diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 0b4aaf544e..292a105266 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -126,7 +126,8 @@ OBJS-$(CONFIG_MPEGAUDIOHEADER)         += mpegaudiodecheader.o mpegaudiotabs.o
 OBJS-$(CONFIG_MPEG4AUDIO)              += mpeg4audio.o mpeg4audio_sample_rates.o
 OBJS-$(CONFIG_MPEGVIDEO)               += mpegvideo.o mpegvideodsp.o rl.o \
                                           mpegvideo_motion.o mpegutils.o \
-                                          mpegvideodata.o mpegpicture.o
+                                          mpegvideodata.o mpegpicture.o  \
+                                          to_upper4.o
 OBJS-$(CONFIG_MPEGVIDEOENC)            += mpegvideo_enc.o mpeg12data.o  \
                                           motion_est.o ratecontrol.o    \
                                           mpegvideoencdsp.o
@@ -993,6 +994,7 @@ OBJS-$(CONFIG_FITS_DEMUXER)            += fits.o
 OBJS-$(CONFIG_TAK_DEMUXER)             += tak.o
 
 # libavformat dependencies for static builds
+STLIBOBJS-$(CONFIG_AVFORMAT)           += to_upper4.o
 STLIBOBJS-$(CONFIG_ISO_MEDIA)          += mpegaudiotabs.o
 STLIBOBJS-$(CONFIG_FLV_MUXER)          += mpeg4audio_sample_rates.o
 STLIBOBJS-$(CONFIG_HLS_DEMUXER)        += ac3_channel_layout_tab.o
diff --git a/libavcodec/internal.h b/libavcodec/internal.h
index d3ee0214c5..72ca1553f6 100644
--- a/libavcodec/internal.h
+++ b/libavcodec/internal.h
@@ -225,7 +225,7 @@ extern const uint8_t ff_log2_run[41];
  */
 int ff_match_2uint16(const uint16_t (*tab)[2], int size, int a, int b);
 
-unsigned int avpriv_toupper4(unsigned int x);
+unsigned int ff_toupper4(unsigned int x);
 
 void ff_color_frame(AVFrame *frame, const int color[4]);
 
diff --git a/libavcodec/mpeg12dec.c b/libavcodec/mpeg12dec.c
index 09b2902bca..172ea92b16 100644
--- a/libavcodec/mpeg12dec.c
+++ b/libavcodec/mpeg12dec.c
@@ -2831,7 +2831,7 @@ static int mpeg_decode_frame(AVCodecContext *avctx, void *data,
     }
 #endif
 
-    s2->codec_tag = avpriv_toupper4(avctx->codec_tag);
+    s2->codec_tag = ff_toupper4(avctx->codec_tag);
     if (s->mpeg_enc_ctx_allocated == 0 && (   s2->codec_tag == AV_RL32("VCR2")
                                            || s2->codec_tag == AV_RL32("BW10")
                                           ))
diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index ba5b51955e..90d0a9fd50 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -707,7 +707,7 @@ void ff_mpv_decode_init(MpegEncContext *s, AVCodecContext *avctx)
     s->workaround_bugs = avctx->workaround_bugs;
 
     /* convert fourcc to upper case */
-    s->codec_tag          = avpriv_toupper4(avctx->codec_tag);
+    s->codec_tag       = ff_toupper4(avctx->codec_tag);
 }
 
 /**
diff --git a/libavcodec/to_upper4.c b/libavcodec/to_upper4.c
new file mode 100644
index 0000000000..29f65bf5c3
--- /dev/null
+++ b/libavcodec/to_upper4.c
@@ -0,0 +1,23 @@
+/*
+ * Converting FOURCCs to uppercase
+ * Copyright (c) 2001 Fabrice Bellard
+ * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "to_upper4.h"
diff --git a/libavcodec/to_upper4.h b/libavcodec/to_upper4.h
new file mode 100644
index 0000000000..d9648b5ef6
--- /dev/null
+++ b/libavcodec/to_upper4.h
@@ -0,0 +1,37 @@
+/*
+ * Converting FOURCCs to uppercase
+ * Copyright (c) 2001 Fabrice Bellard
+ * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_TO_UPPER4_H
+#define AVCODEC_TO_UPPER4_H
+
+#include "libavutil/avstring.h"
+#include "internal.h"
+
+unsigned int ff_toupper4(unsigned int x)
+{
+    return av_toupper(x & 0xFF) |
+          (av_toupper((x >>  8) & 0xFF) << 8)  |
+          (av_toupper((x >> 16) & 0xFF) << 16) |
+((unsigned)av_toupper((x >> 24) & 0xFF) << 24);
+}
+
+#endif
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 4d236ff1cd..b19befef21 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -863,14 +863,6 @@ const AVCodecHWConfig *avcodec_get_hw_config(const AVCodec *codec, int index)
     return &codec->hw_configs[index]->public;
 }
 
