// This function encodes the reference frame
static void write_ref_frames(const VP9_COMMON *cm, const MACROBLOCKD *xd,
vpx_writer *w) {
const MODE_INFO *const mi = xd->mi[0];
const int is_compound = has_second_ref(mi);
const int segment_id = mi->segment_id;
// If segment level coding of this signal is disabled...
// or the segment allows multiple reference frame options
if (segfeature_active(&cm->seg, segment_id, SEG_LVL_REF_FRAME)) {
assert(!is_compound);
assert(mi->ref_frame[0] ==
get_segdata(&cm->seg, segment_id, SEG_LVL_REF_FRAME));
} else {
// does the feature use compound prediction or not
// (if not specified at the frame/segment level)
if (cm->reference_mode == REFERENCE_MODE_SELECT) {
vpx_write(w, is_compound, vp9_get_reference_mode_prob(cm, xd));
} else {
assert(!is_compound == (cm->reference_mode == SINGLE_REFERENCE));
}
if (is_compound) {
vpx_write(w, mi->ref_frame[0] == GOLDEN_FRAME,
vp9_get_pred_prob_comp_ref_p(cm, xd));
} else {
const int bit0 = mi->ref_frame[0] != LAST_FRAME;
vpx_write(w, bit0, vp9_get_pred_prob_single_ref_p1(cm, xd));
if (bit0) {
const int bit1 = mi->ref_frame[0] != GOLDEN_FRAME;
vpx_write(w, bit1, vp9_get_pred_prob_single_ref_p2(cm, xd));
}
}
}
}
static void write_selected_tx_size(const VP9_COMMON *cm,
const MACROBLOCKD *xd, vpx_writer *w) {
TX_SIZE tx_size = xd->mi[0]->tx_size;
BLOCK_SIZE bsize = xd->mi[0]->sb_type;
const TX_SIZE max_tx_size = max_txsize_lookup[bsize];
const vpx_prob *const tx_probs = get_tx_probs2(max_tx_size, xd,
&cm->fc->tx_probs);
vpx_write(w, tx_size != TX_4X4, tx_probs[0]);
if (tx_size != TX_4X4 && max_tx_size >= TX_16X16) {
vpx_write(w, tx_size != TX_8X8, tx_probs[1]);
if (tx_size != TX_8X8 && max_tx_size >= TX_32X32)
vpx_write(w, tx_size != TX_16X16, tx_probs[2]);
}
}
static int write_skip(const VP9_COMMON *cm, const MACROBLOCKD *xd,
int segment_id, const MODE_INFO *mi, vpx_writer *w) {
if (segfeature_active(&cm->seg, segment_id, SEG_LVL_SKIP)) {
return 1;
} else {
const int skip = mi->skip;
vpx_write(w, skip, vp9_get_skip_prob(cm, xd));
return skip;
}
}
static void write_partition(const VP9_COMMON *const cm,
const MACROBLOCKD *const xd,
int hbs, int mi_row, int mi_col,
PARTITION_TYPE p, BLOCK_SIZE bsize, vpx_writer *w) {
const int ctx = partition_plane_context(xd, mi_row, mi_col, bsize);
const vpx_prob *const probs = xd->partition_probs[ctx];
const int has_rows = (mi_row + hbs) < cm->mi_rows;
const int has_cols = (mi_col + hbs) < cm->mi_cols;
if (has_rows && has_cols) {
vp9_write_token(w, vp9_partition_tree, probs, &partition_encodings[p]);
} else if (!has_rows && has_cols) {
assert(p == PARTITION_SPLIT || p == PARTITION_HORZ);
vpx_write(w, p == PARTITION_SPLIT, probs[1]);
} else if (has_rows && !has_cols) {
assert(p == PARTITION_SPLIT || p == PARTITION_VERT);
vpx_write(w, p == PARTITION_SPLIT, probs[2]);
} else {
assert(p == PARTITION_SPLIT);
}
}
void encode_with_adaptive_probability() {
memcpy(tmp, uncompressed, sizeof(uncompressed));
(*transform)(tmp); // this currently is a no-op but it may be helpful for the EXERCISE
DynProb encode;
vpx_writer wri ={0};
vpx_start_encode(&wri, tmp);
for (size_t i = 0; i < sizeof(uncompressed); ++i) {
