diff --git a/vp9/common/vp9_loopfilter.c b/vp9/common/vp9_loopfilter.c
index 2266e0ec29ffac6fa5f87dbe0e9a95f381ff8cdc..dd304c909a7432365d84df674e9714b14a50fd28 100644
--- a/vp9/common/vp9_loopfilter.c
+++ b/vp9/common/vp9_loopfilter.c
@@ -16,26 +16,6 @@
 
 #include "vp9/common/vp9_seg_common.h"
 
-// This structure holds bit masks for all 8x8 blocks in a 64x64 region.
-// Each 1 bit represents a position in which we want to apply the loop filter.
-// Left_ entries refer to whether we apply a filter on the border to the
-// left of the block.   Above_ entries refer to whether or not to apply a
-// filter on the above border.   Int_ entries refer to whether or not to
-// apply borders on the 4x4 edges within the 8x8 block that each bit
-// represents.
-// Since each transform is accompanied by a potentially different type of
-// loop filter there is a different entry in the array for each transform size.
-typedef struct {
-  uint64_t left_y[TX_SIZES];
-  uint64_t above_y[TX_SIZES];
-  uint64_t int_4x4_y;
-  uint16_t left_uv[TX_SIZES];
-  uint16_t above_uv[TX_SIZES];
-  uint16_t int_4x4_uv;
-  uint8_t lfl_y[64];
-  uint8_t lfl_uv[16];
-} LOOP_FILTER_MASK;
-
 // 64 bit masks for left transform size.  Each 1 represents a position where
 // we should apply a loop filter across the left border of an 8x8 block
 // boundary.
@@ -638,9 +618,9 @@ static void build_y_mask(const loop_filter_info_n *const lfi_n,
 // This function sets up the bit masks for the entire 64x64 region represented
 // by mi_row, mi_col.
 // TODO(JBB): This function only works for yv12.
-static void setup_mask(VP9_COMMON *const cm, const int mi_row, const int mi_col,
-                       MODE_INFO **mi_8x8, const int mode_info_stride,
-                       LOOP_FILTER_MASK *lfm) {
+void vp9_setup_mask(VP9_COMMON *const cm, const int mi_row, const int mi_col,
+                    MODE_INFO **mi_8x8, const int mode_info_stride,
+                    LOOP_FILTER_MASK *lfm) {
   int idx_32, idx_16, idx_8;
   const loop_filter_info_n *const lfi_n = &cm->lf_info;
   MODE_INFO **mip = mi_8x8;
@@ -1069,10 +1049,10 @@ static void filter_block_plane_non420(VP9_COMMON *cm,
 }
 #endif
 
-static void filter_block_plane(VP9_COMMON *const cm,
-                               struct macroblockd_plane *const plane,
-                               int mi_row,
-                               LOOP_FILTER_MASK *lfm) {
+void vp9_filter_block_plane(VP9_COMMON *const cm,
+                            struct macroblockd_plane *const plane,
+                            int mi_row,
+                            LOOP_FILTER_MASK *lfm) {
   struct buf_2d *const dst = &plane->dst;
   uint8_t* const dst0 = dst->buf;
   int r, c;
@@ -1244,14 +1224,14 @@ void vp9_loop_filter_rows(const YV12_BUFFER_CONFIG *frame_buffer,
 #if CONFIG_NON420
       if (use_420)
 #endif
-        setup_mask(cm, mi_row, mi_col, mi_8x8 + mi_col, cm->mode_info_stride,
-                   &lfm);
+        vp9_setup_mask(cm, mi_row, mi_col, mi_8x8 + mi_col,
+                       cm->mode_info_stride, &lfm);
 
       for (plane = 0; plane < num_planes; ++plane) {
 #if CONFIG_NON420
         if (use_420)
 #endif
-          filter_block_plane(cm, &xd->plane[plane], mi_row, &lfm);
+          vp9_filter_block_plane(cm, &xd->plane[plane], mi_row, &lfm);
 #if CONFIG_NON420
         else
           filter_block_plane_non420(cm, &xd->plane[plane], mi_8x8 + mi_col,
diff --git a/vp9/common/vp9_loopfilter.h b/vp9/common/vp9_loopfilter.h
index 43373f4b18b4e967d7dbf01f48a9463a20364cd5..668e898cf7845e6c49c46c7e6b8e4e9e12039afa 100644
--- a/vp9/common/vp9_loopfilter.h
+++ b/vp9/common/vp9_loopfilter.h
@@ -60,9 +60,42 @@ typedef struct {
   uint8_t lvl[MAX_SEGMENTS][MAX_REF_FRAMES][MAX_MODE_LF_DELTAS];
 } loop_filter_info_n;
 
