Audaspace: add support for PulseAudio on Linux

This adds PulseAudio as audio backend on Linux.
PulseAudio is the main audio engine used on most,
if not all, Linux distributions today.

Ref T86590

1 files changed, 282 insertions, 0 deletions

diff --git a/extern/audaspace/plugins/pulseaudio/PulseAudioDevice.cpp b/extern/audaspace/plugins/pulseaudio/PulseAudioDevice.cpp
new file mode 100644
index 00000000000..0a50d5db2c7
--- /dev/null
+++ b/extern/audaspace/plugins/pulseaudio/PulseAudioDevice.cpp
@@ -0,0 +1,282 @@
+/*******************************************************************************
+ * Copyright 2009-2016 Jörg Müller
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+
+#include "PulseAudioDevice.h"
+#include "PulseAudioLibrary.h"
+#include "devices/DeviceManager.h"
+#include "devices/IDeviceFactory.h"
+#include "Exception.h"
+#include "IReader.h"
+
+AUD_NAMESPACE_BEGIN
+
+void PulseAudioDevice::PulseAudio_state_callback(pa_context *context, void *data)
+{
+	PulseAudioDevice* device = (PulseAudioDevice*)data;
+
+	device->m_state = AUD_pa_context_get_state(context);
+
+	AUD_pa_threaded_mainloop_signal(device->m_mainloop, 0);
+}
+
+void PulseAudioDevice::PulseAudio_request(pa_stream *stream, size_t num_bytes, void *data)
+{
+	PulseAudioDevice* device = (PulseAudioDevice*)data;
+
+	void* buffer;
+
+	AUD_pa_stream_begin_write(stream, &buffer, &num_bytes);
+
+	device->mix((data_t*)buffer, num_bytes / AUD_DEVICE_SAMPLE_SIZE(device->m_specs));
+
+	AUD_pa_stream_write(stream, buffer, num_bytes, nullptr, 0, PA_SEEK_RELATIVE);
+}
+
+void PulseAudioDevice::PulseAudio_underflow(pa_stream *stream, void *data)
+{
+	PulseAudioDevice* device = (PulseAudioDevice*)data;
+
+	DeviceSpecs specs = device->getSpecs();
+
+	if(++device->m_underflows > 4 && device->m_buffersize < AUD_DEVICE_SAMPLE_SIZE(specs) * specs.rate * 2)
+	{
+		device->m_buffersize <<= 1;
+		device->m_underflows = 0;
+
+		pa_buffer_attr buffer_attr;
+
+		buffer_attr.fragsize = -1U;
+		buffer_attr.maxlength = -1U;
+		buffer_attr.minreq = -1U;
+		buffer_attr.prebuf = -1U;
+		buffer_attr.tlength = device->m_buffersize;
+
+		AUD_pa_stream_set_buffer_attr(stream, &buffer_attr, nullptr, nullptr);
+	}
+}
+
+void PulseAudioDevice::playing(bool playing)
+{
+	m_playback = playing;
+
+	AUD_pa_stream_cork(m_stream, playing ? 0 : 1, nullptr, nullptr);
+}
+
+PulseAudioDevice::PulseAudioDevice(std::string name, DeviceSpecs specs, int buffersize) :
+	m_playback(false),
+	m_state(PA_CONTEXT_UNCONNECTED),
+	m_buffersize(buffersize),
+	m_underflows(0)
+{
+	m_mainloop = AUD_pa_threaded_mainloop_new();
+
+	AUD_pa_threaded_mainloop_lock(m_mainloop);
+
+	m_context = AUD_pa_context_new(AUD_pa_threaded_mainloop_get_api(m_mainloop), name.c_str());
+
+	if(!m_context)
+	{
+		AUD_pa_threaded_mainloop_unlock(m_mainloop);
+		AUD_pa_threaded_mainloop_free(m_mainloop);
+
+		AUD_THROW(DeviceException, "Could not connect to PulseAudio.");
+	}
+
+	AUD_pa_context_set_state_callback(m_context, PulseAudio_state_callback, this);
+
+	AUD_pa_context_connect(m_context, nullptr, PA_CONTEXT_NOFLAGS, nullptr);
+
+	AUD_pa_threaded_mainloop_start(m_mainloop);
+
+	while(m_state != PA_CONTEXT_READY)
+	{
+		switch(m_state)
+		{
+		case PA_CONTEXT_FAILED:
+		case PA_CONTEXT_TERMINATED:
+			AUD_pa_threaded_mainloop_unlock(m_mainloop);
+			AUD_pa_threaded_mainloop_stop(m_mainloop);
+
+			AUD_pa_context_disconnect(m_context);
+			AUD_pa_context_unref(m_context);
+
+			AUD_pa_threaded_mainloop_free(m_mainloop);
+
+			AUD_THROW(DeviceException, "Could not connect to PulseAudio.");
+			break;
+		default:
+			AUD_pa_threaded_mainloop_wait(m_mainloop);