for(int bit = 1; bit < 256; bit <<= 1) {
bool cur_bit = !!(tmp[i] & bit);
vpx_write(&wri, cur_bit, encode.prob);
encode.record_bit(cur_bit); // <-- this a new line for lesson1 that lets the encoder adapt to data
}
}
vpx_stop_encode(&wri);
printf("Buffer encoded with final prob(0) = %.2f results in %d size (%.2f%%)\n",
encode.prob / 255.,
wri.pos,
100 * wri.pos / float(sizeof(uncompressed)));
DynProb decode;
vpx_reader rea={0};
vpx_reader_init(&rea,
wri.buffer,
wri.pos);
memset(roundtrip, 0, sizeof(roundtrip));
for (size_t i = 0; i < sizeof(roundtrip); ++i) {
for(int bit = 1; bit < 256; bit <<= 1) {
if (vpx_read(&rea, decode.prob)) {
roundtrip[i] |= bit;
decode.record_bit(true); // <-- this a new line for lesson1
} else {
decode.record_bit(false); // <-- this a new line for lesson1
}
}
}
assert(vpx_reader_has_error(&rea) == 0);
(*untransform)(uncompressed); // this is, again a no-op, but may be helpful for the EXERCISE
assert(memcmp(uncompressed, roundtrip, sizeof(uncompressed)) == 0);
}
static void update_coef_probs_common(vpx_writer* const bc, VP9_COMP *cpi,
TX_SIZE tx_size,
vp9_coeff_stats *frame_branch_ct,
vp9_coeff_probs_model *new_coef_probs) {
vp9_coeff_probs_model *old_coef_probs = cpi->common.fc->coef_probs[tx_size];
const vpx_prob upd = DIFF_UPDATE_PROB;
const int entropy_nodes_update = UNCONSTRAINED_NODES;
int i, j, k, l, t;
int stepsize = cpi->sf.coeff_prob_appx_step;
switch (cpi->sf.use_fast_coef_updates) {
case TWO_LOOP: {
/* dry run to see if there is any update at all needed */
int savings = 0;
int update[2] = {0, 0};
for (i = 0; i < PLANE_TYPES; ++i) {
for (j = 0; j < REF_TYPES; ++j) {
for (k = 0; k < COEF_BANDS; ++k) {
for (l = 0; l < BAND_COEFF_CONTEXTS(k); ++l) {
for (t = 0; t < entropy_nodes_update; ++t) {
vpx_prob newp = new_coef_probs[i][j][k][l][t];
const vpx_prob oldp = old_coef_probs[i][j][k][l][t];
int s;
int u = 0;
if (t == PIVOT_NODE)
s = vp9_prob_diff_update_savings_search_model(
frame_branch_ct[i][j][k][l][0], oldp, &newp, upd,
stepsize);
else
s = vp9_prob_diff_update_savings_search(
frame_branch_ct[i][j][k][l][t], oldp, &newp, upd);
if (s > 0 && newp != oldp)
u = 1;
if (u)
savings += s - (int)(vp9_cost_zero(upd));
else
savings -= (int)(vp9_cost_zero(upd));
update[u]++;
}
}
}
}
}
// printf("Update %d %d, savings %d\n", update[0], update[1], savings);
/* Is coef updated at all */
if (update[1] == 0 || savings < 0) {
vpx_write_bit(bc, 0);
return;
}
vpx_write_bit(bc, 1);
for (i = 0; i < PLANE_TYPES; ++i) {
for (j = 0; j < REF_TYPES; ++j) {
for (k = 0; k < COEF_BANDS; ++k) {
for (l = 0; l < BAND_COEFF_CONTEXTS(k); ++l) {
// calc probs and branch cts for this frame only
for (t = 0; t < entropy_nodes_update; ++t) {
vpx_prob newp = new_coef_probs[i][j][k][l][t];
vpx_prob *oldp = old_coef_probs[i][j][k][l] + t;
const vpx_prob upd = DIFF_UPDATE_PROB;
int s;
int u = 0;
if (t == PIVOT_NODE)
s = vp9_prob_diff_update_savings_search_model(
frame_branch_ct[i][j][k][l][0],
*oldp, &newp, upd, stepsize);
else
s = vp9_prob_diff_update_savings_search(
frame_branch_ct[i][j][k][l][t],
*oldp, &newp, upd);
if (s > 0 && newp != *oldp)
u = 1;
vpx_write(bc, u, upd);
if (u) {
/* send/use new probability */
