1 files changed, 189 insertions, 0 deletions

diff --git a/src/contrib/service/conversation/speaker.c b/src/contrib/service/conversation/speaker.c
new file mode 100644
index 000000000..38eb1159c
--- /dev/null
+++ b/src/contrib/service/conversation/speaker.c
@@ -0,0 +1,189 @@
+/*
+   This file is part of GNUnet
+   Copyright (C) 2013 GNUnet e.V.
+
+   GNUnet is free software: you can redistribute it and/or modify it
+   under the terms of the GNU Affero General Public License as published
+   by the Free Software Foundation, either version 3 of the License,
+   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
+   Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+     SPDX-License-Identifier: AGPL3.0-or-later
+ */
+
+/**
+ * @file conversation/speaker.c
+ * @brief API to access an audio speaker; provides access to hardware speakers
+ * @author Simon Dieterle
+ * @author Andreas Fuchs
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_speaker_lib.h"
+#include "conversation.h"
+
+
+/**
+ * Internal data structures for the speaker.
+ */
+struct Speaker
+{
+  /**
+   * Our configuration.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Handle for the playback helper
+   */
+  struct GNUNET_HELPER_Handle *playback_helper;
+};
+
+
+/**
+ * Function that enables a speaker.
+ *
+ * @param cls closure with the `struct Speaker`
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
+ */
+static int
+enable (void *cls)
+{
+  struct Speaker *spe = cls;
+  static char *playback_helper_argv[] = {
+    "gnunet-helper-audio-playback",
+    NULL
+  };
+
+  spe->playback_helper = GNUNET_HELPER_start (GNUNET_NO,
+                                              "gnunet-helper-audio-playback",
+                                              playback_helper_argv,
+                                              NULL,
+                                              NULL, spe);
+  if (NULL == spe->playback_helper)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _ ("Could not start playback audio helper.\n"));
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Function that disables a speaker.
+ *
+ * @param cls closure with the `struct Speaker`
+ */
+static void
+disable (void *cls)
+{
+  struct Speaker *spe = cls;
+
+  if (NULL == spe->playback_helper)
+  {
+    GNUNET_break (0);
+    return;
+  }
+  GNUNET_break (GNUNET_OK ==
+                GNUNET_HELPER_kill (spe->playback_helper, GNUNET_NO));
+  GNUNET_HELPER_destroy (spe->playback_helper);
+  spe->playback_helper = NULL;
+}
+
+
+/**
+ * Function to destroy a speaker.
+ *
+ * @param cls closure with the `struct Speaker`
+ */
+static void
+destroy (void *cls)
+{
+  struct Speaker *spe = cls;
+
+  if (NULL != spe->playback_helper)
+    disable (spe);
+}
+
+
+/**
+ * Function to cause a speaker to play audio data.
+ *
+ * @param cls clsoure with the `struct Speaker`
+ * @param data_size number of bytes in @a data
+ * @param data audio data to play, format is
+ *        opaque to the API but should be OPUS.
+ */
+static void
+play (void *cls,
+      size_t data_size,
+      const void *data)
+{
+  struct Speaker *spe = cls;
+  char buf[sizeof(struct AudioMessage) + data_size];
+  struct AudioMessage *am;
+
+  if (NULL == spe->playback_helper)
+  {
+    GNUNET_break (0);
+    return;
+  }
+  am = (struct AudioMessage *) buf;
+  am->header.size = htons (sizeof(struct AudioMessage) + data_size);
+  am->header.type = htons (GNUNET_MESSAGE_TYPE_CONVERSATION_AUDIO);
+  GNUNET_memcpy (&am[1], data, data_size);
+  (void) GNUNET_HELPER_send (spe->playback_helper,
+                             &am->header,
+                             GNUNET_NO,
+                             NULL, NULL);
+}
+
+
+/**
+ * Create a speaker that corresponds to the speaker hardware
+ * of our system.
+ *
+ * @param cfg configuration to use
+ * @return NULL on error
+ */
+struct GNUNET_SPEAKER_Handle *
+GNUNET_SPEAKER_create_from_hardware (const struct
+                                     GNUNET_CONFIGURATION_Handle *cfg)
+{
+  struct GNUNET_SPEAKER_Handle *speaker;
+  struct Speaker *spe;
+
+  spe = GNUNET_new (struct Speaker);
+  spe->cfg = cfg;
+  speaker = GNUNET_new (struct GNUNET_SPEAKER_Handle);
+  speaker->cls = spe;
+  speaker->enable_speaker = &enable;
+  speaker->play = &play;
+  speaker->disable_speaker = &disable;
+  speaker->destroy_speaker = &destroy;
+  return speaker;
+}
+
+
+/**
+ * Destroy a speaker.
+ *
+ * @param speaker speaker to destroy
+ */
+void
+GNUNET_SPEAKER_destroy (struct GNUNET_SPEAKER_Handle *speaker)
+{
+  speaker->destroy_speaker (speaker->cls);
+  GNUNET_free (speaker);
+}
+
+
+/* end of speaker.c */