gstreamer/gst/gstmessage.c
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C

/* GStreamer
* Copyright (C) 2004 Wim Taymans <wim@fluendo.com>
*
* gstmessage.c: GstMessage subsystem
*
* 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:gstmessage
* @short_description: Lightweight objects to signal the application of
* pipeline events
* @see_also: #GstBus, #GstMiniObject, #GstElement
*
* Messages are implemented as a subclass of #GstMiniObject with a generic
* #GstStructure as the content. This allows for writing custom messages without
* requiring an API change while allowing a wide range of different types
* of messages.
*
* Messages are posted by objects in the pipeline and are passed to the
* application using the #GstBus.
*
* The basic use pattern of posting a message on a #GstBus is as follows:
* |[
* gst_bus_post (bus, gst_message_new_eos());
* ]|
*
* A #GstElement usually posts messages on the bus provided by the parent
* container using gst_element_post_message().
*
* Last reviewed on 2005-11-09 (0.9.4)
*/
#include "gst_private.h"
#include <string.h> /* memcpy */
#include "gsterror.h"
#include "gstenumtypes.h"
#include "gstinfo.h"
#include "gstmessage.h"
#include "gsttaglist.h"
#include "gstutils.h"
#include "gstquark.h"
typedef struct
{
GstMessage message;
GstStructure *structure;
} GstMessageImpl;
#define GST_MESSAGE_STRUCTURE(m) (((GstMessageImpl *)(m))->structure)
typedef struct
{
const gint type;
const gchar *name;
GQuark quark;
} GstMessageQuarks;
static GstMessageQuarks message_quarks[] = {
{GST_MESSAGE_UNKNOWN, "unknown", 0},
{GST_MESSAGE_EOS, "eos", 0},
{GST_MESSAGE_ERROR, "error", 0},
{GST_MESSAGE_WARNING, "warning", 0},
{GST_MESSAGE_INFO, "info", 0},
{GST_MESSAGE_TAG, "tag", 0},
{GST_MESSAGE_BUFFERING, "buffering", 0},
{GST_MESSAGE_STATE_CHANGED, "state-changed", 0},
{GST_MESSAGE_STATE_DIRTY, "state-dirty", 0},
{GST_MESSAGE_STEP_DONE, "step-done", 0},
{GST_MESSAGE_CLOCK_PROVIDE, "clock-provide", 0},
{GST_MESSAGE_CLOCK_LOST, "clock-lost", 0},
{GST_MESSAGE_NEW_CLOCK, "new-clock", 0},
{GST_MESSAGE_STRUCTURE_CHANGE, "structure-change", 0},
{GST_MESSAGE_STREAM_STATUS, "stream-status", 0},
{GST_MESSAGE_APPLICATION, "application", 0},
{GST_MESSAGE_ELEMENT, "element", 0},
{GST_MESSAGE_SEGMENT_START, "segment-start", 0},
{GST_MESSAGE_SEGMENT_DONE, "segment-done", 0},
{GST_MESSAGE_DURATION_CHANGED, "duration-changed", 0},
{GST_MESSAGE_LATENCY, "latency", 0},
{GST_MESSAGE_ASYNC_START, "async-start", 0},
{GST_MESSAGE_ASYNC_DONE, "async-done", 0},
{GST_MESSAGE_REQUEST_STATE, "request-state", 0},
{GST_MESSAGE_STEP_START, "step-start", 0},
{GST_MESSAGE_QOS, "qos", 0},
{GST_MESSAGE_PROGRESS, "progress", 0},
{GST_MESSAGE_TOC, "toc", 0},
{GST_MESSAGE_RESET_TIME, "reset-time", 0},
{GST_MESSAGE_STREAM_START, "stream-start", 0},
{GST_MESSAGE_NEED_CONTEXT, "need-context", 0},
{GST_MESSAGE_HAVE_CONTEXT, "have-context", 0},
{0, NULL, 0}
};
static GType _gst_message_type = 0;
GST_DEFINE_MINI_OBJECT_TYPE (GstMessage, gst_message);
void
_priv_gst_message_initialize (void)
{
gint i;
GST_CAT_INFO (GST_CAT_GST_INIT, "init messages");
/* the GstMiniObject types need to be class_ref'd once before it can be
* done from multiple threads;
* see http://bugzilla.gnome.org/show_bug.cgi?id=304551 */
gst_message_get_type ();
for (i = 0; message_quarks[i].name; i++) {
message_quarks[i].quark =
g_quark_from_static_string (message_quarks[i].name);
}
_gst_message_type = gst_message_get_type ();
}
/**
* gst_message_type_get_name:
* @type: the message type
*
* Get a printable name for the given message type. Do not modify or free.
