ref: 86c36a504dd7834e934707b86aa81ceb6384154c
dir: /vp9/decoder/vp9_dthread.c/
/*
* Copyright (c) 2014 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 "./vpx_config.h"
#include "vpx_mem/vpx_mem.h"
#include "vp9/common/vp9_reconinter.h"
#include "vp9/decoder/vp9_dthread.h"
#include "vp9/decoder/vp9_decoder.h"
#if CONFIG_MULTITHREAD
static INLINE void mutex_lock(pthread_mutex_t *const mutex) {
const int kMaxTryLocks = 4000;
int locked = 0;
int i;
for (i = 0; i < kMaxTryLocks; ++i) {
if (!pthread_mutex_trylock(mutex)) {
locked = 1;
break;
}
}
if (!locked)
pthread_mutex_lock(mutex);
}
#endif // CONFIG_MULTITHREAD
static INLINE void sync_read(VP9LfSync *const lf_sync, int r, int c) {
#if CONFIG_MULTITHREAD
const int nsync = lf_sync->sync_range;
if (r && !(c & (nsync - 1))) {
pthread_mutex_t *const mutex = &lf_sync->mutex_[r - 1];
mutex_lock(mutex);
while (c > lf_sync->cur_sb_col[r - 1] - nsync) {
pthread_cond_wait(&lf_sync->cond_[r - 1], mutex);
}
pthread_mutex_unlock(mutex);
}
#else
(void)lf_sync;
(void)r;
(void)c;
#endif // CONFIG_MULTITHREAD
}
static INLINE void sync_write(VP9LfSync *const lf_sync, int r, int c,
const int sb_cols) {
#if CONFIG_MULTITHREAD
const int nsync = lf_sync->sync_range;
int cur;
// Only signal when there are enough filtered SB for next row to run.
int sig = 1;
if (c < sb_cols - 1) {
cur = c;
if (c % nsync)
sig = 0;
} else {
cur = sb_cols + nsync;
}
if (sig) {
mutex_lock(&lf_sync->mutex_[r]);
lf_sync->cur_sb_col[r] = cur;
pthread_cond_signal(&lf_sync->cond_[r]);
pthread_mutex_unlock(&lf_sync->mutex_[r]);
}
#else
(void)lf_sync;
(void)r;
(void)c;
(void)sb_cols;
#endif // CONFIG_MULTITHREAD
}
// Implement row loopfiltering for each thread.
static void loop_filter_rows_mt(const YV12_BUFFER_CONFIG *const frame_buffer,
VP9_COMMON *const cm,
struct macroblockd_plane planes[MAX_MB_PLANE],
int start, int stop, int y_only,
VP9LfSync *const lf_sync) {
const int num_planes = y_only ? 1 : MAX_MB_PLANE;
int r, c; // SB row and col
const int sb_cols = mi_cols_aligned_to_sb(cm->mi_cols) >> MI_BLOCK_SIZE_LOG2;
for (r = start; r < stop; r += lf_sync->num_workers) {
const int mi_row = r << MI_BLOCK_SIZE_LOG2;
MODE_INFO *const mi = cm->mi + mi_row * cm->mi_stride;
for (c = 0; c < sb_cols; ++c) {
const int mi_col = c << MI_BLOCK_SIZE_LOG2;
LOOP_FILTER_MASK lfm;
int plane;
sync_read(lf_sync, r, c);
vp9_setup_dst_planes(planes, frame_buffer, mi_row, mi_col);
vp9_setup_mask(cm, mi_row, mi_col, mi + mi_col, cm->mi_stride, &lfm);
for (plane = 0; plane < num_planes; ++plane) {
vp9_filter_block_plane(cm, &planes[plane], mi_row, &lfm);
}
sync_write(lf_sync, r, c, sb_cols);
}
}
}
// Row-based multi-threaded loopfilter hook
static int loop_filter_row_worker(VP9LfSync *const lf_sync,
LFWorkerData *const lf_data) {
loop_filter_rows_mt(lf_data->frame_buffer, lf_data->cm, lf_data->planes,
lf_data->start, lf_data->stop, lf_data->y_only, lf_sync);
return 1;
}
// VP9 decoder: Implement multi-threaded loopfilter that uses the tile
// threads.
