blob: 3b0e536ba94170a9d7cd2217a8e05c39f0e4ba5b [file] [log] [blame]
/*
* Copyright (c) 2016, Alliance for Open Media. All rights reserved
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#include "av1/encoder/av1_multi_thread.h"
#include "av1/encoder/encodeframe.h"
#include "av1/encoder/encoder.h"
#include "av1/encoder/ethread.h"
#include "av1/encoder/rdopt.h"
#include "aom_dsp/aom_dsp_common.h"
static void accumulate_rd_opt(ThreadData *td, ThreadData *td_t) {
for (int i = 0; i < REFERENCE_MODES; i++)
td->rd_counts.comp_pred_diff[i] += td_t->rd_counts.comp_pred_diff[i];
for (int i = 0; i < REF_FRAMES; i++)
td->rd_counts.global_motion_used[i] +=
td_t->rd_counts.global_motion_used[i];
td->rd_counts.compound_ref_used_flag |=
td_t->rd_counts.compound_ref_used_flag;
td->rd_counts.skip_mode_used_flag |= td_t->rd_counts.skip_mode_used_flag;
}
void av1_row_mt_sync_read_dummy(struct AV1RowMTSyncData *const row_mt_sync,
int r, int c) {
(void)row_mt_sync;
(void)r;
(void)c;
return;
}
void av1_row_mt_sync_write_dummy(struct AV1RowMTSyncData *const row_mt_sync,
int r, int c, const int cols) {
(void)row_mt_sync;
(void)r;
(void)c;
(void)cols;
return;
}
void av1_row_mt_sync_read(AV1RowMTSync *const row_mt_sync, int r, int c) {
#if CONFIG_MULTITHREAD
const int nsync = row_mt_sync->sync_range;
if (r) {
pthread_mutex_t *const mutex = &row_mt_sync->mutex_[r - 1];
pthread_mutex_lock(mutex);
while (c > row_mt_sync->cur_col[r - 1] - nsync) {
pthread_cond_wait(&row_mt_sync->cond_[r - 1], mutex);
}
pthread_mutex_unlock(mutex);
}
#else
(void)row_mt_sync;
(void)r;
(void)c;
#endif // CONFIG_MULTITHREAD
}
void av1_row_mt_sync_write(AV1RowMTSync *const row_mt_sync, int r, int c,
const int cols) {
#if CONFIG_MULTITHREAD
const int nsync = row_mt_sync->sync_range;
int cur;
// Only signal when there are enough encoded blocks for next row to run.
int sig = 1;
if (c < cols - 1) {
cur = c;
if (c % nsync) sig = 0;
} else {
cur = cols + nsync;
}
if (sig) {
pthread_mutex_lock(&row_mt_sync->mutex_[r]);
row_mt_sync->cur_col[r] = cur;
pthread_cond_signal(&row_mt_sync->cond_[r]);
pthread_mutex_unlock(&row_mt_sync->mutex_[r]);
}
#else
(void)row_mt_sync;
(void)r;
(void)c;
(void)cols;
#endif // CONFIG_MULTITHREAD
}
// Allocate memory for row synchronization
void av1_row_mt_sync_mem_alloc(AV1RowMTSync *row_mt_sync, AV1_COMMON *cm,
int rows) {
row_mt_sync->rows = rows;
#if CONFIG_MULTITHREAD
{
int i;
CHECK_MEM_ERROR(cm, row_mt_sync->mutex_,
aom_malloc(sizeof(*row_mt_sync->mutex_) * rows));
if (row_mt_sync->mutex_) {
for (i = 0; i < rows; ++i) {
pthread_mutex_init(&row_mt_sync->mutex_[i], NULL);
}
}
CHECK_MEM_ERROR(cm, row_mt_sync->cond_,
aom_malloc(sizeof(*row_mt_sync->cond_) * rows));
if (row_mt_sync->cond_) {
for (i = 0; i < rows; ++i) {
pthread_cond_init(&row_mt_sync->cond_[i], NULL);
}
}
}
#endif // CONFIG_MULTITHREAD
CHECK_MEM_ERROR(cm, row_mt_sync->cur_col,
aom_malloc(sizeof(*row_mt_sync->cur_col) * rows));
// Set up nsync.
