diff --git a/libavcodec/pthread_slice.c b/libavcodec/pthread_slice.c
index 60f5b78..7223205 100644
--- a/libavcodec/pthread_slice.c
+++ b/libavcodec/pthread_slice.c
@@ -22,6 +22,7 @@
  * @see doc/multithreading.txt
  */
 
+#include <stdatomic.h>
 #include "config.h"
 
 #include "avcodec.h"
@@ -38,21 +39,26 @@
 typedef int (action_func)(AVCodecContext *c, void *arg);
 typedef int (action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr);
 
+typedef struct WorkerContext WorkerContext;
+
 typedef struct SliceThreadContext {
-    pthread_t *workers;
+    AVCodecContext *avctx;
+    WorkerContext *workers;
     action_func *func;
     action_func2 *func2;
     void *args;
     int *rets;
-    int job_count;
-    int job_size;
-
-    pthread_cond_t last_job_cond;
-    pthread_cond_t current_job_cond;
-    pthread_mutex_t current_job_lock;
-    unsigned current_execute;
-    int current_job;
+    unsigned job_count;
+    unsigned job_size;
+
+    pthread_mutex_t mutex_user;
+    pthread_mutex_t mutex_done;
+    pthread_cond_t cond_done;
+    atomic_uint first_job;
+    atomic_uint current_job;
+    atomic_uint nb_finished_jobs;
     int done;
+    int worker_done;
 
     int *entries;
     int entries_count;
@@ -61,42 +67,55 @@ typedef struct SliceThreadContext {
     pthread_mutex_t *progress_mutex;
 } SliceThreadContext;
 
-static void* attribute_align_arg worker(void *v)
+struct WorkerContext {
+    SliceThreadContext  *ctx;
+    pthread_t           thread;
+    pthread_mutex_t     mutex;
+    pthread_cond_t      cond;
+    int                 done;
+};
+
+static unsigned run_jobs(SliceThreadContext *c)
 {
-    AVCodecContext *avctx = v;
-    SliceThreadContext *c = avctx->internal->thread_ctx;
-    unsigned last_execute = 0;
-    int our_job = c->job_count;
-    int thread_count = avctx->thread_count;
-    int self_id;
-
-    pthread_mutex_lock(&c->current_job_lock);
-    self_id = c->current_job++;
-    for (;;){
-        int ret;
-        while (our_job >= c->job_count) {
-            if (c->current_job == thread_count + c->job_count)
-                pthread_cond_signal(&c->last_job_cond);
-
-            while (last_execute == c->current_execute && !c->done)
-                pthread_cond_wait(&c->current_job_cond, &c->current_job_lock);
-            last_execute = c->current_execute;
-            our_job = self_id;
-
-            if (c->done) {
-                pthread_mutex_unlock(&c->current_job_lock);
-                return NULL;
-            }
-        }
-        pthread_mutex_unlock(&c->current_job_lock);
+    unsigned current_job, first_job, nb_finished_jobs;
+
+    current_job = first_job = atomic_fetch_add_explicit(&c->first_job, 1, memory_order_acq_rel);
 
-        ret = c->func ? c->func(avctx, (char*)c->args + our_job*c->job_size):
-                                c->func2(avctx, c->args, our_job, self_id);
+    do {
+        int ret = c->func ? c->func(c->avctx, (char *)c->args + current_job * (size_t) c->job_size)
+                          : c->func2(c->avctx, c->args, current_job, first_job);
         if (c->rets)
-            c->rets[our_job%c->job_count] = ret;
+            c->rets[current_job] = ret;
+        nb_finished_jobs = atomic_fetch_add_explicit(&c->nb_finished_jobs, 1, memory_order_relaxed) + 1;
+    } while ((current_job = atomic_fetch_add_explicit(&c->current_job, 1, memory_order_acq_rel)) < c->job_count);
 
