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DEFINITIONS
This source file includes following definitions.
- compute_NumPoc
- read_short_term_ref_pic_set
- dump_short_term_ref_pic_set
- dump_compact_short_term_ref_pic_set
/*
* H.265 video codec.
* Copyright (c) 2013-2014 struktur AG, Dirk Farin <farin@struktur.de>
*
* This file is part of libde265.
*
* libde265 is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version.
*
* libde265 is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with libde265. If not, see <http://www.gnu.org/licenses/>.
*/
#include "refpic.h"
#include "decctx.h"
#include "util.h"
#include <assert.h>
#include <stdlib.h>
#if defined(_MSC_VER) || defined(__MINGW32__)
# include <malloc.h>
#else
# include <alloca.h>
#endif
static void compute_NumPoc(ref_pic_set* rpset)
{
rpset->NumPocTotalCurr_shortterm_only = 0;
for (int i=0; i<rpset->NumNegativePics; i++)
if (rpset->UsedByCurrPicS0[i])
rpset->NumPocTotalCurr_shortterm_only++;
for (int i=0; i<rpset->NumPositivePics; i++)
if (rpset->UsedByCurrPicS1[i])
rpset->NumPocTotalCurr_shortterm_only++;
/*
NOTE: this is done when reading the slice header.
The value numPocTotalCurr is then stored in the slice header.
for (int i = 0; i < num_long_term_sps + num_long_term_pics; i++ )
if( UsedByCurrPicLt[i] )
NumPocTotalCurr++
}
*/
}
/* A ref-pic-set is coded either coded
- as a list of the relative POC deltas themselves, or
- by shifting an existing ref-pic-set by some number of frames
When shifting an existing set, the frame 0 is also shifted as an additional reference frame.
When coding the ref-pic-sets in the SPS, predicition is always from the previous set.
In the slice header, the ref-pic-set can use any previous set as reference.
*/
bool read_short_term_ref_pic_set(decoder_context* ctx,
const seq_parameter_set* sps,
bitreader* br,
ref_pic_set* out_set, // where to store the read set
int idxRps, // index of the set to be read
const std::vector<ref_pic_set>& sets, // previously read sets
bool sliceRefPicSet) // is this in the slice header?
{
// --- is this set coded in prediction mode (not possible for the first set)
char inter_ref_pic_set_prediction_flag;
if (idxRps != 0) {
inter_ref_pic_set_prediction_flag = get_bits(br,1);
}
else {
inter_ref_pic_set_prediction_flag = 0;
}
if (inter_ref_pic_set_prediction_flag) {
int vlc;
/* Only for the last ref_pic_set (that's the one coded in the slice header),
we can specify relative to which reference set we code the set. */
int delta_idx;
if (sliceRefPicSet) { // idxRps == num_short_term_ref_pic_sets) {
delta_idx = vlc = get_uvlc(br);
delta_idx++;
} else {
delta_idx = 1;
}
int RIdx = idxRps - delta_idx; // this is our source set, which we will modify
assert(RIdx>=0);
int delta_rps_sign = get_bits(br,1);
int abs_delta_rps = vlc = get_uvlc(br);
abs_delta_rps++;
int DeltaRPS = (delta_rps_sign ? -abs_delta_rps : abs_delta_rps);
// bits are stored in this order:
// - all bits for negative Pocs (forward),
// - then all bits for positive Pocs (forward),
// - then bits for '0', shifting of the current picture
// in total, these are 'nDeltaPocsRIdx'+1 bits
logtrace(LogHeaders,"predicted from %d with delta %d\n",RIdx,DeltaRPS);
int nDeltaPocsRIdx= sets[RIdx].NumDeltaPocs; // size of source set
char *const used_by_curr_pic_flag = (char *)alloca((nDeltaPocsRIdx+1) * sizeof(char));
char *const use_delta_flag = (char *)alloca((nDeltaPocsRIdx+1) * sizeof(char));
for (int j=0;j<=nDeltaPocsRIdx;j++) {
used_by_curr_pic_flag[j] = get_bits(br,1);
if (used_by_curr_pic_flag[j]) {
use_delta_flag[j] = 1; // if this frame is used, we also have to apply the delta
} else {
use_delta_flag[j] = get_bits(br,1); // otherwise, it is only optionally included
}
}
logtrace(LogHeaders,"flags: ");
for (int j=0;j<=nDeltaPocsRIdx;j++) {
logtrace(LogHeaders,"%d ", use_delta_flag[j]);
}
logtrace(LogHeaders,"\n");
int nNegativeRIdx = sets[RIdx].NumNegativePics;
int nPositiveRIdx = sets[RIdx].NumPositivePics;
// --- update list 0 (negative Poc) ---
// Iterate through all Pocs in decreasing value order (positive reverse, 0, negative forward).
