diff --git a/doc/APIchanges b/doc/APIchanges
index c00f103bab..df3d6d1fb0 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -15,6 +15,11 @@ libavutil:     2017-10-21
 
 API changes, most recent first:
 
+2020-xx-xx - xxxxxxxxxx - lavc 58.113.100 - avcodec.h
+  Deprecate AVCodecContext.thread_safe_callbacks. Starting with
+  LIBAVCODEC_VERSION_MAJOR=60, user callbacks must always be
+  thread-safe when frame threading is used.
+
 2020-xx-xx - xxxxxxxxxx - lavf 58.64.100 - avformat.h
   Add AVSTREAM_EVENT_FLAG_NEW_PACKETS.
 
diff --git a/doc/multithreading.txt b/doc/multithreading.txt
index 4f645dc147..470194ff85 100644
--- a/doc/multithreading.txt
+++ b/doc/multithreading.txt
@@ -20,8 +20,7 @@ Slice threading -
 
 Frame threading -
 * Restrictions with slice threading also apply.
-* For best performance, the client should set thread_safe_callbacks if it
-  provides a thread-safe get_buffer() callback.
+* Custom get_buffer2() and get_format() callbacks must be thread-safe.
 * There is one frame of delay added for every thread beyond the first one.
   Clients must be able to handle this; the pkt_dts and pkt_pts fields in
   AVFrame will work as usual.
diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index cb7644de6a..c3b9ec01c9 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -2890,7 +2890,9 @@ static int init_input_stream(int ist_index, char *error, int error_len)
         ist->dec_ctx->opaque                = ist;
         ist->dec_ctx->get_format            = get_format;
         ist->dec_ctx->get_buffer2           = get_buffer;
+#if LIBAVCODEC_VERSION_MAJOR < 60
         ist->dec_ctx->thread_safe_callbacks = 1;
+#endif
 
         av_opt_set_int(ist->dec_ctx, "refcounted_frames", 1, 0);
         if (ist->dec_ctx->codec_id == AV_CODEC_ID_DVB_SUBTITLE &&
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 20af3ef00d..3528d1e637 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -1314,9 +1314,9 @@ typedef struct AVCodecContext {
      *
      * Some decoders do not support linesizes changing between frames.
      *
-     * If frame multithreading is used and thread_safe_callbacks is set,
-     * this callback may be called from a different thread, but not from more
-     * than one at once. Does not need to be reentrant.
+     * If frame multithreading is used, this callback may be called from a
+     * different thread, but not from more than one at once. Does not need to be
+     * reentrant.
      *
      * @see avcodec_align_dimensions2()
      *
@@ -1803,6 +1803,7 @@ typedef struct AVCodecContext {
      */
     int active_thread_type;
 
+#if FF_API_THREAD_SAFE_CALLBACKS
     /**
      * Set by the client if its custom get_buffer() callback can be called
      * synchronously from another thread, which allows faster multithreaded decoding.
@@ -1810,8 +1811,14 @@ typedef struct AVCodecContext {
      * Ignored if the default get_buffer() is used.
      * - encoding: Set by user.
      * - decoding: Set by user.
+     *
+     * @deprecated the custom get_buffer2() callback should always be
+     *   thread-safe. Thread-unsafe get_buffer2() implementations will be
+     *   invalid once this field is removed.
      */
+    attribute_deprecated
     int thread_safe_callbacks;
+#endif
 
     /**
      * The codec may call this to execute several independent things.
diff --git a/libavcodec/pthread_frame.c b/libavcodec/pthread_frame.c
index f8a01ad8cd..c9d2e00ce3 100644
--- a/libavcodec/pthread_frame.c
+++ b/libavcodec/pthread_frame.c
@@ -89,6 +89,7 @@ typedef struct PerThreadContext {
 
     atomic_int state;
 
+#if FF_API_THREAD_SAFE_CALLBACKS
     /**
      * Array of frames passed to ff_thread_release_buffer().
      * Frames are released after all threads referencing them are finished.
@@ -102,6 +103,7 @@ typedef struct PerThreadContext {
 
     const enum AVPixelFormat *available_formats; ///< Format array for get_format()
     enum AVPixelFormat result_format;            ///< get_format() result
+#endif
 
     int die;                        ///< Set when the thread should exit.
 