*
* Returns: a reference to the static name of the message.
*/
const gchar *
gst_message_type_get_name (GstMessageType type)
{
gint i;
for (i = 0; message_quarks[i].name; i++) {
if (type == message_quarks[i].type)
return message_quarks[i].name;
}
return "unknown";
}
/**
* gst_message_type_to_quark:
* @type: the message type
*
* Get the unique quark for the given message type.
*
* Returns: the quark associated with the message type
*/
GQuark
gst_message_type_to_quark (GstMessageType type)
{
gint i;
for (i = 0; message_quarks[i].name; i++) {
if (type == message_quarks[i].type)
return message_quarks[i].quark;
}
return 0;
}
static void
_gst_message_free (GstMessage * message)
{
GstStructure *structure;
g_return_if_fail (message != NULL);
GST_CAT_LOG (GST_CAT_MESSAGE, "finalize message %p, %s from %s", message,
GST_MESSAGE_TYPE_NAME (message), GST_MESSAGE_SRC_NAME (message));
if (GST_MESSAGE_SRC (message)) {
gst_object_unref (GST_MESSAGE_SRC (message));
GST_MESSAGE_SRC (message) = NULL;
}
if (message->lock.p) {
GST_MESSAGE_LOCK (message);
GST_MESSAGE_SIGNAL (message);
GST_MESSAGE_UNLOCK (message);
}
structure = GST_MESSAGE_STRUCTURE (message);
if (structure) {
gst_structure_set_parent_refcount (structure, NULL);
gst_structure_free (structure);
}
g_slice_free1 (sizeof (GstMessageImpl), message);
}
static void
gst_message_init (GstMessageImpl * message, GstMessageType type,
GstObject * src);
static GstMessage *
_gst_message_copy (GstMessage * message)
{
GstMessageImpl *copy;
GstStructure *structure;
GST_CAT_LOG (GST_CAT_MESSAGE, "copy message %p, %s from %s", message,
GST_MESSAGE_TYPE_NAME (message),
GST_OBJECT_NAME (GST_MESSAGE_SRC (message)));
copy = g_slice_new0 (GstMessageImpl);
gst_message_init (copy, GST_MESSAGE_TYPE (message),
GST_MESSAGE_SRC (message));
GST_MESSAGE_TIMESTAMP (copy) = GST_MESSAGE_TIMESTAMP (message);
GST_MESSAGE_SEQNUM (copy) = GST_MESSAGE_SEQNUM (message);
structure = GST_MESSAGE_STRUCTURE (message);
if (structure) {
GST_MESSAGE_STRUCTURE (copy) = gst_structure_copy (structure);
gst_structure_set_parent_refcount (GST_MESSAGE_STRUCTURE (copy),
&copy->message.mini_object.refcount);
} else {
GST_MESSAGE_STRUCTURE (copy) = NULL;
}
return GST_MESSAGE_CAST (copy);
}
static void
gst_message_init (GstMessageImpl * message, GstMessageType type,
GstObject * src)
{
gst_mini_object_init (GST_MINI_OBJECT_CAST (message), 0, _gst_message_type,
(GstMiniObjectCopyFunction) _gst_message_copy, NULL,
(GstMiniObjectFreeFunction) _gst_message_free);
GST_MESSAGE_TYPE (message) = type;
if (src)
gst_object_ref (src);
GST_MESSAGE_SRC (message) = src;
GST_MESSAGE_TIMESTAMP (message) = GST_CLOCK_TIME_NONE;
GST_MESSAGE_SEQNUM (message) = gst_util_seqnum_next ();
}
/**
* gst_message_new_custom:
* @type: The #GstMessageType to distinguish messages
* @src: The object originating the message.
* @structure: (transfer full): the structure for the message. The message
* will take ownership of the structure.