if (cm->seq_params.mib_size_log2 == 4)
row_mt_sync->sync_range = 2;
else
row_mt_sync->sync_range = 1;
}
// Deallocate row based multi-threading synchronization related mutex and data
void av1_row_mt_sync_mem_dealloc(AV1RowMTSync *row_mt_sync) {
if (row_mt_sync != NULL) {
#if CONFIG_MULTITHREAD
int i;
if (row_mt_sync->mutex_ != NULL) {
for (i = 0; i < row_mt_sync->rows; ++i) {
pthread_mutex_destroy(&row_mt_sync->mutex_[i]);
}
aom_free(row_mt_sync->mutex_);
}
if (row_mt_sync->cond_ != NULL) {
for (i = 0; i < row_mt_sync->rows; ++i) {
pthread_cond_destroy(&row_mt_sync->cond_[i]);
}
aom_free(row_mt_sync->cond_);
}
#endif // CONFIG_MULTITHREAD
aom_free(row_mt_sync->cur_col);
// clear the structure as the source of this call may be dynamic change
// in tiles in which case this call will be followed by an _alloc()
// which may fail.
av1_zero(*row_mt_sync);
}
}
static void assign_tile_to_thread(MultiThreadHandle *multi_thread_ctxt,
int num_tiles, int num_workers) {
int tile_id = 0;
int i;
for (i = 0; i < num_workers; i++) {
multi_thread_ctxt->thread_id_to_tile_id[i] = tile_id++;
if (tile_id == num_tiles) tile_id = 0;
}
}
static int get_next_job(AV1_COMP *const cpi, int *current_mi_row,
int cur_tile_id) {
AV1_COMMON *const cm = &cpi->common;
TileDataEnc *const this_tile = &cpi->tile_data[cur_tile_id];
AV1RowMTInfo *row_mt_info = &this_tile->row_mt_info;
if (row_mt_info->current_mi_row < this_tile->tile_info.mi_row_end) {
*current_mi_row = row_mt_info->current_mi_row;
row_mt_info->num_threads_working++;
row_mt_info->current_mi_row += cm->seq_params.mib_size;
return 1;
}
return 0;
}
static void switch_tile_and_get_next_job(AV1_COMP *const cpi, int *cur_tile_id,
int *current_mi_row,
int *end_of_frame) {
AV1_COMMON *const cm = &cpi->common;
const int tile_cols = cm->tile_cols;
const int tile_rows = cm->tile_rows;
int tile_id = -1; // Stores the tile ID with minimum proc done
int max_mis_to_encode = 0;
int min_num_threads_working = INT_MAX;
for (int tile_row = 0; tile_row < tile_rows; tile_row++) {
for (int tile_col = 0; tile_col < tile_cols; tile_col++) {
int tile_index = tile_row * tile_cols + tile_col;
TileDataEnc *this_tile = &cpi->tile_data[tile_index];
AV1RowMTInfo *row_mt_info = &this_tile->row_mt_info;
int num_mis_to_encode =
this_tile->tile_info.mi_row_end - row_mt_info->current_mi_row;
// Tile to be processed by this thread is selected on the basis of
// availability of jobs:
// 1) If jobs are available, tile to be processed is chosen on the
// basis of minimum number of threads working for that tile. If two or
// more tiles have same number of threads working for them, then the tile
// with maximum number of jobs available will be chosen.
// 2) If no jobs are available, then end_of_frame is reached.
