[client] audio: initial addition of PipeWire audio support via SPICE

client/include/interface/audiodev.h

@@ -0,0 +1,63 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2021 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _H_I_AUDIODEV_
+#define _H_I_AUDIODEV_
+
+#include <stdbool.h>
+#include <stdint.h>
+
+struct LG_AudioDevOps
+{
+  /* internal name of the audio for debugging */
+  const char * name;
+
+  /* called very early to allow for option registration, optional */
+  void (*earlyInit)(void);
+
+  /* called to initialize the audio backend */
+  bool (*init)(void);
+
+  /* final free */
+  void (*free)(void);
+
+  /* setup the playback audio stream
+   * Note: currently SPICE only supports S16 samples so always assume so
+   */
+  void (*start)(int channels, int sampleRate);
+
+  /* called for each packet of output audio to play
+   * Note: size is the size of data in bytes, not frames/samples
+   */
+  void (*play)(uint8_t * data, int size);
+
+  /* called when SPICE reports the audio stream has stopped */
+  void (*stop)(void);
+};
+
+#define ASSERT_LG_AUDIODEV_VALID(x) \
+  DEBUG_ASSERT((x)->name  ); \
+  DEBUG_ASSERT((x)->init  ); \
+  DEBUG_ASSERT((x)->free  ); \
+  DEBUG_ASSERT((x)->start ); \
+  DEBUG_ASSERT((x)->play  ); \
+  DEBUG_ASSERT((x)->stop  );
+
+#endif