diff --git a/libavformat/internal.h b/libavformat/internal.h
index 08987c76be..30117069a9 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -337,8 +337,6 @@ void ff_free_stream(AVFormatContext *s, AVStream *st);
 void ff_compute_frame_duration(int *pnum, int *pden, AVStream *st,
                                AVCodecParserContext *pc, AVPacket *pkt);
 
-int ff_get_audio_frame_size(AVCodecContext *enc, int size, int mux);
-
 unsigned int ff_codec_get_tag(const AVCodecTag *tags, enum AVCodecID id);
 
 enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag);
diff --git a/libavformat/mux.c b/libavformat/mux.c
index dbb9b55f39..55add43ebb 100644
--- a/libavformat/mux.c
+++ b/libavformat/mux.c
@@ -521,7 +521,7 @@ static int compute_pkt_fields2(AVFormatContext *s, AVStream *st, AVPacket *pkt)
     case AVMEDIA_TYPE_AUDIO:
         frame_size = (pkt->flags & AV_PKT_FLAG_UNCODED_FRAME) ?
                      ((AVFrame *)pkt->data)->nb_samples :
-                     ff_get_audio_frame_size(st->codec, pkt->size, 1);
+                     av_get_audio_frame_duration(st->codec, pkt->size);
 
         /* HACK/FIXME, we skip the initial 0 size packets as they are most
          * likely equal to the encoder delay, but it would be better if we
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 364796aad4..5d146d65e0 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -712,21 +712,6 @@ static int determinable_frame_size(AVCodecContext *avctx)
     return 0;
 }
 
-/**
- * Get the number of samples of an audio frame. Return -1 on error.
- */
-int ff_get_audio_frame_size(AVCodecContext *enc, int size, int mux)
-{
-    int frame_size;
-
-    if ((frame_size = av_get_audio_frame_duration(enc, size)) > 0)
-        return frame_size;
-
-
-
-    return -1;
-}
-
 /**
  * Return the frame duration in seconds. Return 0 if not available.
  */
@@ -762,7 +747,7 @@ void ff_compute_frame_duration(int *pnum, int *pden, AVStream *st,
         }
         break;
     case AVMEDIA_TYPE_AUDIO:
-        frame_size = ff_get_audio_frame_size(st->codec, pkt->size, 0);
+        frame_size = av_get_audio_frame_duration(st->codec, pkt->size);
         if (frame_size <= 0 || st->codec->sample_rate <= 0)
             break;
         *pnum = frame_size;