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.
22 * SECTION:element-latencytracer
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. This elements supports tracing
27 * the entire pipeline latency and per element latency. By default, only
28 * pipeline latency is traced. The 'flags' parameter can be used to enabled
32 * GST_TRACERS="latency(flags=pipeline+element)" GST_DEBUG=GST_TRACER:7 ./...
35 /* TODO(ensonic): if there are two sources feeding into a mixer/muxer and later
36 * we fan-out with tee and have two sinks, each sink would get all two events,
37 * the later event would overwrite the former. Unfortunately when the buffer
38 * arrives on the sink we don't know to which event it correlates. Better would
39 * be to use the buffer meta in 1.0 instead of the event. Or we track a min/max
47 #include "gstlatency.h"
49 GST_DEBUG_CATEGORY_STATIC (gst_latency_debug);
50 #define GST_CAT_DEFAULT gst_latency_debug
53 GST_DEBUG_CATEGORY_INIT (gst_latency_debug, "latency", 0, "latency tracer");
54 #define gst_latency_tracer_parent_class parent_class
55 G_DEFINE_TYPE_WITH_CODE (GstLatencyTracer, gst_latency_tracer, GST_TYPE_TRACER,
58 static void latency_query_stack_destroy (gpointer data);
60 static GQuark latency_probe_id;
61 static GQuark sub_latency_probe_id;
62 static GQuark latency_probe_pad;
63 static GQuark latency_probe_element;
64 static GQuark latency_probe_element_id;
65 static GQuark latency_probe_ts;
66 static GQuark drop_sub_latency_quark;
68 static GstTracerRecord *tr_latency;
69 static GstTracerRecord *tr_element_latency;
70 static GstTracerRecord *tr_element_reported_latency;
72 /* The private stack for each thread */
73 static GPrivate latency_query_stack =
74 G_PRIVATE_INIT (latency_query_stack_destroy);
76 struct LatencyQueryTableValue
78 GstElement *peer_element;
86 * Get the element/bin owning the pad.
92 * out: the element that contains the peer of the proxy
95 * out: the bin owning the ghostpad
97 /* TODO(ensonic): gst_pad_get_parent_element() would not work here, should we
98 * add this as new api, e.g. gst_pad_find_parent_element();
101 get_real_pad_parent (GstPad * pad)
108 parent = GST_OBJECT_PARENT (pad);
110 /* if parent of pad is a ghost-pad, then pad is a proxy_pad */
111 if (parent && GST_IS_GHOST_PAD (parent)) {
112 pad = GST_PAD_CAST (parent);
113 parent = GST_OBJECT_PARENT (pad);
115 return GST_ELEMENT_CAST (parent);
119 latency_query_table_value_destroy (gpointer data)
121 struct LatencyQueryTableValue *v = data;
123 /* Unref the element */
124 if (v->peer_element) {
125 gst_object_unref (v->peer_element);
126 v->peer_element = NULL;
129 /* Destroy the structure */
134 latency_query_stack_destroy (gpointer data)
136 GQueue *queue = data;
137 g_queue_free_full (queue, latency_query_table_value_destroy);
141 local_latency_query_stack_get (void)
143 /* Make sure the stack exists */
144 GQueue *stack = g_private_get (&latency_query_stack);
146 g_private_set (&latency_query_stack, g_queue_new ());
147 stack = g_private_get (&latency_query_stack);
154 static struct LatencyQueryTableValue *
155 local_latency_query_stack_pop (void)
157 GQueue *stack = local_latency_query_stack_get ();
158 return g_queue_pop_tail (stack);
162 local_latency_query_stack_push (struct LatencyQueryTableValue *value)
