Presenting a revised data stores and oh my, a generic speech recognition API! I wonder what we can do with this now...

git-svn-id: http://svn.digium.com/svn/asterisk/trunk@18979 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 346 insertions, 0 deletions

diff --git a/res/res_speech.c b/res/res_speech.c
new file mode 100644
index 000000000..a1857688a
--- /dev/null
+++ b/res/res_speech.c
@@ -0,0 +1,346 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2006, Digium, Inc.
+ *
+ * Joshua Colp <jcolp@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+ *
+ * \brief Generic Speech Recognition API
+ *
+ * \author Joshua Colp <jcolp@digium.com>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$");
+
+#include "asterisk/channel.h"
+#include "asterisk/module.h"
+#include "asterisk/lock.h"
+#include "asterisk/linkedlists.h"
+#include "asterisk/cli.h"
+#include "asterisk/term.h"
+#include "asterisk/options.h"
+#include "asterisk/speech.h"
+
+static char *tdesc = "Generic Speech Recognition API";
+
+static AST_LIST_HEAD_STATIC(engines, ast_speech_engine);
+static struct ast_speech_engine *default_engine = NULL;
+
+/*! \brief Find a speech recognition engine of specified name, if NULL then use the default one */
+static struct ast_speech_engine *find_engine(char *engine_name)
+{
+	struct ast_speech_engine *engine = NULL;
+
+	/* If no name is specified -- use the default engine */
+	if (engine_name == NULL || strlen(engine_name) == 0) {
+		return default_engine;
+	}
+
+	AST_LIST_LOCK(&engines);
+	AST_LIST_TRAVERSE_SAFE_BEGIN(&engines, engine, list) {
+		if (!strcasecmp(engine->name, engine_name)) {
+			break;
+		}
+	}
+	AST_LIST_TRAVERSE_SAFE_END
+	AST_LIST_UNLOCK(&engines);
+
+	return engine;
+}
+
+/*! \brief Activate a loaded (either local or global) grammar */
+int ast_speech_grammar_activate(struct ast_speech *speech, char *grammar_name)
+{
+	int res = 0;
+
+	if (speech->engine->activate != NULL) {
+		res = speech->engine->activate(speech, grammar_name);
+	}
+
+	return res;
+}
+
+/*! \brief Deactivate a loaded grammar on a speech structure */
+int ast_speech_grammar_deactivate(struct ast_speech *speech, char *grammar_name)
+{
+	int res = 0;
+
+        if (speech->engine->deactivate != NULL) {
+                res = speech->engine->deactivate(speech, grammar_name);
+        }
+
+	return res;
+}
+
+/*! \brief Load a local grammar on a speech structure */
+int ast_speech_grammar_load(struct ast_speech *speech, char *grammar_name, char *grammar)
+{
+	int res = 0;
+
+	if (speech->engine->load != NULL) {
+		res = speech->engine->load(speech, grammar_name, grammar);
+	}
+
+	return res;
+}
+
+/*! \brief Unload a local grammar from a speech structure */
+int ast_speech_grammar_unload(struct ast_speech *speech, char *grammar_name)
+{
+        int res = 0;
+
+        if (speech->engine->unload != NULL) {
+                res = speech->engine->unload(speech, grammar_name);
+        }
+
+        return res;
+}
+
+/*! \brief Return the results of a recognition from the speech structure */
+struct ast_speech_result *ast_speech_results_get(struct ast_speech *speech)
+{
+	struct ast_speech_result *result = NULL;
+
+	if (speech->engine->get != NULL) {
+		result = speech->engine->get(speech);
+	}
+
+	return result;
+}
+
+/*! \brief Free a list of results */
+int ast_speech_results_free(struct ast_speech_result *result)
+{
+	struct ast_speech_result *current_result = result, *prev_result = NULL;
+	int res = 0;
+
+	while (current_result != NULL) {
+		prev_result = current_result;
+		/* Deallocate what we can */
+		if (current_result->text != NULL) {
+			free(current_result->text);
+			current_result->text = NULL;
+		}
+		/* Move on and then free ourselves */
+		current_result = current_result->next;
+		free(prev_result);
+		prev_result = NULL;
+	}
+
+	return res;
+}
+
+/*! \brief Start speech recognition on a speech structure */
+void ast_speech_start(struct ast_speech *speech)
+{
+	/* If the engine needs to start stuff up, do it */
+	if (speech->engine->start != NULL) {
+		speech->engine->start(speech);
+	}
+
+	return;
+}
+
+/*! \brief Write in signed linear audio to be recognized */
+int ast_speech_write(struct ast_speech *speech, void *data, int len)
