2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
15 #include "vpx/vpx_encoder.h"
16 #include "vpx_mem/vpx_mem.h"
17 #include "vpx_ports/mem_ops.h"
19 #include "vp9/common/vp9_entropy.h"
20 #include "vp9/common/vp9_entropymode.h"
21 #include "vp9/common/vp9_entropymv.h"
22 #include "vp9/common/vp9_mvref_common.h"
23 #include "vp9/common/vp9_pred_common.h"
24 #include "vp9/common/vp9_seg_common.h"
25 #include "vp9/common/vp9_systemdependent.h"
26 #include "vp9/common/vp9_tile_common.h"
28 #include "vp9/encoder/vp9_cost.h"
29 #include "vp9/encoder/vp9_bitstream.h"
30 #include "vp9/encoder/vp9_encodemv.h"
31 #include "vp9/encoder/vp9_mcomp.h"
32 #include "vp9/encoder/vp9_segmentation.h"
33 #include "vp9/encoder/vp9_subexp.h"
34 #include "vp9/encoder/vp9_tokenize.h"
35 #include "vp9/encoder/vp9_write_bit_buffer.h"
37 static struct vp9_token intra_mode_encodings[INTRA_MODES];
38 static struct vp9_token switchable_interp_encodings[SWITCHABLE_FILTERS];
39 static struct vp9_token partition_encodings[PARTITION_TYPES];
40 static struct vp9_token inter_mode_encodings[INTER_MODES];
42 void vp9_entropy_mode_init() {
43 vp9_tokens_from_tree(intra_mode_encodings, vp9_intra_mode_tree);
44 vp9_tokens_from_tree(switchable_interp_encodings, vp9_switchable_interp_tree);
45 vp9_tokens_from_tree(partition_encodings, vp9_partition_tree);
46 vp9_tokens_from_tree(inter_mode_encodings, vp9_inter_mode_tree);
49 static void write_intra_mode(vp9_writer *w, PREDICTION_MODE mode,
50 const vp9_prob *probs) {
51 vp9_write_token(w, vp9_intra_mode_tree, probs, &intra_mode_encodings[mode]);
54 static void write_inter_mode(vp9_writer *w, PREDICTION_MODE mode,
55 const vp9_prob *probs) {
56 assert(is_inter_mode(mode));
57 vp9_write_token(w, vp9_inter_mode_tree, probs,
58 &inter_mode_encodings[INTER_OFFSET(mode)]);
61 static void encode_unsigned_max(struct vp9_write_bit_buffer *wb,
63 vp9_wb_write_literal(wb, data, get_unsigned_bits(max));
66 static void prob_diff_update(const vp9_tree_index *tree,
67 vp9_prob probs[/*n - 1*/],
68 const unsigned int counts[/*n - 1*/],
69 int n, vp9_writer *w) {
71 unsigned int branch_ct[32][2];
73 // Assuming max number of probabilities <= 32
76 vp9_tree_probs_from_distribution(tree, branch_ct, counts);
77 for (i = 0; i < n - 1; ++i)
78 vp9_cond_prob_diff_update(w, &probs[i], branch_ct[i]);
81 static void write_selected_tx_size(const VP9_COMMON *cm,
82 const MACROBLOCKD *xd,
83 TX_SIZE tx_size, BLOCK_SIZE bsize,
85 const TX_SIZE max_tx_size = max_txsize_lookup[bsize];
86 const vp9_prob *const tx_probs = get_tx_probs2(max_tx_size, xd,
88 vp9_write(w, tx_size != TX_4X4, tx_probs[0]);
89 if (tx_size != TX_4X4 && max_tx_size >= TX_16X16) {
90 vp9_write(w, tx_size != TX_8X8, tx_probs[1]);
91 if (tx_size != TX_8X8 && max_tx_size >= TX_32X32)
92 vp9_write(w, tx_size != TX_16X16, tx_probs[2]);
96 static int write_skip(const VP9_COMMON *cm, const MACROBLOCKD *xd,
97 int segment_id, const MODE_INFO *mi, vp9_writer *w) {
98 if (vp9_segfeature_active(&cm->seg, segment_id, SEG_LVL_SKIP)) {
101 const int skip = mi->mbmi.skip;
102 vp9_write(w, skip, vp9_get_skip_prob(cm, xd));
107 static void update_skip_probs(VP9_COMMON *cm, vp9_writer *w) {
110 for (k = 0; k < SKIP_CONTEXTS; ++k)
111 vp9_cond_prob_diff_update(w, &cm->fc.skip_probs[k], cm->counts.skip[k]);
114 static void update_switchable_interp_probs(VP9_COMMON *cm, vp9_writer *w) {
116 for (j = 0; j < SWITCHABLE_FILTER_CONTEXTS; ++j)
117 prob_diff_update(vp9_switchable_interp_tree,
118 cm->fc.switchable_interp_prob[j],
119 cm->counts.switchable_interp[j], SWITCHABLE_FILTERS, w);
122 static void pack_mb_tokens(vp9_writer *w,
123 TOKENEXTRA **tp, const TOKENEXTRA *const stop,
124 vpx_bit_depth_t bit_depth) {
127 while (p < stop && p->token != EOSB_TOKEN) {
128 const int t = p->token;
129 const struct vp9_token *const a = &vp9_coef_encodings[t];
133 #if CONFIG_VP9_HIGHBITDEPTH
134 const vp9_extra_bit *b;
135 if (bit_depth == VPX_BITS_12)
136 b = &vp9_extra_bits_high12[t];
137 else if (bit_depth == VPX_BITS_10)
138 b = &vp9_extra_bits_high10[t];
140 b = &vp9_extra_bits[t];
142 const vp9_extra_bit *const b = &vp9_extra_bits[t];
144 #endif // CONFIG_VP9_HIGHBITDEPTH
146 /* skip one or two nodes */
147 if (p->skip_eob_node) {
148 n -= p->skip_eob_node;
149 i = 2 * p->skip_eob_node;
152 // TODO(jbb): expanding this can lead to big gains. It allows
153 // much better branch prediction and would enable us to avoid numerous
154 // lookups and compares.
156 // If we have a token that's in the constrained set, the coefficient tree
157 // is split into two treed writes. The first treed write takes care of the
158 // unconstrained nodes. The second treed write takes care of the
159 // constrained nodes.