+			break;
+		}
+	}
+
+	if(specs.channels == CHANNELS_INVALID)
+		specs.channels = CHANNELS_STEREO;
+	if(specs.format == FORMAT_INVALID)
+		specs.format = FORMAT_FLOAT32;
+	if(specs.rate == RATE_INVALID)
+		specs.rate = RATE_48000;
+
+	m_specs = specs;
+
+	pa_sample_spec sample_spec;
+
+	sample_spec.channels = specs.channels;
+	sample_spec.format = PA_SAMPLE_FLOAT32;
+	sample_spec.rate = specs.rate;
+
+	switch(m_specs.format)
+	{
+	case FORMAT_U8:
+		sample_spec.format = PA_SAMPLE_U8;
+		break;
+	case FORMAT_S16:
+		sample_spec.format = PA_SAMPLE_S16NE;
+		break;
+	case FORMAT_S24:
+		sample_spec.format = PA_SAMPLE_S24NE;
+		break;
+	case FORMAT_S32:
+		sample_spec.format = PA_SAMPLE_S32NE;
+		break;
+	case FORMAT_FLOAT32:
+		sample_spec.format = PA_SAMPLE_FLOAT32;
+		break;
+	case FORMAT_FLOAT64:
+		m_specs.format = FORMAT_FLOAT32;
+		break;
+	default:
+		break;
+	}
+
+	m_stream = AUD_pa_stream_new(m_context, "Playback", &sample_spec, nullptr);
+
+	if(!m_stream)
+	{
+		AUD_pa_threaded_mainloop_unlock(m_mainloop);
+		AUD_pa_threaded_mainloop_stop(m_mainloop);
+
+		AUD_pa_context_disconnect(m_context);
+		AUD_pa_context_unref(m_context);
+
+		AUD_pa_threaded_mainloop_free(m_mainloop);
+
+		AUD_THROW(DeviceException, "Could not create PulseAudio stream.");
+	}
+
+	AUD_pa_stream_set_write_callback(m_stream, PulseAudio_request, this);
+	AUD_pa_stream_set_underflow_callback(m_stream, PulseAudio_underflow, this);
+
+	pa_buffer_attr buffer_attr;
+
+	buffer_attr.fragsize = -1U;
+	buffer_attr.maxlength = -1U;
+	buffer_attr.minreq = -1U;
+	buffer_attr.prebuf = -1U;
+	buffer_attr.tlength = buffersize;
+
+	if(AUD_pa_stream_connect_playback(m_stream, nullptr, &buffer_attr, static_cast<pa_stream_flags_t>(PA_STREAM_INTERPOLATE_TIMING | PA_STREAM_ADJUST_LATENCY | PA_STREAM_AUTO_TIMING_UPDATE), nullptr, nullptr) < 0)
+	{
+		AUD_pa_threaded_mainloop_unlock(m_mainloop);
+		AUD_pa_threaded_mainloop_stop(m_mainloop);
+
+		AUD_pa_context_disconnect(m_context);
+		AUD_pa_context_unref(m_context);
+
+		AUD_pa_threaded_mainloop_free(m_mainloop);
+
+		AUD_THROW(DeviceException, "Could not connect PulseAudio stream.");
+	}
+
+	AUD_pa_threaded_mainloop_unlock(m_mainloop);
+
+	create();
+}
+
+PulseAudioDevice::~PulseAudioDevice()
+{
+	AUD_pa_threaded_mainloop_stop(m_mainloop);
+
+	AUD_pa_context_disconnect(m_context);
+	AUD_pa_context_unref(m_context);
+
+	AUD_pa_threaded_mainloop_free(m_mainloop);
+
+	destroy();
+}
+
+class PulseAudioDeviceFactory : public IDeviceFactory
+{
+private:
+	DeviceSpecs m_specs;
+	int m_buffersize;
+	std::string m_name;
+
+public:
+	PulseAudioDeviceFactory() :
+		m_buffersize(AUD_DEFAULT_BUFFER_SIZE),
+		m_name("Audaspace")
+	{
+		m_specs.format = FORMAT_FLOAT32;
+		m_specs.channels = CHANNELS_STEREO;
+		m_specs.rate = RATE_48000;
+	}
+
+	virtual std::shared_ptr<IDevice> openDevice()
+	{
+		return std::shared_ptr<IDevice>(new PulseAudioDevice(m_name, m_specs, m_buffersize));
+	}
+
+	virtual int getPriority()
+	{
+		return 1 << 15;
+	}
+
+	virtual void setSpecs(DeviceSpecs specs)
+	{
+		m_specs = specs;
+	}
+
+	virtual void setBufferSize(int buffersize)
+	{
+		m_buffersize = buffersize;
+	}
+
+	virtual void setName(std::string name)
+	{
+		m_name = name;
+	}
+};
+
+void PulseAudioDevice::registerPlugin()
+{
+	if(loadPulseAudio())
+		DeviceManager::registerDevice("PulseAudio", std::shared_ptr<IDeviceFactory>(new PulseAudioDeviceFactory));
+}
+
+#ifdef PULSEAUDIO_PLUGIN
+extern "C" AUD_PLUGIN_API void registerPlugin()
+{
+	PulseAudioDevice::registerPlugin();
+}
+
+extern "C" AUD_PLUGIN_API const char* getName()
+{
+	return "PulseAudio";
+}
+#endif
+
+AUD_NAMESPACE_END