+// This structure holds bit masks for all 8x8 blocks in a 64x64 region.
+// Each 1 bit represents a position in which we want to apply the loop filter.
+// Left_ entries refer to whether we apply a filter on the border to the
+// left of the block.   Above_ entries refer to whether or not to apply a
+// filter on the above border.   Int_ entries refer to whether or not to
+// apply borders on the 4x4 edges within the 8x8 block that each bit
+// represents.
+// Since each transform is accompanied by a potentially different type of
+// loop filter there is a different entry in the array for each transform size.
+typedef struct {
+  uint64_t left_y[TX_SIZES];
+  uint64_t above_y[TX_SIZES];
+  uint64_t int_4x4_y;
+  uint16_t left_uv[TX_SIZES];
+  uint16_t above_uv[TX_SIZES];
+  uint16_t int_4x4_uv;
+  uint8_t lfl_y[64];
+  uint8_t lfl_uv[16];
+} LOOP_FILTER_MASK;
+
 /* assorted loopfilter functions which get used elsewhere */
 struct VP9Common;
 struct macroblockd;
+struct VP9LfSyncData;
+
+// This function sets up the bit masks for the entire 64x64 region represented
+// by mi_row, mi_col.
+void vp9_setup_mask(struct VP9Common *const cm,
+                    const int mi_row, const int mi_col,
+                    MODE_INFO **mi_8x8, const int mode_info_stride,
+                    LOOP_FILTER_MASK *lfm);
+
+void vp9_filter_block_plane(struct VP9Common *const cm,
+                            struct macroblockd_plane *const plane,
+                            int mi_row,
+                            LOOP_FILTER_MASK *lfm);
 
 void vp9_loop_filter_init(struct VP9Common *cm);
 
@@ -90,6 +123,9 @@ typedef struct LoopFilterWorkerData {
   int start;
   int stop;
   int y_only;
+
+  struct VP9LfSyncData *lf_sync;
+  int num_lf_workers;
 } LFWorkerData;
 
 // Operates on the rows described by LFWorkerData passed as 'arg1'.
diff --git a/vp9/decoder/vp9_decodeframe.c b/vp9/decoder/vp9_decodeframe.c
index 1d9be5322b1356f2026c26f97e927893cf7913ac..311c83e6c34db6e4b7b35ba4c6d7e9cb913ae680 100644
--- a/vp9/decoder/vp9_decodeframe.c
+++ b/vp9/decoder/vp9_decodeframe.c
@@ -33,18 +33,12 @@
 #include "vp9/decoder/vp9_detokenize.h"
 #include "vp9/decoder/vp9_decodemv.h"
 #include "vp9/decoder/vp9_dsubexp.h"
+#include "vp9/decoder/vp9_dthread.h"
 #include "vp9/decoder/vp9_onyxd_int.h"
 #include "vp9/decoder/vp9_read_bit_buffer.h"
 #include "vp9/decoder/vp9_reader.h"
 #include "vp9/decoder/vp9_thread.h"
 
-typedef struct TileWorkerData {
-  VP9_COMMON *cm;
-  vp9_reader bit_reader;
-  DECLARE_ALIGNED(16, MACROBLOCKD, xd);
-  DECLARE_ALIGNED(16, int16_t,  dqcoeff[MAX_MB_PLANE][64 * 64]);
-} TileWorkerData;
-
 static int read_be32(const uint8_t *p) {
   return (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
 }
@@ -982,7 +976,6 @@ static const uint8_t *decode_tiles_mt(VP9D_COMP *pbi, const uint8_t *data) {
       ++pbi->num_tile_workers;
 
       vp9_worker_init(worker);
-      worker->hook = (VP9WorkerHook)tile_worker_hook;
       CHECK_MEM_ERROR(cm, worker->data1,
                       vpx_memalign(32, sizeof(TileWorkerData)));
       CHECK_MEM_ERROR(cm, worker->data2, vpx_malloc(sizeof(TileInfo)));
@@ -993,6 +986,11 @@ static const uint8_t *decode_tiles_mt(VP9D_COMP *pbi, const uint8_t *data) {
     }
   }
 
