Stop instantiating RtAudio all over the place

and instead just have a singleton.  On Windows I saw a situation where
the first instantiation would use ASIO and the second WASAPI, causing
all kinds of confusion.

1 files changed, 77 insertions, 0 deletions

diff --git a/src/wx/audio_backend.cc b/src/wx/audio_backend.cc
new file mode 100644
index 000000000..b77d2cdcd
--- /dev/null
+++ b/src/wx/audio_backend.cc
@@ -0,0 +1,77 @@
+/*
+    Copyright (C) 2024 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic 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.
+
+    DCP-o-matic 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 DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "audio_backend.h"
+
+
+AudioBackend* AudioBackend::_instance = nullptr;
+
+
+#ifdef DCPOMATIC_LINUX
+auto constexpr api = RtAudio::LINUX_PULSE;
+#endif
+#ifdef DCPOMATIC_WINDOWS
+auto constexpr api = RtAudio::UNSPECIFIED;
+#endif
+#ifdef DCPOMATIC_OSX
+auto constexpr api = RtAudio::MACOSX_CORE;
+#endif
+
+
+AudioBackend::AudioBackend()
+#if (RTAUDIO_VERSION_MAJOR >= 6)
+	: _rtaudio(api, boost::bind(&AudioBackend::rtaudio_error_callback, this, _2))
+#else
+	: _rtaudio(api)
+#endif
+{
+
+}
+
+
+#if (RTAUDIO_VERSION_MAJOR >= 6)
+void
+AudioBackend::rtaudio_error_callback(string const& error)
+{
+	boost::mutex::scoped_lock lm(_last_rtaudio_error_mutex);
+	_last_rtaudio_error = error;
+}
+
+string
+AudioBackend::last_rtaudio_error() const
+{
+	boost::mutex::scoped_lock lm(_last_rtaudio_error_mutex);
+	return _last_rtaudio_error;
+}
+#endif
+
+
+AudioBackend*
+AudioBackend::instance()
+{
+	if (!_instance) {
+		_instance = new AudioBackend();
+	}
+
+	return _instance;
+}
+
+