*
* Create a new custom-typed message. This can be used for anything not
* handled by other message-specific functions to pass a message to the
* app. The structure field can be NULL.
*
* Returns: (transfer full): The new message.
*
* MT safe.
*/
GstMessage *
gst_message_new_custom (GstMessageType type, GstObject * src,
GstStructure * structure)
{
GstMessageImpl *message;
message = g_slice_new0 (GstMessageImpl);
GST_CAT_LOG (GST_CAT_MESSAGE, "source %s: creating new message %p %s",
(src ? GST_OBJECT_NAME (src) : "NULL"), message,
gst_message_type_get_name (type));
if (structure) {
/* structure must not have a parent */
if (!gst_structure_set_parent_refcount (structure,
&message->message.mini_object.refcount))
goto had_parent;
}
gst_message_init (message, type, src);
GST_MESSAGE_STRUCTURE (message) = structure;
return GST_MESSAGE_CAST (message);
/* ERRORS */
had_parent:
{
g_slice_free1 (sizeof (GstMessageImpl), message);
g_warning ("structure is already owned by another object");
return NULL;
}
}
/**
* gst_message_get_seqnum:
* @message: A #GstMessage.
*
* Retrieve the sequence number of a message.
*
* Messages have ever-incrementing sequence numbers, which may also be set
* explicitly via gst_message_set_seqnum(). Sequence numbers are typically used
* to indicate that a message corresponds to some other set of messages or
* events, for example a SEGMENT_DONE message corresponding to a SEEK event. It
* is considered good practice to make this correspondence when possible, though
* it is not required.
*
* Note that events and messages share the same sequence number incrementor;
* two events or messages will never have the same sequence number unless
* that correspondence was made explicitly.
*
* Returns: The message's sequence number.
*
* MT safe.
*/
guint32
gst_message_get_seqnum (GstMessage * message)
{
g_return_val_if_fail (GST_IS_MESSAGE (message), -1);
return GST_MESSAGE_SEQNUM (message);
}
/**
* gst_message_set_seqnum:
* @message: A #GstMessage.
* @seqnum: A sequence number.
*
* Set the sequence number of a message.
*
* This function might be called by the creator of a message to indicate that
* the message relates to other messages or events. See gst_message_get_seqnum()
* for more information.
*
* MT safe.
*/
void
gst_message_set_seqnum (GstMessage * message, guint32 seqnum)
{
g_return_if_fail (GST_IS_MESSAGE (message));
GST_MESSAGE_SEQNUM (message) = seqnum;
}
/**
* gst_message_new_eos:
* @src: (transfer none): The object originating the message.
*
* Create a new eos message. This message is generated and posted in
* the sink elements of a GstBin. The bin will only forward the EOS
* message to the application if all sinks have posted an EOS message.
*
* Returns: (transfer full): The new eos message.
*
* MT safe.
*/
GstMessage *
gst_message_new_eos (GstObject * src)
{
GstMessage *message;
message = gst_message_new_custom (GST_MESSAGE_EOS, src, NULL);
return message;
}
/**
* gst_message_new_error:
* @src: (transfer none): The object originating the message.
* @error: (transfer none): The GError for this message.
* @debug: A debugging string.
*
* Create a new error message. The message will copy @error and
* @debug. This message is posted by element when a fatal event
* occurred. The pipeline will probably (partially) stop. The application
* receiving this message should stop the pipeline.
*
* Returns: (transfer full): the new error message.
*
* MT safe.
*/
GstMessage *
gst_message_new_error (GstObject * src, GError * error, const gchar * debug)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_ERROR),
GST_QUARK (GERROR), G_TYPE_ERROR, error,
GST_QUARK (DEBUG), G_TYPE_STRING, debug, NULL);
message = gst_message_new_custom (GST_MESSAGE_ERROR, src, structure);
return message;
}
/**
* gst_message_new_warning:
* @src: (transfer none): The object originating the message.
* @error: (transfer none): The GError for this message.
* @debug: A debugging string.
*
* Create a new warning message. The message will make copies of @error and
* @debug.
*
* Returns: (transfer full): The new warning message.
*
* MT safe.