if (num_mis_to_encode > 0) {
int num_threads_working = row_mt_info->num_threads_working;
if (num_threads_working < min_num_threads_working) {
min_num_threads_working = num_threads_working;
max_mis_to_encode = 0;
}
if (num_threads_working == min_num_threads_working &&
num_mis_to_encode > max_mis_to_encode) {
tile_id = tile_index;
max_mis_to_encode = num_mis_to_encode;
}
}
}
}
if (tile_id == -1) {
*end_of_frame = 1;
} else {
// Update the cur ID to the next tile ID that will be processed,
// which will be the least processed tile
*cur_tile_id = tile_id;
get_next_job(cpi, current_mi_row, *cur_tile_id);
}
}
static int enc_row_mt_worker_hook(void *arg1, void *unused) {
EncWorkerData *const thread_data = (EncWorkerData *)arg1;
AV1_COMP *const cpi = thread_data->cpi;
AV1_COMMON *const cm = &cpi->common;
MultiThreadHandle *multi_thread_ctxt = &cpi->multi_thread_ctxt;
int thread_id = thread_data->thread_id;
int cur_tile_id = multi_thread_ctxt->thread_id_to_tile_id[thread_id];
(void)unused;
assert(cur_tile_id != -1);
int end_of_frame = 0;
while (1) {
int current_mi_row = -1;
#if CONFIG_MULTITHREAD
pthread_mutex_lock(cpi->row_mt_mutex_);
#endif
if (!get_next_job(cpi, &current_mi_row, cur_tile_id)) {
// No jobs are available for the current tile. Query for the status of
// other tiles and get the next job if available
switch_tile_and_get_next_job(cpi, &cur_tile_id, &current_mi_row,
&end_of_frame);
}
#if CONFIG_MULTITHREAD
pthread_mutex_unlock(cpi->row_mt_mutex_);
#endif
if (end_of_frame == 1) break;
TileDataEnc *const this_tile = &cpi->tile_data[cur_tile_id];
int tile_row = this_tile->tile_info.tile_row;
int tile_col = this_tile->tile_info.tile_col;
assert(current_mi_row != -1 &&
current_mi_row <= this_tile->tile_info.mi_row_end);
ThreadData *td = thread_data->td;
td->mb.e_mbd.tile_ctx = td->tctx;
td->mb.backup_tile_ctx = &this_tile->backup_tctx;
if (current_mi_row == this_tile->tile_info.mi_row_start)
memcpy(td->mb.e_mbd.tile_ctx, &this_tile->tctx, sizeof(FRAME_CONTEXT));
av1_init_above_context(cm, &td->mb.e_mbd, tile_row);
// Disable exhaustive search speed features for row based multi-threading of
// encoder.
td->mb.m_search_count_ptr = NULL;
td->mb.ex_search_count_ptr = NULL;
cfl_init(&td->mb.e_mbd.cfl, &cm->seq_params);
av1_crc32c_calculator_init(&td->mb.mb_rd_record.crc_calculator);
av1_encode_sb_row(cpi, td, tile_row, tile_col, current_mi_row);
#if CONFIG_MULTITHREAD
pthread_mutex_lock(cpi->row_mt_mutex_);
#endif
this_tile->row_mt_info.num_threads_working--;
#if CONFIG_MULTITHREAD
pthread_mutex_unlock(cpi->row_mt_mutex_);
#endif
}
return 1;
}
static int enc_worker_hook(void *arg1, void *unused) {
EncWorkerData *const thread_data = (EncWorkerData *)arg1;
AV1_COMP *const cpi = thread_data->cpi;
const AV1_COMMON *const cm = &cpi->common;
const int tile_cols = cm->tile_cols;
const int tile_rows = cm->tile_rows;
int t;
(void)unused;
for (t = thread_data->start; t < tile_rows * tile_cols;
t += cpi->num_workers) {
int tile_row = t / tile_cols;
int tile_col = t % tile_cols;
TileDataEnc *const this_tile =
&cpi->tile_data[tile_row * cm->tile_cols + tile_col];
thread_data->td->tctx = &this_tile->tctx;
thread_data->td->mb.e_mbd.tile_ctx = thread_data->td->tctx;
thread_data->td->mb.backup_tile_ctx = &this_tile->backup_tctx;
av1_encode_tile(cpi, thread_data->td, tile_row, tile_col);
}
return 1;
}
static void create_enc_workers(AV1_COMP *cpi, int num_workers) {
AV1_COMMON *const cm = &cpi->common;
const AVxWorkerInterface *const winterface = aom_get_worker_interface();
CHECK_MEM_ERROR(cm, cpi->workers,
aom_malloc(num_workers * sizeof(*cpi->workers)));
CHECK_MEM_ERROR(cm, cpi->tile_thr_data,
aom_calloc(num_workers, sizeof(*cpi->tile_thr_data)));
#if CONFIG_MULTITHREAD
if (cpi->row_mt == 1) {
if (cpi->row_mt_mutex_ == NULL) {
CHECK_MEM_ERROR(cm, cpi->row_mt_mutex_,
aom_malloc(sizeof(*(cpi->row_mt_mutex_))));
if (cpi->row_mt_mutex_) pthread_mutex_init(cpi->row_mt_mutex_, NULL);
}
}
#endif
for (int i = 0; i < num_workers; i++) {
AVxWorker *const worker = &cpi->workers[i];
EncWorkerData *const thread_data = &cpi->tile_thr_data[i];
++cpi->num_workers;
winterface->init(worker);
worker->thread_name = "aom enc worker";
thread_data->cpi = cpi;
thread_data->thread_id = i;
if (i < num_workers - 1) {
// Allocate thread data.
