From 0834bf4d6fdf19ab410c01c02e65fcda8a5e5ebc Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Wed, 2 Oct 2013 19:29:22 +0000
Subject: -implement microphone library

---
 src/conversation/microphone.c | 199 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 199 insertions(+)
 create mode 100644 src/conversation/microphone.c

(limited to 'src/conversation/microphone.c')

diff --git a/src/conversation/microphone.c b/src/conversation/microphone.c
new file mode 100644
index 000000000..8e9b9e241
--- /dev/null
+++ b/src/conversation/microphone.c
@@ -0,0 +1,199 @@
+/*
+  This file is part of GNUnet
+  (C) 2013 Christian Grothoff (and other contributing authors)
+  
+  GNUnet is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published
+  by the Free Software Foundation; either version 3, or (at your
+  option) any later version.
+  
+  GNUnet 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 GNUnet; see the file COPYING.  If not, write to the
+  Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+  Boston, MA 02111-1307, USA.
+ */
+
+/**
+ * @file conversation/microphone.c
+ * @brief API to access an audio microphone; provides access to hardware microphones;
+ *        actually just wraps the gnunet-helper-audio-record
+ * @author Simon Dieterle
+ * @author Andreas Fuchs
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_microphone_lib.h"
+#include "conversation.h"
+
+
+/**
+ * Internal data structures for the microphone.
+ */
+struct Microphone
+{
+
+  /**
+   * Our configuration.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Handle for the record helper
+   */
+  struct GNUNET_HELPER_Handle *record_helper;
+
+  /**
+   * Function to call with audio data (if we are enabled).
+   */
+  GNUNET_MICROPHONE_RecordedDataCallback rdc;
+
+  /**
+   * Closure for @e rdc.
+   */
+  void *rdc_cls;
+
+};
+
+
+/**
+ * Function to process the audio from the record helper
+ *
+ * @param cls clsoure with our `struct Microphone`
+ * @param client NULL
+ * @param msg the message from the helper
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
+ */
+static int
+process_record_messages (void *cls,
+			 void *client,
+			 const struct GNUNET_MessageHeader *msg)
+{
+  struct Microphone *mic = cls;
+
+  if ( (ntohs (msg->size) != sizeof (struct AudioMessage)) ||
+       (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_CONVERSATION_AUDIO) )
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  mic->rdc (mic->rdc_cls,
+	    sizeof (struct AudioMessage),
+	    (const char *) msg);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Enable a microphone.
+ *
+ * @param cls clsoure with our `struct Microphone`
+ * @param rdc function to call with recorded data
+ * @param rdc_cls closure for @a dc
+ */
+static int
+enable (void *cls,
+	GNUNET_MICROPHONE_RecordedDataCallback rdc,
+	void *rdc_cls)
+{
+  struct Microphone *mic = cls;  
+  char * const record_helper_argv[] = 
+  {
+    "gnunet-helper-audio-record",
+    NULL
+  };
+  mic->rdc = rdc;
+  mic->rdc_cls = rdc_cls;
+  mic->record_helper = GNUNET_HELPER_start (GNUNET_NO,
+					    "gnunet-helper-audio-record",
+					    record_helper_argv,
+					    &process_record_messages, 
+					    NULL, mic);  
+  if (NULL == mic->record_helper)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+		_("Could not start record audio helper\n"));
+    return GNUNET_SYSERR;
+  }  
+  return GNUNET_OK;
+}
+
+
+/**
+ * Function that disables a microphone.
+ *
+ * @param cls clsoure
+ */
+static void
+disable (void *cls)
+{
+  struct Microphone *mic = cls;
+
+  if (NULL == mic->record_helper)
+  {
+    GNUNET_break (0);
+    return;
+  }
+  GNUNET_break (GNUNET_OK ==
+		GNUNET_HELPER_kill (mic->record_helper, GNUNET_NO));
+  GNUNET_HELPER_destroy (mic->record_helper);
+  mic->record_helper = NULL;
+}
+
+
+/**
+ * Function to destroy a microphone.
+ *
+ * @param cls clsoure
+ */
+static void
+destroy (void *cls)
+{
+  struct Microphone *mic = cls;
+
+  if (NULL != mic->record_helper)
+    disable (mic);
+}
+
+
+/**
+ * Create a microphone that corresponds to the microphone hardware
+ * of our system.
+ *
+ * @param cfg configuration to use
+ * @return NULL on error
+ */
+struct GNUNET_MICROPHONE_Handle *
+GNUNET_MICROPHONE_create_from_hardware (const struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  struct GNUNET_MICROPHONE_Handle *microphone;
+  struct Microphone *mic;
+
+  mic = GNUNET_new (struct Microphone);
+  mic->cfg = cfg;
+  microphone = GNUNET_new (struct GNUNET_MICROPHONE_Handle);
+  microphone->cls = mic;
+  microphone->enable_microphone = &enable;
+  microphone->disable_microphone = &disable;
+  microphone->destroy_microphone = &destroy;
+  return microphone;
+}
+
+
+/**
+ * Destroy a microphone.
+ *
+ * @param microphone microphone to destroy
+ */
+void
+GNUNET_MICROPHONE_destroy (struct GNUNET_MICROPHONE_Handle *microphone)
+{
+  microphone->destroy_microphone (microphone->cls);
+  GNUNET_free (microphone);
+}
+
+/* end of microphone.c */
-- 
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