int i=0; // target index
// positive list
for (int j=nPositiveRIdx-1;j>=0;j--) {
int dPoc = sets[RIdx].DeltaPocS1[j] + DeltaRPS; // new delta
if (dPoc<0 && use_delta_flag[nNegativeRIdx+j]) {
out_set->DeltaPocS0[i] = dPoc;
out_set->UsedByCurrPicS0[i] = used_by_curr_pic_flag[nNegativeRIdx+j];
i++;
}
}
// frame 0
if (DeltaRPS<0 && use_delta_flag[nDeltaPocsRIdx]) {
out_set->DeltaPocS0[i] = DeltaRPS;
out_set->UsedByCurrPicS0[i] = used_by_curr_pic_flag[nDeltaPocsRIdx];
i++;
}
// negative list
for (int j=0;j<nNegativeRIdx;j++) {
int dPoc = sets[RIdx].DeltaPocS0[j] + DeltaRPS;
if (dPoc<0 && use_delta_flag[j]) {
out_set->DeltaPocS0[i] = dPoc;
out_set->UsedByCurrPicS0[i] = used_by_curr_pic_flag[j];
i++;
}
}
out_set->NumNegativePics = i;
// --- update list 1 (positive Poc) ---
// Iterate through all Pocs in increasing value order (negative reverse, 0, positive forward)
i=0; // target index
// negative list
for (int j=nNegativeRIdx-1;j>=0;j--) {
int dPoc = sets[RIdx].DeltaPocS0[j] + DeltaRPS;
if (dPoc>0 && use_delta_flag[j]) {
out_set->DeltaPocS1[i] = dPoc;
out_set->UsedByCurrPicS1[i] = used_by_curr_pic_flag[j];
i++;
}
}
// frame 0
if (DeltaRPS>0 && use_delta_flag[nDeltaPocsRIdx]) {
out_set->DeltaPocS1[i] = DeltaRPS;
out_set->UsedByCurrPicS1[i] = used_by_curr_pic_flag[nDeltaPocsRIdx];
i++;
}
// positive list
for (int j=0;j<nPositiveRIdx;j++) {
int dPoc = sets[RIdx].DeltaPocS1[j] + DeltaRPS;
if (dPoc>0 && use_delta_flag[nNegativeRIdx+j]) {
out_set->DeltaPocS1[i] = dPoc;
out_set->UsedByCurrPicS1[i] = used_by_curr_pic_flag[nNegativeRIdx+j];
i++;
}
}
out_set->NumPositivePics = i;
out_set->NumDeltaPocs = out_set->NumNegativePics + out_set->NumPositivePics;
} else {
// --- first, read the number of past and future frames in this set ---
int num_negative_pics = get_uvlc(br);
int num_positive_pics = get_uvlc(br);
// total number of reference pictures may not exceed buffer capacity
if (num_negative_pics + num_positive_pics >
sps->sps_max_dec_pic_buffering[ sps->sps_max_sub_layers-1 ]) {
out_set->NumNegativePics = 0;
out_set->NumPositivePics = 0;
out_set->NumDeltaPocs = 0;
out_set->NumPocTotalCurr_shortterm_only = 0;
ctx->add_warning(DE265_WARNING_MAX_NUM_REF_PICS_EXCEEDED, false);
return false;
}
out_set->NumNegativePics = num_negative_pics;
out_set->NumPositivePics = num_positive_pics;
out_set->NumDeltaPocs = num_positive_pics + num_negative_pics;
// --- now, read the deltas between the reference frames to fill the lists ---
// past frames
int lastPocS=0;
for (int i=0;i<num_negative_pics;i++) {
int delta_poc_s0 = get_uvlc(br)+1;
char used_by_curr_pic_s0_flag = get_bits(br,1);
out_set->DeltaPocS0[i] = lastPocS - delta_poc_s0;
out_set->UsedByCurrPicS0[i] = used_by_curr_pic_s0_flag;
lastPocS = out_set->DeltaPocS0[i];
}
// future frames
lastPocS=0;
for (int i=0;i<num_positive_pics;i++) {
int delta_poc_s1 = get_uvlc(br)+1;
char used_by_curr_pic_s1_flag = get_bits(br,1);
out_set->DeltaPocS1[i] = lastPocS + delta_poc_s1;
out_set->UsedByCurrPicS1[i] = used_by_curr_pic_s1_flag;
lastPocS = out_set->DeltaPocS1[i];
}
}
compute_NumPoc(out_set);
return true;
}
void dump_short_term_ref_pic_set(const ref_pic_set* set, FILE* fh)
{
log2fh(fh,"NumDeltaPocs: %d [-:%d +:%d]\n", set->NumDeltaPocs,
set->NumNegativePics, set->NumPositivePics);
log2fh(fh,"DeltaPocS0:");
for (int i=0;i<set->NumNegativePics;i++) {
if (i) { log2fh(fh,","); }
log2fh(fh," %d/%d",set->DeltaPocS0[i],set->UsedByCurrPicS0[i]);
}
log2fh(fh,"\n");
log2fh(fh,"DeltaPocS1:");
for (int i=0;i<set->NumPositivePics;i++) {
if (i) { log2fh(fh,","); }
log2fh(fh," %d/%d",set->DeltaPocS1[i],set->UsedByCurrPicS1[i]);
}
log2fh(fh,"\n");
}
void dump_compact_short_term_ref_pic_set(const ref_pic_set* set, int range, FILE* fh)
{
char *const log = (char *)alloca((range+1+range+1) * sizeof(char));
log[2*range+1] = 0;
for (int i=0;i<2*range+1;i++) log[i]='.';
log[range]='|';
for (int i=set->NumNegativePics-1;i>=0;i--) {
int n = set->DeltaPocS0[i];
if (n>=-range) {
if (set->UsedByCurrPicS0[i]) log[n+range] = 'X';
else log[n+range] = 'o';
} else { log2fh(fh,"*%d%c ",n, set->UsedByCurrPicS0[i] ? 'X':'o'); }
}
for (int i=set->NumPositivePics-1;i>=0;i--) {
int n = set->DeltaPocS1[i];
if (n<=range) {
if (set->UsedByCurrPicS1[i]) log[n+range] = 'X';
else log[n+range] = 'o';
} else { log2fh(fh,"*%d%c ",n, set->UsedByCurrPicS1[i] ? 'X':'o'); }
}
log2fh(fh,"*%s\n",log);
}