CHECK_MEM_ERROR(cm, thread_data->td,
aom_memalign(32, sizeof(*thread_data->td)));
av1_zero(*thread_data->td);
// Set up pc_tree.
thread_data->td->pc_tree = NULL;
av1_setup_pc_tree(cm, thread_data->td);
CHECK_MEM_ERROR(cm, thread_data->td->above_pred_buf,
(uint8_t *)aom_memalign(
16, MAX_MB_PLANE * MAX_SB_SQUARE *
sizeof(*thread_data->td->above_pred_buf)));
CHECK_MEM_ERROR(cm, thread_data->td->left_pred_buf,
(uint8_t *)aom_memalign(
16, MAX_MB_PLANE * MAX_SB_SQUARE *
sizeof(*thread_data->td->left_pred_buf)));
CHECK_MEM_ERROR(
cm, thread_data->td->wsrc_buf,
(int32_t *)aom_memalign(
16, MAX_SB_SQUARE * sizeof(*thread_data->td->wsrc_buf)));
#if CONFIG_COLLECT_INTER_MODE_RD_STATS
CHECK_MEM_ERROR(cm, thread_data->td->inter_modes_info,
(InterModesInfo *)aom_malloc(
sizeof(*thread_data->td->inter_modes_info)));
#endif
for (int x = 0; x < 2; x++)
for (int y = 0; y < 2; y++)
CHECK_MEM_ERROR(
cm, thread_data->td->hash_value_buffer[x][y],
(uint32_t *)aom_malloc(
AOM_BUFFER_SIZE_FOR_BLOCK_HASH *
sizeof(*thread_data->td->hash_value_buffer[0][0])));
CHECK_MEM_ERROR(
cm, thread_data->td->mask_buf,
(int32_t *)aom_memalign(
16, MAX_SB_SQUARE * sizeof(*thread_data->td->mask_buf)));
// Allocate frame counters in thread data.
CHECK_MEM_ERROR(cm, thread_data->td->counts,
aom_calloc(1, sizeof(*thread_data->td->counts)));
// Allocate buffers used by palette coding mode.
CHECK_MEM_ERROR(
cm, thread_data->td->palette_buffer,
aom_memalign(16, sizeof(*thread_data->td->palette_buffer)));
CHECK_MEM_ERROR(
cm, thread_data->td->tmp_conv_dst,
aom_memalign(32, MAX_SB_SIZE * MAX_SB_SIZE *
sizeof(*thread_data->td->tmp_conv_dst)));
for (int j = 0; j < 2; ++j) {
CHECK_MEM_ERROR(
cm, thread_data->td->tmp_obmc_bufs[j],
aom_memalign(32, 2 * MAX_MB_PLANE * MAX_SB_SQUARE *
sizeof(*thread_data->td->tmp_obmc_bufs[j])));
}
// Create threads
if (!winterface->reset(worker))
aom_internal_error(&cm->error, AOM_CODEC_ERROR,
"Tile encoder thread creation failed");
} else {
// Main thread acts as a worker and uses the thread data in cpi.
thread_data->td = &cpi->td;
}
if (cpi->row_mt == 1)
CHECK_MEM_ERROR(
cm, thread_data->td->tctx,
(FRAME_CONTEXT *)aom_memalign(16, sizeof(*thread_data->td->tctx)));
winterface->sync(worker);
}
}
static void launch_enc_workers(AV1_COMP *cpi, int num_workers) {
const AVxWorkerInterface *const winterface = aom_get_worker_interface();
// Encode a frame
for (int i = 0; i < num_workers; i++) {
AVxWorker *const worker = &cpi->workers[i];
EncWorkerData *const thread_data = (EncWorkerData *)worker->data1;
// Set the starting tile for each thread.