*/
GstMessage *
gst_message_new_warning (GstObject * src, GError * error, const gchar * debug)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_WARNING),
GST_QUARK (GERROR), G_TYPE_ERROR, error,
GST_QUARK (DEBUG), G_TYPE_STRING, debug, NULL);
message = gst_message_new_custom (GST_MESSAGE_WARNING, src, structure);
return message;
}
/**
* gst_message_new_info:
* @src: (transfer none): The object originating the message.
* @error: (transfer none): The GError for this message.
* @debug: A debugging string.
*
* Create a new info message. The message will make copies of @error and
* @debug.
*
* MT safe.
*
* Returns: (transfer full): the new info message.
*/
GstMessage *
gst_message_new_info (GstObject * src, GError * error, const gchar * debug)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_INFO),
GST_QUARK (GERROR), G_TYPE_ERROR, error,
GST_QUARK (DEBUG), G_TYPE_STRING, debug, NULL);
message = gst_message_new_custom (GST_MESSAGE_INFO, src, structure);
return message;
}
/**
* gst_message_new_tag:
* @src: (transfer none): The object originating the message.
* @tag_list: (transfer full): the tag list for the message.
*
* Create a new tag message. The message will take ownership of the tag list.
* The message is posted by elements that discovered a new taglist.
*
* Returns: (transfer full): the new tag message.
*
* MT safe.
*/
GstMessage *
gst_message_new_tag (GstObject * src, GstTagList * tag_list)
{
GstStructure *s;
GstMessage *message;
GValue val = G_VALUE_INIT;
g_return_val_if_fail (GST_IS_TAG_LIST (tag_list), NULL);
s = gst_structure_new_id_empty (GST_QUARK (MESSAGE_TAG));
g_value_init (&val, GST_TYPE_TAG_LIST);
g_value_take_boxed (&val, tag_list);
gst_structure_id_take_value (s, GST_QUARK (TAGLIST), &val);
message = gst_message_new_custom (GST_MESSAGE_TAG, src, s);
return message;
}
/**
* gst_message_new_buffering:
* @src: (transfer none): The object originating the message.
* @percent: The buffering percent
*
* Create a new buffering message. This message can be posted by an element that
* needs to buffer data before it can continue processing. @percent should be a
* value between 0 and 100. A value of 100 means that the buffering completed.
*
* When @percent is < 100 the application should PAUSE a PLAYING pipeline. When
* @percent is 100, the application can set the pipeline (back) to PLAYING.
* The application must be prepared to receive BUFFERING messages in the
* PREROLLING state and may only set the pipeline to PLAYING after receiving a
* message with @percent set to 100, which can happen after the pipeline
* completed prerolling.
*
* MT safe.
*
* Returns: (transfer full): The new buffering message.
*/
GstMessage *
gst_message_new_buffering (GstObject * src, gint percent)
{
GstMessage *message;
GstStructure *structure;
gint64 buffering_left;
g_return_val_if_fail (percent >= 0 && percent <= 100, NULL);
buffering_left = (percent == 100 ? 0 : -1);
structure = gst_structure_new_id (GST_QUARK (MESSAGE_BUFFERING),
GST_QUARK (BUFFER_PERCENT), G_TYPE_INT, percent,
GST_QUARK (BUFFERING_MODE), GST_TYPE_BUFFERING_MODE, GST_BUFFERING_STREAM,
GST_QUARK (AVG_IN_RATE), G_TYPE_INT, -1,
GST_QUARK (AVG_OUT_RATE), G_TYPE_INT, -1,
GST_QUARK (BUFFERING_LEFT), G_TYPE_INT64, buffering_left, NULL);
message = gst_message_new_custom (GST_MESSAGE_BUFFERING, src, structure);
return message;
}
/**
* gst_message_new_state_changed:
* @src: (transfer none): the object originating the message
* @oldstate: the previous state
* @newstate: the new (current) state
* @pending: the pending (target) state
*
* Create a state change message. This message is posted whenever an element
* changed its state.
*
* Returns: (transfer full): the new state change message.
*
* MT safe.