-        pthread_mutex_lock(&c->current_job_lock);
-        our_job = c->current_job++;
+    return nb_finished_jobs;
+}
+
+static void* attribute_align_arg worker(void *v)
+{
+    WorkerContext *w = v;
+    SliceThreadContext *c = w->ctx;
+
+    pthread_mutex_lock(&w->mutex);
+    pthread_cond_signal(&w->cond);
+
+    while (1) {
+        w->done = 1;
+        while (w->done)
+            pthread_cond_wait(&w->cond, &w->mutex);
+
+        if (c->done) {
+            pthread_mutex_unlock(&w->mutex);
+            return NULL;
+        }
+
+        if (run_jobs(c) == c->job_count) {
+            pthread_mutex_lock(&c->mutex_done);
+            c->worker_done = 1;
+            pthread_cond_signal(&c->cond_done);
+            pthread_mutex_unlock(&c->mutex_done);
+        }
     }
 }
 
@@ -105,24 +124,36 @@ void ff_slice_thread_free(AVCodecContext *avctx)
     SliceThreadContext *c = avctx->internal->thread_ctx;
     int i;
 
-    pthread_mutex_lock(&c->current_job_lock);
+    for (i = 0; i < avctx->thread_count; i++)
+        pthread_mutex_lock(&c->workers[i].mutex);
+
     c->done = 1;
-    pthread_cond_broadcast(&c->current_job_cond);
+
     for (i = 0; i < c->thread_count; i++)
         pthread_cond_broadcast(&c->progress_cond[i]);
-    pthread_mutex_unlock(&c->current_job_lock);
 
-    for (i=0; i<avctx->thread_count; i++)
-         pthread_join(c->workers[i], NULL);
+    for (i = 0; i < avctx->thread_count; i++) {
+        WorkerContext *w = &c->workers[i];
+        w->done = 0;
+        pthread_cond_signal(&w->cond);
+        pthread_mutex_unlock(&w->mutex);
+    }
+
+    for (i = 0; i < avctx->thread_count; i++) {
+        WorkerContext *w = &c->workers[i];
+        pthread_join(w->thread, NULL);
+        pthread_cond_destroy(&w->cond);
+        pthread_mutex_destroy(&w->mutex);
+    }
 
     for (i = 0; i < c->thread_count; i++) {
         pthread_mutex_destroy(&c->progress_mutex[i]);
         pthread_cond_destroy(&c->progress_cond[i]);
     }
 
-    pthread_mutex_destroy(&c->current_job_lock);
-    pthread_cond_destroy(&c->current_job_cond);
-    pthread_cond_destroy(&c->last_job_cond);
+    pthread_cond_destroy(&c->cond_done);
+    pthread_mutex_destroy(&c->mutex_done);
+    pthread_mutex_lock(&c->mutex_user);
 
     av_freep(&c->entries);
     av_freep(&c->progress_mutex);
@@ -132,16 +163,11 @@ void ff_slice_thread_free(AVCodecContext *avctx)
     av_freep(&avctx->internal->thread_ctx);
 }
 
-static av_always_inline void thread_park_workers(SliceThreadContext *c, int thread_count)
-{
-    while (c->current_job != thread_count + c->job_count)
-        pthread_cond_wait(&c->last_job_cond, &c->current_job_lock);
-    pthread_mutex_unlock(&c->current_job_lock);
-}
-
-static int thread_execute(AVCodecContext *avctx, action_func* func, void *arg, int *ret, int job_count, int job_size)
+static int thread_execute_internal(AVCodecContext *avctx, action_func *func, action_func2 *func2,
+                                   void *arg, int *ret, int job_count, int job_size)
 {
     SliceThreadContext *c = avctx->internal->thread_ctx;
+    int i, nb_workers;
 
     if (!(avctx->active_thread_type&FF_THREAD_SLICE) || avctx->thread_count <= 1)
         return avcodec_default_execute(avctx, func, arg, ret, job_count, job_size);
@@ -149,27 +175,49 @@ static int thread_execute(AVCodecContext *avctx, action_func* func, void *arg, i
     if (job_count <= 0)
         return 0;
 
-    pthread_mutex_lock(&c->current_job_lock);
+    // last worker is unused
+    nb_workers = FFMIN(job_count - 1, avctx->thread_count - 1);
+
+    for (i = 0; i < nb_workers; i++)
+        pthread_mutex_lock(&c->workers[i].mutex);
 