vp9_write_prob_diff_update(bc, newp, *oldp);
*oldp = newp;
}
}
}
}
}
}
return;
}
case ONE_LOOP_REDUCED: {
int updates = 0;
int noupdates_before_first = 0;
for (i = 0; i < PLANE_TYPES; ++i) {
for (j = 0; j < REF_TYPES; ++j) {
for (k = 0; k < COEF_BANDS; ++k) {
for (l = 0; l < BAND_COEFF_CONTEXTS(k); ++l) {
// calc probs and branch cts for this frame only
for (t = 0; t < entropy_nodes_update; ++t) {
vpx_prob newp = new_coef_probs[i][j][k][l][t];
vpx_prob *oldp = old_coef_probs[i][j][k][l] + t;
int s;
int u = 0;
if (t == PIVOT_NODE) {
s = vp9_prob_diff_update_savings_search_model(
frame_branch_ct[i][j][k][l][0],
*oldp, &newp, upd, stepsize);
} else {
s = vp9_prob_diff_update_savings_search(
frame_branch_ct[i][j][k][l][t],
*oldp, &newp, upd);
}
if (s > 0 && newp != *oldp)
u = 1;
updates += u;
if (u == 0 && updates == 0) {
noupdates_before_first++;
continue;
}
if (u == 1 && updates == 1) {
int v;
// first update
vpx_write_bit(bc, 1);
for (v = 0; v < noupdates_before_first; ++v)
vpx_write(bc, 0, upd);
}
vpx_write(bc, u, upd);
if (u) {
/* send/use new probability */
vp9_write_prob_diff_update(bc, newp, *oldp);
*oldp = newp;
}
}
}
}
}
}
if (updates == 0) {
vpx_write_bit(bc, 0); // no updates
}
return;
}
default:
assert(0);
}
}
static void pack_inter_mode_mvs(VP9_COMP *cpi, const MODE_INFO *mi,
vpx_writer *w) {
VP9_COMMON *const cm = &cpi->common;
const nmv_context *nmvc = &cm->fc->nmvc;
const MACROBLOCK *const x = &cpi->td.mb;
const MACROBLOCKD *const xd = &x->e_mbd;
const struct segmentation *const seg = &cm->seg;
const MB_MODE_INFO_EXT *const mbmi_ext = x->mbmi_ext;
const PREDICTION_MODE mode = mi->mode;
const int segment_id = mi->segment_id;
const BLOCK_SIZE bsize = mi->sb_type;
const int allow_hp = cm->allow_high_precision_mv;
const int is_inter = is_inter_block(mi);
const int is_compound = has_second_ref(mi);
int skip, ref;
if (seg->update_map) {
if (seg->temporal_update) {
const int pred_flag = mi->seg_id_predicted;
vpx_prob pred_prob = vp9_get_pred_prob_seg_id(seg, xd);
vpx_write(w, pred_flag, pred_prob);
if (!pred_flag)
write_segment_id(w, seg, segment_id);
} else {
write_segment_id(w, seg, segment_id);
}
}
skip = write_skip(cm, xd, segment_id, mi, w);
if (!segfeature_active(seg, segment_id, SEG_LVL_REF_FRAME))
vpx_write(w, is_inter, vp9_get_intra_inter_prob(cm, xd));
if (bsize >= BLOCK_8X8 && cm->tx_mode == TX_MODE_SELECT &&
!(is_inter && skip)) {
write_selected_tx_size(cm, xd, w);
}
if (!is_inter) {
if (bsize >= BLOCK_8X8) {
write_intra_mode(w, mode, cm->fc->y_mode_prob[size_group_lookup[bsize]]);
} else {
int idx, idy;
const int num_4x4_w = num_4x4_blocks_wide_lookup[bsize];
const int num_4x4_h = num_4x4_blocks_high_lookup[bsize];
for (idy = 0; idy < 2; idy += num_4x4_h) {
for (idx = 0; idx < 2; idx += num_4x4_w) {
const PREDICTION_MODE b_mode = mi->bmi[idy * 2 + idx].as_mode;
write_intra_mode(w, b_mode, cm->fc->y_mode_prob[0]);
}
}
}
write_intra_mode(w, mi->uv_mode, cm->fc->uv_mode_prob[mode]);
} else {
const int mode_ctx = mbmi_ext->mode_context[mi->ref_frame[0]];
const vpx_prob *const inter_probs = cm->fc->inter_mode_probs[mode_ctx];
write_ref_frames(cm, xd, w);
// If segment skip is not enabled code the mode.
