ocarina/lib/audio.cpp

/*
 * Copyright 2013 (c) Anna Schumaker.
 */
#include <audio.h>
#include <deck.h>
#include <library.h>

#include <string.h>

static GstElement *ocarina_player;
static bool track_loaded = false;
static unsigned int cur_trackid = 0;

static gboolean on_message(GstBus *bus, GstMessage *message, gpointer data)
{
	return TRUE;
}

static bool change_state(GstState state)
{
	GstStateChangeReturn ret;

	ret = gst_element_set_state(GST_ELEMENT(ocarina_player), state);
	switch (ret) {
	case GST_STATE_CHANGE_SUCCESS:
	case GST_STATE_CHANGE_ASYNC:
		return true;
	default:
		return false;
	}
}

static bool load_song(library :: Song &song)
{
	GstState state;
	gchar *escaped;
	std::string filepath = song.library->root_path + "/" + song.track->filepath;

	gst_element_get_state(GST_ELEMENT(ocarina_player), &state,
			      NULL, GST_CLOCK_TIME_NONE);

	escaped = gst_filename_to_uri(filepath.c_str(), NULL);
	g_object_set(G_OBJECT(ocarina_player), "uri", escaped, NULL);
	g_free(escaped);

	return change_state(state);
}

void audio :: init(int *argc, char ***argv)
{
	GstBus *bus;

	gst_init(argc, argv);

	ocarina_player = gst_element_factory_make("playbin", "ocarina_player");
	bus = gst_pipeline_get_bus(GST_PIPELINE(ocarina_player));

	gst_bus_add_watch(bus, on_message, NULL);
}

bool audio :: play()
{
	if (track_loaded == false)
		return false;
	return change_state(GST_STATE_PLAYING);
}

bool audio :: pause()
{
	if (track_loaded == false)
		return false;
	return change_state(GST_STATE_PAUSED);
}

bool audio :: stop()
{
	if (pause() == false)
		return false;
	return seek_to(0);
}

bool audio :: seek_to(long pos)
{
	bool ret;
	if (track_loaded == false)
		return false;
	ret = gst_element_seek_simple(GST_ELEMENT(ocarina_player),
					GST_FORMAT_TIME,
					GST_SEEK_FLAG_FLUSH,
					pos);
	return ret;
}

static bool _next()
{
	library :: Song song;
	unsigned int id = deck :: next();

	if (library :: lookup(id, &song) == false)
		return false;
	if (load_song(song) == false)
		return false;
	cur_trackid = id;
	return true;
}

bool audio :: next()
{
	try {
		track_loaded = _next();
	} catch (int) {
		track_loaded = false;
	}
	return track_loaded;
}

unsigned int audio :: current_trackid()
{
	if (track_loaded == false)
		throw -1;
	return cur_trackid;
}

long audio :: position()
{
	long position;

	if (track_loaded == false)
		return 0;
	if (!gst_element_query_position(GST_ELEMENT(ocarina_player), GST_FORMAT_TIME, &position))
		return 0;
	return position;
}

long audio :: duration()
{
	long duration;

	if (track_loaded == false)
		return 0;
	if (!gst_element_query_duration(ocarina_player, GST_FORMAT_TIME, &duration))
		return 0;
	return duration;
}