gstreamer/plugins/elements/gstoutputselector.c
Sebastian Dröge 485b15d8a9 output-selector: Make access to the active pad and last buffer thread-safe
Both can be modified from different threads at the same time.
2016-01-16 10:48:02 +01:00

658 lines
19 KiB
C

/* GStreamer output selector
* Copyright (C) 2008 Nokia Corporation. (contact <stefan.kost@nokia.com>)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:element-output-selector
* @see_also: #GstOutputSelector, #GstInputSelector
*
* Direct input stream to one out of N output pads.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "gstoutputselector.h"
GST_DEBUG_CATEGORY_STATIC (output_selector_debug);
#define GST_CAT_DEFAULT output_selector_debug
static GstStaticPadTemplate gst_output_selector_sink_factory =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static GstStaticPadTemplate gst_output_selector_src_factory =
GST_STATIC_PAD_TEMPLATE ("src_%u",
GST_PAD_SRC,
GST_PAD_REQUEST,
GST_STATIC_CAPS_ANY);
#define GST_TYPE_OUTPUT_SELECTOR_PAD_NEGOTIATION_MODE (gst_output_selector_pad_negotiation_mode_get_type())
static GType
gst_output_selector_pad_negotiation_mode_get_type (void)
{
static GType pad_negotiation_mode_type = 0;
static const GEnumValue pad_negotiation_modes[] = {
{GST_OUTPUT_SELECTOR_PAD_NEGOTIATION_MODE_NONE, "None", "none"},
{GST_OUTPUT_SELECTOR_PAD_NEGOTIATION_MODE_ALL, "All", "all"},
{GST_OUTPUT_SELECTOR_PAD_NEGOTIATION_MODE_ACTIVE, "Active", "active"},
{0, NULL, NULL}
};
if (!pad_negotiation_mode_type) {
pad_negotiation_mode_type =
g_enum_register_static ("GstOutputSelectorPadNegotiationMode",
pad_negotiation_modes);
}
return pad_negotiation_mode_type;
}
enum
{
PROP_0,
PROP_ACTIVE_PAD,
PROP_RESEND_LATEST,
PROP_PAD_NEGOTIATION_MODE
};
#define DEFAULT_PAD_NEGOTIATION_MODE GST_OUTPUT_SELECTOR_PAD_NEGOTIATION_MODE_ALL
#define _do_init \
GST_DEBUG_CATEGORY_INIT (output_selector_debug, \
"output-selector", 0, "Output stream selector");
#define gst_output_selector_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstOutputSelector, gst_output_selector,
GST_TYPE_ELEMENT, _do_init);
static void gst_output_selector_dispose (GObject * object);
static void gst_output_selector_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec);
static void gst_output_selector_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec);
static GstPad *gst_output_selector_request_new_pad (GstElement * element,
GstPadTemplate * templ, const gchar * unused, const GstCaps * caps);
static void gst_output_selector_release_pad (GstElement * element,
GstPad * pad);
static GstFlowReturn gst_output_selector_chain (GstPad * pad,
GstObject * parent, GstBuffer * buf);
static GstStateChangeReturn gst_output_selector_change_state (GstElement *
element, GstStateChange transition);
static gboolean gst_output_selector_event (GstPad * pad, GstObject * parent,
GstEvent * event);
static gboolean gst_output_selector_query (GstPad * pad, GstObject * parent,
GstQuery * query);
static void gst_output_selector_switch_pad_negotiation_mode (GstOutputSelector *
sel, gint mode);
static void