if (!segfeature_active(seg, segment_id, SEG_LVL_SKIP)) {
if (bsize >= BLOCK_8X8) {
write_inter_mode(w, mode, inter_probs);
}
}
if (cm->interp_filter == SWITCHABLE) {
const int ctx = vp9_get_pred_context_switchable_interp(xd);
vp9_write_token(w, vp9_switchable_interp_tree,
cm->fc->switchable_interp_prob[ctx],
&switchable_interp_encodings[mi->interp_filter]);
++cpi->interp_filter_selected[0][mi->interp_filter];
} else {
assert(mi->interp_filter == cm->interp_filter);
}
if (bsize < BLOCK_8X8) {
const int num_4x4_w = num_4x4_blocks_wide_lookup[bsize];
const int num_4x4_h = num_4x4_blocks_high_lookup[bsize];
int idx, idy;
for (idy = 0; idy < 2; idy += num_4x4_h) {
for (idx = 0; idx < 2; idx += num_4x4_w) {
const int j = idy * 2 + idx;
const PREDICTION_MODE b_mode = mi->bmi[j].as_mode;
write_inter_mode(w, b_mode, inter_probs);
if (b_mode == NEWMV) {
for (ref = 0; ref < 1 + is_compound; ++ref)
vp9_encode_mv(cpi, w, &mi->bmi[j].as_mv[ref].as_mv,
&mbmi_ext->ref_mvs[mi->ref_frame[ref]][0].as_mv,
nmvc, allow_hp);
}
}
}
} else {
if (mode == NEWMV) {
for (ref = 0; ref < 1 + is_compound; ++ref)
vp9_encode_mv(cpi, w, &mi->mv[ref].as_mv,
&mbmi_ext->ref_mvs[mi->ref_frame[ref]][0].as_mv, nmvc,
allow_hp);
}
}
}
}
static void pack_mb_tokens(vpx_writer *w,
TOKENEXTRA **tp, const TOKENEXTRA *const stop,
vpx_bit_depth_t bit_depth) {
const TOKENEXTRA *p;
const vp9_extra_bit *const extra_bits =
#if CONFIG_VP9_HIGHBITDEPTH
(bit_depth == VPX_BITS_12) ? vp9_extra_bits_high12 :
(bit_depth == VPX_BITS_10) ? vp9_extra_bits_high10 :
vp9_extra_bits;
#else
vp9_extra_bits;
(void) bit_depth;
#endif // CONFIG_VP9_HIGHBITDEPTH
for (p = *tp; p < stop && p->token != EOSB_TOKEN; ++p) {
if (p->token == EOB_TOKEN) {
vpx_write(w, 0, p->context_tree[0]);
continue;
}
vpx_write(w, 1, p->context_tree[0]);
while (p->token == ZERO_TOKEN) {
vpx_write(w, 0, p->context_tree[1]);
++p;
if (p == stop || p->token == EOSB_TOKEN) {
*tp = (TOKENEXTRA*)(uintptr_t)p + (p->token == EOSB_TOKEN);
return;
}
}
{
const int t = p->token;
const vpx_prob *const context_tree = p->context_tree;
assert(t != ZERO_TOKEN);
assert(t != EOB_TOKEN);
assert(t != EOSB_TOKEN);
vpx_write(w, 1, context_tree[1]);
if (t == ONE_TOKEN) {
vpx_write(w, 0, context_tree[2]);
vpx_write_bit(w, p->extra & 1);
} else { // t >= TWO_TOKEN && t < EOB_TOKEN
const struct vp9_token *const a = &vp9_coef_encodings[t];
const int v = a->value;
const int n = a->len;
const int e = p->extra;
vpx_write(w, 1, context_tree[2]);
vp9_write_tree(w, vp9_coef_con_tree,
vp9_pareto8_full[context_tree[PIVOT_NODE] - 1], v,
n - UNCONSTRAINED_NODES, 0);
if (t >= CATEGORY1_TOKEN) {
const vp9_extra_bit *const b = &extra_bits[t];
const unsigned char *pb = b->prob;
int v = e >> 1;
int n = b->len; // number of bits in v, assumed nonzero
do {
const int bb = (v >> --n) & 1;
vpx_write(w, bb, *pb++);
} while (n);
}
vpx_write_bit(w, e & 1);
}
}
}
*tp = (TOKENEXTRA*)(uintptr_t)p + (p->token == EOSB_TOKEN);
}