-unsigned int avpriv_toupper4(unsigned int x)
-{
-    return av_toupper(x & 0xFF) +
-          (av_toupper((x >>  8) & 0xFF) << 8)  +
-          (av_toupper((x >> 16) & 0xFF) << 16) +
-((unsigned)av_toupper((x >> 24) & 0xFF) << 24);
-}
-
 int ff_thread_ref_frame(ThreadFrame *dst, const ThreadFrame *src)
 {
     int ret;
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 6e93d082d9..c5c9e78fa8 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -677,7 +677,7 @@ OBJS-$(CONFIG_LIBSSH_PROTOCOL)           += libssh.o
 OBJS-$(CONFIG_LIBZMQ_PROTOCOL)           += libzmq.o
 
 # Objects duplicated from other libraries for shared builds
-SHLIBOBJS                                += log2_tab.o
+SHLIBOBJS                                += log2_tab.o to_upper4.o
 SHLIBOBJS-$(CONFIG_ISO_MEDIA)            += mpegaudiotabs.o
 SHLIBOBJS-$(CONFIG_FLV_MUXER)            += mpeg4audio_sample_rates.o
 SHLIBOBJS-$(CONFIG_HLS_DEMUXER)          += ac3_channel_layout_tab.o
diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 7216331fa1..fc309fb416 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -1716,7 +1716,7 @@ static unsigned int validate_codec_tag(const AVCodecTag *const *tags,
     for (i = 0; tags && tags[i]; i++) {
         const AVCodecTag *codec_tags = tags[i];
         while (codec_tags->id != AV_CODEC_ID_NONE) {
-            if (avpriv_toupper4(codec_tags->tag) == avpriv_toupper4(tag) &&
+            if (ff_toupper4(codec_tags->tag) == ff_toupper4(tag) &&
                 codec_tags->id == codec_id)
                 return codec_tags->tag;
             codec_tags++;
diff --git a/libavformat/mux.c b/libavformat/mux.c
index d93dc73f8e..b9c4abb9cf 100644
--- a/libavformat/mux.c
+++ b/libavformat/mux.c
@@ -204,7 +204,7 @@ static int validate_codec_tag(AVFormatContext *s, AVStream *st)
     for (int n = 0; s->oformat->codec_tag[n]; n++) {
         avctag = s->oformat->codec_tag[n];
         while (avctag->id != AV_CODEC_ID_NONE) {
-            if (avpriv_toupper4(avctag->tag) == avpriv_toupper4(st->codecpar->codec_tag)) {
+            if (ff_toupper4(avctag->tag) == ff_toupper4(st->codecpar->codec_tag)) {
                 id = avctag->id;
                 if (id == st->codecpar->codec_id)
                     return 1;
diff --git a/libavformat/to_upper4.c b/libavformat/to_upper4.c
new file mode 100644
index 0000000000..e84c803675
--- /dev/null
+++ b/libavformat/to_upper4.c
@@ -0,0 +1,23 @@
+/*
+ * Converting FOURCCs to uppercase
+ * Copyright (c) 2001 Fabrice Bellard
+ * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavcodec/to_upper4.h"
diff --git a/libavformat/utils.c b/libavformat/utils.c
index b5a4a09ae8..bd076d532b 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -361,7 +361,7 @@ enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
         if (tag == tags[i].tag)
             return tags[i].id;
     for (int i = 0; tags[i].id != AV_CODEC_ID_NONE; i++)
-        if (avpriv_toupper4(tag) == avpriv_toupper4(tags[i].tag))
+        if (ff_toupper4(tag) == ff_toupper4(tags[i].tag))
             return tags[i].id;
     return AV_CODEC_ID_NONE;
 }