gst_output_selector_class_init (GstOutputSelectorClass * klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);
gobject_class->dispose = gst_output_selector_dispose;
gobject_class->set_property = gst_output_selector_set_property;
gobject_class->get_property = gst_output_selector_get_property;
g_object_class_install_property (gobject_class, PROP_ACTIVE_PAD,
g_param_spec_object ("active-pad", "Active pad",
"Currently active src pad", GST_TYPE_PAD,
G_PARAM_READWRITE | GST_PARAM_MUTABLE_PLAYING |
G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_RESEND_LATEST,
g_param_spec_boolean ("resend-latest", "Resend latest buffer",
"Resend latest buffer after a switch to a new pad", FALSE,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_PAD_NEGOTIATION_MODE,
g_param_spec_enum ("pad-negotiation-mode", "Pad negotiation mode",
"The mode to be used for pad negotiation",
GST_TYPE_OUTPUT_SELECTOR_PAD_NEGOTIATION_MODE,
DEFAULT_PAD_NEGOTIATION_MODE,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
gst_element_class_set_static_metadata (gstelement_class, "Output selector",
"Generic", "1-to-N output stream selector",
"Stefan Kost <stefan.kost@nokia.com>");
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&gst_output_selector_sink_factory));
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&gst_output_selector_src_factory));
gstelement_class->request_new_pad =
GST_DEBUG_FUNCPTR (gst_output_selector_request_new_pad);
gstelement_class->release_pad =
GST_DEBUG_FUNCPTR (gst_output_selector_release_pad);
gstelement_class->change_state = gst_output_selector_change_state;
}
static void
gst_output_selector_init (GstOutputSelector * sel)
{
sel->sinkpad =
gst_pad_new_from_static_template (&gst_output_selector_sink_factory,
"sink");
gst_pad_set_chain_function (sel->sinkpad,
GST_DEBUG_FUNCPTR (gst_output_selector_chain));
gst_pad_set_event_function (sel->sinkpad,
GST_DEBUG_FUNCPTR (gst_output_selector_event));
gst_pad_set_query_function (sel->sinkpad,
GST_DEBUG_FUNCPTR (gst_output_selector_query));
gst_element_add_pad (GST_ELEMENT (sel), sel->sinkpad);
/* srcpad management */
sel->active_srcpad = NULL;
sel->nb_srcpads = 0;
gst_segment_init (&sel->segment, GST_FORMAT_UNDEFINED);
sel->pending_srcpad = NULL;
sel->resend_latest = FALSE;
sel->latest_buffer = NULL;
gst_output_selector_switch_pad_negotiation_mode (sel,
DEFAULT_PAD_NEGOTIATION_MODE);
}
static void
gst_output_selector_reset (GstOutputSelector * osel)
{
GST_OBJECT_LOCK (osel);
if (osel->pending_srcpad != NULL) {
gst_object_unref (osel->pending_srcpad);
osel->pending_srcpad = NULL;
}
if (osel->latest_buffer != NULL) {
gst_buffer_unref (osel->latest_buffer);
osel->latest_buffer = NULL;
}
GST_OBJECT_UNLOCK (osel);
gst_segment_init (&osel->segment, GST_FORMAT_UNDEFINED);
}
static void
gst_output_selector_dispose (GObject * object)
{
GstOutputSelector *osel = GST_OUTPUT_SELECTOR (object);
gst_output_selector_reset (osel);
G_OBJECT_CLASS (parent_class)->dispose (object);
}
static void
gst_output_selector_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstOutputSelector *sel = GST_OUTPUT_SELECTOR (object);
