2 * Copyright (C) 2013 Stefan Sauer <ensonic@users.sf.net>
4 * gstlatency.c: tracing module that logs processing latency stats
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
23 * @short_description: log processing latency stats
25 * A tracing module that determines src-to-sink latencies by injecting custom
26 * events at sources and process them at sinks.
28 /* TODO(ensonic): if there are two sources feeding into a mixer/muxer and later
29 * we fan-out with tee and have two sinks, each sink would get all two events,
30 * the later event would overwrite the former. Unfortunately when the buffer
31 * arrives on the sink we don't know to which event it correlates. Better would
32 * be to use the buffer meta in 1.0 instead of the event. Or we track a min/max
40 #include "gstlatency.h"
42 GST_DEBUG_CATEGORY_STATIC (gst_latency_debug);
43 #define GST_CAT_DEFAULT gst_latency_debug
46 GST_DEBUG_CATEGORY_INIT (gst_latency_debug, "latency", 0, "latency tracer");
47 #define gst_latency_tracer_parent_class parent_class
48 G_DEFINE_TYPE_WITH_CODE (GstLatencyTracer, gst_latency_tracer, GST_TYPE_TRACER,
51 static GQuark latency_probe_id;
52 static GQuark latency_probe_pad;
53 static GQuark latency_probe_ts;
58 * Get the element/bin owning the pad.
64 * out: the element that contains the peer of the proxy
67 * out: the bin owning the ghostpad
69 /* TODO(ensonic): gst_pad_get_parent_element() would not work here, should we
70 * add this as new api, e.g. gst_pad_find_parent_element();
73 get_real_pad_parent (GstPad * pad)
80 parent = GST_OBJECT_PARENT (pad);
82 /* if parent of pad is a ghost-pad, then pad is a proxy_pad */
83 if (parent && GST_IS_GHOST_PAD (parent)) {
84 pad = GST_PAD_CAST (parent);
85 parent = GST_OBJECT_PARENT (pad);
87 return GST_ELEMENT_CAST (parent);
92 static void gst_latency_tracer_invoke (GstTracer * obj, GstTracerHookId id,
93 GstTracerMessageId mid, va_list var_args);
96 gst_latency_tracer_class_init (GstLatencyTracerClass * klass)
98 GstTracerClass *gst_tracer_class = GST_TRACER_CLASS (klass);
100 gst_tracer_class->invoke = gst_latency_tracer_invoke;
102 latency_probe_id = g_quark_from_static_string ("latency_probe.id");
103 latency_probe_pad = g_quark_from_static_string ("latency_probe.pad");
104 latency_probe_ts = g_quark_from_static_string ("latency_probe.ts");
108 gst_latency_tracer_init (GstLatencyTracer * self)
110 g_object_set (self, "mask", GST_TRACER_HOOK_BUFFERS | GST_TRACER_HOOK_EVENTS,
117 log_latency (const GstStructure * data, GstPad * sink_pad, guint64 sink_ts)
123 gst_structure_id_get (data,
124 latency_probe_pad, GST_TYPE_PAD, &src_pad,
125 latency_probe_ts, G_TYPE_UINT64, &src_ts, NULL);
127 src = g_strdup_printf ("%s_%s", GST_DEBUG_PAD_NAME (src_pad));
128 sink = g_strdup_printf ("%s_%s", GST_DEBUG_PAD_NAME (sink_pad));
130 /* TODO(ensonic): report format is still unstable */
131 gst_tracer_log_trace (gst_structure_new ("latency",
132 "src", G_TYPE_STRING, src,
133 "sink", G_TYPE_STRING, sink,
134 "time", G_TYPE_UINT64, GST_CLOCK_DIFF (src_ts, sink_ts), NULL));
140 send_latency_probe (GstLatencyTracer * self, GstElement * parent, GstPad * pad,
143 if (parent && (!GST_IS_BIN (parent)) &&
144 GST_OBJECT_FLAG_IS_SET (parent, GST_ELEMENT_FLAG_SOURCE)) {
