ocarina/libsaria/audio.cpp

// Copyright (c) 2011 Bryan Schumaker.
#include <deck.h>
#include <audio.h>
#include <print.h>

#include <sstream>
using namespace std;

static GstElement *player = NULL;
static GstFormat fmt_time = GST_FORMAT_TIME;
static GstState cur_state = GST_STATE_READY;

static void notify_state_change(GstState state)
{
	if (state == GST_STATE_PLAYING)
		libsaria::notify(PLAYING, NULL);
	else if (state == GST_STATE_PAUSED)
		libsaria::notify(PAUSED, NULL);
}

static bool change_state(GstState new_state)
{
	GstStateChangeReturn ret;
	ret = gst_element_set_state(GST_ELEMENT(player), new_state);

	switch(ret) {
		case GST_STATE_CHANGE_SUCCESS:
		case GST_STATE_CHANGE_ASYNC:
			cur_state = new_state;
			notify_state_change(cur_state);
			return true;
		default:
			return false;
	}
}

void load_file(GstElement *playbin, string file, GstState state)
{
	gchar *escaped;
	if (file == "" || !libsaria::exists(file))
		return;

	println("Loading file: " + file);
	escaped = gst_filename_to_uri(file.c_str(), NULL);

	/* Set pipeline to the requested state */
	change_state(GST_STATE_READY);
	g_object_set(G_OBJECT(playbin), "uri", escaped, NULL);
	change_state(state);

	g_free(escaped);
}

static string to_string(gint64 time)
{
	stringstream stream;
	int minutes, seconds;

	if (time == 0)
		return "";

	time = time / GST_SECOND;
	minutes = time / 60;
	seconds = time - (minutes * 60);
	stream << minutes << ":";
	if (seconds < 10)
		stream << "0";
	stream << seconds;
	return stream.str();
}

static void parse_error(GstMessage *error)
{
	GError *err;
	gchar  *debug;

	gst_message_parse_error(error, &err, &debug);
	g_print("Error: %s\n", err->message);
	g_error_free(err);
	g_free(debug);
}

static gboolean on_message(GstBus *bus, GstMessage *message, gpointer data)
{
	switch (GST_MESSAGE_TYPE(message)) {
		case GST_MESSAGE_ERROR:
			parse_error(message);
		case GST_MESSAGE_EOS:
			libsaria::deck::next();
		default:
			break;
	}
	return TRUE;
}

namespace libsaria
{

	void audio::play()
	{
		change_state(GST_STATE_PLAYING);
	}

	void audio::pause()
	{
		change_state(GST_STATE_PAUSED);
	}

	void audio::toggle_play()
	{
		if (cur_state == GST_STATE_PLAYING)
			pause();
		else
			play();
	}

	GstState audio::get_state()
	{
		return cur_state;
	}

	void audio::stop()
	{
		pause();
		seek_to(0);
	}

	void audio::load(string file, bool play)
	{
		GstState state = GST_STATE_PLAYING;
		if (!play)
			state = GST_STATE_PAUSED;
		load_file(player, file, state);
	}

	/* Seek to this many seconds into the song */
	void audio::seek_to(double pos)
	{
		gst_element_seek_simple(GST_ELEMENT(player),
					GST_FORMAT_TIME,
					GST_SEEK_FLAG_FLUSH,
					pos);
	}

	gint64 audio::duration()
	{
		gint64 duration;
		if (!gst_element_query_duration(player, &fmt_time, &duration))
			return 0;
		if (duration < 0)
			duration = 0;
		return duration;
	}

	gint64 audio::position()
	{
		gint64 position;
		if (!gst_element_query_position(player, &fmt_time, &position))
			return 0;
		return position;
	}

	string audio::posstr()
	{
		return to_string(position());
	}

	bool audio::played()
	{
		return position() > ((duration() * 3) / 4);
	}

	void audio::init(int argc, char **argv)
	{
		static GstBus *bus;
		println("Initializing libsaria audio");
		gst_init(&argc, &argv);

		player = gst_element_factory_make("playbin2", "player");
		bus    = gst_pipeline_get_bus(GST_PIPELINE(player));

		gst_bus_add_watch(bus, on_message, NULL);
	}

	void audio::quit()
	{
		gst_deinit();
	}

};