+{
+	int res = 0;
+
+	/* Make sure the speech engine is ready to accept audio */
+	if (speech->state != AST_SPEECH_STATE_READY) {
+		return -1;
+	}
+
+	if (speech->engine->write != NULL) {
+		speech->engine->write(speech, data, len);
+	}
+
+	return res;
+}
+
+/*! \brief Create a new speech structure using the engine specified */
+struct ast_speech *ast_speech_new(char *engine_name, int format)
+{
+	struct ast_speech_engine *engine = NULL;
+	struct ast_speech *new_speech = NULL;
+
+	/* Try to find the speech recognition engine that was requested */
+	engine = find_engine(engine_name);
+	if (engine == NULL) {
+		/* Invalid engine or no engine available */
+		return NULL;
+	}
+
+	/* Allocate our own speech structure, and try to allocate a structure from the engine too */
+	new_speech = ast_calloc(1, sizeof(*new_speech));
+	if (new_speech == NULL) {
+		/* Ran out of memory while trying to allocate some for a speech structure */
+		return NULL;
+	}
+
+	/* Initialize the lock */
+	ast_mutex_init(&new_speech->lock);
+
+	/* Copy over our engine pointer */
+	new_speech->engine = engine;
+
+	/* We are not ready to accept audio yet */
+	ast_speech_change_state(new_speech, AST_SPEECH_STATE_NOT_READY);
+
+	/* Pass ourselves to the engine so they can set us up some more */
+	engine->new(new_speech);
+
+	return new_speech;
+}
+
+/*! \brief Destroy a speech structure */
+int ast_speech_destroy(struct ast_speech *speech)
+{
+	int res = 0;
+
+	/* Call our engine so we are destroyed properly */
+	speech->engine->destroy(speech);
+
+	/* Deinitialize the lock */
+	ast_mutex_destroy(&speech->lock);
+
+	/* If a processing sound is set - free the memory used by it */
+	if (speech->processing_sound != NULL) {
+		free(speech->processing_sound);
+		speech->processing_sound = NULL;
+	}
+
+	/* Aloha we are done */
+	free(speech);
+	speech = NULL;
+
+	return res;
+}
+
+/*! \brief Change state of a speech structure */
+int ast_speech_change_state(struct ast_speech *speech, int state)
+{
+	int res = 0;
+
+	speech->state = state;
+
+	return res;
+}
+
+/*! \brief Register a speech recognition engine */
+int ast_speech_register(struct ast_speech_engine *engine)
+{
+	struct ast_speech_engine *existing_engine = NULL;
+	int res = 0;
+
+	existing_engine = find_engine(engine->name);
+	if (existing_engine != NULL) {
+		/* Engine already loaded */
+		return -1;
+	}
+
+	if (option_verbose > 1)
+		ast_verbose(VERBOSE_PREFIX_2 "Registered speech recognition engine '%s'\n", engine->name);
+
+	/* Add to the engine linked list and make default if needed */
+	AST_LIST_LOCK(&engines);
+	AST_LIST_INSERT_HEAD(&engines, engine, list);
+	if (default_engine == NULL) {
+		default_engine = engine;
+		if (option_verbose > 1)
+			ast_verbose(VERBOSE_PREFIX_2 "Made '%s' the default speech recognition engine\n", engine->name);
+	}
+	AST_LIST_UNLOCK(&engines);
+
+	return res;
+}
+
+/*! \brief Unregister a speech recognition engine */
+int ast_speech_unregister(char *engine_name)
+{
+	struct ast_speech_engine *engine = NULL;
+	int res = -1;
+
+	if (engine_name == NULL) {
+		return res;
+	}
+
+	AST_LIST_LOCK(&engines);
+	AST_LIST_TRAVERSE_SAFE_BEGIN(&engines, engine, list) {
+		if (!strcasecmp(engine->name, engine_name)) {
+			/* We have our engine... removed it */
+			AST_LIST_REMOVE_CURRENT(&engines, list);
+			/* If this was the default engine, we need to pick a new one */
+			if (default_engine == engine) {
+				default_engine = AST_LIST_FIRST(&engines);
+			}
+			if (option_verbose > 1)
+				ast_verbose(VERBOSE_PREFIX_2 "Unregistered speech recognition engine '%s'\n", engine_name);
+			/* All went well */
+			res = 0;
+			break;
+		}
+	}
+	AST_LIST_TRAVERSE_SAFE_END
+	AST_LIST_UNLOCK(&engines);
+
+	return res;
+}
+
+int unload_module(void)
+{
+	/* We can not be unloaded */
+	return -1;
+}
+
+int load_module(void)
+{
+	int res = 0;
+
+	/* Initialize our list of engines */
+	AST_LIST_HEAD_INIT_NOLOCK(&engines);
+
+	return res;
+}
+
+int reload(void)
+{
+	return 0;
+}
+
+const char *description(void)
+{
+	return tdesc;
+}
+
+int usecount(void)
+{
+	int res = 0;
+
+	return res;
+}
+
+const char *key()
+{
+	return ASTERISK_GPL_KEY;
+}