160 if (t >= TWO_TOKEN && t < EOB_TOKEN) {
161 int len = UNCONSTRAINED_NODES - p->skip_eob_node;
162 int bits = v >> (n - len);
163 vp9_write_tree(w, vp9_coef_tree, p->context_tree, bits, len, i);
164 vp9_write_tree(w, vp9_coef_con_tree,
165 vp9_pareto8_full[p->context_tree[PIVOT_NODE] - 1],
168 vp9_write_tree(w, vp9_coef_tree, p->context_tree, v, n, i);
172 const int e = p->extra, l = b->len;
175 const unsigned char *pb = b->prob;
177 int n = l; /* number of bits in v, assumed nonzero */
181 const int bb = (v >> --n) & 1;
182 vp9_write(w, bb, pb[i >> 1]);
187 vp9_write_bit(w, e & 1);
192 *tp = p + (p->token == EOSB_TOKEN);
195 static void write_segment_id(vp9_writer *w, const struct segmentation *seg,
197 if (seg->enabled && seg->update_map)
198 vp9_write_tree(w, vp9_segment_tree, seg->tree_probs, segment_id, 3, 0);
201 // This function encodes the reference frame
202 static void write_ref_frames(const VP9_COMMON *cm, const MACROBLOCKD *xd,
204 const MB_MODE_INFO *const mbmi = &xd->mi[0].src_mi->mbmi;
205 const int is_compound = has_second_ref(mbmi);
206 const int segment_id = mbmi->segment_id;
208 // If segment level coding of this signal is disabled...
209 // or the segment allows multiple reference frame options
210 if (vp9_segfeature_active(&cm->seg, segment_id, SEG_LVL_REF_FRAME)) {
211 assert(!is_compound);
212 assert(mbmi->ref_frame[0] ==
213 vp9_get_segdata(&cm->seg, segment_id, SEG_LVL_REF_FRAME));
215 // does the feature use compound prediction or not
216 // (if not specified at the frame/segment level)
217 if (cm->reference_mode == REFERENCE_MODE_SELECT) {
218 vp9_write(w, is_compound, vp9_get_reference_mode_prob(cm, xd));
220 assert(!is_compound == (cm->reference_mode == SINGLE_REFERENCE));
224 vp9_write(w, mbmi->ref_frame[0] == GOLDEN_FRAME,
225 vp9_get_pred_prob_comp_ref_p(cm, xd));
227 const int bit0 = mbmi->ref_frame[0] != LAST_FRAME;
228 vp9_write(w, bit0, vp9_get_pred_prob_single_ref_p1(cm, xd));
230 const int bit1 = mbmi->ref_frame[0] != GOLDEN_FRAME;
231 vp9_write(w, bit1, vp9_get_pred_prob_single_ref_p2(cm, xd));
237 static void pack_inter_mode_mvs(VP9_COMP *cpi, const MODE_INFO *mi,
239 VP9_COMMON *const cm = &cpi->common;
240 const nmv_context *nmvc = &cm->fc.nmvc;
241 const MACROBLOCK *const x = &cpi->mb;
242 const MACROBLOCKD *const xd = &x->e_mbd;
243 const struct segmentation *const seg = &cm->seg;
244 const MB_MODE_INFO *const mbmi = &mi->mbmi;
245 const PREDICTION_MODE mode = mbmi->mode;
246 const int segment_id = mbmi->segment_id;
247 const BLOCK_SIZE bsize = mbmi->sb_type;
248 const int allow_hp = cm->allow_high_precision_mv;
249 const int is_inter = is_inter_block(mbmi);
250 const int is_compound = has_second_ref(mbmi);
253 if (seg->update_map) {
254 if (seg->temporal_update) {
255 const int pred_flag = mbmi->seg_id_predicted;
256 vp9_prob pred_prob = vp9_get_pred_prob_seg_id(seg, xd);
257 vp9_write(w, pred_flag, pred_prob);
259 write_segment_id(w, seg, segment_id);
261 write_segment_id(w, seg, segment_id);
265 skip = write_skip(cm, xd, segment_id, mi, w);
267 if (!vp9_segfeature_active(seg, segment_id, SEG_LVL_REF_FRAME))
268 vp9_write(w, is_inter, vp9_get_intra_inter_prob(cm, xd));
270 if (bsize >= BLOCK_8X8 && cm->tx_mode == TX_MODE_SELECT &&
272 (skip || vp9_segfeature_active(seg, segment_id, SEG_LVL_SKIP)))) {
273 write_selected_tx_size(cm, xd, mbmi->tx_size, bsize, w);
277 if (bsize >= BLOCK_8X8) {
278 write_intra_mode(w, mode, cm->fc.y_mode_prob[size_group_lookup[bsize]]);
281 const int num_4x4_w = num_4x4_blocks_wide_lookup[bsize];
282 const int num_4x4_h = num_4x4_blocks_high_lookup[bsize];
283 for (idy = 0; idy < 2; idy += num_4x4_h) {
284 for (idx = 0; idx < 2; idx += num_4x4_w) {
285 const PREDICTION_MODE b_mode = mi->bmi[idy * 2 + idx].as_mode;
286 write_intra_mode(w, b_mode, cm->fc.y_mode_prob[0]);
290 write_intra_mode(w, mbmi->uv_mode, cm->fc.uv_mode_prob[mode]);
292 const int mode_ctx = mbmi->mode_context[mbmi->ref_frame[0]];
293 const vp9_prob *const inter_probs = cm->fc.inter_mode_probs[mode_ctx];
294 write_ref_frames(cm, xd, w);
296 // If segment skip is not enabled code the mode.
