|
@@ -0,0 +1,86 @@
|
|
|
+/*
|
|
|
+ * OSLEC - A line echo canceller. This code is being developed
|
|
|
+ * against and partially complies with G168. Using code from SpanDSP
|
|
|
+ *
|
|
|
+ * Written by Steve Underwood <steveu@coppice.org>
|
|
|
+ * and David Rowe <david_at_rowetel_dot_com>
|
|
|
+ *
|
|
|
+ * Copyright (C) 2001 Steve Underwood and 2007-2008 David Rowe
|
|
|
+ *
|
|
|
+ * All rights reserved.
|
|
|
+ *
|
|
|
+ * This program is free software; you can redistribute it and/or modify
|
|
|
+ * it under the terms of the GNU General Public License version 2, as
|
|
|
+ * published by the Free Software Foundation.
|
|
|
+ *
|
|
|
+ * This program is distributed in the hope that it will be useful,
|
|
|
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
+ * GNU General Public License for more details.
|
|
|
+ *
|
|
|
+ * You should have received a copy of the GNU General Public License
|
|
|
+ * along with this program; if not, write to the Free Software
|
|
|
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
|
+ *
|
|
|
+ */
|
|
|
+
|
|
|
+#ifndef __OSLEC_H
|
|
|
+#define __OSLEC_H
|
|
|
+
|
|
|
+/* TODO: document interface */
|
|
|
+
|
|
|
+/* Mask bits for the adaption mode */
|
|
|
+#define ECHO_CAN_USE_ADAPTION 0x01
|
|
|
+#define ECHO_CAN_USE_NLP 0x02
|
|
|
+#define ECHO_CAN_USE_CNG 0x04
|
|
|
+#define ECHO_CAN_USE_CLIP 0x08
|
|
|
+#define ECHO_CAN_USE_TX_HPF 0x10
|
|
|
+#define ECHO_CAN_USE_RX_HPF 0x20
|
|
|
+#define ECHO_CAN_DISABLE 0x40
|
|
|
+
|
|
|
+/*!
|
|
|
+ G.168 echo canceller descriptor. This defines the working state for a line
|
|
|
+ echo canceller.
|
|
|
+*/
|
|
|
+typedef struct echo_can_state echo_can_state_t;
|
|
|
+
|
|
|
+/*! Create a voice echo canceller context.
|
|
|
+ \param len The length of the canceller, in samples.
|
|
|
+ \return The new canceller context, or NULL if the canceller could not be created.
|
|
|
+*/
|
|
|
+echo_can_state_t *echo_can_create(int len, int adaption_mode);
|
|
|
+
|
|
|
+/*! Free a voice echo canceller context.
|
|
|
+ \param ec The echo canceller context.
|
|
|
+*/
|
|
|
+void echo_can_free(echo_can_state_t *ec);
|
|
|
+
|
|
|
+/*! Flush (reinitialise) a voice echo canceller context.
|
|
|
+ \param ec The echo canceller context.
|
|
|
+*/
|
|
|
+void echo_can_flush(echo_can_state_t *ec);
|
|
|
+
|
|
|
+/*! Set the adaption mode of a voice echo canceller context.
|
|
|
+ \param ec The echo canceller context.
|
|
|
+ \param adapt The mode.
|
|
|
+*/
|
|
|
+void echo_can_adaption_mode(echo_can_state_t *ec, int adaption_mode);
|
|
|
+
|
|
|
+void echo_can_snapshot(echo_can_state_t *ec);
|
|
|
+
|
|
|
+/*! Process a sample through a voice echo canceller.
|
|
|
+ \param ec The echo canceller context.
|
|
|
+ \param tx The transmitted audio sample.
|
|
|
+ \param rx The received audio sample.
|
|
|
+ \return The clean (echo cancelled) received sample.
|
|
|
+*/
|
|
|
+int16_t echo_can_update(echo_can_state_t *ec, int16_t tx, int16_t rx);
|
|
|
+
|
|
|
+/*! Process to high pass filter the tx signal.
|
|
|
+ \param ec The echo canceller context.
|
|
|
+ \param tx The transmitted auio sample.
|
|
|
+ \return The HP filtered transmit sample, send this to your D/A.
|
|
|
+*/
|
|
|
+int16_t echo_can_hpf_tx(echo_can_state_t *ec, int16_t tx);
|
|
|
+
|
|
|
+#endif /* __OSLEC_H */
|