diff --git a/include/osmocom/codec/ecu.h b/include/osmocom/codec/ecu.h
index ec0a2f8..ec94670 100644
--- a/include/osmocom/codec/ecu.h
+++ b/include/osmocom/codec/ecu.h
@@ -13,3 +13,57 @@
 
 void osmo_ecu_fr_reset(struct osmo_ecu_fr_state *state, const uint8_t *frame);
 int osmo_ecu_fr_conceal(struct osmo_ecu_fr_state *state, uint8_t *frame);
+
+enum osmo_ecu_codec {
+	OSMO_ECU_CODEC_HR,
+	OSMO_ECU_CODEC_FR,
+	OSMO_ECU_CODEC_EFR,
+	OSMO_ECU_CODEC_AMR,
+	_NUM_OSMO_ECU_CODECS
+};
+
+/***********************************************************************
+ * Generic ECU abstraction layer below
+ ***********************************************************************/
+
+/* As the developer and copyright holder of the related code, I hereby
+ * state that any ECU implementation using 'struct osmo_ecu_ops' and
+ * registering with the 'osmo_ecu_register()' function shall not be
+ * considered as a derivative work under any applicable copyright law;
+ * the copyleft terms of GPLv2 shall hence not apply to any such ECU
+ * implementation.
+ *
+ * The intent of the above exception is to allow anyone to combine third
+ * party Error Concealment Unit implementations with libosmocodec.
+ * including but not limited to such published by ETSI.
+ *
+ *   -- Harald Welte <laforge@gnumonks.org> on August 1, 2019.
+ */
+
+struct osmo_ecu_state {
+	enum osmo_ecu_codec codec;
+	uint8_t data[0];
+};
+
+/* initialize an ECU instance */
+struct osmo_ecu_state *osmo_ecu_init(void *ctx, enum osmo_ecu_codec codec);
+
+/* destroy an ECU instance */
+void osmo_ecu_destroy(struct osmo_ecu_state *st);
+
+/* process a received frame a substitute/erroneous frame */
+int osmo_ecu_frame_in(struct osmo_ecu_state *st, bool bfi,
+		      const uint8_t *frame, unsigned int frame_bytes);
+
+/* generate output data for a substitute/erroneous frame */
+int osmo_ecu_frame_out(struct osmo_ecu_state *st, uint8_t *frame_out);
+
+struct osmo_ecu_ops {
+	struct osmo_ecu_state * (*init)(void *ctx, enum osmo_ecu_codec codec);
+	void (*destroy)(struct osmo_ecu_state *);
+	int (*frame_in)(struct osmo_ecu_state *st, bool bfi,
+			const uint8_t *frame, unsigned int frame_bytes);
+	int (*frame_out)(struct osmo_ecu_state *st, uint8_t *frame_out);
+};
+
+int osmo_ecu_register(const struct osmo_ecu_ops *ops, enum osmo_ecu_codec codec);