297 if (!vp9_segfeature_active(seg, segment_id, SEG_LVL_SKIP)) {
298 if (bsize >= BLOCK_8X8) {
299 write_inter_mode(w, mode, inter_probs);
300 ++cm->counts.inter_mode[mode_ctx][INTER_OFFSET(mode)];
304 if (cm->interp_filter == SWITCHABLE) {
305 const int ctx = vp9_get_pred_context_switchable_interp(xd);
306 vp9_write_token(w, vp9_switchable_interp_tree,
307 cm->fc.switchable_interp_prob[ctx],
308 &switchable_interp_encodings[mbmi->interp_filter]);
309 ++cpi->interp_filter_selected[0][mbmi->interp_filter];
311 assert(mbmi->interp_filter == cm->interp_filter);
314 if (bsize < BLOCK_8X8) {
315 const int num_4x4_w = num_4x4_blocks_wide_lookup[bsize];
316 const int num_4x4_h = num_4x4_blocks_high_lookup[bsize];
318 for (idy = 0; idy < 2; idy += num_4x4_h) {
319 for (idx = 0; idx < 2; idx += num_4x4_w) {
320 const int j = idy * 2 + idx;
321 const PREDICTION_MODE b_mode = mi->bmi[j].as_mode;
322 write_inter_mode(w, b_mode, inter_probs);
323 ++cm->counts.inter_mode[mode_ctx][INTER_OFFSET(b_mode)];
324 if (b_mode == NEWMV) {
325 for (ref = 0; ref < 1 + is_compound; ++ref)
326 vp9_encode_mv(cpi, w, &mi->bmi[j].as_mv[ref].as_mv,
327 &mbmi->ref_mvs[mbmi->ref_frame[ref]][0].as_mv,
334 for (ref = 0; ref < 1 + is_compound; ++ref)
335 vp9_encode_mv(cpi, w, &mbmi->mv[ref].as_mv,
336 &mbmi->ref_mvs[mbmi->ref_frame[ref]][0].as_mv, nmvc,
343 static void write_mb_modes_kf(const VP9_COMMON *cm, const MACROBLOCKD *xd,
344 MODE_INFO *mi_8x8, vp9_writer *w) {
345 const struct segmentation *const seg = &cm->seg;
346 const MODE_INFO *const mi = mi_8x8;
347 const MODE_INFO *const above_mi = mi_8x8[-xd->mi_stride].src_mi;
348 const MODE_INFO *const left_mi =
349 xd->left_available ? mi_8x8[-1].src_mi : NULL;
350 const MB_MODE_INFO *const mbmi = &mi->mbmi;
351 const BLOCK_SIZE bsize = mbmi->sb_type;
354 write_segment_id(w, seg, mbmi->segment_id);
356 write_skip(cm, xd, mbmi->segment_id, mi, w);
358 if (bsize >= BLOCK_8X8 && cm->tx_mode == TX_MODE_SELECT)
359 write_selected_tx_size(cm, xd, mbmi->tx_size, bsize, w);
361 if (bsize >= BLOCK_8X8) {
362 write_intra_mode(w, mbmi->mode, get_y_mode_probs(mi, above_mi, left_mi, 0));
364 const int num_4x4_w = num_4x4_blocks_wide_lookup[bsize];
365 const int num_4x4_h = num_4x4_blocks_high_lookup[bsize];
368 for (idy = 0; idy < 2; idy += num_4x4_h) {
369 for (idx = 0; idx < 2; idx += num_4x4_w) {
370 const int block = idy * 2 + idx;
371 write_intra_mode(w, mi->bmi[block].as_mode,
372 get_y_mode_probs(mi, above_mi, left_mi, block));
377 write_intra_mode(w, mbmi->uv_mode, vp9_kf_uv_mode_prob[mbmi->mode]);
380 static void write_modes_b(VP9_COMP *cpi, const TileInfo *const tile,
381 vp9_writer *w, TOKENEXTRA **tok,
382 const TOKENEXTRA *const tok_end,
383 int mi_row, int mi_col) {
384 const VP9_COMMON *const cm = &cpi->common;
385 MACROBLOCKD *const xd = &cpi->mb.e_mbd;
388 xd->mi = cm->mi + (mi_row * cm->mi_stride + mi_col);
391 set_mi_row_col(xd, tile,
392 mi_row, num_8x8_blocks_high_lookup[m->mbmi.sb_type],
393 mi_col, num_8x8_blocks_wide_lookup[m->mbmi.sb_type],
394 cm->mi_rows, cm->mi_cols);
395 if (frame_is_intra_only(cm)) {
396 write_mb_modes_kf(cm, xd, xd->mi, w);
398 pack_inter_mode_mvs(cpi, m, w);
401 assert(*tok < tok_end);
402 pack_mb_tokens(w, tok, tok_end, cm->bit_depth);
405 static void write_partition(const VP9_COMMON *const cm,
406 const MACROBLOCKD *const xd,
407 int hbs, int mi_row, int mi_col,
408 PARTITION_TYPE p, BLOCK_SIZE bsize, vp9_writer *w) {
409 const int ctx = partition_plane_context(xd, mi_row, mi_col, bsize);
410 const vp9_prob *const probs = get_partition_probs(cm, ctx);
411 const int has_rows = (mi_row + hbs) < cm->mi_rows;
412 const int has_cols = (mi_col + hbs) < cm->mi_cols;
414 if (has_rows && has_cols) {
415 vp9_write_token(w, vp9_partition_tree, probs, &partition_encodings[p]);
416 } else if (!has_rows && has_cols) {
417 assert(p == PARTITION_SPLIT || p == PARTITION_HORZ);
418 vp9_write(w, p == PARTITION_SPLIT, probs[1]);
419 } else if (has_rows && !has_cols) {
420 assert(p == PARTITION_SPLIT || p == PARTITION_VERT);
421 vp9_write(w, p == PARTITION_SPLIT, probs[2]);
423 assert(p == PARTITION_SPLIT);
427 static void write_modes_sb(VP9_COMP *cpi,
428 const TileInfo *const tile, vp9_writer *w,
429 TOKENEXTRA **tok, const TOKENEXTRA *const tok_end,
430 int mi_row, int mi_col, BLOCK_SIZE bsize) {
431 const VP9_COMMON *const cm = &cpi->common;
432 MACROBLOCKD *const xd = &cpi->mb.e_mbd;
434 const int bsl = b_width_log2_lookup[bsize];
435 const int bs = (1 << bsl) / 4;
436 PARTITION_TYPE partition;
438 const MODE_INFO *m = NULL;
440 if (mi_row >= cm->mi_rows || mi_col >= cm->mi_cols)
443 m = cm->mi[mi_row * cm->mi_stride + mi_col].src_mi;
445 partition = partition_lookup[bsl][m->mbmi.sb_type];
446 write_partition(cm, xd, bs, mi_row, mi_col, partition, bsize, w);
