--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libgsmhr1/tw_gsmhr.h	Sat Jun 15 04:51:30 2024 +0000
@@ -0,0 +1,58 @@
+/*
+ * This header file is the external public interface to libgsmhr1:
+ * Themyscira Wireless implementation of GSM HRv1 speech codec
+ * based on the original ETSI code of GSM 06.06.
+ *
+ * This header file should be installed in some system include directory
+ * such that it can be included by C sources as <tw_gsmhr.h>.
+ */
+
+#ifndef	__THEMWI_GSMHR_H
+#define	__THEMWI_GSMHR_H
+
+#include <stdint.h>
+
+#define	GSMHR_NUM_PARAMS	18	/* actual codec parameters */
+#define	GSMHR_NUM_PARAMS_ENC	20	/* output from the encoder */
+#define	GSMHR_NUM_PARAMS_DEC	22	/* input to the decoder */
+
+#define	GSMHR_FRAME_LEN_RPF	14	/* raw packed format */
+#define	GSMHR_FRAME_LEN_5993	15	/* RFC 5993 and TW-TS-002 */
+
+/* stateful encoder and decoder engines */
+
+struct gsmhr_encoder_state;	/* opaque to external users */
+struct gsmhr_decoder_state;	/* ditto */
+
+struct gsmhr_encoder_state *gsmhr_encoder_create(int dtx);
+struct gsmhr_decoder_state *gsmhr_decoder_create(void);
+/* use standard free() call to free both afterward */
+
+/* reset state to initial */
+void gsmhr_encoder_reset(struct gsmhr_encoder_state *st, int dtx);
+void gsmhr_decoder_reset(struct gsmhr_decoder_state *st);
+
+/* encoder and decoder main functions */
+void gsmhr_encode_frame(struct gsmhr_encoder_state *st, const int16_t *pcm,
+			int16_t *param);
+void gsmhr_decode_frame(struct gsmhr_decoder_state *st, const int16_t *param,
+			int16_t *pcm);
+
+/* stateless format conversion functions */
+
+void gsmhr_pack_ts101318(const int16_t *param, uint8_t *payload);
+void gsmhr_unpack_ts101318(const uint8_t *payload, int16_t *param);
+
+void gsmhr_encoder_twts002_out(const int16_t *param, uint8_t *payload);
+int gsmhr_decoder_twts002_in(const uint8_t *payload, int16_t *param);
+
+/* perfect SID detection and regeneration */
+
+int gsmhr_ts101318_is_perfect_sid(const uint8_t *payload);
+void gsmhr_ts101318_set_sid_codeword(uint8_t *payload);
+
+/* public const data item */
+
+extern const int16_t gsmhr_decoder_homing_frame[GSMHR_NUM_PARAMS];
+
+#endif	/* include guard */