*/
GstMessage *
gst_message_new_state_changed (GstObject * src,
GstState oldstate, GstState newstate, GstState pending)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_STATE_CHANGED),
GST_QUARK (OLD_STATE), GST_TYPE_STATE, (gint) oldstate,
GST_QUARK (NEW_STATE), GST_TYPE_STATE, (gint) newstate,
GST_QUARK (PENDING_STATE), GST_TYPE_STATE, (gint) pending, NULL);
message = gst_message_new_custom (GST_MESSAGE_STATE_CHANGED, src, structure);
return message;
}
/**
* gst_message_new_state_dirty:
* @src: (transfer none): the object originating the message
*
* Create a state dirty message. This message is posted whenever an element
* changed its state asynchronously and is used internally to update the
* states of container objects.
*
* Returns: (transfer full): the new state dirty message.
*
* MT safe.
*/
GstMessage *
gst_message_new_state_dirty (GstObject * src)
{
GstMessage *message;
message = gst_message_new_custom (GST_MESSAGE_STATE_DIRTY, src, NULL);
return message;
}
/**
* gst_message_new_clock_provide:
* @src: (transfer none): the object originating the message.
* @clock: (transfer none): the clock it provides
* @ready: TRUE if the sender can provide a clock
*
* Create a clock provide message. This message is posted whenever an
* element is ready to provide a clock or lost its ability to provide
* a clock (maybe because it paused or became EOS).
*
* This message is mainly used internally to manage the clock
* selection.
*
* Returns: (transfer full): the new provide clock message.
*
* MT safe.
*/
GstMessage *
gst_message_new_clock_provide (GstObject * src, GstClock * clock,
gboolean ready)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_CLOCK_PROVIDE),
GST_QUARK (CLOCK), GST_TYPE_CLOCK, clock,
GST_QUARK (READY), G_TYPE_BOOLEAN, ready, NULL);
message = gst_message_new_custom (GST_MESSAGE_CLOCK_PROVIDE, src, structure);
return message;
}
/**
* gst_message_new_clock_lost:
* @src: (transfer none): the object originating the message.
* @clock: (transfer none): the clock that was lost
*
* Create a clock lost message. This message is posted whenever the
* clock is not valid anymore.
*
* If this message is posted by the pipeline, the pipeline will
* select a new clock again when it goes to PLAYING. It might therefore
* be needed to set the pipeline to PAUSED and PLAYING again.
*
* Returns: (transfer full): The new clock lost message.
*
* MT safe.
*/
GstMessage *
gst_message_new_clock_lost (GstObject * src, GstClock * clock)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_CLOCK_LOST),
GST_QUARK (CLOCK), GST_TYPE_CLOCK, clock, NULL);
message = gst_message_new_custom (GST_MESSAGE_CLOCK_LOST, src, structure);
return message;
}
/**
* gst_message_new_new_clock:
* @src: (transfer none): The object originating the message.
* @clock: (transfer none): the new selected clock
*
* Create a new clock message. This message is posted whenever the
* pipeline selects a new clock for the pipeline.
*
* Returns: (transfer full): The new new clock message.
*
* MT safe.
*/
GstMessage *
gst_message_new_new_clock (GstObject * src, GstClock * clock)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_NEW_CLOCK),
GST_QUARK (CLOCK), GST_TYPE_CLOCK, clock, NULL);
message = gst_message_new_custom (GST_MESSAGE_NEW_CLOCK, src, structure);
return message;
}
/**
* gst_message_new_structure_change:
* @src: (transfer none): The object originating the message.
* @type: The change type.
* @owner: (transfer none): The owner element of @src.
* @busy: Whether the structure change is busy.
*
* Create a new structure change message. This message is posted when the
* structure of a pipeline is in the process of being changed, for example
* when pads are linked or unlinked.
*
* @src should be the sinkpad that unlinked or linked.
*
* Returns: (transfer full): the new structure change message.
*
* MT safe.
*/
GstMessage *
gst_message_new_structure_change (GstObject * src, GstStructureChangeType type,
GstElement * owner, gboolean busy)
{
GstMessage *message;
GstStructure *structure;
g_return_val_if_fail (GST_IS_PAD (src), NULL);
/* g_return_val_if_fail (GST_PAD_DIRECTION (src) == GST_PAD_SINK, NULL); */
g_return_val_if_fail (GST_IS_ELEMENT (owner), NULL);
structure = gst_structure_new_id (GST_QUARK (MESSAGE_STRUCTURE_CHANGE),
GST_QUARK (TYPE), GST_TYPE_STRUCTURE_CHANGE_TYPE, type,
GST_QUARK (OWNER), GST_TYPE_ELEMENT, owner,
GST_QUARK (BUSY), G_TYPE_BOOLEAN, busy, NULL);
message = gst_message_new_custom (GST_MESSAGE_STRUCTURE_CHANGE, src,
structure);
return message;
}
/**
* gst_message_new_segment_start:
* @src: (transfer none): The object originating the message.
