diff --git a/modules/access/rtp/test/Makefile.am b/modules/access/rtp/test/Makefile.am
index 31c41e31c80e8d1a412cb1052ba9baed8186eab3..3bcbd3172662d12bac2e131993272a549412d7c3 100644
--- a/modules/access/rtp/test/Makefile.am
+++ b/modules/access/rtp/test/Makefile.am
@@ -1,8 +1,12 @@
+rtpfmt_test_SOURCES = \
+	access/rtp/rtpfmt.c \
+	access/rtp/sdp.c \
+	access/rtp/test/rtpfmt.c
 sdp_test_SOURCES = \
 	access/rtp/sdp.c \
 	access/rtp/test/sdp.c
-check_PROGRAMS += sdp_test
-TESTS += sdp_test
+check_PROGRAMS += rtpfmt_test sdp_test
+TESTS += rtpfmt_test sdp_test
 
 srtp_aes_test_SOURCES = access/rtp/test/srtp-aes.c
 srtp_aes_test_LDADD = $(GCRYPT_LIBS)
diff --git a/modules/access/rtp/test/rtpfmt.c b/modules/access/rtp/test/rtpfmt.c
new file mode 100644
index 0000000000000000000000000000000000000000..f2aafe8efe060dc536a87f98a5925497b4c7d0e9
--- /dev/null
+++ b/modules/access/rtp/test/rtpfmt.c
@@ -0,0 +1,138 @@
+/**
+ * @file rtpfmt_test.c
+ */
+/*****************************************************************************
+ * Copyright © 2021 Rémi Denis-Courmont
+ *
+ * This library 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.
+ *
+ * This library 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 this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ ****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#undef NDEBUG
+#include <assert.h>
+#include <stdbool.h>
+#include <string.h>
+#include "../sdp.h"
+#include <vlc_common.h>
+#include <vlc_block.h>
+#include "../rtp.h"
+
+const char vlc_module_name[] = "rtpfmt_test";
+
+static const struct vlc_rtp_pt_operations ops = {
+    NULL, NULL, NULL, NULL,
+};
+
+int vlc_rtp_pt_instantiate(vlc_object_t *obj, struct vlc_rtp_pt *restrict pt,
+                           const struct vlc_sdp_pt *restrict desc)
+{
+    assert(obj == NULL);
+    assert(pt != NULL);
+    assert(desc != NULL);
+    pt->ops = &ops;
+    return 0;
+}
+
+uint8_t ptmask[16];
+
+int rtp_add_type(rtp_session_t *s, struct vlc_rtp_pt *pt)
+{
+    unsigned int num = pt->number;
+
+    assert(s == NULL);
+    assert(num < 128);
+    assert((ptmask[num / 8] >> (num % 8)) & 1);
+    ptmask[num / 8] &= ~(1 << (num % 8));
+    vlc_rtp_pt_release(pt);
+    return 0;
+}
+
+static const struct vlc_rtp_pt_owner owner = {
+    NULL, NULL,
+};
+
+#define EXPECT_PTS(...) \
+{ \
+     static const unsigned char nums[] = { __VA_ARGS__ }; \
+     for (size_t i = 0; i < sizeof (ptmask); i++) \
+         assert(ptmask[i] == 0); \
+     for (int i = 0; i < (int)ARRAY_SIZE(nums); i++) \
+         ptmask[nums[i] / 8] |= 1 << (nums[i] % 8); \
+}
+
+int main(void)
+{
+    static const char sdptext[] =
+        "v=0\r\n"
+        "o=- 1 1 IN IP4 192.0.2.1\r\n"
+        "s=Title here\r\n"
+        "t=0 0\r\n"
+        "m=audio 5004 RTP/AVP 0 3 8 12 14 33 96 97\r\n"
+        "a=rtpmap:96 L16/44100/6\r\n"
+        "a=rtpmap:97 L16/44100\r\n"
+        "m=video 5006 RTP/AVP 32 33 98\r\n"
+        "a=rtpmap:98 H264/90000\r\n"
+        "a=fmtp:98 profile-level-id=42A01E; packetization-mode=1\r\n"
+        "m=text 5008 RTP/AVP 127\r\n"
+        "a=rtpmap:127 t140/1000\r\n"
+        "m=naughty 5010 RTP/AVP 64 64 foobar 128 255\r\n"
+        "a=rtpmap:64 invalid/0/0\r\n"
+        "m=evil 5010 RTP/AVP 42 128 255\r\n"
+        "a=rtpmap:128 overflow/90000\r\n";
+
+    int val;
+
+    struct vlc_sdp *sdp = vlc_sdp_parse(sdptext, strlen(sdptext));
+    assert(sdp != NULL);
+
+    /* audio */
+    struct vlc_sdp_media *media = sdp->media;
+    assert(media != NULL);
+    EXPECT_PTS(0, 3, 8, 12, 14, 33, 96, 97);
+    val = vlc_rtp_add_media_types(NULL, NULL, media, &owner);
+    assert(val == 0);
+
+    /* video */
+    media = media->next;
+    assert(media != NULL);
+    EXPECT_PTS(32, 33, 98);
+    val = vlc_rtp_add_media_types(NULL, NULL, media, &owner);
+    assert(val == 0);
+    /* text */
+    media = media->next;
+    assert(media != NULL);
+    EXPECT_PTS(127);
+    val = vlc_rtp_add_media_types(NULL, NULL, media, &owner);
+    assert(val == 0);
+    /* naughty */
+    media = media->next;
+    assert(media != NULL);
+    EXPECT_PTS();
+    vlc_rtp_add_media_types(NULL, NULL, media, &owner);
+    /* evil */
+    media = media->next;
+    assert(media != NULL);
+    EXPECT_PTS();
+    vlc_rtp_add_media_types(NULL, NULL, media, &owner);
+
+    media = media->next;
+    EXPECT_PTS();
+    assert(media == NULL);
+    vlc_sdp_free(sdp);
+    return 0;
+}