1 files changed, 344 insertions, 0 deletions
diff --git a/trunk/res/res_speech.c b/trunk/res/res_speech.c
new file mode 100644
index 000000000..902955da1
--- /dev/null
+++ b/trunk/res/res_speech.c
@@ -0,0 +1,344 @@
+/*
+ * 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 "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/speech.h"
+
+
+static AST_RWLIST_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 (ast_strlen_zero(engine_name))
+		return default_engine;
+
+	AST_RWLIST_RDLOCK(&engines);
+	AST_RWLIST_TRAVERSE(&engines, engine, list) {
+		if (!strcasecmp(engine->name, engine_name)) {
+			break;
+		}
+	}
+	AST_RWLIST_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)
+{
+	return (speech->engine->activate ? speech->engine->activate(speech, grammar_name) : -1);
+}
+
+/*! \brief Deactivate a loaded grammar on a speech structure */
+int ast_speech_grammar_deactivate(struct ast_speech *speech, char *grammar_name)
+{
+	return (speech->engine->deactivate ? speech->engine->deactivate(speech, grammar_name) : -1);
+}
+
+/*! \brief Load a local grammar on a speech structure */
+int ast_speech_grammar_load(struct ast_speech *speech, char *grammar_name, char *grammar)
+{
+	return (speech->engine->load ? speech->engine->load(speech, grammar_name, grammar) : -1);
+}
+
+/*! \brief Unload a local grammar from a speech structure */
+int ast_speech_grammar_unload(struct ast_speech *speech, char *grammar_name)
+{
+	return (speech->engine->unload ? speech->engine->unload(speech, grammar_name) : -1);
+}
+
+/*! \brief Return the results of a recognition from the speech structure */
+struct ast_speech_result *ast_speech_results_get(struct ast_speech *speech)
+{
+	return (speech->engine->get ? speech->engine->get(speech) : NULL);
+}
+
+/*! \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) {
+			ast_free(current_result->text);
+			current_result->text = NULL;
+		}
+		if (current_result->grammar != NULL) {
+			ast_free(current_result->grammar);
+			current_result->grammar = NULL;
+		}
+		/* Move on and then free ourselves */
+		current_result = AST_LIST_NEXT(current_result, list);
+		ast_free(prev_result);
+		prev_result = NULL;
+	}
+
+	return res;
+}
+
+/*! \brief Start speech recognition on a speech structure */
+void ast_speech_start(struct ast_speech *speech)
+{
+
+	/* Clear any flags that may affect things */
+	ast_clear_flag(speech, AST_SPEECH_SPOKE);
+	ast_clear_flag(speech, AST_SPEECH_QUIET);
+	ast_clear_flag(speech, AST_SPEECH_HAVE_RESULTS);
+
+	/* If results are on the structure, free them since we are starting again */
+	if (speech->results) {
+		ast_speech_results_free(speech->results);
+		speech->results = NULL;
+	}
+
+	/* If the engine needs to start stuff up, do it */
+	if (speech->engine->start)
+		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)
+{
+	/* Make sure the speech engine is ready to accept audio */
+	if (speech->state != AST_SPEECH_STATE_READY)
+		return -1;
+
+	return speech->engine->write(speech, data, len);
+}
+
+/*! \brief Signal to the engine that DTMF was received */
+int ast_speech_dtmf(struct ast_speech *speech, const char *dtmf)
+{
+	int res = 0;
+
+	if (speech->state != AST_SPEECH_STATE_READY)
+		return -1;
+
+	if (speech->engine->dtmf != NULL) {
+		res = speech->engine->dtmf(speech, dtmf);
+	}
+
+	return res;
+}
+
+/*! \brief Change an engine specific attribute */
+int ast_speech_change(struct ast_speech *speech, char *name, const char *value)
+{
+	return (speech->engine->change ? speech->engine->change(speech, name, value) : -1);
+}
+
+/*! \brief Create a new speech structure using the engine specified */
+struct ast_speech *ast_speech_new(char *engine_name, int formats)
+{
+	struct ast_speech_engine *engine = NULL;
+	struct ast_speech *new_speech = NULL;
+	int format = AST_FORMAT_SLINEAR;
+
+	/* Try to find the speech recognition engine that was requested */
+	if (!(engine = find_engine(engine_name)))
+		return NULL;
+