+  // Reset tile decoding hook
+  for (n = 0; n < pbi->num_tile_workers; ++n) {
+    pbi->tile_workers[n].hook = (VP9WorkerHook)tile_worker_hook;
+  }
+
   // Note: this memset assumes above_context[0], [1] and [2]
   // are allocated as part of the same buffer.
   vpx_memset(pbi->above_context[0], 0,
@@ -1393,9 +1391,6 @@ int vp9_decode_frame(VP9D_COMP *pbi, const uint8_t **p_data_end) {
     *p_data_end = decode_tiles(pbi, data + first_partition_size);
   }
 
-  cm->last_width = cm->width;
-  cm->last_height = cm->height;
-
   new_fb->corrupted |= xd->corrupted;
 
   if (!pbi->decoded_key_frame) {
diff --git a/vp9/decoder/vp9_dthread.c b/vp9/decoder/vp9_dthread.c
new file mode 100644
index 0000000000000000000000000000000000000000..280e351ae5abe2185c7009ca6e16aeefa1ab9104
--- /dev/null
+++ b/vp9/decoder/vp9_dthread.c
@@ -0,0 +1,259 @@
+/*
+ *  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 "vp9/common/vp9_reconinter.h"
+#include "vp9/decoder/vp9_dthread.h"
+#include "vp9/decoder/vp9_onyxd_int.h"
+#include "vpx_mem/vpx_mem.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))) {
+    mutex_lock(&lf_sync->mutex_[r - 1]);
+
+    while (c > lf_sync->cur_sb_col[r - 1] - nsync) {
+      pthread_cond_wait(&lf_sync->cond_[r - 1],
+                        &lf_sync->mutex_[r - 1]);
+    }
+    pthread_mutex_unlock(&lf_sync->mutex_[r - 1]);
+  }
+#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, MACROBLOCKD *const xd,
+                                int start, int stop, int y_only,
+                                VP9LfSync *const lf_sync, int num_lf_workers) {
+  const int num_planes = y_only ? 1 : MAX_MB_PLANE;
+  int r, c;  // SB row and col
+  LOOP_FILTER_MASK lfm;
+  const int sb_cols = mi_cols_aligned_to_sb(cm->mi_cols) >> MI_BLOCK_SIZE_LOG2;
+
+  for (r = start; r < stop; r += num_lf_workers) {
+    const int mi_row = r << MI_BLOCK_SIZE_LOG2;
+    MODE_INFO **mi_8x8 = cm->mi_grid_visible + mi_row * cm->mode_info_stride;
+
+    for (c = 0; c < sb_cols; ++c) {
+      const int mi_col = c << MI_BLOCK_SIZE_LOG2;
+      int plane;
+
+      sync_read(lf_sync, r, c);
+
+      setup_dst_planes(xd, frame_buffer, mi_row, mi_col);
+      vp9_setup_mask(cm, mi_row, mi_col, mi_8x8 + mi_col, cm->mode_info_stride,
+                     &lfm);
+
+      for (plane = 0; plane < num_planes; ++plane) {
+        vp9_filter_block_plane(cm, &xd->plane[plane], mi_row, &lfm);
+      }
+
+      sync_write(lf_sync, r, c, sb_cols);
+    }
+  }
+}
+
+// Row-based multi-threaded loopfilter hook
+static int loop_filter_row_worker(void *arg1, void *arg2) {
+  TileWorkerData *const tile_data = (TileWorkerData*)arg1;
+  LFWorkerData *const lf_data = &tile_data->lfdata;
+
+  loop_filter_rows_mt(lf_data->frame_buffer, lf_data->cm, &lf_data->xd,
+                      lf_data->start, lf_data->stop, lf_data->y_only,
+                      lf_data->lf_sync, lf_data->num_lf_workers);
+  return 1;
+}
+