switch (prop_id) {
case PROP_ACTIVE_PAD:
{
GstPad *next_pad;
next_pad = g_value_get_object (value);
GST_INFO_OBJECT (sel, "Activating pad %s:%s",
GST_DEBUG_PAD_NAME (next_pad));
GST_OBJECT_LOCK (object);
if (next_pad != sel->active_srcpad) {
/* switch to new srcpad in next chain run */
if (sel->pending_srcpad != NULL) {
GST_INFO ("replacing pending switch");
gst_object_unref (sel->pending_srcpad);
}
if (next_pad)
gst_object_ref (next_pad);
sel->pending_srcpad = next_pad;
} else {
GST_INFO ("pad already active");
if (sel->pending_srcpad != NULL) {
gst_object_unref (sel->pending_srcpad);
sel->pending_srcpad = NULL;
}
}
GST_OBJECT_UNLOCK (object);
break;
}
case PROP_RESEND_LATEST:{
sel->resend_latest = g_value_get_boolean (value);
break;
}
case PROP_PAD_NEGOTIATION_MODE:{
gst_output_selector_switch_pad_negotiation_mode (sel,
g_value_get_enum (value));
break;
}
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_output_selector_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstOutputSelector *sel = GST_OUTPUT_SELECTOR (object);
switch (prop_id) {
case PROP_ACTIVE_PAD:
GST_OBJECT_LOCK (object);
g_value_set_object (value,
sel->pending_srcpad ? sel->pending_srcpad : sel->active_srcpad);
GST_OBJECT_UNLOCK (object);
break;
case PROP_RESEND_LATEST:{
GST_OBJECT_LOCK (object);
g_value_set_boolean (value, sel->resend_latest);
GST_OBJECT_UNLOCK (object);
break;
}
case PROP_PAD_NEGOTIATION_MODE:
g_value_set_enum (value, sel->pad_negotiation_mode);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static GstPad *
gst_output_selector_get_active (GstOutputSelector * sel)
{
GstPad *active = NULL;
GST_OBJECT_LOCK (sel);
if (sel->pending_srcpad)
active = gst_object_ref (sel->pending_srcpad);
else if (sel->active_srcpad)
active = gst_object_ref (sel->active_srcpad);
GST_OBJECT_UNLOCK (sel);
return active;
}
static void
gst_output_selector_switch_pad_negotiation_mode (GstOutputSelector * sel,
gint mode)
{
sel->pad_negotiation_mode = mode;
}
static gboolean
forward_sticky_events (GstPad * pad, GstEvent ** event, gpointer user_data)
{
GstPad *srcpad = GST_PAD_CAST (user_data);
gst_pad_push_event (srcpad, gst_event_ref (*event));
return TRUE;
}
static GstPad *
gst_output_selector_request_new_pad (GstElement * element,
GstPadTemplate * templ, const gchar * name, const GstCaps * caps)
{
gchar *padname;
GstPad *srcpad;
GstOutputSelector *osel;
osel = GST_OUTPUT_SELECTOR (element);
GST_DEBUG_OBJECT (osel, "requesting pad");
GST_OBJECT_LOCK (osel);
padname = g_strdup_printf ("src_%u", osel->nb_srcpads++);
srcpad = gst_pad_new_from_template (templ, padname);
GST_OBJECT_UNLOCK (osel);
gst_pad_set_active (srcpad, TRUE);
/* Forward sticky events to the new srcpad */
gst_pad_sticky_events_foreach (osel->sinkpad, forward_sticky_events, srcpad);
gst_element_add_pad (GST_ELEMENT (osel), srcpad);
/* Set the first requested src pad as active by default */
GST_OBJECT_LOCK (osel);
if (osel->active_srcpad == NULL) {
osel->active_srcpad = srcpad;
GST_OBJECT_UNLOCK (osel);
g_object_notify (G_OBJECT (osel), "active-pad");
} else {
GST_OBJECT_UNLOCK (osel);
}