@@ -137,8 +139,10 @@ typedef struct FrameThreadContext {
                                     */
 } FrameThreadContext;
 
+#if FF_API_THREAD_SAFE_CALLBACKS
 #define THREAD_SAFE_CALLBACKS(avctx) \
 ((avctx)->thread_safe_callbacks || (avctx)->get_buffer2 == avcodec_default_get_buffer2)
+#endif
 
 static void async_lock(FrameThreadContext *fctx)
 {
@@ -178,8 +182,14 @@ static attribute_align_arg void *frame_worker_thread(void *arg)
 
         if (p->die) break;
 
-        if (!codec->update_thread_context && THREAD_SAFE_CALLBACKS(avctx))
+FF_DISABLE_DEPRECATION_WARNINGS
+        if (!codec->update_thread_context
+#if FF_API_THREAD_SAFE_CALLBACKS
+            && THREAD_SAFE_CALLBACKS(avctx)
+#endif
+            )
             ff_thread_finish_setup(avctx);
+FF_ENABLE_DEPRECATION_WARNINGS
 
         /* If a decoder supports hwaccel, then it must call ff_get_format().
          * Since that call must happen before ff_thread_finish_setup(), the
@@ -344,7 +354,11 @@ static int update_context_from_user(AVCodecContext *dst, AVCodecContext *src)
 
     dst->frame_number     = src->frame_number;
     dst->reordered_opaque = src->reordered_opaque;
+#if FF_API_THREAD_SAFE_CALLBACKS
+FF_DISABLE_DEPRECATION_WARNINGS
     dst->thread_safe_callbacks = src->thread_safe_callbacks;
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
 
     if (src->slice_count && src->slice_offset) {
         if (dst->slice_count < src->slice_count) {
@@ -360,6 +374,7 @@ static int update_context_from_user(AVCodecContext *dst, AVCodecContext *src)
     return 0;
 }
 
+#if FF_API_THREAD_SAFE_CALLBACKS
 /// Releases the buffers that this decoding thread was the last user of.
 static void release_delayed_buffers(PerThreadContext *p)
 {
@@ -380,6 +395,7 @@ static void release_delayed_buffers(PerThreadContext *p)
         pthread_mutex_unlock(&fctx->buffer_mutex);
     }
 }
+#endif
 
 static int submit_packet(PerThreadContext *p, AVCodecContext *user_avctx,
                          AVPacket *avpkt)
@@ -403,7 +419,9 @@ static int submit_packet(PerThreadContext *p, AVCodecContext *user_avctx,
                           (p->avctx->debug & FF_DEBUG_THREADS) != 0,
                           memory_order_relaxed);
 
+#if FF_API_THREAD_SAFE_CALLBACKS
     release_delayed_buffers(p);
+#endif
 
     if (prev_thread) {
         int err;
@@ -433,6 +451,8 @@ static int submit_packet(PerThreadContext *p, AVCodecContext *user_avctx,
     pthread_cond_signal(&p->input_cond);
     pthread_mutex_unlock(&p->mutex);
 
+#if FF_API_THREAD_SAFE_CALLBACKS
+FF_DISABLE_DEPRECATION_WARNINGS
     /*
      * If the client doesn't have a thread-safe get_buffer(),
      * then decoding threads call back to the main thread,
@@ -466,6 +486,8 @@ static int submit_packet(PerThreadContext *p, AVCodecContext *user_avctx,
             pthread_mutex_unlock(&p->progress_mutex);
         }
     }
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
 
     fctx->prev_thread = p;
     fctx->next_decoding++;
@@ -657,7 +679,7 @@ void ff_frame_thread_free(AVCodecContext *avctx, int thread_count)
 {
     FrameThreadContext *fctx = avctx->internal->thread_ctx;
     const AVCodec *codec = avctx->codec;
-    int i, j;
+    int i;
 
     park_frame_worker_threads(fctx, thread_count);
 
@@ -690,7 +712,9 @@ void ff_frame_thread_free(AVCodecContext *avctx, int thread_count)
         if (codec->close && p->avctx)
             codec->close(p->avctx);
 
+#if FF_API_THREAD_SAFE_CALLBACKS
         release_delayed_buffers(p);
+#endif
         av_frame_free(&p->frame);
     }
 