+// VP9 decoder: Implement multi-threaded loopfilter that uses the tile
+// threads.
+void vp9_loop_filter_frame_mt(VP9D_COMP *pbi,
+                              VP9_COMMON *cm,
+                              MACROBLOCKD *xd,
+                              int frame_filter_level,
+                              int y_only, int partial) {
+  // Number of superblock rows and cols
+  const int sb_rows = mi_cols_aligned_to_sb(cm->mi_rows) >> MI_BLOCK_SIZE_LOG2;
+  int i;
+
+  // Allocate memory used in thread synchronization.
+  // This always needs to be done even if frame_filter_level is 0.
+  if (!cm->current_video_frame || cm->last_height != cm->height) {
+    VP9LfSync *const lf_sync = &pbi->lf_row_sync;
+
+    if (cm->last_height != cm->height) {
+      const int aligned_last_height =
+          ALIGN_POWER_OF_TWO(cm->last_height, MI_SIZE_LOG2);
+      const int last_sb_rows =
+          mi_cols_aligned_to_sb(aligned_last_height >> MI_SIZE_LOG2) >>
+          MI_BLOCK_SIZE_LOG2;
+
+      vp9_loop_filter_dealloc(lf_sync, last_sb_rows);
+    }
+
+    vp9_loop_filter_alloc(cm, lf_sync, sb_rows, cm->width);
+  }
+
+  if (!frame_filter_level) return;
+
+  vp9_loop_filter_frame_init(cm, frame_filter_level);
+
+  // Initialize cur_sb_col to -1 for all SB rows.
+  vpx_memset(pbi->lf_row_sync.cur_sb_col, -1,
+             sizeof(*pbi->lf_row_sync.cur_sb_col) * sb_rows);
+
+  // Set up loopfilter thread data.
+  for (i = 0; i < pbi->num_tile_workers; ++i) {
+    VP9Worker *const worker = &pbi->tile_workers[i];
+    TileWorkerData *const tile_data = (TileWorkerData*)worker->data1;
+    LFWorkerData *const lf_data = &tile_data->lfdata;
+
+    worker->hook = (VP9WorkerHook)loop_filter_row_worker;
+
+    // Loopfilter data
+    lf_data->frame_buffer = get_frame_new_buffer(cm);
+    lf_data->cm = cm;
+    lf_data->xd = pbi->mb;
+    lf_data->start = i;
+    lf_data->stop = sb_rows;
+    lf_data->y_only = y_only;   // always do all planes in decoder
+
+    lf_data->lf_sync = &pbi->lf_row_sync;
+    lf_data->num_lf_workers = pbi->num_tile_workers;
+
+    // Start loopfiltering
+    if (i == pbi->num_tile_workers - 1) {
+      vp9_worker_execute(worker);
+    } else {
+      vp9_worker_launch(worker);
+    }
+  }
+
+  // Wait till all rows are finished
+  for (i = 0; i < pbi->num_tile_workers; ++i) {
+    vp9_worker_sync(&pbi->tile_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(VP9_COMMON *cm, VP9LfSync *lf_sync, int rows,
+                           int width) {
+#if CONFIG_MULTITHREAD
+  int i;
+
+  CHECK_MEM_ERROR(cm, lf_sync->mutex_,
+                  vpx_malloc(sizeof(*lf_sync->mutex_) * rows));
+  CHECK_MEM_ERROR(cm, lf_sync->cond_,
+                  vpx_malloc(sizeof(*lf_sync->cond_) * rows));
+
+  for (i = 0; i < rows; ++i) {
+    pthread_mutex_init(&lf_sync->mutex_[i], NULL);
+    pthread_cond_init(&lf_sync->cond_[i], NULL);
+  }
+#endif  // CONFIG_MULTITHREAD
+