g_free (padname);
return srcpad;
}
static void
gst_output_selector_release_pad (GstElement * element, GstPad * pad)
{
GstOutputSelector *osel;
osel = GST_OUTPUT_SELECTOR (element);
GST_DEBUG_OBJECT (osel, "releasing pad");
/* Disable active pad if it's the to be removed pad */
GST_OBJECT_LOCK (osel);
if (osel->active_srcpad == pad) {
osel->active_srcpad = NULL;
GST_OBJECT_UNLOCK (osel);
g_object_notify (G_OBJECT (osel), "active-pad");
} else {
GST_OBJECT_UNLOCK (osel);
}
gst_pad_set_active (pad, FALSE);
gst_element_remove_pad (GST_ELEMENT_CAST (osel), pad);
}
static gboolean
gst_output_selector_switch (GstOutputSelector * osel)
{
gboolean res = FALSE;
GstEvent *ev = NULL;
GstSegment *seg = NULL;
GstPad *active_srcpad;
/* Switch */
GST_OBJECT_LOCK (osel);
GST_INFO_OBJECT (osel, "switching to pad %" GST_PTR_FORMAT,
osel->pending_srcpad);
if (!osel->pending_srcpad) {
GST_OBJECT_UNLOCK (osel);
return TRUE;
}
if (gst_pad_is_linked (osel->pending_srcpad)) {
osel->active_srcpad = osel->pending_srcpad;
res = TRUE;
}
gst_object_unref (osel->pending_srcpad);
osel->pending_srcpad = NULL;
active_srcpad = res ? gst_object_ref (osel->active_srcpad) : NULL;
GST_OBJECT_UNLOCK (osel);
/* Send SEGMENT event and latest buffer if switching succeeded
* and we already have a valid segment configured */
if (res) {
GstBuffer *latest_buffer;
g_object_notify (G_OBJECT (osel), "active-pad");
GST_OBJECT_LOCK (osel);
latest_buffer =
osel->latest_buffer ? gst_buffer_ref (osel->latest_buffer) : NULL;
GST_OBJECT_UNLOCK (osel);
gst_pad_sticky_events_foreach (osel->sinkpad, forward_sticky_events,
active_srcpad);
/* update segment if required */
if (osel->segment.format != GST_FORMAT_UNDEFINED) {
/* Send SEGMENT to the pad we are going to switch to */
seg = &osel->segment;
/* If resending then mark segment start and position accordingly */
if (osel->resend_latest && latest_buffer &&
GST_BUFFER_TIMESTAMP_IS_VALID (latest_buffer)) {
seg->position = GST_BUFFER_TIMESTAMP (latest_buffer);
}
ev = gst_event_new_segment (seg);
if (!gst_pad_push_event (active_srcpad, ev)) {
GST_WARNING_OBJECT (osel,
"newsegment handling failed in %" GST_PTR_FORMAT, active_srcpad);
}
}
/* Resend latest buffer to newly switched pad */
if (osel->resend_latest && latest_buffer) {
GST_INFO ("resending latest buffer");
gst_pad_push (active_srcpad, latest_buffer);
} else if (latest_buffer) {
gst_buffer_unref (latest_buffer);
}
gst_object_unref (active_srcpad);
} else {
GST_WARNING_OBJECT (osel, "switch failed, pad not linked");
}
return res;
}
static GstFlowReturn
gst_output_selector_chain (GstPad * pad, GstObject * parent, GstBuffer * buf)
{
GstFlowReturn res;
GstOutputSelector *osel;
GstClockTime position, duration;
GstPad *active_srcpad;
osel = GST_OUTPUT_SELECTOR (parent);
/*
* The _switch function might push a buffer if 'resend-latest' is true.
*
* Elements/Applications (e.g. camerabin) might use pad probes to
* switch output-selector's active pad. If we simply switch and don't
* recheck any pending pad switch the following codepath could end
* up pushing a buffer on a non-active pad. This is bad.