447 subsize = get_subsize(bsize, partition);
448 if (subsize < BLOCK_8X8) {
449 write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col);
453 write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col);
456 write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col);
457 if (mi_row + bs < cm->mi_rows)
458 write_modes_b(cpi, tile, w, tok, tok_end, mi_row + bs, mi_col);
461 write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col);
462 if (mi_col + bs < cm->mi_cols)
463 write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col + bs);
465 case PARTITION_SPLIT:
466 write_modes_sb(cpi, tile, w, tok, tok_end, mi_row, mi_col, subsize);
467 write_modes_sb(cpi, tile, w, tok, tok_end, mi_row, mi_col + bs,
469 write_modes_sb(cpi, tile, w, tok, tok_end, mi_row + bs, mi_col,
471 write_modes_sb(cpi, tile, w, tok, tok_end, mi_row + bs, mi_col + bs,
479 // update partition context
480 if (bsize >= BLOCK_8X8 &&
481 (bsize == BLOCK_8X8 || partition != PARTITION_SPLIT))
482 update_partition_context(xd, mi_row, mi_col, subsize, bsize);
485 static void write_modes(VP9_COMP *cpi,
486 const TileInfo *const tile, vp9_writer *w,
487 TOKENEXTRA **tok, const TOKENEXTRA *const tok_end) {
490 for (mi_row = tile->mi_row_start; mi_row < tile->mi_row_end;
491 mi_row += MI_BLOCK_SIZE) {
492 vp9_zero(cpi->mb.e_mbd.left_seg_context);
493 for (mi_col = tile->mi_col_start; mi_col < tile->mi_col_end;
494 mi_col += MI_BLOCK_SIZE)
495 write_modes_sb(cpi, tile, w, tok, tok_end, mi_row, mi_col,
500 static void build_tree_distribution(VP9_COMP *cpi, TX_SIZE tx_size,
501 vp9_coeff_stats *coef_branch_ct,
502 vp9_coeff_probs_model *coef_probs) {
503 vp9_coeff_count *coef_counts = cpi->coef_counts[tx_size];
504 unsigned int (*eob_branch_ct)[REF_TYPES][COEF_BANDS][COEFF_CONTEXTS] =
505 cpi->common.counts.eob_branch[tx_size];
508 for (i = 0; i < PLANE_TYPES; ++i) {
509 for (j = 0; j < REF_TYPES; ++j) {
510 for (k = 0; k < COEF_BANDS; ++k) {
511 for (l = 0; l < BAND_COEFF_CONTEXTS(k); ++l) {
512 vp9_tree_probs_from_distribution(vp9_coef_tree,
513 coef_branch_ct[i][j][k][l],
514 coef_counts[i][j][k][l]);
515 coef_branch_ct[i][j][k][l][0][1] = eob_branch_ct[i][j][k][l] -
516 coef_branch_ct[i][j][k][l][0][0];
517 for (m = 0; m < UNCONSTRAINED_NODES; ++m)
518 coef_probs[i][j][k][l][m] = get_binary_prob(
519 coef_branch_ct[i][j][k][l][m][0],
520 coef_branch_ct[i][j][k][l][m][1]);
527 static void update_coef_probs_common(vp9_writer* const bc, VP9_COMP *cpi,
529 vp9_coeff_stats *frame_branch_ct,
530 vp9_coeff_probs_model *new_coef_probs) {
531 vp9_coeff_probs_model *old_coef_probs = cpi->common.fc.coef_probs[tx_size];
532 const vp9_prob upd = DIFF_UPDATE_PROB;
533 const int entropy_nodes_update = UNCONSTRAINED_NODES;
535 switch (cpi->sf.use_fast_coef_updates) {
537 /* dry run to see if there is any update at all needed */
539 int update[2] = {0, 0};
540 for (i = 0; i < PLANE_TYPES; ++i) {
541 for (j = 0; j < REF_TYPES; ++j) {
542 for (k = 0; k < COEF_BANDS; ++k) {
543 for (l = 0; l < BAND_COEFF_CONTEXTS(k); ++l) {
544 for (t = 0; t < entropy_nodes_update; ++t) {
545 vp9_prob newp = new_coef_probs[i][j][k][l][t];
546 const vp9_prob oldp = old_coef_probs[i][j][k][l][t];
550 s = vp9_prob_diff_update_savings_search_model(
551 frame_branch_ct[i][j][k][l][0],
552 old_coef_probs[i][j][k][l], &newp, upd);
554 s = vp9_prob_diff_update_savings_search(
555 frame_branch_ct[i][j][k][l][t], oldp, &newp, upd);
556 if (s > 0 && newp != oldp)
559 savings += s - (int)(vp9_cost_zero(upd));
561 savings -= (int)(vp9_cost_zero(upd));
569 // printf("Update %d %d, savings %d\n", update[0], update[1], savings);
570 /* Is coef updated at all */
571 if (update[1] == 0 || savings < 0) {
572 vp9_write_bit(bc, 0);
575 vp9_write_bit(bc, 1);
576 for (i = 0; i < PLANE_TYPES; ++i) {
577 for (j = 0; j < REF_TYPES; ++j) {
578 for (k = 0; k < COEF_BANDS; ++k) {
579 for (l = 0; l < BAND_COEFF_CONTEXTS(k); ++l) {
580 // calc probs and branch cts for this frame only
581 for (t = 0; t < entropy_nodes_update; ++t) {
582 vp9_prob newp = new_coef_probs[i][j][k][l][t];
583 vp9_prob *oldp = old_coef_probs[i][j][k][l] + t;
584 const vp9_prob upd = DIFF_UPDATE_PROB;
588 s = vp9_prob_diff_update_savings_search_model(
589 frame_branch_ct[i][j][k][l][0],
590 old_coef_probs[i][j][k][l], &newp, upd);
592 s = vp9_prob_diff_update_savings_search(
593 frame_branch_ct[i][j][k][l][t],
595 if (s > 0 && newp != *oldp)
597 vp9_write(bc, u, upd);
599 /* send/use new probability */
600 vp9_write_prob_diff_update(bc, newp, *oldp);
612 case ONE_LOOP_REDUCED: {
613 const int prev_coef_contexts_to_update =
614 cpi->sf.use_fast_coef_updates == ONE_LOOP_REDUCED ?
615 COEFF_CONTEXTS >> 1 : COEFF_CONTEXTS;
616 const int coef_band_to_update =
617 cpi->sf.use_fast_coef_updates == ONE_LOOP_REDUCED ?