@@ -704,9 +728,11 @@ void ff_frame_thread_free(AVCodecContext *avctx, int thread_count)
         pthread_cond_destroy(&p->output_cond);
         av_packet_unref(&p->avpkt);
 
-        for (j = 0; j < p->released_buffers_allocated; j++)
+#if FF_API_THREAD_SAFE_CALLBACKS
+        for (int j = 0; j < p->released_buffers_allocated; j++)
             av_frame_free(&p->released_buffers[j]);
         av_freep(&p->released_buffers);
+#endif
 
         if (p->avctx) {
             if (codec->priv_class)
@@ -889,7 +915,9 @@ void ff_thread_flush(AVCodecContext *avctx)
         av_frame_unref(p->frame);
         p->result = 0;
 
+#if FF_API_THREAD_SAFE_CALLBACKS
         release_delayed_buffers(p);
+#endif
 
         if (avctx->codec->flush)
             avctx->codec->flush(p->avctx);
@@ -899,10 +927,16 @@ void ff_thread_flush(AVCodecContext *avctx)
 int ff_thread_can_start_frame(AVCodecContext *avctx)
 {
     PerThreadContext *p = avctx->internal->thread_ctx;
+FF_DISABLE_DEPRECATION_WARNINGS
     if ((avctx->active_thread_type&FF_THREAD_FRAME) && atomic_load(&p->state) != STATE_SETTING_UP &&
-        (avctx->codec->update_thread_context || !THREAD_SAFE_CALLBACKS(avctx))) {
+        (avctx->codec->update_thread_context
+#if FF_API_THREAD_SAFE_CALLBACKS
+         || !THREAD_SAFE_CALLBACKS(avctx)
+#endif
+         )) {
         return 0;
     }
+FF_ENABLE_DEPRECATION_WARNINGS
     return 1;
 }
 
@@ -916,8 +950,14 @@ static int thread_get_buffer_internal(AVCodecContext *avctx, ThreadFrame *f, int
     if (!(avctx->active_thread_type & FF_THREAD_FRAME))
         return ff_get_buffer(avctx, f->f, flags);
 
+FF_DISABLE_DEPRECATION_WARNINGS
     if (atomic_load(&p->state) != STATE_SETTING_UP &&
-        (avctx->codec->update_thread_context || !THREAD_SAFE_CALLBACKS(avctx))) {
+        (avctx->codec->update_thread_context
+#if FF_API_THREAD_SAFE_CALLBACKS
+         || !THREAD_SAFE_CALLBACKS(avctx)
+#endif
+         )) {
+FF_ENABLE_DEPRECATION_WARNINGS
         av_log(avctx, AV_LOG_ERROR, "get_buffer() cannot be called after ff_thread_finish_setup()\n");
         return -1;
     }
@@ -935,6 +975,10 @@ static int thread_get_buffer_internal(AVCodecContext *avctx, ThreadFrame *f, int
     }
 
     pthread_mutex_lock(&p->parent->buffer_mutex);
+#if !FF_API_THREAD_SAFE_CALLBACKS
+    err = ff_get_buffer(avctx, f->f, flags);
+#else
+FF_DISABLE_DEPRECATION_WARNINGS
     if (THREAD_SAFE_CALLBACKS(avctx)) {
         err = ff_get_buffer(avctx, f->f, flags);
     } else {
@@ -954,6 +998,8 @@ static int thread_get_buffer_internal(AVCodecContext *avctx, ThreadFrame *f, int
     }
     if (!THREAD_SAFE_CALLBACKS(avctx) && !avctx->codec->update_thread_context)
         ff_thread_finish_setup(avctx);
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
     if (err)
         av_buffer_unref(&f->progress);
 
@@ -962,6 +1008,8 @@ static int thread_get_buffer_internal(AVCodecContext *avctx, ThreadFrame *f, int
     return err;
 }
 