164 GQueue *stack = local_latency_query_stack_get ();
165 g_queue_push_tail (stack, value);
171 log_latency (const GstStructure * data, GstElement * sink_parent,
172 GstPad * sink_pad, guint64 sink_ts)
175 const char *src, *element_src, *id_element_src;
177 gchar *sink, *element_sink, *id_element_sink;
179 value = gst_structure_id_get_value (data, latency_probe_ts);
180 src_ts = g_value_get_uint64 (value);
182 value = gst_structure_id_get_value (data, latency_probe_pad);
183 src = g_value_get_string (value);
185 value = gst_structure_id_get_value (data, latency_probe_element);
186 element_src = g_value_get_string (value);
188 value = gst_structure_id_get_value (data, latency_probe_element_id);
189 id_element_src = g_value_get_string (value);
191 id_element_sink = g_strdup_printf ("%p", sink_parent);
192 element_sink = gst_element_get_name (sink_parent);
193 sink = gst_pad_get_name (sink_pad);
194 gst_tracer_record_log (tr_latency, id_element_src, element_src, src,
195 id_element_sink, element_sink, sink, GST_CLOCK_DIFF (src_ts, sink_ts),
198 g_free (element_sink);
199 g_free (id_element_sink);
203 log_element_latency (const GstStructure * data, GstElement * parent,
204 GstPad * pad, guint64 sink_ts)
207 gchar *pad_name, *element_name, *element_id;
210 element_id = g_strdup_printf ("%p", parent);
211 element_name = gst_element_get_name (parent);
212 pad_name = gst_pad_get_name (pad);
216 value = gst_structure_id_get_value (data, latency_probe_ts);
217 src_ts = g_value_get_uint64 (value);
219 gst_tracer_record_log (tr_element_latency, element_id, element_name, pad_name,
220 GST_CLOCK_DIFF (src_ts, sink_ts), sink_ts);
223 g_free (element_name);
228 send_latency_probe (GstLatencyTracer * self, GstElement * parent, GstPad * pad,
231 GstPad *peer_pad = GST_PAD_PEER (pad);
232 GstElement *peer_parent = get_real_pad_parent (peer_pad);
234 /* allow for non-parented pads to send latency probes as used in e.g.
235 * rtspsrc for TCP connections */
236 if (peer_pad && (!parent || (!GST_IS_BIN (parent)))) {
237 gchar *pad_name, *element_name, *element_id;
238 GstEvent *latency_probe;
240 if (self->flags & GST_LATENCY_TRACER_FLAG_PIPELINE &&
241 GST_OBJECT_FLAG_IS_SET (parent, GST_ELEMENT_FLAG_SOURCE)) {
242 element_id = g_strdup_printf ("%p", parent);
243 element_name = gst_element_get_name (parent);
244 pad_name = gst_pad_get_name (pad);
246 GST_DEBUG ("%s: Sending latency event", pad_name);
248 latency_probe = gst_event_new_custom (GST_EVENT_CUSTOM_DOWNSTREAM,
249 gst_structure_new_id (latency_probe_id,
250 latency_probe_element_id, G_TYPE_STRING, element_id,
251 latency_probe_element, G_TYPE_STRING, element_name,
252 latency_probe_pad, G_TYPE_STRING, pad_name,
253 latency_probe_ts, G_TYPE_UINT64, ts, NULL));
255 g_free (element_name);
257 gst_pad_push_event (pad, latency_probe);
260 if (self->flags & GST_LATENCY_TRACER_FLAG_ELEMENT) {
261 GST_DEBUG ("%s_%s: Sending sub-latency event", GST_DEBUG_PAD_NAME (pad));
263 element_id = g_strdup_printf ("%p", peer_parent);
264 element_name = gst_element_get_name (peer_parent);
265 pad_name = gst_pad_get_name (peer_pad);
266 latency_probe = gst_event_new_custom (GST_EVENT_CUSTOM_DOWNSTREAM,
267 gst_structure_new_id (sub_latency_probe_id,
268 latency_probe_element, G_TYPE_STRING, element_id,
269 latency_probe_element, G_TYPE_STRING, element_name,