618 COEF_BANDS >> 1 : COEF_BANDS;
620 int noupdates_before_first = 0;
621 for (i = 0; i < PLANE_TYPES; ++i) {
622 for (j = 0; j < REF_TYPES; ++j) {
623 for (k = 0; k < COEF_BANDS; ++k) {
624 for (l = 0; l < BAND_COEFF_CONTEXTS(k); ++l) {
625 // calc probs and branch cts for this frame only
626 for (t = 0; t < entropy_nodes_update; ++t) {
627 vp9_prob newp = new_coef_probs[i][j][k][l][t];
628 vp9_prob *oldp = old_coef_probs[i][j][k][l] + t;
631 if (l >= prev_coef_contexts_to_update ||
632 k >= coef_band_to_update) {
636 s = vp9_prob_diff_update_savings_search_model(
637 frame_branch_ct[i][j][k][l][0],
638 old_coef_probs[i][j][k][l], &newp, upd);
640 s = vp9_prob_diff_update_savings_search(
641 frame_branch_ct[i][j][k][l][t],
643 if (s > 0 && newp != *oldp)
647 if (u == 0 && updates == 0) {
648 noupdates_before_first++;
651 if (u == 1 && updates == 1) {
654 vp9_write_bit(bc, 1);
655 for (v = 0; v < noupdates_before_first; ++v)
656 vp9_write(bc, 0, upd);
658 vp9_write(bc, u, upd);
660 /* send/use new probability */
661 vp9_write_prob_diff_update(bc, newp, *oldp);
670 vp9_write_bit(bc, 0); // no updates
680 static void update_coef_probs(VP9_COMP *cpi, vp9_writer* w) {
681 const TX_MODE tx_mode = cpi->common.tx_mode;
682 const TX_SIZE max_tx_size = tx_mode_to_biggest_tx_size[tx_mode];
684 vp9_coeff_stats frame_branch_ct[TX_SIZES][PLANE_TYPES];
685 vp9_coeff_probs_model frame_coef_probs[TX_SIZES][PLANE_TYPES];
687 for (tx_size = TX_4X4; tx_size <= TX_32X32; ++tx_size)
688 build_tree_distribution(cpi, tx_size, frame_branch_ct[tx_size],
689 frame_coef_probs[tx_size]);
691 for (tx_size = TX_4X4; tx_size <= max_tx_size; ++tx_size)
692 update_coef_probs_common(w, cpi, tx_size, frame_branch_ct[tx_size],
693 frame_coef_probs[tx_size]);
696 static void encode_loopfilter(struct loopfilter *lf,
697 struct vp9_write_bit_buffer *wb) {
700 // Encode the loop filter level and type
701 vp9_wb_write_literal(wb, lf->filter_level, 6);
702 vp9_wb_write_literal(wb, lf->sharpness_level, 3);
704 // Write out loop filter deltas applied at the MB level based on mode or
705 // ref frame (if they are enabled).
706 vp9_wb_write_bit(wb, lf->mode_ref_delta_enabled);
708 if (lf->mode_ref_delta_enabled) {
709 vp9_wb_write_bit(wb, lf->mode_ref_delta_update);
710 if (lf->mode_ref_delta_update) {
711 for (i = 0; i < MAX_REF_LF_DELTAS; i++) {
712 const int delta = lf->ref_deltas[i];
713 const int changed = delta != lf->last_ref_deltas[i];
714 vp9_wb_write_bit(wb, changed);
716 lf->last_ref_deltas[i] = delta;
717 vp9_wb_write_literal(wb, abs(delta) & 0x3F, 6);
718 vp9_wb_write_bit(wb, delta < 0);
722 for (i = 0; i < MAX_MODE_LF_DELTAS; i++) {
723 const int delta = lf->mode_deltas[i];
724 const int changed = delta != lf->last_mode_deltas[i];
725 vp9_wb_write_bit(wb, changed);
727 lf->last_mode_deltas[i] = delta;
728 vp9_wb_write_literal(wb, abs(delta) & 0x3F, 6);
729 vp9_wb_write_bit(wb, delta < 0);
736 static void write_delta_q(struct vp9_write_bit_buffer *wb, int delta_q) {
738 vp9_wb_write_bit(wb, 1);
739 vp9_wb_write_literal(wb, abs(delta_q), 4);
740 vp9_wb_write_bit(wb, delta_q < 0);
742 vp9_wb_write_bit(wb, 0);
746 static void encode_quantization(const VP9_COMMON *const cm,
747 struct vp9_write_bit_buffer *wb) {
748 vp9_wb_write_literal(wb, cm->base_qindex, QINDEX_BITS);
749 write_delta_q(wb, cm->y_dc_delta_q);
750 write_delta_q(wb, cm->uv_dc_delta_q);
751 write_delta_q(wb, cm->uv_ac_delta_q);
754 static void encode_segmentation(VP9_COMMON *cm, MACROBLOCKD *xd,
755 struct vp9_write_bit_buffer *wb) {
758 const struct segmentation *seg = &cm->seg;
760 vp9_wb_write_bit(wb, seg->enabled);
765 vp9_wb_write_bit(wb, seg->update_map);
766 if (seg->update_map) {
767 // Select the coding strategy (temporal or spatial)
768 vp9_choose_segmap_coding_method(cm, xd);
769 // Write out probabilities used to decode unpredicted macro-block segments
770 for (i = 0; i < SEG_TREE_PROBS; i++) {
771 const int prob = seg->tree_probs[i];
772 const int update = prob != MAX_PROB;
773 vp9_wb_write_bit(wb, update);
775 vp9_wb_write_literal(wb, prob, 8);
778 // Write out the chosen coding method.
