module-echo-cancel: Move backends to dynamic libaries

Move all backends to dynamic libaries loaded with spa_plugin_loader so
new backends not needs changes in pipewire or pipewire dependency to
external code

Change-Id: I702ce047598d0c318d6dc6ac8248062a5c12f643

spa/plugins/aec/aec-null.c

@@ -0,0 +1,185 @@
+/* PipeWire
+ *
+ * Copyright © 2021 Wim Taymans <wim.taymans@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <spa/interfaces/audio/aec.h>
+#include <spa/support/log.h>
+#include <spa/utils/string.h>
+#include <spa/utils/names.h>
+#include <spa/support/plugin.h>
+
+struct impl {
+	struct spa_handle handle;
+	struct spa_log *log;
+	uint32_t channels;
+};
+
+static struct spa_log_topic log_topic = SPA_LOG_TOPIC(0, "spa.aec.null");
+#undef SPA_LOG_TOPIC_DEFAULT
+#define SPA_LOG_TOPIC_DEFAULT &log_topic
+
+static int null_create(struct spa_handle *handle, const struct spa_dict *args, const struct spa_audio_info_raw *info)
+{
+	struct impl *impl;
+	impl = (struct impl *) handle;
+	impl->channels = info->channels;
+
+	return 0;
+}
+
+static int null_run(struct spa_handle *handle, const float *rec[], const float *play[], float *out[], uint32_t n_samples)
+{
+	struct impl *impl = (struct impl *) handle;
+	uint32_t i;
+	for (i = 0; i < impl->channels; i++)
+		memcpy(out[i], rec[i], n_samples * sizeof(float));
+	return 0;
+}
+
+struct spa_dict *null_get_properties(SPA_UNUSED struct spa_handle *handle)
+{
+	/* Not supported */
+	return NULL;
+}
+
+int null_set_properties(SPA_UNUSED struct spa_handle *handle, SPA_UNUSED const struct spa_dict *args)
+{
+	/* Not supported */
+	return -1;
+}
+
+static struct echo_cancel_info echo_cancel_null_impl = {
+	.name = "null",
+	.info = SPA_DICT_INIT(NULL, 0),
+	.latency = NULL,
+	.create = null_create,
+	.run = null_run,
+	.get_properties = null_get_properties,
+	.set_properties = null_set_properties,
+};
+
+static int impl_get_interface(struct spa_handle *handle, const char *type, void **interface)
+{
+
+	spa_return_val_if_fail(handle != NULL, -EINVAL);
+	spa_return_val_if_fail(interface != NULL, -EINVAL);
+
+	if (spa_streq(type, SPA_TYPE_INTERFACE_AEC))
+		*interface = &echo_cancel_null_impl;
+	else
+		return -ENOENT;
+
+	return 0;
+}
+
+static int impl_clear(struct spa_handle *handle)
+{
+	spa_return_val_if_fail(handle != NULL, -EINVAL);
+
+	return 0;
+}
+
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
+static int
+impl_init(const struct spa_handle_factory *factory,
+	  struct spa_handle *handle,
+	  const struct spa_dict *info,
+	  const struct spa_support *support,
+	  uint32_t n_support)
+{
+	struct impl *impl;
+
+	spa_return_val_if_fail(factory != NULL, -EINVAL);
+	spa_return_val_if_fail(handle != NULL, -EINVAL);
+
+	echo_cancel_null_impl.iface = SPA_INTERFACE_INIT(
+		SPA_TYPE_INTERFACE_AEC,
+		SPA_VERSION_AUDIO_AEC,
+		NULL,
+		NULL);
+
+	handle->get_interface = impl_get_interface;
+	handle->clear = impl_clear;
+	impl = (struct impl *) handle;
+	impl->log = (struct spa_log*)spa_support_find(support, n_support, SPA_TYPE_INTERFACE_Log);
+	spa_log_topic_init(impl->log, &log_topic);
+
+	return 0;
+}
+
+static const struct spa_interface_info impl_interfaces[] = {
+	{SPA_TYPE_INTERFACE_AEC,},
+};
+
+static int
+impl_enum_interface_info(const struct spa_handle_factory *factory,
+			 const struct spa_interface_info **info,
+			 uint32_t *index)
+{
+	spa_return_val_if_fail(factory != NULL, -EINVAL);
+	spa_return_val_if_fail(info != NULL, -EINVAL);
+	spa_return_val_if_fail(index != NULL, -EINVAL);
+
+	switch (*index) {
+	case 0:
+		*info = &impl_interfaces[*index];
+		break;
+	default:
+		return 0;
+	}
+	(*index)++;
+	return 1;
+}
+
+const struct spa_handle_factory spa_aec_exaudio_factory = {
+	SPA_VERSION_HANDLE_FACTORY,
+	SPA_NAME_AEC,
+	NULL,
+	impl_get_size,
+	impl_init,
+	impl_enum_interface_info,
+};
+
+
+SPA_EXPORT
+int spa_handle_factory_enum(const struct spa_handle_factory **factory, uint32_t *index)
+{
+	spa_return_val_if_fail(factory != NULL, -EINVAL);
+	spa_return_val_if_fail(index != NULL, -EINVAL);
+
+	switch (*index) {
+	case 0:
+		*factory = &spa_aec_exaudio_factory;
+		break;
+	default:
+		return 0;
+	}
+	(*index)++;
+	return 1;
+}