--- a/libgsmhr1/Makefile	Sun Aug 25 19:00:03 2024 +0000
+++ b/libgsmhr1/Makefile	Sun Aug 25 19:14:40 2024 +0000
@@ -1,7 +1,7 @@
 OBJS=	dhf_packed.o dhf_params.o enc_out_order.o mathdp31.o mathhalf.o \
-	pack_frame.o paramval_cod.o paramval_common.o rtp_in.o rtp_in_direct.o \
-	sid_detect.o sid_reset.o sp_rom.o twts002_in.o twts002_out.o \
-	unpack_frame.o
+	pack_frame.o paramval_cod.o paramval_common.o paramval_dec.o rtp_in.o \
+	rtp_in_direct.o sid_detect.o sid_reset.o sp_rom.o twts002_in.o \
+	twts002_out.o unpack_frame.o
 HDRS=	enc_out_order.h mathdp31.h mathhalf.h namespace.h sp_rom.h tw_gsmhr.h \
 	typedefs.h
 LIB=	libgsmhr1.a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libgsmhr1/paramval_dec.c	Sun Aug 25 19:14:40 2024 +0000
@@ -0,0 +1,23 @@
+/*
+ * The function implemented in this module examines a frame of 22 int16_t words
+ * that corresponds to GSM-HR decoder input format, and checks if the unused
+ * upper bits of each int16_t word are cleared as they should be.
+ * This function should be used when reading from ETSI-format *.dec files,
+ * to guard against reading garbage or wrong endian.
+ */
+
+#include <stdint.h>
+#include "tw_gsmhr.h"
+
+int gsmhr_check_decoder_params(const int16_t *params)
+{
+	if (params[18] < 0 || params[18] > 2)	/* BFI */
+		return -1;
+	if (params[19] < 0 || params[19] > 1)	/* UFI */
+		return -1;
+	if (params[20] < 0 || params[20] > 2)	/* SID */
+		return -1;
+	if (params[21] < 0 || params[21] > 1)	/* TAF */
+		return -1;
+	return gsmhr_check_common_params(params);
+}