void vp9_loop_filter_frame_mt(VP9LfSync *lf_sync,
YV12_BUFFER_CONFIG *frame,
struct macroblockd_plane planes[MAX_MB_PLANE],
VP9_COMMON *cm,
VP9Worker *workers, int nworkers,
int frame_filter_level,
int y_only) {
const VP9WorkerInterface *const winterface = vp9_get_worker_interface();
// Number of superblock rows and cols
const int sb_rows = mi_cols_aligned_to_sb(cm->mi_rows) >> MI_BLOCK_SIZE_LOG2;
const int tile_cols = 1 << cm->log2_tile_cols;
const int num_workers = MIN(nworkers, tile_cols);
int i;
if (!frame_filter_level) return;
if (!lf_sync->sync_range || cm->last_height != cm->height ||
num_workers > lf_sync->num_workers) {
vp9_loop_filter_dealloc(lf_sync);
vp9_loop_filter_alloc(lf_sync, cm, sb_rows, cm->width, num_workers);
}
vp9_loop_filter_frame_init(cm, frame_filter_level);
// Initialize cur_sb_col to -1 for all SB rows.
vpx_memset(lf_sync->cur_sb_col, -1, sizeof(*lf_sync->cur_sb_col) * sb_rows);
// Set up loopfilter thread data.
// The decoder is capping num_workers because it has been observed that using
// more threads on the loopfilter than there are cores will hurt performance
// on Android. This is because the system will only schedule the tile decode
// workers on cores equal to the number of tile columns. Then if the decoder
// tries to use more threads for the loopfilter, it will hurt performance
// because of contention. If the multithreading code changes in the future
// then the number of workers used by the loopfilter should be revisited.
for (i = 0; i < num_workers; ++i) {
VP9Worker *const worker = &workers[i];
LFWorkerData *const lf_data = &lf_sync->lfdata[i];
worker->hook = (VP9WorkerHook)loop_filter_row_worker;
worker->data1 = lf_sync;
worker->data2 = lf_data;
// Loopfilter data
vp9_loop_filter_data_reset(lf_data, frame, cm, planes);
lf_data->start = i;
lf_data->stop = sb_rows;
lf_data->y_only = y_only;
// Start loopfiltering
if (i == num_workers - 1) {
winterface->execute(worker);
} else {
winterface->launch(worker);
}
}
// Wait till all rows are finished
for (i = 0; i < num_workers; ++i) {
winterface->sync(&workers[i]);
}
}
// Set up nsync by width.
static int get_sync_range(int width) {
// nsync numbers are picked by testing. For example, for 4k
// video, using 4 gives best performance.
if (width < 640)
return 1;
else if (width <= 1280)
return 2;
else if (width <= 4096)
return 4;
else
return 8;
}
// Allocate memory for lf row synchronization
void vp9_loop_filter_alloc(VP9LfSync *lf_sync, VP9_COMMON *cm, int rows,
int width, int num_workers) {
lf_sync->rows = rows;
#if CONFIG_MULTITHREAD
{
int i;
CHECK_MEM_ERROR(cm, lf_sync->mutex_,
vpx_malloc(sizeof(*lf_sync->mutex_) * rows));
if (lf_sync->mutex_) {
for (i = 0; i < rows; ++i) {
pthread_mutex_init(&lf_sync->mutex_[i], NULL);
}
}
CHECK_MEM_ERROR(cm, lf_sync->cond_,
vpx_malloc(sizeof(*lf_sync->cond_) * rows));
if (lf_sync->cond_) {
for (i = 0; i < rows; ++i) {
pthread_cond_init(&lf_sync->cond_[i], NULL);
}
}
}
#endif // CONFIG_MULTITHREAD
CHECK_MEM_ERROR(cm, lf_sync->lfdata,
vpx_malloc(num_workers * sizeof(*lf_sync->lfdata)));
lf_sync->num_workers = num_workers;
CHECK_MEM_ERROR(cm, lf_sync->cur_sb_col,
vpx_malloc(sizeof(*lf_sync->cur_sb_col) * rows));
// Set up nsync.
lf_sync->sync_range = get_sync_range(width);
}
// Deallocate lf synchronization related mutex and data
void vp9_loop_filter_dealloc(VP9LfSync *lf_sync) {
if (lf_sync != NULL) {
#if CONFIG_MULTITHREAD
int i;
if (lf_sync->mutex_ != NULL) {
for (i = 0; i < lf_sync->rows; ++i) {
pthread_mutex_destroy(&lf_sync->mutex_[i]);
}
vpx_free(lf_sync->mutex_);
}
if (lf_sync->cond_ != NULL) {
for (i = 0; i < lf_sync->rows; ++i) {
pthread_cond_destroy(&lf_sync->cond_[i]);
}
vpx_free(lf_sync->cond_);
}
#endif // CONFIG_MULTITHREAD
vpx_free(lf_sync->lfdata);
vpx_free(lf_sync->cur_sb_col);
// clear the structure as the source of this call may be a resize in which
// case this call will be followed by an _alloc() which may fail.
vp9_zero(*lf_sync);
}
}