path: root/src/output/osx_plugin.c

/*
 * Copyright (C) 2003-2010 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"
#include "output_api.h"
#include "fifo_buffer.h"

#include <glib.h>
#include <AudioUnit/AudioUnit.h>
#include <CoreServices/CoreServices.h>

#undef G_LOG_DOMAIN
#define G_LOG_DOMAIN "osx"

struct osx_output {
	AudioUnit au;
	GMutex *mutex;
	GCond *condition;

	struct fifo_buffer *buffer;
};

/**
 * The quark used for GError.domain.
 */
static inline GQuark
osx_output_quark(void)
{
	return g_quark_from_static_string("osx_output");
}

static bool
osx_output_test_default_device(void)
{
	/* on a Mac, this is always the default plugin, if nothing
	   else is configured */
	return true;
}

static void *
osx_output_init(G_GNUC_UNUSED const struct audio_format *audio_format,
		G_GNUC_UNUSED const struct config_param *param,
		G_GNUC_UNUSED GError **error)
{
	struct osx_output *oo = g_new(struct osx_output, 1);

	oo->mutex = g_mutex_new();
	oo->condition = g_cond_new();

	return oo;
}

static void osx_output_finish(void *data)
{
	struct osx_output *od = data;

	g_mutex_free(od->mutex);
	g_cond_free(od->condition);
	g_free(od);
}

static void osx_output_cancel(void *data)
{
	struct osx_output *od = data;

	g_mutex_lock(od->mutex);
	fifo_buffer_clear(od->buffer);
	g_mutex_unlock(od->mutex);
}

static void osx_output_close(void *data)
{
	struct osx_output *od = data;

	AudioOutputUnitStop(od->au);
	AudioUnitUninitialize(od->au);
	CloseComponent(od->au);

	fifo_buffer_free(od->buffer);
}

static OSStatus
osx_render(void *vdata,
	   G_GNUC_UNUSED AudioUnitRenderActionFlags *io_action_flags,
	   G_GNUC_UNUSED const AudioTimeStamp *in_timestamp,
	   G_GNUC_UNUSED UInt32 in_bus_number,
	   G_GNUC_UNUSED UInt32 in_number_frames,
	   AudioBufferList *buffer_list)
{
	struct osx_output *od = (struct osx_output *) vdata;
	AudioBuffer *buffer = &buffer_list->mBuffers[0];
	size_t buffer_size = buffer->mDataByteSize;

	assert(od->buffer != NULL);

	g_mutex_lock(od->mutex);

	size_t nbytes;
	const void *src = fifo_buffer_read(od->buffer, &nbytes);

	if (src != NULL) {
		if (nbytes > buffer_size)
			nbytes = buffer_size;

		memcpy(buffer->mData, src, nbytes);
		fifo_buffer_consume(od->buffer, nbytes);
	} else
		nbytes = 0;

	g_cond_signal(od->condition);
	g_mutex_unlock(od->mutex);

	if (nbytes < buffer_size)
		memset((unsigned char*)buffer->mData + nbytes, 0,
		       buffer_size - nbytes);

	return 0;
}

static bool
osx_output_open(void *data, struct audio_format *audio_format, GError **error)
{
	struct osx_output *od = data;
	ComponentDescription desc;
	Component comp;
	AURenderCallbackStruct callback;
	AudioStreamBasicDescription stream_description;
	OSStatus status;
	ComponentResult result;

	desc.componentType = kAudioUnitType_Output;
	desc.componentSubType = kAudioUnitSubType_DefaultOutput;
	desc.componentManufacturer = kAudioUnitManufacturer_Apple;
	desc.componentFlags = 0;
	desc.componentFlagsMask = 0;

	comp = FindNextComponent(NULL, &desc);
	if (comp == 0) {
		g_set_error(error, osx_output_quark(), 0,
			    "Error finding OS X component");
		return false;
	}

