#define DEFAULT_BUFSIZE 65536
#define DEFAULT_CLIENT_NAME "gst-aseq-appsrc"
#define DEFAULT_TICK_PERIOD_MS 10
-#define DEFAULT_POLL_TIMEOUT_MS (DEFAULT_TICK_PERIOD_MS / 2)
GST_DEBUG_CATEGORY (mysource_debug);
#define GST_CAT_DEFAULT mysource_debug
int npfds;
guint64 tick;
+ guint64 delay;
};
static App s_app;
return ret;
}
+static void
+schedule_tick (App * app)
+{
+ snd_seq_event_t ev;
+ snd_seq_real_time_t time;
+ int ret;
+
+ snd_seq_ev_clear (&ev);
+ snd_seq_ev_set_source (&ev, 0);
+ snd_seq_ev_set_dest (&ev, snd_seq_client_id (app->seq), 0);
+
+ ev.type = SND_SEQ_EVENT_TICK;
+
+ GST_TIME_TO_TIMESPEC (app->tick * DEFAULT_TICK_PERIOD_MS * GST_MSECOND, time);
+ app->tick += 1;
+
+ snd_seq_ev_schedule_real (&ev, app->queue, 0, &time);
+
+ ret = snd_seq_event_output (app->seq, &ev);
+ if (ret < 0)
+ GST_ERROR ("Event output error: %s\n", snd_strerror (ret));
+
+ ret = snd_seq_drain_output (app->seq);
+ if (ret < 0)
+ GST_ERROR ("Event drain error: %s\n", snd_strerror (ret));
+}
+
static int
create_port (App * app)
{
if (ret < 0)
GST_ERROR ("Cannot create port - %s", snd_strerror (ret));
- ret = start_queue_timer (app->seq, app->queue);
-
return ret;
}
}
static void
-push_buffer (App * app, gpointer data, guint size)
+push_buffer (App * app, gpointer data, guint size, GstClockTime time)
{
- GstClockTime time;
gpointer local_data;
GstBuffer *buffer;
int ret;
buffer = gst_buffer_new ();
- time = app->tick * DEFAULT_TICK_PERIOD_MS * GST_MSECOND;
-
GST_BUFFER_DTS (buffer) = time;
GST_BUFFER_PTS (buffer) = time;
(gpointer) buffer, app->tick, size);
g_signal_emit_by_name (app->appsrc, "push-buffer", buffer, &ret);
gst_buffer_unref (buffer);
-
- app->tick += 1;
}
static void
-push_tick_buffer (App * app)
+push_tick_buffer (App * app, GstClockTime time)
{
app->buffer[0] = 0xf9;
- push_buffer (app, app->buffer, 1);
+ push_buffer (app, app->buffer, 1, time);
}
/* This method is called by the need-data signal callback, we feed data into the
static void
feed_data (GstElement * appsrc, guint size, App * app)
{
- long size_ev = 0;
+ GstClockTime time;
+ long size_ev;
int err;
int ret;
+poll:
snd_seq_poll_descriptors (app->seq, app->pfds, app->npfds, POLLIN);
- ret = poll (app->pfds, app->npfds, DEFAULT_POLL_TIMEOUT_MS);
- if (ret < 0) {
+ ret = poll (app->pfds, app->npfds, -1);
+ if (ret <= 0) {
GST_ERROR ("ERROR in poll: %s", strerror (errno));
gst_app_src_end_of_stream (GST_APP_SRC (appsrc));
- } else if (ret == 0) {
- push_tick_buffer (app);
} else {
do {
snd_seq_event_t *event;
break;
}
if (event) {
+ time = GST_TIMESPEC_TO_TIME (event->time.time) + app->delay;
+
+ /*
+ * Special handling is needed because decoding SND_SEQ_EVENT_TICK is
+ * not supported by the ALSA sequencer.
+ */
+ if (event->type == SND_SEQ_EVENT_TICK) {
+ push_tick_buffer (app, time);
+ schedule_tick (app);
+ break;
+ }
+
size_ev =
snd_midi_event_decode (app->parser, app->buffer, DEFAULT_BUFSIZE,
event);
/* ENOENT indicates an event that is not a MIDI message, silently skip it */
if (-ENOENT == size_ev) {
GST_WARNING ("Warning: Received non-MIDI message");
- push_tick_buffer (app);
+ goto poll;
} else {
GST_ERROR ("Error decoding event from ALSA to output: %s",
strerror (-size_ev));
break;
}
} else {
- push_buffer (app, app->buffer, size_ev);
+ push_buffer (app, app->buffer, size_ev, time);
}
}
} while (err > 0);
g_main_loop_quit (app->loop);
break;
}
+ case GST_MESSAGE_STATE_CHANGED:
+ {
+ GstState old_state, new_state;
+
+ gst_message_parse_state_changed (message, &old_state, &new_state, NULL);
+ if (new_state == GST_STATE_PLAYING) {
+ GstClockTime gst_time;
+ GstClockTime base_time;
+ GstClockTime running_time;
+ GstClockTime queue_time;
+ GstClock *clock;
+ snd_seq_queue_status_t *status;
+
+ if (app->tick == 0) {
+ start_queue_timer (app->seq, app->queue);
+ schedule_tick (app);
+ }
+
+ clock = gst_element_get_clock (GST_ELEMENT (app->appsrc));
+ gst_time = gst_clock_get_time (clock);
+ gst_object_unref (clock);
+ base_time = gst_element_get_base_time (GST_ELEMENT (app->appsrc));
+ running_time = gst_time - base_time;
+
+ snd_seq_queue_status_malloc (&status);
+ snd_seq_get_queue_status (app->seq, 0, status);
+ queue_time = GST_TIMESPEC_TO_TIME (*snd_seq_queue_status_get_real_time (status));
+ snd_seq_queue_status_free (status);
+
+ app->delay = running_time - queue_time;
+ }
+ break;
+ }
case GST_MESSAGE_EOS:
g_main_loop_quit (app->loop);
break;