+  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, int rows) {
+#if CONFIG_MULTITHREAD
+  if (lf_sync != NULL) {
+    int i;
+
+    for (i = 0; i < rows; ++i) {
+      pthread_mutex_destroy(&lf_sync->mutex_[i]);
+      pthread_cond_destroy(&lf_sync->cond_[i]);
+    }
+
+    vpx_free(lf_sync->mutex_);
+    vpx_free(lf_sync->cond_);
+    vpx_free(lf_sync->cur_sb_col);
+  }
+#else
+  (void)rows;
+  if (lf_sync != NULL)
+    vpx_free(lf_sync->cur_sb_col);
+#endif  // CONFIG_MULTITHREAD
+}
diff --git a/vp9/decoder/vp9_dthread.h b/vp9/decoder/vp9_dthread.h
new file mode 100644
index 0000000000000000000000000000000000000000..4478354baa996e5089e1baaa8bfe16e0b740f2e5
--- /dev/null
+++ b/vp9/decoder/vp9_dthread.h
@@ -0,0 +1,60 @@
+/*
+ *  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.
+ */
+
+#ifndef VP9_DECODER_VP9_DTHREAD_H_
+#define VP9_DECODER_VP9_DTHREAD_H_
+
+#include "./vpx_config.h"
+#include "vp9/common/vp9_loopfilter.h"
+#include "vp9/decoder/vp9_reader.h"
+#include "vp9/decoder/vp9_thread.h"
+
+struct macroblockd;
+struct VP9Common;
+struct VP9Decompressor;
+
+typedef struct TileWorkerData {
+  struct VP9Common *cm;
+  vp9_reader bit_reader;
+  DECLARE_ALIGNED(16, struct macroblockd, xd);
+  DECLARE_ALIGNED(16, int16_t, dqcoeff[MAX_MB_PLANE][64 * 64]);
+
+  // Row-based parallel loopfilter data
+  LFWorkerData lfdata;
+} TileWorkerData;
+
+// Loopfilter row synchronization
+typedef struct VP9LfSyncData {
+#if CONFIG_MULTITHREAD
+  pthread_mutex_t *mutex_;
+  pthread_cond_t *cond_;
+#endif
+  // Allocate memory to store the loop-filtered superblock index in each row.
+  int *cur_sb_col;
+  // The optimal sync_range for different resolution and platform should be
+  // determined by testing. Currently, it is chosen to be a power-of-2 number.
+  int sync_range;
+} VP9LfSync;
+
+// Allocate memory for loopfilter row synchronization.
+void vp9_loop_filter_alloc(struct VP9Common *cm, struct VP9LfSyncData *lf_sync,
+                           int rows, int width);
+
+// Deallocate loopfilter synchronization related mutex and data.
+void vp9_loop_filter_dealloc(struct VP9LfSyncData *lf_sync, int rows);
+
+// Multi-threaded loopfilter that uses the tile threads.
+void vp9_loop_filter_frame_mt(struct VP9Decompressor *pbi,
+                              struct VP9Common *cm,
+                              struct macroblockd *xd,
+                              int frame_filter_level,
+                              int y_only, int partial);
+
+#endif  // VP9_DECODER_VP9_DTHREAD_H_
diff --git a/vp9/decoder/vp9_onyxd_if.c b/vp9/decoder/vp9_onyxd_if.c
index c6e9205bb527d81b91c16e87c96f506757686127..c14a05d1e79274a025e22f19987853904e13b8ce 100644
--- a/vp9/decoder/vp9_onyxd_if.c
+++ b/vp9/decoder/vp9_onyxd_if.c
@@ -27,6 +27,7 @@
 #include "vpx_ports/vpx_timer.h"
 #include "vp9/decoder/vp9_decodeframe.h"
 #include "vp9/decoder/vp9_detokenize.h"
+#include "vp9/decoder/vp9_dthread.h"
 #include "./vpx_scale_rtcd.h"
 
