diff --git a/libavcodec/internal.h b/libavcodec/internal.h
index e5824cc62d..faa923c11f 100644
--- a/libavcodec/internal.h
+++ b/libavcodec/internal.h
@@ -64,6 +64,10 @@
  * dimensions to coded rather than display values.
  */
 #define FF_CODEC_CAP_EXPORTS_CROPPING       (1 << 4)
+/**
+ * Codec initializes slice-based threading with a main function
+ */
+#define FF_CODEC_CAP_SLICE_THREAD_HAS_MF    (1 << 5)
 
 #ifdef TRACE
 #   define ff_tlog(ctx, ...) av_log(ctx, AV_LOG_TRACE, __VA_ARGS__)
diff --git a/libavcodec/pthread_slice.c b/libavcodec/pthread_slice.c
index c781d350dc..d659f9b0ba 100644
--- a/libavcodec/pthread_slice.c
+++ b/libavcodec/pthread_slice.c
@@ -38,11 +38,13 @@
 
 typedef int (action_func)(AVCodecContext *c, void *arg);
 typedef int (action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr);
+typedef int (main_func)(AVCodecContext *c);
 
 typedef struct SliceThreadContext {
     AVSliceThread *thread;
     action_func *func;
     action_func2 *func2;
+    main_func *mainfunc;
     void *args;
     int *rets;
     int job_size;
@@ -54,6 +56,12 @@ typedef struct SliceThreadContext {
     pthread_mutex_t *progress_mutex;
 } SliceThreadContext;
 
+static void main_function(void *priv) {
+    AVCodecContext *avctx = priv;
+    SliceThreadContext *c = avctx->internal->thread_ctx;
+    c->mainfunc(avctx);
+}
+
 static void worker_func(void *priv, int jobnr, int threadnr, int nb_jobs, int nb_threads)
 {
     AVCodecContext *avctx = priv;
@@ -99,7 +107,7 @@ static int thread_execute(AVCodecContext *avctx, action_func* func, void *arg, i
     c->func = func;
     c->rets = ret;
 
-    avpriv_slicethread_execute(c->thread, job_count, 0);
+    avpriv_slicethread_execute(c->thread, job_count, !!c->mainfunc  );
     return 0;
 }
 
@@ -110,10 +118,19 @@ static int thread_execute2(AVCodecContext *avctx, action_func2* func2, void *arg
     return thread_execute(avctx, NULL, arg, ret, job_count, 0);
 }
 
+int ff_slice_thread_execute_with_mainfunc(AVCodecContext *avctx, action_func2* func2, main_func *mainfunc, void *arg, int *ret, int job_count)
+{
+    SliceThreadContext *c = avctx->internal->thread_ctx;
+    c->func2 = func2;
+    c->mainfunc = mainfunc;
+    return thread_execute(avctx, NULL, arg, ret, job_count, 0);
+}
+
 int ff_slice_thread_init(AVCodecContext *avctx)
 {
     SliceThreadContext *c;
     int thread_count = avctx->thread_count;
+    static void (*mainfunc)(void *);
 
 #if HAVE_W32THREADS
     w32thread_init();
@@ -142,7 +159,8 @@ int ff_slice_thread_init(AVCodecContext *avctx)
     }
 
     avctx->internal->thread_ctx = c = av_mallocz(sizeof(*c));
-    if (!c || (thread_count = avpriv_slicethread_create(&c->thread, avctx, worker_func, NULL, thread_count)) <= 1) {
+    mainfunc = avctx->codec->caps_internal & FF_CODEC_CAP_SLICE_THREAD_HAS_MF ? &main_function : NULL;
+    if (!c || (thread_count = avpriv_slicethread_create(&c->thread, avctx, worker_func, mainfunc, thread_count)) <= 1) {
         if (c)
             avpriv_slicethread_free(&c->thread);
         av_freep(&avctx->internal->thread_ctx);
diff --git a/libavcodec/thread.h b/libavcodec/thread.h
index 90864b59d9..318619316c 100644
--- a/libavcodec/thread.h
+++ b/libavcodec/thread.h
@@ -133,8 +133,10 @@ void ff_thread_release_buffer(AVCodecContext *avctx, ThreadFrame *f);
 int ff_thread_ref_frame(ThreadFrame *dst, ThreadFrame *src);
 
 int ff_thread_init(AVCodecContext *s);
+int ff_slice_thread_execute_with_mainfunc(AVCodecContext *avctx,
+        int (*action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr),
+        int (*main_func)(AVCodecContext *c), void *arg, int *ret, int job_count);
 void ff_thread_free(AVCodecContext *s);
-
 int ff_alloc_entries(AVCodecContext *avctx, int count);
 void ff_reset_entries(AVCodecContext *avctx);
 void ff_thread_report_progress2(AVCodecContext *avctx, int field, int thread, int n);