diff --git a/fftools/ffmpeg_dec.c b/fftools/ffmpeg_dec.c
index c41c5748e5..ed411b6bf8 100644
--- a/fftools/ffmpeg_dec.c
+++ b/fftools/ffmpeg_dec.c
@@ -1207,6 +1207,19 @@ static int dec_open(DecoderPriv *dp, AVDictionary **dec_opts,
         return ret;
     }
 
+    if (dp->dec_ctx->hw_device_ctx) {
+        // Update decoder extra_hw_frames option to account for the
+        // frames held in queues inside the ffmpeg utility.  This is
+        // called after avcodec_open2() because the user-set value of
+        // extra_hw_frames becomes valid in there, and we need to add
+        // this on top of it.
+        int extra_frames = DEFAULT_FRAME_THREAD_QUEUE_SIZE;
+        if (dp->dec_ctx->extra_hw_frames >= 0)
+            dp->dec_ctx->extra_hw_frames += extra_frames;
+        else
+            dp->dec_ctx->extra_hw_frames = extra_frames;
+    }
+
     ret = check_avoptions(*dec_opts);
     if (ret < 0)
         return ret;
diff --git a/fftools/ffmpeg_sched.c b/fftools/ffmpeg_sched.c
index f739066921..ec88017e21 100644
--- a/fftools/ffmpeg_sched.c
+++ b/fftools/ffmpeg_sched.c
@@ -365,7 +365,21 @@ static int queue_alloc(ThreadQueue **ptq, unsigned nb_streams, unsigned queue_si
     ThreadQueue *tq;
     ObjPool *op;
 
-    queue_size = queue_size > 0 ? queue_size : 8;
+    if (queue_size <= 0) {
+        if (type == QUEUE_FRAMES)
+            queue_size = DEFAULT_FRAME_THREAD_QUEUE_SIZE;
+        else
+            queue_size = DEFAULT_PACKET_THREAD_QUEUE_SIZE;
+    }
+
+    if (type == QUEUE_FRAMES) {
+        // This queue length is used in the decoder code to ensure that
+        // there are enough entries in fixed-size frame pools to account
+        // for frames held in queues inside the ffmpeg utility.  If this
+        // can ever dynamically change then the corresponding decode
+        // code needs to be updated as well.
+        av_assert0(queue_size == DEFAULT_FRAME_THREAD_QUEUE_SIZE);
+    }
 
     op = (type == QUEUE_PACKETS) ? objpool_alloc_packets() :
                                    objpool_alloc_frames();
diff --git a/fftools/ffmpeg_sched.h b/fftools/ffmpeg_sched.h
index a9190bd3d1..e51c26cec9 100644
--- a/fftools/ffmpeg_sched.h
+++ b/fftools/ffmpeg_sched.h
@@ -233,6 +233,18 @@ int sch_add_filtergraph(Scheduler *sch, unsigned nb_inputs, unsigned nb_outputs,
  */
 int sch_add_mux(Scheduler *sch, SchThreadFunc func, int (*init)(void *),
                 void *ctx, int sdp_auto, unsigned thread_queue_size);
+
+/**
+ * Default size of a packet thread queue.  For muxing this can be overridden by
+ * the thread_queue_size option as passed to a call to sch_add_mux().
+ */
+#define DEFAULT_PACKET_THREAD_QUEUE_SIZE 8
+
+/**
+ * Default size of a frame thread queue.
+ */
+#define DEFAULT_FRAME_THREAD_QUEUE_SIZE 8
+
 /**
  * Add a muxed stream for a previously added muxer.
  *