mpd/src/output_all.c

/*
 * Copyright (C) 2003-2009 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 "output_all.h"
#include "output_internal.h"
#include "output_control.h"
#include "conf.h"
#include "pipe.h"
#include "buffer.h"

#ifndef NDEBUG
#include "chunk.h"
#endif

#include <assert.h>
#include <string.h>

#undef G_LOG_DOMAIN
#define G_LOG_DOMAIN "output"

static struct audio_format input_audio_format;

static struct audio_output *audio_outputs;
static unsigned int num_audio_outputs;

/**
 * The #music_buffer object where consumed chunks are returned.
 */
static struct music_buffer *g_music_buffer;

/**
 * The #music_pipe object which feeds all audio outputs.  It is filled
 * by audio_output_all_play().
 */
static struct music_pipe *g_mp;

unsigned int audio_output_count(void)
{
	return num_audio_outputs;
}

struct audio_output *
audio_output_get(unsigned i)
{
	assert(i < num_audio_outputs);

	return &audio_outputs[i];
}

struct audio_output *
audio_output_find(const char *name)
{
	for (unsigned i = 0; i < num_audio_outputs; ++i) {
		struct audio_output *ao = audio_output_get(i);

		if (strcmp(ao->name, name) == 0)
			return ao;
	}

	/* name not found */
	return NULL;
}

static unsigned
audio_output_config_count(void)
{
	unsigned int nr = 0;
	const struct config_param *param = NULL;

	while ((param = config_get_next_param(CONF_AUDIO_OUTPUT, param)))
		nr++;
	if (!nr)
		nr = 1; /* we'll always have at least one device  */
	return nr;
}

void
audio_output_all_init(void)
{
	const struct config_param *param = NULL;
	unsigned int i;
	GError *error = NULL;

	notify_init(&audio_output_client_notify);

	num_audio_outputs = audio_output_config_count();
	audio_outputs = g_new(struct audio_output, num_audio_outputs);

	for (i = 0; i < num_audio_outputs; i++)
	{
		struct audio_output *output = &audio_outputs[i];
		unsigned int j;

		param = config_get_next_param(CONF_AUDIO_OUTPUT, param);

		/* only allow param to be NULL if there just one audioOutput */
		assert(param || (num_audio_outputs == 1));

		if (!audio_output_init(output, param, &error))
			g_error("line %i: %s", param->line, error->message);

		/* require output names to be unique: */
		for (j = 0; j < i; j++) {
			if (!strcmp(output->name, audio_outputs[j].name)) {
				g_error("output devices with identical "
					"names: %s\n", output->name);
			}
		}
	}
}

void
audio_output_all_finish(void)
{
	unsigned int i;

	for (i = 0; i < num_audio_outputs; i++) {
		audio_output_finish(&audio_outputs[i]);
	}

	g_free(audio_outputs);
	audio_outputs = NULL;
	num_audio_outputs = 0;

	notify_deinit(&audio_output_client_notify);
}


/**
 * Determine if all (active) outputs have finished the current
 * command.
 */
static bool
audio_output_all_finished(void)
{
	for (unsigned i = 0; i < num_audio_outputs; ++i)
		if (audio_output_is_open(&audio_outputs[i]) &&
		    !audio_output_command_is_finished(&audio_outputs[i]))
			return false;

	return true;
}

static void audio_output_wait_all(void)
{
	while (!audio_output_all_finished())
		notify_wait(&audio_output_client_notify);
}

/**
 * Resets the "reopen" flag on all audio devices.  MPD should
 * immediately retry to open the device instead of waiting for the
 * timeout when the user wants to start playback.
 */
static void
audio_output_all_reset_reopen(void)
{
	for (unsigned i = 0; i < num_audio_outputs; ++i) {
		struct audio_output *ao = &audio_outputs[i];

		if (!ao->open && ao->fail_timer != NULL) {
			g_timer_destroy(ao->fail_timer);
			ao->fail_timer = NULL;
		}
	}
}

/**
 * Opens all output devices which are enabled, but closed.
 *
 * @return true if there is at least open output device which is open
 */
static bool
audio_output_all_update(void)
{
	unsigned int i;
	bool ret = false;

	if (!audio_format_defined(&input_audio_format))
		return false;

	for (i = 0; i < num_audio_outputs; ++i)
		ret = audio_output_update(&audio_outputs[i],
					  &input_audio_format, g_mp) || ret;

	return ret;
}

bool
audio_output_all_play(struct music_chunk *chunk)
{
	bool ret;
	unsigned int i;

	assert(g_music_buffer != NULL);
	assert(g_mp != NULL);
	assert(chunk != NULL);
	assert(music_chunk_check_format(chunk, &input_audio_format));

	ret = audio_output_all_update();
	if (!ret)
		return false;

	music_pipe_push(g_mp, chunk);

	for (i = 0; i < num_audio_outputs; ++i)
		if (audio_output_is_open(&audio_outputs[i]))
			audio_output_play(&audio_outputs[i]);

	return ret;
}

bool
audio_output_all_open(const struct audio_format *audio_format,
		      struct music_buffer *buffer)
{
	bool ret = false, enabled = false;
	unsigned int i;

	assert(audio_format != NULL);
	assert(buffer != NULL);
	assert(g_music_buffer == NULL || g_music_buffer == buffer);
	assert((g_mp == NULL) == (g_music_buffer == NULL));

	g_music_buffer = buffer;