270 latency_probe_pad, G_TYPE_STRING, pad_name,
271 latency_probe_ts, G_TYPE_UINT64, ts, NULL));
272 gst_pad_push_event (pad, latency_probe);
274 g_free (element_name);
281 calculate_latency (GstElement * parent, GstPad * pad, guint64 ts)
283 GstElement *peer_parent = get_real_pad_parent (GST_PAD_PEER (pad));
285 if (parent && (!GST_IS_BIN (parent)) &&
286 (!GST_OBJECT_FLAG_IS_SET (parent, GST_ELEMENT_FLAG_SOURCE))) {
289 /* FIXME unsafe use of peer */
290 if (GST_OBJECT_FLAG_IS_SET (peer_parent, GST_ELEMENT_FLAG_SINK)) {
291 GST_DEBUG ("%s_%s: Should log full lantency now",
292 GST_DEBUG_PAD_NAME (pad));
293 ev = g_object_get_qdata ((GObject *) pad, latency_probe_id);
295 g_object_set_qdata ((GObject *) pad, latency_probe_id, NULL);
296 log_latency (gst_event_get_structure (ev), peer_parent,
297 GST_PAD_PEER (pad), ts);
298 gst_event_unref (ev);
302 GST_DEBUG ("%s_%s: Should log sub lantency now", GST_DEBUG_PAD_NAME (pad));
303 ev = g_object_get_qdata ((GObject *) pad, sub_latency_probe_id);
305 g_object_set_qdata ((GObject *) pad, sub_latency_probe_id, NULL);
306 log_element_latency (gst_event_get_structure (ev), parent, pad, ts);
307 gst_event_unref (ev);
313 do_push_buffer_pre (GstTracer * tracer, guint64 ts, GstPad * pad)
315 GstLatencyTracer *self = (GstLatencyTracer *) tracer;
316 GstElement *parent = get_real_pad_parent (pad);
318 send_latency_probe (self, parent, pad, ts);
319 calculate_latency (parent, pad, ts);
323 do_pull_range_pre (GstTracer * tracer, guint64 ts, GstPad * pad)
325 GstLatencyTracer *self = (GstLatencyTracer *) tracer;
326 GstPad *peer_pad = GST_PAD_PEER (pad);
327 GstElement *parent = get_real_pad_parent (peer_pad);
329 send_latency_probe (self, parent, peer_pad, ts);
333 do_pull_range_post (GstTracer * self, guint64 ts, GstPad * pad)
335 GstElement *parent = get_real_pad_parent (pad);
337 calculate_latency (parent, pad, ts);
340 static GstPadProbeReturn
341 do_drop_sub_latency_event (GstPad * pad, GstPadProbeInfo * info,
344 GstEvent *ev = info->data;
345 GstPadProbeReturn ret = GST_PAD_PROBE_OK;
347 if (GST_EVENT_TYPE (ev) == GST_EVENT_CUSTOM_DOWNSTREAM) {
348 const GstStructure *data = gst_event_get_structure (ev);
350 if (gst_structure_get_name_id (data) == sub_latency_probe_id) {
352 /* FIXME unsafe peer pad usage */
353 gchar *pad_name = g_strdup_printf ("%s_%s",
354 GST_DEBUG_PAD_NAME (GST_PAD_PEER (pad)));
356 value = gst_structure_id_get_value (data, latency_probe_pad);
357 if (!g_str_equal (g_value_get_string (value), pad_name)) {
358 GST_DEBUG ("%s: Dropping sub-latency event", pad_name);
359 ret = GST_PAD_PROBE_DROP;
370 do_push_event_pre (GstTracer * self, guint64 ts, GstPad * pad, GstEvent * ev)
372 GstElement *parent = get_real_pad_parent (pad);
373 GstPad *peer_pad = GST_PAD_PEER (pad);
374 GstElement *peer_parent = get_real_pad_parent (peer_pad);
376 if (parent && (!GST_IS_BIN (parent)) &&
377 (!GST_OBJECT_FLAG_IS_SET (parent, GST_ELEMENT_FLAG_SOURCE)) &&
378 GST_EVENT_TYPE (ev) == GST_EVENT_CUSTOM_DOWNSTREAM) {
379 const GstStructure *data = gst_event_get_structure (ev);
381 /* if not set yet, add a pad probe that prevents sub-latency event from
383 if (gst_structure_get_name_id (data) == latency_probe_id) {
385 if (!g_object_get_qdata ((GObject *) pad, drop_sub_latency_quark)) {