 #define WRITE_RECON_BUFFER 0
@@ -177,6 +178,16 @@ void vp9_remove_decompressor(VP9D_PTR ptr) {
     vpx_free(worker->data2);
   }
   vpx_free(pbi->tile_workers);
+
+  if (pbi->num_tile_workers) {
+    VP9_COMMON *const cm = &pbi->common;
+    const int sb_rows =
+        mi_cols_aligned_to_sb(cm->mi_rows) >> MI_BLOCK_SIZE_LOG2;
+    VP9LfSync *const lf_sync = &pbi->lf_row_sync;
+
+    vp9_loop_filter_dealloc(lf_sync, sb_rows);
+  }
+
   vpx_free(pbi->mi_streams);
   vpx_free(pbi->above_context[0]);
   vpx_free(pbi->above_seg_context);
@@ -370,7 +381,13 @@ int vp9_receive_compressed_data(VP9D_PTR ptr,
 #endif
 
   if (!pbi->do_loopfilter_inline) {
-    vp9_loop_filter_frame(cm, &pbi->mb, pbi->common.lf.filter_level, 0, 0);
+    // If multiple threads are used to decode tiles, then we use those threads
+    // to do parallel loopfiltering.
+    if (pbi->num_tile_workers) {
+      vp9_loop_filter_frame_mt(pbi, cm, &pbi->mb, cm->lf.filter_level, 0, 0);
+    } else {
+      vp9_loop_filter_frame(cm, &pbi->mb, cm->lf.filter_level, 0, 0);
+    }
   }
 