thread_data->start = i;
if (i == cpi->num_workers - 1)
winterface->execute(worker);
else
winterface->launch(worker);
}
}
static void sync_enc_workers(AV1_COMP *cpi, int num_workers) {
const AVxWorkerInterface *const winterface = aom_get_worker_interface();
int had_error = 0;
// Encoding ends.
for (int i = 0; i < num_workers; i++) {
AVxWorker *const worker = &cpi->workers[i];
had_error |= !winterface->sync(worker);
}
if (had_error)
aom_internal_error(&cpi->common.error, AOM_CODEC_ERROR,
"Failed to encode tile data");
}
static void accumulate_counters_enc_workers(AV1_COMP *cpi, int num_workers) {
for (int i = 0; i < num_workers; i++) {
AVxWorker *const worker = &cpi->workers[i];
EncWorkerData *const thread_data = (EncWorkerData *)worker->data1;
cpi->intrabc_used |= thread_data->td->intrabc_used;
// Accumulate counters.
if (i < cpi->num_workers - 1) {
av1_accumulate_frame_counts(&cpi->counts, thread_data->td->counts);
accumulate_rd_opt(&cpi->td, thread_data->td);
cpi->td.mb.txb_split_count += thread_data->td->mb.txb_split_count;
}
}
}
static void prepare_enc_workers(AV1_COMP *cpi, AVxWorkerHook hook,
int num_workers) {
for (int i = 0; i < num_workers; i++) {
AVxWorker *const worker = &cpi->workers[i];
EncWorkerData *const thread_data = &cpi->tile_thr_data[i];
worker->hook = hook;
worker->data1 = thread_data;
worker->data2 = NULL;
thread_data->td->intrabc_used = 0;
// Before encoding a frame, copy the thread data from cpi.
if (thread_data->td != &cpi->td) {
thread_data->td->mb = cpi->td.mb;
thread_data->td->rd_counts = cpi->td.rd_counts;
thread_data->td->mb.above_pred_buf = thread_data->td->above_pred_buf;
thread_data->td->mb.left_pred_buf = thread_data->td->left_pred_buf;
thread_data->td->mb.wsrc_buf = thread_data->td->wsrc_buf;
#if CONFIG_COLLECT_INTER_MODE_RD_STATS
thread_data->td->mb.inter_modes_info = thread_data->td->inter_modes_info;
#endif
for (int x = 0; x < 2; x++) {
for (int y = 0; y < 2; y++) {
memcpy(thread_data->td->hash_value_buffer[x][y],
cpi->td.mb.hash_value_buffer[x][y],
AOM_BUFFER_SIZE_FOR_BLOCK_HASH *
sizeof(*thread_data->td->hash_value_buffer[0][0]));
thread_data->td->mb.hash_value_buffer[x][y] =
thread_data->td->hash_value_buffer[x][y];
}
}
thread_data->td->mb.mask_buf = thread_data->td->mask_buf;
}
if (thread_data->td->counts != &cpi->counts) {
memcpy(thread_data->td->counts, &cpi->counts, sizeof(cpi->counts));
}
if (i < num_workers - 1) {
thread_data->td->mb.palette_buffer = thread_data->td->palette_buffer;
thread_data->td->mb.tmp_conv_dst = thread_data->td->tmp_conv_dst;
for (int j = 0; j < 2; ++j) {
thread_data->td->mb.tmp_obmc_bufs[j] =
thread_data->td->tmp_obmc_bufs[j];
}
thread_data->td->mb.e_mbd.tmp_conv_dst = thread_data->td->mb.tmp_conv_dst;
for (int j = 0; j < 2; ++j) {
thread_data->td->mb.e_mbd.tmp_obmc_bufs[j] =
thread_data->td->mb.tmp_obmc_bufs[j];
}
}
}
}
void av1_encode_tiles_mt(AV1_COMP *cpi) {
AV1_COMMON *const cm = &cpi->common;
const int tile_cols = cm->tile_cols;
const int tile_rows = cm->tile_rows;
int num_workers = AOMMIN(cpi->oxcf.max_threads, tile_cols * tile_rows);
if (cpi->tile_data == NULL || cpi->allocated_tiles < tile_cols * tile_rows)
av1_alloc_tile_data(cpi);
av1_init_tile_data(cpi);
// Only run once to create threads and allocate thread data.