386 GST_DEBUG ("%s_%s: Adding pad probe to drop sub-latency event",
387 GST_DEBUG_PAD_NAME (pad));
388 gst_pad_add_probe (pad, GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM,
389 do_drop_sub_latency_event, NULL, NULL);
390 g_object_set_qdata ((GObject *) pad, drop_sub_latency_quark,
394 /* FIXME unsafe peer access */
395 if (GST_OBJECT_FLAG_IS_SET (peer_parent, GST_ELEMENT_FLAG_SINK)) {
396 GST_DEBUG ("%s_%s: Storing latency event", GST_DEBUG_PAD_NAME (pad));
398 /* store event so that we can calculate latency when the buffer that
399 * follows has been processed */
400 if (!g_object_get_qdata ((GObject *) pad, latency_probe_id))
401 g_object_set_qdata ((GObject *) pad, latency_probe_id,
406 if (gst_structure_get_name_id (data) == sub_latency_probe_id) {
408 gchar *pad_name = g_strdup_printf ("%s_%s",
409 GST_DEBUG_PAD_NAME (peer_pad));
411 value = gst_structure_id_get_value (data, latency_probe_pad);
413 if (!g_str_equal (g_value_get_string (value), pad_name)) {
414 GST_DEBUG ("%s: Storing sub-latency event", pad_name);
415 if (!g_object_get_qdata ((GObject *) pad, sub_latency_probe_id))
416 g_object_set_qdata ((GObject *) pad, sub_latency_probe_id,
426 do_query_post (GstLatencyTracer * tracer, GstClockTime ts, GstPad * pad,
427 GstQuery * query, gboolean res)
429 /* Only check for latency queries if flag is enabled */
430 if ((tracer->flags & GST_LATENCY_TRACER_FLAG_REPORTED_ELEMENT) &&
431 (GST_QUERY_TYPE (query) == GST_QUERY_LATENCY)) {
433 guint64 min = 0, max = 0, min_prev = 0, max_prev = 0;
434 gchar *element_name, *element_id;
435 struct LatencyQueryTableValue *value;
436 GstElement *element = get_real_pad_parent (pad);
437 GstElement *peer_element = get_real_pad_parent (GST_PAD_PEER (pad));
439 /* Parse the query */
440 gst_query_parse_latency (query, &live, &min, &max);
443 value = local_latency_query_stack_pop ();
444 while (value && value->peer_element == element) {
445 min_prev = MAX (value->min, min_prev);
446 max_prev = MAX (value->max, max_prev);
447 value = local_latency_query_stack_pop ();
451 value = g_new0 (struct LatencyQueryTableValue, 1);
452 value->peer_element = gst_object_ref (peer_element);
455 local_latency_query_stack_push (value);
457 /* Get the pad name */
458 element_id = g_strdup_printf ("%p", element);
459 element_name = gst_element_get_name (element);
461 /* Log reported latency */
462 gst_tracer_record_log (tr_element_reported_latency, element_id,
463 element_name, live, GST_CLOCK_DIFF (min_prev, min),
464 GST_CLOCK_DIFF (max_prev, max), ts);
467 g_free (element_name);
475 gst_latency_tracer_constructed (GObject * object)
477 GstLatencyTracer *self = GST_LATENCY_TRACER (object);
479 GstStructure *params_struct = NULL;
481 g_object_get (self, "params", ¶ms, NULL);
486 tmp = g_strdup_printf ("latency,%s", params);
487 params_struct = gst_structure_from_string (tmp, NULL);
490 /* Read the flags if available */
492 const gchar *flags = gst_structure_get_string (params_struct, "flags");
497 GStrv split = g_strsplit (flags, "+", -1);
500 for (i = 0; split[i]; i++) {
501 if (g_str_equal (split[i], "pipeline"))
502 self->flags |= GST_LATENCY_TRACER_FLAG_PIPELINE;
503 else if (g_str_equal (split[i], "element"))
504 self->flags |= GST_LATENCY_TRACER_FLAG_ELEMENT;
505 else if (g_str_equal (split[i], "reported"))
