diff --git a/ietf/rtp3640.h b/ietf/rtp3640.h
new file mode 100644
index 0000000..e1b4558
--- /dev/null
+++ b/ietf/rtp3640.h
@@ -0,0 +1,85 @@
+/*****************************************************************************
+ * rtp3640.h: RTP Payload Format for Transport of MPEG-4 Elementary Streams
+ *****************************************************************************
+ * Copyright (C) 2017 VideoLAN
+ *
+ * Authors: Christophe Massiot
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject
+ * to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *****************************************************************************/
+
+/*
+ * Normative references:
+ *  - IETF RFC 3640 RTP Payload Format for Transport of MPEG-4 ES
+ */
+
+#ifndef __BITSTREAM_IETF_RTP3640_H__
+# define __BITSTREAM_IETF_RTP3640_H__
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#define RTP3640_AU_HEADERS_LENGTH_SIZE  2
+#define RTP3640_AU_HEADER_AAC_HBR_SIZE  2
+
+static inline void rtp3640_set_au_headers_length(uint8_t *header, uint16_t size)
+{
+    header[0] = size >> 8;
+    header[1] = size & 0xff;
+}
+
+static inline uint16_t rtp3640_get_au_headers_length(const uint8_t *header)
+{
+    return (header[0] << 8) | header[1];
+}
+
+static inline void rtp3640_set_aac_hbr_au_size(uint8_t *header, uint16_t size)
+{
+    header[0] = (size >> 5) & 0xff;
+    header[1] &= ~0xf8;
+    header[1] |= (size << 3) & 0xf8;
+}
+
+static inline uint16_t rtp3640_get_aac_hbr_au_size(const uint8_t *header)
+{
+    return (header[0] << 5) | (header[1] >> 3);
+}
+
+
+static inline void rtp3640_set_aac_hbr_au_index(uint8_t *header, uint8_t index)
+{
+    header[1] &= ~0x7;
+    header[1] |= index & 0x7;
+}
+
+static inline uint8_t rtp3640_get_aac_hbr_au_index(const uint8_t *header)
+{
+    return (header[1] & 0x7);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* !__BITSTREAM_IETF_RTP3640_H__ */