	/* the audio format must be the same as existing chunks in the
	   pipe */
	assert(g_mp == NULL || music_pipe_check_format(g_mp, audio_format));

	if (g_mp == NULL)
		g_mp = music_pipe_new();
	else
		/* if the pipe hasn't been cleared, the the audio
		   format must not have changed */
		assert(music_pipe_size(g_mp) == 0 ||
		       audio_format_equals(audio_format,
					   &input_audio_format));

	input_audio_format = *audio_format;

	audio_output_all_reset_reopen();
	audio_output_all_update();

	for (i = 0; i < num_audio_outputs; ++i) {
		if (audio_outputs[i].enabled)
			enabled = true;

		if (audio_outputs[i].open)
			ret = true;
	}

	if (!enabled)
		g_warning("All audio outputs are disabled");

	if (!ret)
		/* close all devices if there was an error */
		audio_output_all_close();

	return ret;
}

/**
 * Has the specified audio output already consumed this chunk?
 */
static bool
chunk_is_consumed_in(const struct audio_output *ao,
		     const struct music_chunk *chunk)
{
	if (ao->chunk == NULL)
		return false;

	assert(chunk == ao->chunk || music_pipe_contains(g_mp, ao->chunk));

	if (chunk != ao->chunk) {
		assert(chunk->next != NULL);
		return true;
	}

	return ao->chunk_finished && chunk->next == NULL;
}

/**
 * Has this chunk been consumed by all audio outputs?
 */
static bool
chunk_is_consumed(const struct music_chunk *chunk)
{
	for (unsigned i = 0; i < num_audio_outputs; ++i) {
		const struct audio_output *ao = &audio_outputs[i];
		bool consumed;

		if (!ao->open)
			continue;

		g_mutex_lock(ao->mutex);
		consumed = chunk_is_consumed_in(ao, chunk);
		g_mutex_unlock(ao->mutex);

		if (!consumed)
			return false;
	}

	return true;
}

/**
 * There's only one chunk left in the pipe (#g_mp), and all audio
 * outputs have consumed it already.  Clear the reference.
 */
static void
clear_tail_chunk(const struct music_chunk *chunk, bool *locked)
{
	assert(chunk->next == NULL);
	assert(music_pipe_contains(g_mp, chunk));

	for (unsigned i = 0; i < num_audio_outputs; ++i) {
		struct audio_output *ao = &audio_outputs[i];

		locked[i] = ao->open;

		if (!locked[i])
			continue;

		/* this mutex will be unlocked by the caller when it's
		   ready */
		g_mutex_lock(ao->mutex);

		assert(ao->chunk == chunk);
		assert(ao->chunk_finished);
		ao->chunk = NULL;
	}
}

unsigned
audio_output_all_check(void)
{
	const struct music_chunk *chunk;
	bool is_tail;
	struct music_chunk *shifted;
	bool locked[num_audio_outputs];

	assert(g_music_buffer != NULL);
	assert(g_mp != NULL);

	while ((chunk = music_pipe_peek(g_mp)) != NULL) {
		assert(music_pipe_size(g_mp) > 0);

		if (!chunk_is_consumed(chunk))
			/* at least one output is not finished playing
			   this chunk */
			return music_pipe_size(g_mp);

		is_tail = chunk->next == NULL;
		if (is_tail)
			/* this is the tail of the pipe - clear the
			   chunk reference in all outputs */
			clear_tail_chunk(chunk, locked);

		/* remove the chunk from the pipe */
		shifted = music_pipe_shift(g_mp);
		assert(shifted == chunk);

		if (is_tail)
			/* unlock all audio outputs which were locked
			   by clear_tail_chunk() */
			for (unsigned i = 0; i < num_audio_outputs; ++i)
				if (locked[i])
					g_mutex_unlock(audio_outputs[i].mutex);

		/* return the chunk to the buffer */
		music_buffer_return(g_music_buffer, shifted);
	}

	return 0;
}

void
audio_output_all_pause(void)
{
	unsigned int i;

	audio_output_all_update();

	for (i = 0; i < num_audio_outputs; ++i)
		if (audio_output_is_open(&audio_outputs[i]))
			audio_output_pause(&audio_outputs[i]);

	audio_output_wait_all();
}

void
audio_output_all_cancel(void)
{
	unsigned int i;

	audio_output_all_update();

	/* send the cancel() command to all audio outputs */

	for (i = 0; i < num_audio_outputs; ++i) {
		if (audio_output_is_open(&audio_outputs[i]))
			audio_output_cancel(&audio_outputs[i]);
	}

	audio_output_wait_all();

	/* clear the music pipe and return all chunks to the buffer */

	if (g_mp != NULL)
		music_pipe_clear(g_mp, g_music_buffer);
}

void
audio_output_all_close(void)
{
	unsigned int i;

	for (i = 0; i < num_audio_outputs; ++i)
		audio_output_close(&audio_outputs[i]);

	if (g_mp != NULL) {
		assert(g_music_buffer != NULL);

		music_pipe_clear(g_mp, g_music_buffer);
		music_pipe_free(g_mp);
		g_mp = NULL;
	}

	g_music_buffer = NULL;

	audio_format_clear(&input_audio_format);
}