Stub implementatio of output stream driver for GDx devices

meson.build

@@ -163,7 +163,8 @@ gdx_src = ['openrtx/src/core/xmodem.c',
            'platform/drivers/display/UC1701_GDx.c',
            'platform/drivers/keyboard/keyboard_GDx.c',
            'platform/drivers/audio/audio_GDx.c',
-           'platform/drivers/audio/inputStream_GDx.c']
+           'platform/drivers/audio/inputStream_GDx.c',
+           'platform/drivers/audio/outputStream_GDx.c']
 
 ##
 ## --------------------- MCU-dependent source files ----------------------------

platform/drivers/audio/outputStream_GDx.c

@@ -0,0 +1,63 @@
+/***************************************************************************
+ *   Copyright (C) 2021 - 2022 by Federico Amedeo Izzo IU2NUO,             *
+ *                                Niccolò Izzo IU2KIN                      *
+ *                                Frederik Saraci IU2NRO                   *
+ *                                Silvano Seva IU2KWO                      *
+ *                                                                         *
+ *   This program 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 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program 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 this program; if not, see <http://www.gnu.org/licenses/>   *
+ ***************************************************************************/
+
+#include <interfaces/audio_stream.h>
+
+streamId outputStream_start(const enum AudioSink destination,
+                            const enum AudioPriority prio,
+                            stream_sample_t * const buf,
+                            const size_t length,
+                            const enum BufMode mode,
+                            const uint32_t sampleRate)
+{
+    (void) destination;
+    (void) prio;
+    (void) buf;
+    (void) length;
+    (void) mode;
+    (void) sampleRate;
+
+    return -1;
+}
+
+stream_sample_t *outputStream_getIdleBuffer(const streamId id)
+{
+    (void) id;
+
+    return NULL;
+}
+
+bool outputStream_sync(const streamId id, const bool bufChanged)
+{
+    (void) id;
+    (void) bufChanged;
+
+    return false;
+}
+
+void outputStream_stop(const streamId id)
+{
+    (void) id;
+}
+
+void outputStream_terminate(const streamId id)
+{
+    (void) id;
+}