506 self->flags |= GST_LATENCY_TRACER_FLAG_REPORTED_ELEMENT;
508 GST_WARNING ("Invalid latency tracer flags %s", split[i]);
519 gst_latency_tracer_class_init (GstLatencyTracerClass * klass)
521 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
523 gobject_class->constructed = gst_latency_tracer_constructed;
525 latency_probe_id = g_quark_from_static_string ("latency_probe.id");
526 sub_latency_probe_id = g_quark_from_static_string ("sub_latency_probe.id");
527 latency_probe_pad = g_quark_from_static_string ("latency_probe.pad");
528 latency_probe_element = g_quark_from_static_string ("latency_probe.element");
529 latency_probe_element_id =
530 g_quark_from_static_string ("latency_probe.element_id");
531 latency_probe_ts = g_quark_from_static_string ("latency_probe.ts");
532 drop_sub_latency_quark =
533 g_quark_from_static_string ("drop_sub_latency.quark");
535 /* announce trace formats */
537 tr_latency = gst_tracer_record_new ("latency.class",
538 "src-element-id", GST_TYPE_STRUCTURE, gst_structure_new ("scope",
539 "type", G_TYPE_GTYPE, G_TYPE_STRING,
540 "related-to", GST_TYPE_TRACER_VALUE_SCOPE,
541 GST_TRACER_VALUE_SCOPE_ELEMENT,
543 "src-element", GST_TYPE_STRUCTURE, gst_structure_new ("scope",
544 "type", G_TYPE_GTYPE, G_TYPE_STRING,
545 "related-to", GST_TYPE_TRACER_VALUE_SCOPE,
546 GST_TRACER_VALUE_SCOPE_ELEMENT,
548 "src", GST_TYPE_STRUCTURE, gst_structure_new ("scope",
549 "type", G_TYPE_GTYPE, G_TYPE_STRING,
550 "related-to", GST_TYPE_TRACER_VALUE_SCOPE, GST_TRACER_VALUE_SCOPE_PAD,
552 "sink-element-id", GST_TYPE_STRUCTURE, gst_structure_new ("scope",
553 "type", G_TYPE_GTYPE, G_TYPE_STRING,
554 "related-to", GST_TYPE_TRACER_VALUE_SCOPE,
555 GST_TRACER_VALUE_SCOPE_ELEMENT,
557 "sink-element", GST_TYPE_STRUCTURE, gst_structure_new ("scope",
558 "type", G_TYPE_GTYPE, G_TYPE_STRING,
559 "related-to", GST_TYPE_TRACER_VALUE_SCOPE,
560 GST_TRACER_VALUE_SCOPE_ELEMENT,
562 "sink", GST_TYPE_STRUCTURE, gst_structure_new ("scope",
563 "type", G_TYPE_GTYPE, G_TYPE_STRING,
564 "related-to", GST_TYPE_TRACER_VALUE_SCOPE, GST_TRACER_VALUE_SCOPE_PAD,
566 "time", GST_TYPE_STRUCTURE, gst_structure_new ("value",
567 "type", G_TYPE_GTYPE, G_TYPE_UINT64,
568 "description", G_TYPE_STRING,
569 "time it took for the buffer to go from src to sink ns",
570 "min", G_TYPE_UINT64, G_GUINT64_CONSTANT (0),
571 "max", G_TYPE_UINT64, G_MAXUINT64,
573 "ts", GST_TYPE_STRUCTURE, gst_structure_new ("value",
574 "type", G_TYPE_GTYPE, G_TYPE_UINT64,
575 "description", G_TYPE_STRING, "ts when the latency has been logged",
576 "min", G_TYPE_UINT64, G_GUINT64_CONSTANT (0),
577 "max", G_TYPE_UINT64, G_MAXUINT64,
581 tr_element_latency = gst_tracer_record_new ("element-latency.class",
582 "element-id", GST_TYPE_STRUCTURE, gst_structure_new ("scope",
583 "type", G_TYPE_GTYPE, G_TYPE_STRING,
584 "related-to", GST_TYPE_TRACER_VALUE_SCOPE,
585 GST_TRACER_VALUE_SCOPE_ELEMENT,
587 "element", GST_TYPE_STRUCTURE, gst_structure_new ("scope",
588 "type", G_TYPE_GTYPE, G_TYPE_STRING,
589 "related-to", GST_TYPE_TRACER_VALUE_SCOPE,
590 GST_TRACER_VALUE_SCOPE_ELEMENT,
592 "src", GST_TYPE_STRUCTURE, gst_structure_new ("scope",
593 "type", G_TYPE_GTYPE, G_TYPE_STRING,
594 "related-to", GST_TYPE_TRACER_VALUE_SCOPE, GST_TRACER_VALUE_SCOPE_PAD,
596 "time", GST_TYPE_STRUCTURE, gst_structure_new ("value",