* @format: The format of the position being played
* @position: The position of the segment being played
*
* Create a new segment message. This message is posted by elements that
* start playback of a segment as a result of a segment seek. This message
* is not received by the application but is used for maintenance reasons in
* container elements.
*
* Returns: (transfer full): the new segment start message.
*
* MT safe.
*/
GstMessage *
gst_message_new_segment_start (GstObject * src, GstFormat format,
gint64 position)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_SEGMENT_START),
GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
GST_QUARK (POSITION), G_TYPE_INT64, position, NULL);
message = gst_message_new_custom (GST_MESSAGE_SEGMENT_START, src, structure);
return message;
}
/**
* gst_message_new_segment_done:
* @src: (transfer none): the object originating the message.
* @format: The format of the position being done
* @position: The position of the segment being done
*
* Create a new segment done message. This message is posted by elements that
* finish playback of a segment as a result of a segment seek. This message
* is received by the application after all elements that posted a segment_start
* have posted the segment_done.
*
* Returns: (transfer full): the new segment done message.
*
* MT safe.
*/
GstMessage *
gst_message_new_segment_done (GstObject * src, GstFormat format,
gint64 position)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_SEGMENT_DONE),
GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
GST_QUARK (POSITION), G_TYPE_INT64, position, NULL);
message = gst_message_new_custom (GST_MESSAGE_SEGMENT_DONE, src, structure);
return message;
}
/**
* gst_message_new_application:
* @src: (transfer none): the object originating the message.
* @structure: (transfer full): the structure for the message. The message
* will take ownership of the structure.
*
* Create a new application-typed message. GStreamer will never create these
* messages; they are a gift from us to you. Enjoy.
*
* Returns: (transfer full): The new application message.
*
* MT safe.
*/
GstMessage *
gst_message_new_application (GstObject * src, GstStructure * structure)
{
return gst_message_new_custom (GST_MESSAGE_APPLICATION, src, structure);
}
/**
* gst_message_new_element:
* @src: (transfer none): The object originating the message.
* @structure: (transfer full): The structure for the message. The message
* will take ownership of the structure.
*
* Create a new element-specific message. This is meant as a generic way of
* allowing one-way communication from an element to an application, for example
* "the firewire cable was unplugged". The format of the message should be
* documented in the element's documentation. The structure field can be NULL.
*
* Returns: (transfer full): The new element message.
*
* MT safe.
*/
GstMessage *
gst_message_new_element (GstObject * src, GstStructure * structure)
{
return gst_message_new_custom (GST_MESSAGE_ELEMENT, src, structure);
}
/**
* gst_message_new_duration_changed:
* @src: (transfer none): The object originating the message.
*
* Create a new duration changed message. This message is posted by elements
* that know the duration of a stream when the duration changes. This message
* is received by bins and is used to calculate the total duration of a
* pipeline. Elements may post a duration message with a duration of
* GST_CLOCK_TIME_NONE to indicate that the duration has changed and the
* cached duration should be discarded. The new duration can then be
* retrieved via a query.
*
* Returns: (transfer full): The new duration-changed message.
*
* MT safe.
*/
GstMessage *
gst_message_new_duration_changed (GstObject * src)
{
GstMessage *message;
message = gst_message_new_custom (GST_MESSAGE_DURATION_CHANGED, src,
gst_structure_new_id_empty (GST_QUARK (MESSAGE_DURATION_CHANGED)));
return message;
}
/**
* gst_message_new_async_start:
* @src: (transfer none): The object originating the message.
*
* This message is posted by elements when they start an ASYNC state change.
*
* Returns: (transfer full): The new async_start message.
*
* MT safe.
*/
GstMessage *
gst_message_new_async_start (GstObject * src)
{
GstMessage *message;
message = gst_message_new_custom (GST_MESSAGE_ASYNC_START, src, NULL);
return message;
}
/**
* gst_message_new_async_done:
* @src: (transfer none): The object originating the message.
