1 files changed, 222 insertions, 0 deletions

diff --git a/modules/speex_aec/speex_aec.c b/modules/speex_aec/speex_aec.c
new file mode 100644
index 0000000..15ea552
--- /dev/null
+++ b/modules/speex_aec/speex_aec.c
@@ -0,0 +1,222 @@
+/**
+ * @file speex_aec.c  Speex Acoustic Echo Cancellation
+ *
+ * Copyright (C) 2010 Creytiv.com
+ */
+#include <stdlib.h>
+#include <string.h>
+#include <speex/speex.h>
+#include <speex/speex_echo.h>
+#include <re.h>
+#include <baresip.h>
+
+
+struct speex_st {
+	int16_t *out;
+	SpeexEchoState *state;
+};
+
+struct enc_st {
+	struct aufilt_enc_st af;  /* base class */
+	struct speex_st *st;
+};
+
+struct dec_st {
+	struct aufilt_dec_st af;  /* base class */
+	struct speex_st *st;
+};
+
+
+static void enc_destructor(void *arg)
+{
+	struct enc_st *st = arg;
+
+	list_unlink(&st->af.le);
+	mem_deref(st->st);
+}
+
+
+static void dec_destructor(void *arg)
+{
+	struct dec_st *st = arg;
+
+	list_unlink(&st->af.le);
+	mem_deref(st->st);
+}
+
+
+#ifdef SPEEX_SET_VBR_MAX_BITRATE
+static void speex_aec_destructor(void *arg)
+{
+	struct speex_st *st = arg;
+
+	if (st->state)
+		speex_echo_state_destroy(st->state);
+
+	mem_deref(st->out);
+}
+
+
+static int aec_alloc(struct speex_st **stp, void **ctx, struct aufilt_prm *prm)
+{
+	struct speex_st *st;
+	uint32_t sampc;
+	int err, tmp, fl;
+
+	if (!stp || !ctx || !prm)
+		return EINVAL;
+
+	if (*ctx) {
+		*stp = mem_ref(*ctx);
+		return 0;
+	}
+
+	st = mem_zalloc(sizeof(*st), speex_aec_destructor);
+	if (!st)
+		return ENOMEM;
+
+	sampc = prm->srate * prm->ch * prm->ptime / 1000;
+
+	st->out = mem_alloc(2 * sampc, NULL);
+	if (!st->out) {
+		err = ENOMEM;
+		goto out;
+	}
+
+	/* Echo canceller with 200 ms tail length */
+	fl = 10 * sampc;
+	st->state = speex_echo_state_init(sampc, fl);
+	if (!st->state) {
+		err = ENOMEM;
+		goto out;
+	}
+
+	tmp = prm->srate;
+	err = speex_echo_ctl(st->state, SPEEX_ECHO_SET_SAMPLING_RATE, &tmp);
+	if (err < 0) {
+		warning("speex_aec: speex_echo_ctl: err=%d\n", err);
+	}
+
+	info("speex_aec: Speex AEC loaded: srate = %uHz\n", prm->srate);
+
+ out:
+	if (err)
+		mem_deref(st);
+	else
+		*ctx = *stp = st;
+
+	return err;
+}
+
+
+static int encode_update(struct aufilt_enc_st **stp, void **ctx,
+			 const struct aufilt *af, struct aufilt_prm *prm)
+{
+	struct enc_st *st;
+	int err;
+
+	if (!stp || !ctx || !af || !prm)
+		return EINVAL;
+
+	if (*stp)
+		return 0;
+
+	st = mem_zalloc(sizeof(*st), enc_destructor);
+	if (!st)
+		return ENOMEM;
+
+	err = aec_alloc(&st->st, ctx, prm);
+
+	if (err)
+		mem_deref(st);
+	else
+		*stp = (struct aufilt_enc_st *)st;
+
+	return err;
+}
+
+
+static int decode_update(struct aufilt_dec_st **stp, void **ctx,
+			 const struct aufilt *af, struct aufilt_prm *prm)
+{
+	struct dec_st *st;
+	int err;
+
+	if (!stp || !ctx || !af || !prm)
+		return EINVAL;
+
+	if (*stp)
+		return 0;
+
+	st = mem_zalloc(sizeof(*st), dec_destructor);
+	if (!st)
+		return ENOMEM;
+
+	err = aec_alloc(&st->st, ctx, prm);
+
+	if (err)
+		mem_deref(st);
+	else
+		*stp = (struct aufilt_dec_st *)st;
+
+	return err;
+}
+
+
+static int encode(struct aufilt_enc_st *st, int16_t *sampv, size_t *sampc)
+{
+	struct enc_st *est = (struct enc_st *)st;
+	struct speex_st *sp = est->st;
+
+	if (*sampc) {
+		speex_echo_capture(sp->state, sampv, sp->out);
+		memcpy(sampv, sp->out, *sampc * 2);
+	}
+
+	return 0;
+}
+
+
+static int decode(struct aufilt_dec_st *st, int16_t *sampv, size_t *sampc)
+{
+	struct dec_st *dst = (struct dec_st *)st;
+	struct speex_st *sp = dst->st;
+
+	if (*sampc)
+		speex_echo_playback(sp->state, sampv);
+
+	return 0;
+}
+#endif
+
+
+static struct aufilt speex_aec = {
+	LE_INIT, "speex_aec", encode_update, encode, decode_update, decode
+};
+
+
+static int module_init(void)
+{
+	/* Note: Hack to check libspeex version */
+#ifdef SPEEX_SET_VBR_MAX_BITRATE
+	aufilt_register(&speex_aec);
+	return 0;
+#else
+	return ENOSYS;
+#endif
+}
+
+
+static int module_close(void)
+{
+	aufilt_unregister(&speex_aec);
+	return 0;
+}
+
+
+EXPORT_SYM const struct mod_export DECL_EXPORTS(speex_aec) = {
+	"speex_aec",
+	"filter",
+	module_init,
+	module_close
+};