+	/* Before even allocating the memory below do some codec negotiation, we choose the best codec possible and fall back to signed linear if possible */
+	if ((format = (engine->formats & formats)))
+		format = ast_best_codec(format);
+	else if ((engine->formats & AST_FORMAT_SLINEAR))
+		format = AST_FORMAT_SLINEAR;
+	else
+		return NULL;
+
+	/* Allocate our own speech structure, and try to allocate a structure from the engine too */
+	if (!(new_speech = ast_calloc(1, sizeof(*new_speech))))
+		return NULL;
+
+	/* Initialize the lock */
+	ast_mutex_init(&new_speech->lock);
+
+	/* Make sure no results are present */
+	new_speech->results = NULL;
+
+	/* Copy over our engine pointer */
+	new_speech->engine = engine;
+
+	/* Can't forget the format audio is going to be in */
+	new_speech->format = format;
+
+	/* 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 and if they error out then do not create a structure */
+	if (engine->create(new_speech, format)) {
+		ast_mutex_destroy(&new_speech->lock);
+		ast_free(new_speech);
+		new_speech = NULL;
+	}
+
+	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 results exist on the speech structure, destroy them */
+	if (speech->results)
+		ast_speech_results_free(speech->results);
+
+	/* If a processing sound is set - free the memory used by it */
+	if (speech->processing_sound)
+		ast_free(speech->processing_sound);
+
+	/* Aloha we are done */
+	ast_free(speech);
+
+	return res;
+}
+
+/*! \brief Change state of a speech structure */
+int ast_speech_change_state(struct ast_speech *speech, int state)
+{
+	int res = 0;
+
+	switch (state) {
+	case AST_SPEECH_STATE_WAIT:
+		/* The engine heard audio, so they spoke */
+		ast_set_flag(speech, AST_SPEECH_SPOKE);
+	default:
+		speech->state = state;
+		break;
+	}
+
+	return res;
+}
+
+/*! \brief Change the type of results we want */
+int ast_speech_change_results_type(struct ast_speech *speech, enum ast_speech_results_type results_type)
+{
+	speech->results_type = results_type;
+
+	return (speech->engine->change_results_type ? speech->engine->change_results_type(speech, results_type) : 0);
+}
+
+/*! \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;
+
+	/* Confirm the engine meets the minimum API requirements */
+	if (!engine->create || !engine->write || !engine->destroy) {
+		ast_log(LOG_WARNING, "Speech recognition engine '%s' did not meet minimum API requirements.\n", engine->name);
+		return -1;
+	}
+
+	/* If an engine is already loaded with this name, error out */
+	if ((existing_engine = find_engine(engine->name))) {
+		ast_log(LOG_WARNING, "Speech recognition engine '%s' already exists.\n", engine->name);
+		return -1;
+	}
+
+	ast_verb(2, "Registered speech recognition engine '%s'\n", engine->name);
+
+	/* Add to the engine linked list and make default if needed */
+	AST_RWLIST_WRLOCK(&engines);
+	AST_RWLIST_INSERT_HEAD(&engines, engine, list);
+	if (!default_engine) {
+		default_engine = engine;
+		ast_verb(2, "Made '%s' the default speech recognition engine\n", engine->name);
+	}
+	AST_RWLIST_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 (ast_strlen_zero(engine_name))
+		return -1;
+
+	AST_RWLIST_WRLOCK(&engines);
+	AST_RWLIST_TRAVERSE_SAFE_BEGIN(&engines, engine, list) {
+		if (!strcasecmp(engine->name, engine_name)) {
+			/* We have our engine... removed it */
+			AST_RWLIST_REMOVE_CURRENT(list);
+			/* If this was the default engine, we need to pick a new one */
+			if (!default_engine)
+				default_engine = AST_RWLIST_FIRST(&engines);
+			ast_verb(2, "Unregistered speech recognition engine '%s'\n", engine_name);
+			/* All went well */
+			res = 0;
+			break;
+		}
+	}
+	AST_RWLIST_TRAVERSE_SAFE_END;
+	AST_RWLIST_UNLOCK(&engines);
+
+	return res;
+}
+
+static int unload_module(void)
+{
+	/* We can not be unloaded */
+	return -1;
+}
+
+static int load_module(void)
+{
+	return AST_MODULE_LOAD_SUCCESS;
+}
+
+AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS, "Generic Speech Recognition API",
+		.load = load_module,
+		.unload = unload_module,
+		);