779 vp9_wb_write_bit(wb, seg->temporal_update);
780 if (seg->temporal_update) {
781 for (i = 0; i < PREDICTION_PROBS; i++) {
782 const int prob = seg->pred_probs[i];
783 const int update = prob != MAX_PROB;
784 vp9_wb_write_bit(wb, update);
786 vp9_wb_write_literal(wb, prob, 8);
792 vp9_wb_write_bit(wb, seg->update_data);
793 if (seg->update_data) {
794 vp9_wb_write_bit(wb, seg->abs_delta);
796 for (i = 0; i < MAX_SEGMENTS; i++) {
797 for (j = 0; j < SEG_LVL_MAX; j++) {
798 const int active = vp9_segfeature_active(seg, i, j);
799 vp9_wb_write_bit(wb, active);
801 const int data = vp9_get_segdata(seg, i, j);
802 const int data_max = vp9_seg_feature_data_max(j);
804 if (vp9_is_segfeature_signed(j)) {
805 encode_unsigned_max(wb, abs(data), data_max);
806 vp9_wb_write_bit(wb, data < 0);
808 encode_unsigned_max(wb, data, data_max);
816 static void encode_txfm_probs(VP9_COMMON *cm, vp9_writer *w) {
818 vp9_write_literal(w, MIN(cm->tx_mode, ALLOW_32X32), 2);
819 if (cm->tx_mode >= ALLOW_32X32)
820 vp9_write_bit(w, cm->tx_mode == TX_MODE_SELECT);
823 if (cm->tx_mode == TX_MODE_SELECT) {
825 unsigned int ct_8x8p[TX_SIZES - 3][2];
826 unsigned int ct_16x16p[TX_SIZES - 2][2];
827 unsigned int ct_32x32p[TX_SIZES - 1][2];
830 for (i = 0; i < TX_SIZE_CONTEXTS; i++) {
831 tx_counts_to_branch_counts_8x8(cm->counts.tx.p8x8[i], ct_8x8p);
832 for (j = 0; j < TX_SIZES - 3; j++)
833 vp9_cond_prob_diff_update(w, &cm->fc.tx_probs.p8x8[i][j], ct_8x8p[j]);
836 for (i = 0; i < TX_SIZE_CONTEXTS; i++) {
837 tx_counts_to_branch_counts_16x16(cm->counts.tx.p16x16[i], ct_16x16p);
838 for (j = 0; j < TX_SIZES - 2; j++)
839 vp9_cond_prob_diff_update(w, &cm->fc.tx_probs.p16x16[i][j],
843 for (i = 0; i < TX_SIZE_CONTEXTS; i++) {
844 tx_counts_to_branch_counts_32x32(cm->counts.tx.p32x32[i], ct_32x32p);
845 for (j = 0; j < TX_SIZES - 1; j++)
846 vp9_cond_prob_diff_update(w, &cm->fc.tx_probs.p32x32[i][j],
852 static void write_interp_filter(INTERP_FILTER filter,
853 struct vp9_write_bit_buffer *wb) {
854 const int filter_to_literal[] = { 1, 0, 2, 3 };
856 vp9_wb_write_bit(wb, filter == SWITCHABLE);
857 if (filter != SWITCHABLE)
858 vp9_wb_write_literal(wb, filter_to_literal[filter], 2);
861 static void fix_interp_filter(VP9_COMMON *cm) {
862 if (cm->interp_filter == SWITCHABLE) {
863 // Check to see if only one of the filters is actually used
864 int count[SWITCHABLE_FILTERS];
866 for (i = 0; i < SWITCHABLE_FILTERS; ++i) {
868 for (j = 0; j < SWITCHABLE_FILTER_CONTEXTS; ++j)
869 count[i] += cm->counts.switchable_interp[j][i];
873 // Only one filter is used. So set the filter at frame level
874 for (i = 0; i < SWITCHABLE_FILTERS; ++i) {
876 cm->interp_filter = i;
884 static void write_tile_info(const VP9_COMMON *const cm,
885 struct vp9_write_bit_buffer *wb) {
886 int min_log2_tile_cols, max_log2_tile_cols, ones;
887 vp9_get_tile_n_bits(cm->mi_cols, &min_log2_tile_cols, &max_log2_tile_cols);
890 ones = cm->log2_tile_cols - min_log2_tile_cols;
892 vp9_wb_write_bit(wb, 1);
894 if (cm->log2_tile_cols < max_log2_tile_cols)
895 vp9_wb_write_bit(wb, 0);
898 vp9_wb_write_bit(wb, cm->log2_tile_rows != 0);
899 if (cm->log2_tile_rows != 0)
900 vp9_wb_write_bit(wb, cm->log2_tile_rows != 1);
903 static int get_refresh_mask(VP9_COMP *cpi) {
904 if (vp9_preserve_existing_gf(cpi)) {
905 // We have decided to preserve the previously existing golden frame as our
906 // new ARF frame. However, in the short term we leave it in the GF slot and,
907 // if we're updating the GF with the current decoded frame, we save it
908 // instead to the ARF slot.
909 // Later, in the function vp9_encoder.c:vp9_update_reference_frames() we
910 // will swap gld_fb_idx and alt_fb_idx to achieve our objective. We do it
911 // there so that it can be done outside of the recode loop.
912 // Note: This is highly specific to the use of ARF as a forward reference,
913 // and this needs to be generalized as other uses are implemented
914 // (like RTC/temporal scalability).
915 return (cpi->refresh_last_frame << cpi->lst_fb_idx) |
916 (cpi->refresh_golden_frame << cpi->alt_fb_idx);
918 int arf_idx = cpi->alt_fb_idx;
919 if ((cpi->oxcf.pass == 2) && cpi->multi_arf_allowed) {
920 const GF_GROUP *const gf_group = &cpi->twopass.gf_group;
921 arf_idx = gf_group->arf_update_idx[gf_group->index];
923 return (cpi->refresh_last_frame << cpi->lst_fb_idx) |
924 (cpi->refresh_golden_frame << cpi->gld_fb_idx) |
925 (cpi->refresh_alt_ref_frame << arf_idx);
929 static size_t encode_tiles(VP9_COMP *cpi, uint8_t *data_ptr) {
930 VP9_COMMON *const cm = &cpi->common;
931 vp9_writer residual_bc;
933 int tile_row, tile_col;
934 TOKENEXTRA *tok[4][1 << 6], *tok_end;
935 size_t total_size = 0;
936 const int tile_cols = 1 << cm->log2_tile_cols;
937 const int tile_rows = 1 << cm->log2_tile_rows;
939 vpx_memset(cm->above_seg_context, 0, sizeof(*cm->above_seg_context) *
940 mi_cols_aligned_to_sb(cm->mi_cols));
