int c = events [mv_max];
- is_short_ct [0] += c; // Short vector
- short_ct [0] += c; // Magnitude distribution
- }
- //j: 1 ~ mv_max (1023)
- {
- int j = 1;
- do
- {
- const int c1 = events [mv_max + j]; //positive
- const int c2 = events [mv_max - j]; //negative
- const int c = c1 + c2;
- int a = j;
- sign_ct [0] += c1;
- sign_ct [1] += c2;
- if (a < mvnum_short)
- {
- is_short_ct [0] += c; // Short vector
- short_ct [a] += c; // Magnitude distribution
- }
- else
- {
- int k = mvlong_width - 1;
- is_short_ct [1] += c; // Long vector
- /* bit 3 not always encoded. */
- do
- bit_ct [k] [(a >> k) & 1] += c;
- while (--k >= 0);
- }
- }
- while (++j <= mv_max);
- }
- /*
- {
- int j = -mv_max;
- do
- {
- const int c = events [mv_max + j];
- int a = j;
- if( j < 0)
- {
- sign_ct [1] += c;
- a = -j;
- }
- else if( j)
- sign_ct [0] += c;
- if( a < mvnum_short)
- {
- is_short_ct [0] += c; // Short vector
- short_ct [a] += c; // Magnitude distribution
- }
- else
- {
- int k = mvlong_width - 1;
- is_short_ct [1] += c; // Long vector
- // bit 3 not always encoded.
- do
- bit_ct [k] [(a >> k) & 1] += c;
- while( --k >= 0);
- }
- } while( ++j <= mv_max);
- }
- */
- calc_prob(Pnew + mvpis_short, is_short_ct);
- calc_prob(Pnew + MVPsign, sign_ct);
- {
- vp8_prob p [mvnum_short - 1]; /* actually only need branch ct */
- int j = 0;
- vp8_tree_probs_from_distribution(
- 8, vp8_small_mvencodings, vp8_small_mvtree,
- p, short_bct, short_ct,
- 256, 1
- );
- do
- calc_prob(Pnew + MVPshort + j, short_bct[j]);
- while (++j < mvnum_short - 1);
- }
- {
- int j = 0;
- do
- calc_prob(Pnew + MVPbits + j, bit_ct[j]);
- while (++j < mvlong_width);
- }
- update(w, is_short_ct, Pcur + mvpis_short, Pnew[mvpis_short], *Pupdate++, updated);
- update(w, sign_ct, Pcur + MVPsign, Pnew[MVPsign], *Pupdate++, updated);
- {
- const vp8_prob *const new_p = Pnew + MVPshort;
- vp8_prob *const cur_p = Pcur + MVPshort;
- int j = 0;
- do
- update(w, short_bct[j], cur_p + j, new_p[j], *Pupdate++, updated);
- while (++j < mvnum_short - 1);
- }
- {
- const vp8_prob *const new_p = Pnew + MVPbits;
- vp8_prob *const cur_p = Pcur + MVPbits;
- int j = 0;
- do
- update(w, bit_ct[j], cur_p + j, new_p[j], *Pupdate++, updated);
- while (++j < mvlong_width);
- }
- }
- void vp8_write_mvprobs(VP8_COMP *cpi)
- {
- vp8_writer *const w = & cpi->bc;
- MV_CONTEXT *mvc = cpi->common.fc.mvc;
- int flags[2] = {0, 0};
- #ifdef ENTROPY_STATS
- active_section = 4;
- #endif
- write_component_probs(
- w, &mvc[0], &vp8_default_mv_context[0], &vp8_mv_update_probs[0], cpi->MVcount[0], 0, &flags[0]
- );
- write_component_probs(
- w, &mvc[1], &vp8_default_mv_context[1], &vp8_mv_update_probs[1], cpi->MVcount[1], 1, &flags[1]
- );
- if (flags[0] || flags[1])
- vp8_build_component_cost_table(cpi->mb.mvcost, (const MV_CONTEXT *) cpi->common.fc.mvc, flags);
- #ifdef ENTROPY_STATS
- active_section = 5;
- #endif
- }