 #if WRITE_RECON_BUFFER == 2
@@ -390,6 +407,9 @@ int vp9_receive_compressed_data(VP9D_PTR ptr,
 
   vp9_clear_system_state();
 
+  cm->last_width = cm->width;
+  cm->last_height = cm->height;
+
   if (!cm->show_existing_frame)
     cm->last_show_frame = cm->show_frame;
   if (cm->show_frame) {
diff --git a/vp9/decoder/vp9_onyxd_int.h b/vp9/decoder/vp9_onyxd_int.h
index 242c600ccd1d102e9e7b49fcb72141e9a6639136..6c6c239265892829d4161e2c49fa3a66d27ed1b8 100644
--- a/vp9/decoder/vp9_onyxd_int.h
+++ b/vp9/decoder/vp9_onyxd_int.h
@@ -14,6 +14,7 @@
 #include "./vpx_config.h"
 
 #include "vp9/common/vp9_onyxc_int.h"
+#include "vp9/decoder/vp9_dthread.h"
 #include "vp9/decoder/vp9_onyxd.h"
 #include "vp9/decoder/vp9_thread.h"
 
@@ -49,6 +50,8 @@ typedef struct VP9Decompressor {
   VP9Worker *tile_workers;
   int num_tile_workers;
 
+  VP9LfSync lf_row_sync;
+
   /* Each tile column has its own MODE_INFO stream. This array indexes them by
      tile column index. */
   MODE_INFO **mi_streams;
diff --git a/vp9/decoder/vp9_thread.c b/vp9/decoder/vp9_thread.c
index d953e72b333aa724e7174e9f3b564e41b9e6501b..5d31d3d98b08dfa983f87646a6ca6eb9697cf2a8 100644
--- a/vp9/decoder/vp9_thread.c
+++ b/vp9/decoder/vp9_thread.c
@@ -24,116 +24,6 @@ extern "C" {
 
 #if CONFIG_MULTITHREAD
 
-#if defined(_WIN32)
-
-//------------------------------------------------------------------------------
-// simplistic pthread emulation layer
-
-#include <process.h>  // NOLINT
-
-// _beginthreadex requires __stdcall
-#define THREADFN unsigned int __stdcall
-#define THREAD_RETURN(val) (unsigned int)((DWORD_PTR)val)
-
-static int pthread_create(pthread_t* const thread, const void* attr,
-                          unsigned int (__stdcall *start)(void*), void* arg) {
-  (void)attr;
-  *thread = (pthread_t)_beginthreadex(NULL,   /* void *security */
-                                      0,      /* unsigned stack_size */
-                                      start,
-                                      arg,
-                                      0,      /* unsigned initflag */
-                                      NULL);  /* unsigned *thrdaddr */
-  if (*thread == NULL) return 1;
-  SetThreadPriority(*thread, THREAD_PRIORITY_ABOVE_NORMAL);
-  return 0;
-}
-
-static int pthread_join(pthread_t thread, void** value_ptr) {
-  (void)value_ptr;
-  return (WaitForSingleObject(thread, INFINITE) != WAIT_OBJECT_0 ||
-          CloseHandle(thread) == 0);
-}
-
-// Mutex
-static int pthread_mutex_init(pthread_mutex_t* const mutex, void* mutexattr) {
-  (void)mutexattr;
-  InitializeCriticalSection(mutex);
-  return 0;
-}
-
-static int pthread_mutex_lock(pthread_mutex_t* const mutex) {
-  EnterCriticalSection(mutex);
-  return 0;
-}
-
-static int pthread_mutex_unlock(pthread_mutex_t* const mutex) {
-  LeaveCriticalSection(mutex);
-  return 0;
-}
-
-static int pthread_mutex_destroy(pthread_mutex_t* const mutex) {
-  DeleteCriticalSection(mutex);
-  return 0;
-}
-
-// Condition
-static int pthread_cond_destroy(pthread_cond_t* const condition) {
-  int ok = 1;
-  ok &= (CloseHandle(condition->waiting_sem_) != 0);
-  ok &= (CloseHandle(condition->received_sem_) != 0);
-  ok &= (CloseHandle(condition->signal_event_) != 0);
-  return !ok;
-}
-
-static int pthread_cond_init(pthread_cond_t* const condition, void* cond_attr) {
-  (void)cond_attr;
-  condition->waiting_sem_ = CreateSemaphore(NULL, 0, 1, NULL);
-  condition->received_sem_ = CreateSemaphore(NULL, 0, 1, NULL);
-  condition->signal_event_ = CreateEvent(NULL, FALSE, FALSE, NULL);
-  if (condition->waiting_sem_ == NULL ||
-      condition->received_sem_ == NULL ||
-      condition->signal_event_ == NULL) {
-    pthread_cond_destroy(condition);
-    return 1;
-  }
-  return 0;
-}
-
-static int pthread_cond_signal(pthread_cond_t* const condition) {
-  int ok = 1;
-  if (WaitForSingleObject(condition->waiting_sem_, 0) == WAIT_OBJECT_0) {
-    // a thread is waiting in pthread_cond_wait: allow it to be notified
-    ok = SetEvent(condition->signal_event_);
-    // wait until the event is consumed so the signaler cannot consume
-    // the event via its own pthread_cond_wait.
-    ok &= (WaitForSingleObject(condition->received_sem_, INFINITE) !=
-           WAIT_OBJECT_0);
-  }
-  return !ok;
-}
-
-static int pthread_cond_wait(pthread_cond_t* const condition,
-                             pthread_mutex_t* const mutex) {
-  int ok;
-  // note that there is a consumer available so the signal isn't dropped in
-  // pthread_cond_signal
-  if (!ReleaseSemaphore(condition->waiting_sem_, 1, NULL))
-    return 1;
-  // now unlock the mutex so pthread_cond_signal may be issued
-  pthread_mutex_unlock(mutex);
-  ok = (WaitForSingleObject(condition->signal_event_, INFINITE) ==
-        WAIT_OBJECT_0);
-  ok &= ReleaseSemaphore(condition->received_sem_, 1, NULL);
-  pthread_mutex_lock(mutex);
-  return !ok;
-}
-
-#else  // _WIN32
-# define THREADFN void*
-# define THREAD_RETURN(val) val
-#endif
-
 //------------------------------------------------------------------------------
 