-    c->current_job = avctx->thread_count;
+    atomic_store_explicit(&c->first_job, 0, memory_order_relaxed);
+    atomic_store_explicit(&c->current_job, avctx->thread_count, memory_order_relaxed);
+    atomic_store_explicit(&c->nb_finished_jobs, 0, memory_order_relaxed);
     c->job_count = job_count;
     c->job_size = job_size;
     c->args = arg;
     c->func = func;
+    c->func2 = func2;
     c->rets = ret;
-    c->current_execute++;
-    pthread_cond_broadcast(&c->current_job_cond);
 
-    thread_park_workers(c, avctx->thread_count);
+    for (i = 0; i < nb_workers; i++) {
+        WorkerContext *w = &c->workers[i];
+        w->done = 0;
+        pthread_cond_signal(&w->cond);
+        pthread_mutex_unlock(&w->mutex);
+    }
+
+    // emulate the last worker, no need to wait if all jobs is complete
+    if (run_jobs(c) != c->job_count) {
+        pthread_mutex_lock(&c->mutex_done);
+        while (!c->worker_done)
+            pthread_cond_wait(&c->cond_done, &c->mutex_done);
+        c->worker_done = 0;
+        pthread_mutex_unlock(&c->mutex_done);
+    }
 
     return 0;
 }
 
+static int thread_execute(AVCodecContext *avctx, action_func *func, void *arg, int *ret, int job_count, int job_size)
+{
+    return thread_execute_internal(avctx, func, NULL, arg, ret, job_count, job_size);
+}
+
 static int thread_execute2(AVCodecContext *avctx, action_func2* func2, void *arg, int *ret, int job_count)
 {
-    SliceThreadContext *c = avctx->internal->thread_ctx;
-    c->func2 = func2;
-    return thread_execute(avctx, NULL, arg, ret, job_count, 0);
+    return thread_execute_internal(avctx, NULL, func2, arg, ret, job_count, 0);
 }
 
 int ff_slice_thread_init(AVCodecContext *avctx)
@@ -208,31 +256,48 @@ int ff_slice_thread_init(AVCodecContext *avctx)
     if (!c)
         return -1;
 
-    c->workers = av_mallocz_array(thread_count, sizeof(pthread_t));
+    // allocate thread_count workers, but currently last worker is unused, emulated by main thread
+    // anticipate when main thread needs to do something
+    c->workers = av_mallocz_array(thread_count, sizeof(*c->workers));
     if (!c->workers) {
         av_free(c);
         return -1;
     }
 
     avctx->internal->thread_ctx = c;
-    c->current_job = 0;
+    c->avctx = avctx;
+    pthread_mutex_init(&c->mutex_user, NULL);
+    pthread_mutex_init(&c->mutex_done, NULL);
+    pthread_cond_init(&c->cond_done, NULL);
+    atomic_init(&c->first_job, 0);
+    atomic_init(&c->current_job, 0);
+    atomic_init(&c->nb_finished_jobs, 0);
     c->job_count = 0;
     c->job_size = 0;
     c->done = 0;
-    pthread_cond_init(&c->current_job_cond, NULL);
-    pthread_cond_init(&c->last_job_cond, NULL);
-    pthread_mutex_init(&c->current_job_lock, NULL);
-    pthread_mutex_lock(&c->current_job_lock);
-    for (i=0; i<thread_count; i++) {
-        if(pthread_create(&c->workers[i], NULL, worker, avctx)) {
-           avctx->thread_count = i;
-           pthread_mutex_unlock(&c->current_job_lock);
+    c->worker_done = 0;
+
+    for (i = 0; i < thread_count; i++) {
+        WorkerContext *w = &c->workers[i];
+
+        w->ctx = c;
+        pthread_mutex_init(&w->mutex, NULL);
+        pthread_cond_init(&w->cond, NULL);
+        pthread_mutex_lock(&w->mutex);
+        w->done = 0;
+        if (pthread_create(&w->thread, NULL, worker, w)) {
+           avctx->thread_count = i + 1;
+           pthread_mutex_unlock(&w->mutex);
+           pthread_cond_destroy(&w->cond);
+           pthread_mutex_destroy(&w->mutex);
            ff_thread_free(avctx);
            return -1;
         }
-    }
 
-    thread_park_workers(c, thread_count);
+        while (!w->done)
+            pthread_cond_wait(&w->cond, &w->mutex);
+        pthread_mutex_unlock(&w->mutex);
+    }
 
     avctx->execute = thread_execute;
     avctx->execute2 = thread_execute2;