if (cpi->num_workers == 0) {
create_enc_workers(cpi, num_workers);
} else {
num_workers = AOMMIN(num_workers, cpi->num_workers);
}
prepare_enc_workers(cpi, enc_worker_hook, num_workers);
launch_enc_workers(cpi, num_workers);
sync_enc_workers(cpi, num_workers);
accumulate_counters_enc_workers(cpi, num_workers);
}
// Accumulate frame counts. FRAME_COUNTS consist solely of 'unsigned int'
// members, so we treat it as an array, and sum over the whole length.
void av1_accumulate_frame_counts(FRAME_COUNTS *acc_counts,
const FRAME_COUNTS *counts) {
unsigned int *const acc = (unsigned int *)acc_counts;
const unsigned int *const cnt = (const unsigned int *)counts;
const unsigned int n_counts = sizeof(FRAME_COUNTS) / sizeof(unsigned int);
for (unsigned int i = 0; i < n_counts; i++) acc[i] += cnt[i];
}
void av1_encode_tiles_row_mt(AV1_COMP *cpi) {
AV1_COMMON *const cm = &cpi->common;
const int tile_cols = cm->tile_cols;
const int tile_rows = cm->tile_rows;
MultiThreadHandle *multi_thread_ctxt = &cpi->multi_thread_ctxt;
int num_workers = 0;
int total_num_sb_rows = 0;
int max_sb_rows = 0;
if (cpi->tile_data == NULL || cpi->allocated_tiles < tile_cols * tile_rows) {
av1_row_mt_mem_dealloc(cpi);
av1_alloc_tile_data(cpi);
}
av1_init_tile_data(cpi);
for (int row = 0; row < tile_rows; row++) {
for (int col = 0; col < tile_cols; col++) {
TileDataEnc *tile_data = &cpi->tile_data[row * cm->tile_cols + col];
int num_sb_rows_in_tile =
av1_get_sb_rows_in_tile(cm, tile_data->tile_info);
total_num_sb_rows += num_sb_rows_in_tile;
max_sb_rows = AOMMAX(max_sb_rows, num_sb_rows_in_tile);
}
}
num_workers = AOMMIN(cpi->oxcf.max_threads, total_num_sb_rows);
if (multi_thread_ctxt->allocated_tile_cols != tile_cols ||
multi_thread_ctxt->allocated_tile_rows != tile_rows ||
multi_thread_ctxt->allocated_sb_rows != max_sb_rows) {
av1_row_mt_mem_dealloc(cpi);
av1_row_mt_mem_alloc(cpi, max_sb_rows);
}
memset(multi_thread_ctxt->thread_id_to_tile_id, -1,
sizeof(*multi_thread_ctxt->thread_id_to_tile_id) * MAX_NUM_THREADS);
for (int tile_row = 0; tile_row < tile_rows; tile_row++) {
for (int tile_col = 0; tile_col < tile_cols; tile_col++) {
int tile_id = tile_row * tile_cols + tile_col;
TileDataEnc *this_tile = &cpi->tile_data[tile_id];
// Initialize cur_col to -1 for all rows.
memset(this_tile->row_mt_sync.cur_col, -1,
sizeof(*this_tile->row_mt_sync.cur_col) * max_sb_rows);
this_tile->row_mt_info.current_mi_row = this_tile->tile_info.mi_row_start;
this_tile->row_mt_info.num_threads_working = 0;
#if CONFIG_COLLECT_INTER_MODE_RD_STATS
av1_inter_mode_data_init(this_tile);
#endif
av1_zero_above_context(cm, &cpi->td.mb.e_mbd,
this_tile->tile_info.mi_col_start,
this_tile->tile_info.mi_col_end, tile_row);
this_tile->m_search_count = 0; // Count of motion search hits.
this_tile->ex_search_count = 0; // Exhaustive mesh search hits.
}
}
// Only run once to create threads and allocate thread data.
if (cpi->num_workers == 0) {
create_enc_workers(cpi, num_workers);
} else {
num_workers = AOMMIN(num_workers, cpi->num_workers);
}
assign_tile_to_thread(multi_thread_ctxt, tile_cols * tile_rows, num_workers);
prepare_enc_workers(cpi, enc_row_mt_worker_hook, num_workers);
launch_enc_workers(cpi, num_workers);
sync_enc_workers(cpi, num_workers);
accumulate_counters_enc_workers(cpi, num_workers);
}