--- a/libtwamr/Makefile	Thu May 09 07:06:31 2024 +0000
+++ b/libtwamr/Makefile	Thu May 09 07:19:42 2024 +0000
@@ -9,17 +9,17 @@
 	dhf_subst.o dhf_tables.o dtx_dec.o dtx_enc.o e_homing.o ec_gains.o \
 	enc_lag3.o enc_lag6.o enc_main.o ex_ctrl.o fr_type_conv.o g_adapt.o \
 	g_code.o g_pitch.o gain_q.o gains_tab.o gc_pred.o gmed_n.o graytab.o \
-	hp_max.o ietf_fo.o ietf_in.o ietf_out.o if1_bit_order.o if1_pack.o \
-	if1_unpack.o int_lpc.o int_lsf.o inter_36.o inv_sqrt.o lag_wind.o \
-	levinson.o lflg_upd.o log2.o lpc.o lsfwt.o lsp.o lsp_avg.o lsp_az.o \
-	lsp_lsf.o lsp_tab.o mac_32.o ol_ltp.o oper_32b.o p_ol_wgh.o ph_disp.o \
-	pitch_fr.o pitch_ol.o post_pro.o pow2.o pre_big.o pre_proc.o pred_lt.o \
-	preemph.o prm2bits.o prmno.o pstfilt.o q_gain_c.o q_gain_p.o q_plsf.o \
-	q_plsf3_tab.o q_plsf5_tab.o q_plsf_3.o q_plsf_5.o qgain475.o qgain795.o\
-	qua_gain.o qua_gain_tab.o r_fft.o reorder.o residu.o s10_8pf.o \
-	set_sign.o sid_sync.o spreproc.o spstproc.o sqrt_l.o syn_filt.o \
-	tls_flags.o ton_stab.o tseq_in.o tseq_out.o vad1.o vad2.o vad_reset.o \
-	weight_a.o window.o
+	hp_max.o ietf_fo.o ietf_hdr.o ietf_in.o ietf_out.o if1_bit_order.o \
+	if1_pack.o if1_unpack.o int_lpc.o int_lsf.o inter_36.o inv_sqrt.o \
+	lag_wind.o levinson.o lflg_upd.o log2.o lpc.o lsfwt.o lsp.o lsp_avg.o \
+	lsp_az.o lsp_lsf.o lsp_tab.o mac_32.o ol_ltp.o oper_32b.o p_ol_wgh.o \
+	ph_disp.o pitch_fr.o pitch_ol.o post_pro.o pow2.o pre_big.o pre_proc.o \
+	pred_lt.o preemph.o prm2bits.o prmno.o pstfilt.o q_gain_c.o q_gain_p.o \
+	q_plsf.o q_plsf3_tab.o q_plsf5_tab.o q_plsf_3.o q_plsf_5.o qgain475.o \
+	qgain795.o qua_gain.o qua_gain_tab.o r_fft.o reorder.o residu.o \
+	s10_8pf.o set_sign.o sid_sync.o spreproc.o spstproc.o sqrt_l.o \
+	syn_filt.o tls_flags.o ton_stab.o tseq_in.o tseq_out.o vad1.o vad2.o \
+	vad_reset.o weight_a.o window.o
 HDRS=	a_refl.h agc.h autocorr.h az_lsp.h b_cn_cod.h basic_op.h bgnscd.h \
 	bitno.h bits2prm.h c1035pf.h c2_11pf.h c2_9pf.h c3_14pf.h c4_17pf.h \
 	c8_31pf.h c_g_aver.h calc_cor.h calc_en.h cbsearch.h cl_ltp.h cnst.h \

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtwamr/ietf_hdr.c	Thu May 09 07:19:42 2024 +0000
@@ -0,0 +1,8 @@
+/*
+ * This module provides one public const datum: RFC 4867 file header.
+ */
+
+#include <stdint.h>
+#include "tw_amr.h"
+
+const uint8_t amr_file_header_magic[AMR_IETF_HDR_LEN] = "#!AMR\n";

--- a/libtwamr/tw_amr.h	Thu May 09 07:06:31 2024 +0000
+++ b/libtwamr/tw_amr.h	Thu May 09 07:19:42 2024 +0000
@@ -110,4 +110,8 @@
 extern const int16_t amr_dhf_mr122[AMR_MAX_PRM];
 extern const int16_t amr_dhf_gsmefr[AMR_MAX_PRM];
 
+/* public const datum: RFC 4867 file header */
+
+extern const uint8_t amr_file_header_magic[AMR_IETF_HDR_LEN];
+
 #endif	/* include guard */