145 GstEvent *latency_probe = gst_event_new_custom (GST_EVENT_CUSTOM_DOWNSTREAM,
146 gst_structure_new_id (latency_probe_id,
147 latency_probe_pad, GST_TYPE_PAD, pad,
148 latency_probe_ts, G_TYPE_UINT64, ts,
150 gst_pad_push_event (pad, latency_probe);
155 do_push_buffer_pre (GstLatencyTracer * self, va_list var_args)
157 guint64 ts = va_arg (var_args, guint64);
158 GstPad *pad = va_arg (var_args, GstPad *);
159 GstElement *parent = get_real_pad_parent (pad);
161 send_latency_probe (self, parent, pad, ts);
165 do_pull_buffer_pre (GstLatencyTracer * self, va_list var_args)
167 guint64 ts = va_arg (var_args, guint64);
168 GstPad *pad = va_arg (var_args, GstPad *);
169 GstPad *peer_pad = GST_PAD_PEER (pad);
170 GstElement *parent = get_real_pad_parent (peer_pad);
172 send_latency_probe (self, parent, peer_pad, ts);
176 calculate_latency (GstLatencyTracer * self, GstElement * parent, GstPad * pad,
179 if (parent && (!GST_IS_BIN (parent)) &&
180 GST_OBJECT_FLAG_IS_SET (parent, GST_ELEMENT_FLAG_SINK)) {
181 GstEvent *ev = g_object_get_qdata ((GObject *) pad, latency_probe_id);
183 log_latency (gst_event_get_structure (ev), pad, ts);
184 gst_event_unref (ev);
189 do_push_buffer_post (GstLatencyTracer * self, va_list var_args)
191 guint64 ts = va_arg (var_args, guint64);
192 GstPad *pad = va_arg (var_args, GstPad *);
193 GstPad *peer_pad = GST_PAD_PEER (pad);
194 GstElement *parent = get_real_pad_parent (peer_pad);
196 calculate_latency (self, parent, peer_pad, ts);
200 do_pull_range_post (GstLatencyTracer * self, va_list var_args)
202 guint64 ts = va_arg (var_args, guint64);
203 GstPad *pad = va_arg (var_args, GstPad *);
204 GstElement *parent = get_real_pad_parent (pad);
206 calculate_latency (self, parent, pad, ts);
210 do_push_event_pre (GstLatencyTracer * self, va_list var_args)
212 G_GNUC_UNUSED guint64 ts = va_arg (var_args, guint64);
213 GstPad *pad = va_arg (var_args, GstPad *);
214 GstEvent *ev = va_arg (var_args, GstEvent *);
215 GstPad *peer_pad = GST_PAD_PEER (pad);
216 GstElement *parent = get_real_pad_parent (peer_pad);
218 if (parent && (!GST_IS_BIN (parent)) &&
219 GST_OBJECT_FLAG_IS_SET (parent, GST_ELEMENT_FLAG_SINK)) {
220 if (GST_EVENT_TYPE (ev) == GST_EVENT_CUSTOM_DOWNSTREAM) {
221 const GstStructure *data = gst_event_get_structure (ev);
223 if (gst_structure_get_name_id (data) == latency_probe_id) {
224 /* store event and calculate latency when the buffer that follows
225 * has been processed */
226 g_object_set_qdata ((GObject *) peer_pad, latency_probe_id,
234 gst_latency_tracer_invoke (GstTracer * obj, GstTracerHookId hid,
235 GstTracerMessageId mid, va_list var_args)
237 GstLatencyTracer *self = GST_LATENCY_TRACER_CAST (obj);
240 case GST_TRACER_MESSAGE_ID_PAD_PUSH_PRE:
241 case GST_TRACER_MESSAGE_ID_PAD_PUSH_LIST_PRE:
242 do_push_buffer_pre (self, var_args);
244 case GST_TRACER_MESSAGE_ID_PAD_PUSH_POST:
245 case GST_TRACER_MESSAGE_ID_PAD_PUSH_LIST_POST:
246 do_push_buffer_post (self, var_args);
248 case GST_TRACER_MESSAGE_ID_PAD_PULL_RANGE_PRE:
249 do_pull_buffer_pre (self, var_args);
251 case GST_TRACER_MESSAGE_ID_PAD_PULL_RANGE_POST:
252 do_pull_range_post (self, var_args);
254 case GST_TRACER_MESSAGE_ID_PAD_PUSH_EVENT_PRE:
255 do_push_event_pre (self, var_args);