+#if FF_API_THREAD_SAFE_CALLBACKS
+FF_DISABLE_DEPRECATION_WARNINGS
 enum AVPixelFormat ff_thread_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt)
 {
     enum AVPixelFormat res;
@@ -987,6 +1035,8 @@ enum AVPixelFormat ff_thread_get_format(AVCodecContext *avctx, const enum AVPixe
 
     return res;
 }
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
 
 int ff_thread_get_buffer(AVCodecContext *avctx, ThreadFrame *f, int flags)
 {
@@ -998,12 +1048,16 @@ int ff_thread_get_buffer(AVCodecContext *avctx, ThreadFrame *f, int flags)
 
 void ff_thread_release_buffer(AVCodecContext *avctx, ThreadFrame *f)
 {
+#if FF_API_THREAD_SAFE_CALLBACKS
+FF_DISABLE_DEPRECATION_WARNINGS
     PerThreadContext *p = avctx->internal->thread_ctx;
     FrameThreadContext *fctx;
     AVFrame *dst;
     int ret = 0;
     int can_direct_free = !(avctx->active_thread_type & FF_THREAD_FRAME) ||
                           THREAD_SAFE_CALLBACKS(avctx);
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
 
     if (!f->f)
         return;
@@ -1014,6 +1068,9 @@ void ff_thread_release_buffer(AVCodecContext *avctx, ThreadFrame *f)
     av_buffer_unref(&f->progress);
     f->owner[0] = f->owner[1] = NULL;
 
+#if !FF_API_THREAD_SAFE_CALLBACKS
+    av_frame_unref(f->f);
+#else
     // when the frame buffers are not allocated, just reset it to clean state
     if (can_direct_free || !f->f->buf[0]) {
         av_frame_unref(f->f);
@@ -1055,4 +1112,5 @@ fail:
             memset(f->f->extended_buf, 0, f->f->nb_extended_buf * sizeof(*f->f->extended_buf));
         av_frame_unref(f->f);
     }
+#endif
 }
diff --git a/libavcodec/thread.h b/libavcodec/thread.h
index 87bf154da9..413196269f 100644
--- a/libavcodec/thread.h
+++ b/libavcodec/thread.h
@@ -96,6 +96,7 @@ void ff_thread_report_progress(ThreadFrame *f, int progress, int field);
  */
 void ff_thread_await_progress(ThreadFrame *f, int progress, int field);
 
+#if FF_API_THREAD_SAFE_CALLBACKS
 /**
  * Wrapper around get_format() for frame-multithreaded codecs.
  * Call this function instead of avctx->get_format().
@@ -105,6 +106,9 @@ void ff_thread_await_progress(ThreadFrame *f, int progress, int field);
  * @param fmt The list of available formats.
  */
 enum AVPixelFormat ff_thread_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt);
+#else
+#define ff_thread_get_format ff_get_format
+#endif
 
 /**
  * Wrapper around get_buffer() for frame-multithreaded codecs.
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index fb40962c47..9ac13fadfe 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -678,6 +678,19 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *code
         goto free_and_end;
     }
 
+#if FF_API_THREAD_SAFE_CALLBACKS
+FF_DISABLE_DEPRECATION_WARNINGS
+    if ((avctx->thread_type & FF_THREAD_FRAME) &&
+        avctx->get_buffer2 != avcodec_default_get_buffer2 &&
+        !avctx->thread_safe_callbacks) {
+        av_log(avctx, AV_LOG_WARNING, "Requested frame threading with a "
+               "custom get_buffer2() implementation which is not marked as "
+               "thread safe. This is not supported anymore, make your "
+               "callback thread-safe.\n");
+    }
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
+
     avctx->codec = codec;
     if ((avctx->codec_type == AVMEDIA_TYPE_UNKNOWN || avctx->codec_type == codec->type) &&
         avctx->codec_id == AV_CODEC_ID_NONE) {
diff --git a/libavcodec/version.h b/libavcodec/version.h
index 78c4dd64ee..187a59bee7 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -28,7 +28,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVCODEC_VERSION_MAJOR  58
-#define LIBAVCODEC_VERSION_MINOR 112
+#define LIBAVCODEC_VERSION_MINOR 113
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
@@ -147,5 +147,8 @@
 #ifndef FF_API_AVPRIV_PUT_BITS
 #define FF_API_AVPRIV_PUT_BITS     (LIBAVCODEC_VERSION_MAJOR < 59)
 #endif
+#ifndef FF_API_THREAD_SAFE_CALLBACKS
+#define FF_API_THREAD_SAFE_CALLBACKS (LIBAVCODEC_VERSION_MAJOR < 60)
+#endif
 
 #endif /* AVCODEC_VERSION_H */