942 tok[0][0] = cpi->tok;
943 for (tile_row = 0; tile_row < tile_rows; tile_row++) {
945 tok[tile_row][0] = tok[tile_row - 1][tile_cols - 1] +
946 cpi->tok_count[tile_row - 1][tile_cols - 1];
948 for (tile_col = 1; tile_col < tile_cols; tile_col++)
949 tok[tile_row][tile_col] = tok[tile_row][tile_col - 1] +
950 cpi->tok_count[tile_row][tile_col - 1];
953 for (tile_row = 0; tile_row < tile_rows; tile_row++) {
954 for (tile_col = 0; tile_col < tile_cols; tile_col++) {
957 vp9_tile_init(&tile, cm, tile_row, tile_col);
958 tok_end = tok[tile_row][tile_col] + cpi->tok_count[tile_row][tile_col];
960 if (tile_col < tile_cols - 1 || tile_row < tile_rows - 1)
961 vp9_start_encode(&residual_bc, data_ptr + total_size + 4);
963 vp9_start_encode(&residual_bc, data_ptr + total_size);
965 write_modes(cpi, &tile, &residual_bc, &tok[tile_row][tile_col], tok_end);
966 assert(tok[tile_row][tile_col] == tok_end);
967 vp9_stop_encode(&residual_bc);
968 if (tile_col < tile_cols - 1 || tile_row < tile_rows - 1) {
970 mem_put_be32(data_ptr + total_size, residual_bc.pos);
974 total_size += residual_bc.pos;
981 static void write_display_size(const VP9_COMMON *cm,
982 struct vp9_write_bit_buffer *wb) {
983 const int scaling_active = cm->width != cm->display_width ||
984 cm->height != cm->display_height;
985 vp9_wb_write_bit(wb, scaling_active);
986 if (scaling_active) {
987 vp9_wb_write_literal(wb, cm->display_width - 1, 16);
988 vp9_wb_write_literal(wb, cm->display_height - 1, 16);
992 static void write_frame_size(const VP9_COMMON *cm,
993 struct vp9_write_bit_buffer *wb) {
994 vp9_wb_write_literal(wb, cm->width - 1, 16);
995 vp9_wb_write_literal(wb, cm->height - 1, 16);
997 write_display_size(cm, wb);
1000 static void write_frame_size_with_refs(VP9_COMP *cpi,
1001 struct vp9_write_bit_buffer *wb) {
1002 VP9_COMMON *const cm = &cpi->common;
1005 MV_REFERENCE_FRAME ref_frame;
1006 for (ref_frame = LAST_FRAME; ref_frame <= ALTREF_FRAME; ++ref_frame) {
1007 YV12_BUFFER_CONFIG *cfg = get_ref_frame_buffer(cpi, ref_frame);
1008 found = cm->width == cfg->y_crop_width &&
1009 cm->height == cfg->y_crop_height;
1011 // Set "found" to 0 for temporal svc and for spatial svc key frame
1013 ((cpi->svc.number_temporal_layers > 1 &&
1014 cpi->oxcf.rc_mode == VPX_CBR) ||
1015 (cpi->svc.number_spatial_layers > 1 &&
1016 cpi->svc.layer_context[cpi->svc.spatial_layer_id].is_key_frame) ||
1017 (is_two_pass_svc(cpi) &&
1018 cpi->svc.encode_empty_frame_state == ENCODING &&
1019 cpi->svc.layer_context[0].frames_from_key_frame <
1020 cpi->svc.number_temporal_layers + 1))) {
1023 vp9_wb_write_bit(wb, found);
1030 vp9_wb_write_literal(wb, cm->width - 1, 16);
1031 vp9_wb_write_literal(wb, cm->height - 1, 16);
1034 write_display_size(cm, wb);
1037 static void write_sync_code(struct vp9_write_bit_buffer *wb) {
1038 vp9_wb_write_literal(wb, VP9_SYNC_CODE_0, 8);
1039 vp9_wb_write_literal(wb, VP9_SYNC_CODE_1, 8);
1040 vp9_wb_write_literal(wb, VP9_SYNC_CODE_2, 8);
1043 static void write_profile(BITSTREAM_PROFILE profile,
1044 struct vp9_write_bit_buffer *wb) {
1047 vp9_wb_write_literal(wb, 0, 2);
1050 vp9_wb_write_literal(wb, 2, 2);
1053 vp9_wb_write_literal(wb, 1, 2);
1056 vp9_wb_write_literal(wb, 6, 3);
1063 static void write_bitdepth_colorspace_sampling(
1064 VP9_COMMON *const cm, struct vp9_write_bit_buffer *wb) {
1065 if (cm->profile >= PROFILE_2) {
1066 assert(cm->bit_depth > VPX_BITS_8);
1067 vp9_wb_write_bit(wb, cm->bit_depth == VPX_BITS_10 ? 0 : 1);
1069 vp9_wb_write_literal(wb, cm->color_space, 3);
1070 if (cm->color_space != SRGB) {
1071 vp9_wb_write_bit(wb, 0); // 0: [16, 235] (i.e. xvYCC), 1: [0, 255]
1072 if (cm->profile == PROFILE_1 || cm->profile == PROFILE_3) {
1073 assert(cm->subsampling_x != 1 || cm->subsampling_y != 1);
1074 vp9_wb_write_bit(wb, cm->subsampling_x);
1075 vp9_wb_write_bit(wb, cm->subsampling_y);
1076 vp9_wb_write_bit(wb, 0); // unused
1078 assert(cm->subsampling_x == 1 && cm->subsampling_y == 1);
1081 assert(cm->profile == PROFILE_1 || cm->profile == PROFILE_3);
1082 vp9_wb_write_bit(wb, 0); // unused
1086 static void write_uncompressed_header(VP9_COMP *cpi,
1087 struct vp9_write_bit_buffer *wb) {
1088 VP9_COMMON *const cm = &cpi->common;
1090 vp9_wb_write_literal(wb, VP9_FRAME_MARKER, 2);
1092 write_profile(cm->profile, wb);
1094 vp9_wb_write_bit(wb, 0); // show_existing_frame
1095 vp9_wb_write_bit(wb, cm->frame_type);
1096 vp9_wb_write_bit(wb, cm->show_frame);
1097 vp9_wb_write_bit(wb, cm->error_resilient_mode);
1099 if (cm->frame_type == KEY_FRAME) {
1100 write_sync_code(wb);
1101 write_bitdepth_colorspace_sampling(cm, wb);
1102 write_frame_size(cm, wb);
1104 // In spatial svc if it's not error_resilient_mode then we need to code all
1105 // visible frames as invisible. But we need to keep the show_frame flag so
1106 // that the publisher could know whether it is supposed to be visible.