*
* So we always should check the pending_srcpad before going further down
* the chain and pushing the new buffer
*/
while (osel->pending_srcpad) {
/* Do the switch */
gst_output_selector_switch (osel);
}
active_srcpad = gst_output_selector_get_active (osel);
if (!active_srcpad) {
GST_DEBUG_OBJECT (osel, "No active srcpad");
gst_buffer_unref (buf);
return GST_FLOW_OK;
}
GST_OBJECT_LOCK (osel);
if (osel->latest_buffer) {
gst_buffer_unref (osel->latest_buffer);
osel->latest_buffer = NULL;
}
if (osel->resend_latest) {
/* Keep reference to latest buffer to resend it after switch */
osel->latest_buffer = gst_buffer_ref (buf);
}
GST_OBJECT_UNLOCK (osel);
/* Keep track of last stop and use it in SEGMENT start after
switching to a new src pad */
position = GST_BUFFER_TIMESTAMP (buf);
if (GST_CLOCK_TIME_IS_VALID (position)) {
duration = GST_BUFFER_DURATION (buf);
if (GST_CLOCK_TIME_IS_VALID (duration)) {
position += duration;
}
GST_LOG_OBJECT (osel, "setting last stop %" GST_TIME_FORMAT,
GST_TIME_ARGS (position));
osel->segment.position = position;
}
GST_LOG_OBJECT (osel, "pushing buffer to %" GST_PTR_FORMAT, active_srcpad);
res = gst_pad_push (active_srcpad, buf);
gst_object_unref (active_srcpad);
return res;
}
static GstStateChangeReturn
gst_output_selector_change_state (GstElement * element,
GstStateChange transition)
{
GstOutputSelector *sel;
GstStateChangeReturn result;
sel = GST_OUTPUT_SELECTOR (element);
switch (transition) {
case GST_STATE_CHANGE_READY_TO_PAUSED:
break;
default:
break;
}
result = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
switch (transition) {
case GST_STATE_CHANGE_PAUSED_TO_READY:
gst_output_selector_reset (sel);
break;
default:
break;
}
return result;
}
static gboolean
gst_output_selector_forward_event (GstOutputSelector * sel, GstEvent * event)
{
gboolean res = TRUE;
GstPad *active;
switch (sel->pad_negotiation_mode) {
case GST_OUTPUT_SELECTOR_PAD_NEGOTIATION_MODE_ALL:
/* Send to all src pads */
res = gst_pad_event_default (sel->sinkpad, GST_OBJECT_CAST (sel), event);
break;
case GST_OUTPUT_SELECTOR_PAD_NEGOTIATION_MODE_NONE:
gst_event_unref (event);
break;
default:
active = gst_output_selector_get_active (sel);
if (active) {
res = gst_pad_push_event (active, event);
gst_object_unref (active);
} else {
gst_event_unref (event);
}
break;
}
return res;
}
static gboolean
gst_output_selector_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
gboolean res = TRUE;
GstOutputSelector *sel;
GstPad *active = NULL;
sel = GST_OUTPUT_SELECTOR (parent);
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_EOS:
{
res = gst_output_selector_forward_event (sel, event);
break;
}
case GST_EVENT_SEGMENT:
{
gst_event_copy_segment (event, &sel->segment);
GST_DEBUG_OBJECT (sel, "configured SEGMENT %" GST_SEGMENT_FORMAT,
&sel->segment);
/* fall through */
}
default:
{
active = gst_output_selector_get_active (sel);
if (active) {
res = gst_pad_push_event (active, event);
gst_object_unref (active);
} else {
gst_event_unref (event);
}
break;
}
}
return res;
}
static gboolean
gst_output_selector_query (GstPad * pad, GstObject * parent, GstQuery * query)
{
gboolean res = TRUE;
GstOutputSelector *sel;
GstPad *active = NULL;
sel = GST_OUTPUT_SELECTOR (parent);
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_CAPS:
{
switch (sel->pad_negotiation_mode) {
case GST_OUTPUT_SELECTOR_PAD_NEGOTIATION_MODE_ALL:
/* Send caps to all src pads */
res = gst_pad_proxy_query_caps (pad, query);
break;
case GST_OUTPUT_SELECTOR_PAD_NEGOTIATION_MODE_NONE:
res = FALSE;
break;
default:
active = gst_output_selector_get_active (sel);
if (active) {
res = gst_pad_peer_query (active, query);
gst_object_unref (active);
} else {
res = FALSE;
}
break;
}
break;
}
case GST_QUERY_DRAIN:
if (sel->latest_buffer) {
gst_buffer_unref (sel->latest_buffer);
sel->latest_buffer = NULL;
}
/* fall through */
default:
res = gst_pad_query_default (pad, parent, query);
break;
}
return res;
}