 static THREADFN thread_loop(void *ptr) {    // thread loop
diff --git a/vp9/decoder/vp9_thread.h b/vp9/decoder/vp9_thread.h
index bc69cfa1f5fb5ef51aebbc04c5d3d74e98691451..2f8728dcf6e524b9e0db7b68a86d12f522f9a12c 100644
--- a/vp9/decoder/vp9_thread.h
+++ b/vp9/decoder/vp9_thread.h
@@ -26,7 +26,8 @@ extern "C" {
 #if CONFIG_MULTITHREAD
 
 #if defined(_WIN32)
-
+#include <errno.h>  // NOLINT
+#include <process.h>  // NOLINT
 #include <windows.h>  // NOLINT
 typedef HANDLE pthread_t;
 typedef CRITICAL_SECTION pthread_mutex_t;
@@ -36,12 +37,120 @@ typedef struct {
   HANDLE signal_event_;
 } pthread_cond_t;
 
-#else
-
+//------------------------------------------------------------------------------
+// simplistic pthread emulation layer
+
+// _beginthreadex requires __stdcall
+#define THREADFN unsigned int __stdcall
+#define THREAD_RETURN(val) (unsigned int)((DWORD_PTR)val)
+
+static INLINE int pthread_create(pthread_t* const thread, const void* attr,
+                                 unsigned int (__stdcall *start)(void*),
+                                 void* arg) {
+  (void)attr;
+  *thread = (pthread_t)_beginthreadex(NULL,   /* void *security */
+                                      0,      /* unsigned stack_size */
+                                      start,
+                                      arg,
+                                      0,      /* unsigned initflag */
+                                      NULL);  /* unsigned *thrdaddr */
+  if (*thread == NULL) return 1;
+  SetThreadPriority(*thread, THREAD_PRIORITY_ABOVE_NORMAL);
+  return 0;
+}
+
+static INLINE int pthread_join(pthread_t thread, void** value_ptr) {
+  (void)value_ptr;
+  return (WaitForSingleObject(thread, INFINITE) != WAIT_OBJECT_0 ||
+          CloseHandle(thread) == 0);
+}
+
+// Mutex
+static INLINE int pthread_mutex_init(pthread_mutex_t *const mutex,
+                                     void* mutexattr) {
+  (void)mutexattr;
+  InitializeCriticalSection(mutex);
+  return 0;
+}
+
+static INLINE int pthread_mutex_trylock(pthread_mutex_t *const mutex) {
+  return TryEnterCriticalSection(mutex) ? 0 : EBUSY;
+}
+
+static INLINE int pthread_mutex_lock(pthread_mutex_t *const mutex) {
+  EnterCriticalSection(mutex);
+  return 0;
+}
+
+static INLINE int pthread_mutex_unlock(pthread_mutex_t *const mutex) {
+  LeaveCriticalSection(mutex);
+  return 0;
+}
+
+static INLINE int pthread_mutex_destroy(pthread_mutex_t *const mutex) {
+  DeleteCriticalSection(mutex);
+  return 0;
+}
+
+// Condition
+static INLINE int pthread_cond_destroy(pthread_cond_t *const condition) {
+  int ok = 1;
+  ok &= (CloseHandle(condition->waiting_sem_) != 0);
+  ok &= (CloseHandle(condition->received_sem_) != 0);
+  ok &= (CloseHandle(condition->signal_event_) != 0);
+  return !ok;
+}
+
+static INLINE int pthread_cond_init(pthread_cond_t *const condition,
+                                    void* cond_attr) {
+  (void)cond_attr;
+  condition->waiting_sem_ = CreateSemaphore(NULL, 0, 1, NULL);
+  condition->received_sem_ = CreateSemaphore(NULL, 0, 1, NULL);
+  condition->signal_event_ = CreateEvent(NULL, FALSE, FALSE, NULL);
+  if (condition->waiting_sem_ == NULL ||
+      condition->received_sem_ == NULL ||
+      condition->signal_event_ == NULL) {
+    pthread_cond_destroy(condition);
+    return 1;
+  }
+  return 0;
+}
+
+static INLINE int pthread_cond_signal(pthread_cond_t *const condition) {
+  int ok = 1;
+  if (WaitForSingleObject(condition->waiting_sem_, 0) == WAIT_OBJECT_0) {
+    // a thread is waiting in pthread_cond_wait: allow it to be notified
+    ok = SetEvent(condition->signal_event_);
+    // wait until the event is consumed so the signaler cannot consume
+    // the event via its own pthread_cond_wait.
+    ok &= (WaitForSingleObject(condition->received_sem_, INFINITE) !=
+           WAIT_OBJECT_0);
+  }
+  return !ok;
+}
+
+static INLINE int pthread_cond_wait(pthread_cond_t *const condition,
+                                    pthread_mutex_t *const mutex) {
+  int ok;
+  // note that there is a consumer available so the signal isn't dropped in
+  // pthread_cond_signal
+  if (!ReleaseSemaphore(condition->waiting_sem_, 1, NULL))
+    return 1;
+  // now unlock the mutex so pthread_cond_signal may be issued
+  pthread_mutex_unlock(mutex);
+  ok = (WaitForSingleObject(condition->signal_event_, INFINITE) ==
+        WAIT_OBJECT_0);
+  ok &= ReleaseSemaphore(condition->received_sem_, 1, NULL);
+  pthread_mutex_lock(mutex);
+  return !ok;
+}
+#else  // _WIN32
 #include <pthread.h> // NOLINT
+# define THREADFN void*
+# define THREAD_RETURN(val) val
+#endif
 
-#endif    /* _WIN32 */
-#endif    /* CONFIG_MULTITHREAD */
+#endif  // CONFIG_MULTITHREAD
 
 // State of the worker thread object
 typedef enum {
diff --git a/vp9/vp9dx.mk b/vp9/vp9dx.mk
index b722200f7df7a6c86c38294b1ad174f1649df79f..de210f4b77f2b7c451a9893f75d199b969ae099a 100644
--- a/vp9/vp9dx.mk
+++ b/vp9/vp9dx.mk
@@ -21,6 +21,8 @@ VP9_DX_SRCS-yes += decoder/vp9_decodemv.c
 VP9_DX_SRCS-yes += decoder/vp9_decodeframe.c
 VP9_DX_SRCS-yes += decoder/vp9_decodeframe.h
 VP9_DX_SRCS-yes += decoder/vp9_detokenize.c
+VP9_DX_SRCS-yes += decoder/vp9_dthread.c
+VP9_DX_SRCS-yes += decoder/vp9_dthread.h
 VP9_DX_SRCS-yes += decoder/vp9_reader.h
 VP9_DX_SRCS-yes += decoder/vp9_reader.c
 VP9_DX_SRCS-yes += decoder/vp9_read_bit_buffer.h