1107 // So we will code the show_frame flag as it is. Then code the intra_only
1108 // bit here. This will make the bitstream incompatible. In the player we
1109 // will change to show_frame flag to 0, then add an one byte frame with
1110 // show_existing_frame flag which tells the decoder which frame we want to
1112 if (!cm->show_frame)
1113 vp9_wb_write_bit(wb, cm->intra_only);
1115 if (!cm->error_resilient_mode)
1116 vp9_wb_write_literal(wb, cm->reset_frame_context, 2);
1118 if (cm->intra_only) {
1119 write_sync_code(wb);
1121 // Note for profile 0, 420 8bpp is assumed.
1122 if (cm->profile > PROFILE_0) {
1123 write_bitdepth_colorspace_sampling(cm, wb);
1126 vp9_wb_write_literal(wb, get_refresh_mask(cpi), REF_FRAMES);
1127 write_frame_size(cm, wb);
1129 MV_REFERENCE_FRAME ref_frame;
1130 vp9_wb_write_literal(wb, get_refresh_mask(cpi), REF_FRAMES);
1131 for (ref_frame = LAST_FRAME; ref_frame <= ALTREF_FRAME; ++ref_frame) {
1132 vp9_wb_write_literal(wb, get_ref_frame_idx(cpi, ref_frame),
1134 vp9_wb_write_bit(wb, cm->ref_frame_sign_bias[ref_frame]);
1137 write_frame_size_with_refs(cpi, wb);
1139 vp9_wb_write_bit(wb, cm->allow_high_precision_mv);
1141 fix_interp_filter(cm);
1142 write_interp_filter(cm->interp_filter, wb);
1146 if (!cm->error_resilient_mode) {
1147 vp9_wb_write_bit(wb, cm->refresh_frame_context);
1148 vp9_wb_write_bit(wb, cm->frame_parallel_decoding_mode);
1151 vp9_wb_write_literal(wb, cm->frame_context_idx, FRAME_CONTEXTS_LOG2);
1153 encode_loopfilter(&cm->lf, wb);
1154 encode_quantization(cm, wb);
1155 encode_segmentation(cm, &cpi->mb.e_mbd, wb);
1157 write_tile_info(cm, wb);
1160 static size_t write_compressed_header(VP9_COMP *cpi, uint8_t *data) {
1161 VP9_COMMON *const cm = &cpi->common;
1162 MACROBLOCKD *const xd = &cpi->mb.e_mbd;
1163 FRAME_CONTEXT *const fc = &cm->fc;
1164 vp9_writer header_bc;
1166 vp9_start_encode(&header_bc, data);
1169 cm->tx_mode = ONLY_4X4;
1171 encode_txfm_probs(cm, &header_bc);
1173 update_coef_probs(cpi, &header_bc);
1174 update_skip_probs(cm, &header_bc);
1176 if (!frame_is_intra_only(cm)) {
1179 for (i = 0; i < INTER_MODE_CONTEXTS; ++i)
1180 prob_diff_update(vp9_inter_mode_tree, cm->fc.inter_mode_probs[i],
1181 cm->counts.inter_mode[i], INTER_MODES, &header_bc);
1183 vp9_zero(cm->counts.inter_mode);
1185 if (cm->interp_filter == SWITCHABLE)
1186 update_switchable_interp_probs(cm, &header_bc);
1188 for (i = 0; i < INTRA_INTER_CONTEXTS; i++)
1189 vp9_cond_prob_diff_update(&header_bc, &fc->intra_inter_prob[i],
1190 cm->counts.intra_inter[i]);
1192 if (cm->allow_comp_inter_inter) {
1193 const int use_compound_pred = cm->reference_mode != SINGLE_REFERENCE;
1194 const int use_hybrid_pred = cm->reference_mode == REFERENCE_MODE_SELECT;
1196 vp9_write_bit(&header_bc, use_compound_pred);
1197 if (use_compound_pred) {
1198 vp9_write_bit(&header_bc, use_hybrid_pred);
1199 if (use_hybrid_pred)
1200 for (i = 0; i < COMP_INTER_CONTEXTS; i++)
1201 vp9_cond_prob_diff_update(&header_bc, &fc->comp_inter_prob[i],
1202 cm->counts.comp_inter[i]);
1206 if (cm->reference_mode != COMPOUND_REFERENCE) {
1207 for (i = 0; i < REF_CONTEXTS; i++) {
1208 vp9_cond_prob_diff_update(&header_bc, &fc->single_ref_prob[i][0],
1209 cm->counts.single_ref[i][0]);
1210 vp9_cond_prob_diff_update(&header_bc, &fc->single_ref_prob[i][1],
1211 cm->counts.single_ref[i][1]);
1215 if (cm->reference_mode != SINGLE_REFERENCE)
1216 for (i = 0; i < REF_CONTEXTS; i++)
1217 vp9_cond_prob_diff_update(&header_bc, &fc->comp_ref_prob[i],
1218 cm->counts.comp_ref[i]);
1220 for (i = 0; i < BLOCK_SIZE_GROUPS; ++i)
1221 prob_diff_update(vp9_intra_mode_tree, cm->fc.y_mode_prob[i],
1222 cm->counts.y_mode[i], INTRA_MODES, &header_bc);
1224 for (i = 0; i < PARTITION_CONTEXTS; ++i)
1225 prob_diff_update(vp9_partition_tree, fc->partition_prob[i],
1226 cm->counts.partition[i], PARTITION_TYPES, &header_bc);
1228 vp9_write_nmv_probs(cm, cm->allow_high_precision_mv, &header_bc);
1231 vp9_stop_encode(&header_bc);
1232 assert(header_bc.pos <= 0xffff);
1234 return header_bc.pos;
1237 void vp9_pack_bitstream(VP9_COMP *cpi, uint8_t *dest, size_t *size) {
1238 uint8_t *data = dest;
1239 size_t first_part_size, uncompressed_hdr_size;
1240 struct vp9_write_bit_buffer wb = {data, 0};
1241 struct vp9_write_bit_buffer saved_wb;
1243 write_uncompressed_header(cpi, &wb);
1245 vp9_wb_write_literal(&wb, 0, 16); // don't know in advance first part. size
1247 uncompressed_hdr_size = vp9_wb_bytes_written(&wb);
1248 data += uncompressed_hdr_size;
1250 vp9_clear_system_state();
1252 first_part_size = write_compressed_header(cpi, data);
1253 data += first_part_size;
1254 // TODO(jbb): Figure out what to do if first_part_size > 16 bits.
1255 vp9_wb_write_literal(&saved_wb, (int)first_part_size, 16);
1257 data += encode_tiles(cpi, data);
1259 *size = data - dest;