597 "type", G_TYPE_GTYPE, G_TYPE_UINT64,
598 "description", G_TYPE_STRING,
599 "time it took for the buffer to go from src to sink ns",
600 "min", G_TYPE_UINT64, G_GUINT64_CONSTANT (0),
601 "max", G_TYPE_UINT64, G_MAXUINT64,
603 "ts", GST_TYPE_STRUCTURE, gst_structure_new ("value",
604 "type", G_TYPE_GTYPE, G_TYPE_UINT64,
605 "description", G_TYPE_STRING, "ts when the latency has been logged",
606 "min", G_TYPE_UINT64, G_GUINT64_CONSTANT (0),
607 "max", G_TYPE_UINT64, G_MAXUINT64,
612 tr_element_reported_latency = gst_tracer_record_new (
613 "element-reported-latency.class",
614 "element-id", GST_TYPE_STRUCTURE, gst_structure_new ("scope",
615 "type", G_TYPE_GTYPE, G_TYPE_STRING,
616 "related-to", GST_TYPE_TRACER_VALUE_SCOPE,
617 GST_TRACER_VALUE_SCOPE_ELEMENT,
619 "element", GST_TYPE_STRUCTURE, gst_structure_new ("scope",
620 "type", G_TYPE_GTYPE, G_TYPE_STRING,
621 "related-to", GST_TYPE_TRACER_VALUE_SCOPE,
622 GST_TRACER_VALUE_SCOPE_ELEMENT,
624 "live", GST_TYPE_STRUCTURE, gst_structure_new ("value",
625 "type", G_TYPE_GTYPE, G_TYPE_BOOLEAN,
626 "description", G_TYPE_STRING,
627 "wether the it is a live stream or not",
629 "min", GST_TYPE_STRUCTURE, gst_structure_new ("value",
630 "type", G_TYPE_GTYPE, G_TYPE_UINT64,
631 "description", G_TYPE_STRING,
632 "the minimum reported latency",
633 "min", G_TYPE_UINT64, G_GUINT64_CONSTANT (0),
634 "max", G_TYPE_UINT64, G_MAXUINT64,
636 "max", GST_TYPE_STRUCTURE, gst_structure_new ("value",
637 "type", G_TYPE_GTYPE, G_TYPE_UINT64,
638 "description", G_TYPE_STRING, "the maximum reported latency",
639 "min", G_TYPE_UINT64, G_GUINT64_CONSTANT (0),
640 "max", G_TYPE_UINT64, G_MAXUINT64,
642 "ts", GST_TYPE_STRUCTURE, gst_structure_new ("value",
643 "type", G_TYPE_GTYPE, G_TYPE_UINT64,
644 "description", G_TYPE_STRING, "ts when the latency has been reported",
645 "min", G_TYPE_UINT64, G_GUINT64_CONSTANT (0),
646 "max", G_TYPE_UINT64, G_MAXUINT64,
653 gst_latency_tracer_init (GstLatencyTracer * self)
655 GstTracer *tracer = GST_TRACER (self);
657 /* only trace pipeline latency by default */
658 self->flags = GST_LATENCY_TRACER_FLAG_PIPELINE;
660 /* in push mode, pre/post will be called before/after the peer chain
661 * function has been called. For this reaosn, we only use -pre to avoid
662 * accounting for the processing time of the peer element (the sink) */
663 gst_tracing_register_hook (tracer, "pad-push-pre",
664 G_CALLBACK (do_push_buffer_pre));
665 gst_tracing_register_hook (tracer, "pad-push-list-pre",
666 G_CALLBACK (do_push_buffer_pre));
668 /* while in pull mode, pre/post will happen before and after the upstream
669 * pull_range call is made, so it already only account for the upstream
670 * processing time. As a side effect, in pull mode, we can measure the
671 * source processing latency, while in push mode, we can't */
672 gst_tracing_register_hook (tracer, "pad-pull-range-pre",
673 G_CALLBACK (do_pull_range_pre));
674 gst_tracing_register_hook (tracer, "pad-pull-range-post",
675 G_CALLBACK (do_pull_range_post));
677 gst_tracing_register_hook (tracer, "pad-push-event-pre",
678 G_CALLBACK (do_push_event_pre));
680 /* Add pad query post hook to get the reported per-element latency */
681 gst_tracing_register_hook (tracer, "pad-query-post",
682 G_CALLBACK (do_query_post));