	status = OpenAComponent(comp, &od->au);
	if (status != noErr) {
		g_set_error(error, osx_output_quark(), 0,
			    "Unable to open OS X component: %s",
			    GetMacOSStatusCommentString(status));
		return false;
	}

	status = AudioUnitInitialize(od->au);
	if (status != noErr) {
		CloseComponent(od->au);
		g_set_error(error, osx_output_quark(), 0,
			    "Unable to initialize OS X audio unit: %s",
			    GetMacOSStatusCommentString(status));
		return false;
	}

	callback.inputProc = osx_render;
	callback.inputProcRefCon = od;

	result = AudioUnitSetProperty(od->au,
				      kAudioUnitProperty_SetRenderCallback,
				      kAudioUnitScope_Input, 0,
				      &callback, sizeof(callback));
	if (result != noErr) {
		AudioUnitUninitialize(od->au);
		CloseComponent(od->au);
		g_set_error(error, osx_output_quark(), 0,
			    "unable to set callback for OS X audio unit");
		return false;
	}

	stream_description.mSampleRate = audio_format->sample_rate;
	stream_description.mFormatID = kAudioFormatLinearPCM;
	stream_description.mFormatFlags = kLinearPCMFormatFlagIsSignedInteger;

	switch (audio_format->format) {
	case SAMPLE_FORMAT_S8:
		stream_description.mBitsPerChannel = 8;
		break;

	case SAMPLE_FORMAT_S16:
		stream_description.mBitsPerChannel = 16;
		break;

	default:
		audio_format->format = SAMPLE_FORMAT_S16;
		stream_description.mBitsPerChannel = 16;
		break;
	}

#if G_BYTE_ORDER == G_BIG_ENDIAN
	stream_description.mFormatFlags |= kLinearPCMFormatFlagIsBigEndian;
#endif

	stream_description.mBytesPerPacket =
		audio_format_frame_size(audio_format);
	stream_description.mFramesPerPacket = 1;
	stream_description.mBytesPerFrame = stream_description.mBytesPerPacket;
	stream_description.mChannelsPerFrame = audio_format->channels;

	result = AudioUnitSetProperty(od->au, kAudioUnitProperty_StreamFormat,
				      kAudioUnitScope_Input, 0,
				      &stream_description,
				      sizeof(stream_description));
	if (result != noErr) {
		AudioUnitUninitialize(od->au);
		CloseComponent(od->au);
		g_set_error(error, osx_output_quark(), 0,
			    "Unable to set format on OS X device");
		return false;
	}

	/* create a buffer of 1s */
	od->buffer = fifo_buffer_new(audio_format->sample_rate *
				     audio_format_frame_size(audio_format));

	status = AudioOutputUnitStart(od->au);
	if (status != 0) {
		fifo_buffer_free(od->buffer);
		g_set_error(error, osx_output_quark(), 0,
			    "unable to start audio output: %s",
			    GetMacOSStatusCommentString(status));
		return false;
	}

	return true;
}

static size_t
osx_output_play(void *data, const void *chunk, size_t size,
		G_GNUC_UNUSED GError **error)
{
	struct osx_output *od = data;

	g_mutex_lock(od->mutex);

	void *dest;
	size_t max_length;

	while (true) {
		dest = fifo_buffer_write(od->buffer, &max_length);
		if (dest != NULL)
			break;

		/* wait for some free space in the buffer */
		g_cond_wait(od->condition, od->mutex);
	}

	if (size > max_length)
		size = max_length;

	memcpy(dest, chunk, size);
	fifo_buffer_append(od->buffer, size);

	g_mutex_unlock(od->mutex);

	return size;
}

const struct audio_output_plugin osxPlugin = {
	.name = "osx",
	.test_default_device = osx_output_test_default_device,
	.init = osx_output_init,
	.finish = osx_output_finish,
	.open = osx_output_open,
	.close = osx_output_close,
	.play = osx_output_play,
	.cancel = osx_output_cancel,
};