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, 58 insertions, 0 deletions

diff --git a/src/wx/audio_backend.h b/src/wx/audio_backend.h
new file mode 100644
index 000000000..cf1bbad05
--- /dev/null
+++ b/src/wx/audio_backend.h
@@ -0,0 +1,58 @@
+/*
+    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 <dcp/warnings.h>
+LIBDCP_DISABLE_WARNINGS
+#include <RtAudio.h>
+LIBDCP_ENABLE_WARNINGS
+
+
+
+class AudioBackend
+{
+public:
+	AudioBackend();
+
+	AudioBackend(AudioBackend const&) = delete;
+	AudioBackend& operator=(AudioBackend const&) = delete;
+
+	RtAudio& rtaudio() {
+		return _rtaudio;
+	}
+
+#if (RTAUDIO_VERSION_MAJOR >= 6)
+	std::string last_rtaudio_error() const;
+#endif
+
+	static AudioBackend* instance();
+
+private:
+	static AudioBackend* _instance;
+
+	RtAudio _rtaudio;
+
+#if (RTAUDIO_VERSION_MAJOR >= 6)
+	void rtaudio_error_callback(std::string const& error);
+	mutable boost::mutex _last_rtaudio_error_mutex;
+	std::string _last_rtaudio_error;
+#endif
+};
+