* @running_time: the desired running_time
*
* The message is posted when elements completed an ASYNC state change.
* @running_time contains the time of the desired running_time when this
* elements goes to PLAYING. A value of #GST_CLOCK_TIME_NONE for @running_time
* means that the element has no clock interaction and thus doesn't care about
* the running_time of the pipeline.
*
* Returns: (transfer full): The new async_done message.
*
* MT safe.
*/
GstMessage *
gst_message_new_async_done (GstObject * src, GstClockTime running_time)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_ASYNC_DONE),
GST_QUARK (RUNNING_TIME), G_TYPE_UINT64, running_time, NULL);
message = gst_message_new_custom (GST_MESSAGE_ASYNC_DONE, src, structure);
return message;
}
/**
* gst_message_new_latency:
* @src: (transfer none): The object originating the message.
*
* This message can be posted by elements when their latency requirements have
* changed.
*
* Returns: (transfer full): The new latency message.
*
* MT safe.
*/
GstMessage *
gst_message_new_latency (GstObject * src)
{
GstMessage *message;
message = gst_message_new_custom (GST_MESSAGE_LATENCY, src, NULL);
return message;
}
/**
* gst_message_new_request_state:
* @src: (transfer none): the object originating the message.
* @state: The new requested state
*
* This message can be posted by elements when they want to have their state
* changed. A typical use case would be an audio server that wants to pause the
* pipeline because a higher priority stream is being played.
*
* Returns: (transfer full): the new request state message.
*
* MT safe.
*/
GstMessage *
gst_message_new_request_state (GstObject * src, GstState state)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_REQUEST_STATE),
GST_QUARK (NEW_STATE), GST_TYPE_STATE, (gint) state, NULL);
message = gst_message_new_custom (GST_MESSAGE_REQUEST_STATE, src, structure);
return message;
}
/**
* gst_message_get_structure:
* @message: The #GstMessage.
*
* Access the structure of the message.
*
* Returns: (transfer none): The structure of the message. The structure is
* still owned by the message, which means that you should not free it and
* that the pointer becomes invalid when you free the message.
*
* MT safe.
*/
const GstStructure *
gst_message_get_structure (GstMessage * message)
{
g_return_val_if_fail (GST_IS_MESSAGE (message), NULL);
return GST_MESSAGE_STRUCTURE (message);
}
/**
* gst_message_has_name:
* @message: The #GstMessage.
* @name: name to check
*
* Checks if @message has the given @name. This function is usually used to
* check the name of a custom message.
*
* Returns: %TRUE if @name matches the name of the message structure.
*/
gboolean
gst_message_has_name (GstMessage * message, const gchar * name)
{
GstStructure *structure;
g_return_val_if_fail (GST_IS_MESSAGE (message), FALSE);
structure = GST_MESSAGE_STRUCTURE (message);
if (structure == NULL)
return FALSE;
return gst_structure_has_name (structure, name);
}
/**
* gst_message_parse_tag:
* @message: A valid #GstMessage of type GST_MESSAGE_TAG.
* @tag_list: (out callee-allocates): return location for the tag-list.
*
* Extracts the tag list from the GstMessage. The tag list returned in the
* output argument is a copy; the caller must free it when done.
*
* Typical usage of this function might be:
* |[
* ...
* switch (GST_MESSAGE_TYPE (msg)) {
* case GST_MESSAGE_TAG: {
* GstTagList *tags = NULL;
*
* gst_message_parse_tag (msg, &amp;tags);
* g_print ("Got tags from element %s\n", GST_OBJECT_NAME (msg->src));
* handle_tags (tags);
* gst_tag_list_unref (tags);
* break;
* }
* ...
* }
* ...
* ]|
*
* MT safe.
*/
void
gst_message_parse_tag (GstMessage * message, GstTagList ** tag_list)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_TAG);
g_return_if_fail (tag_list != NULL);
gst_structure_id_get (GST_MESSAGE_STRUCTURE (message),
GST_QUARK (TAGLIST), GST_TYPE_TAG_LIST, tag_list, NULL);
}
/**
* gst_message_parse_buffering:
* @message: A valid #GstMessage of type GST_MESSAGE_BUFFERING.
* @percent: (out) (allow-none): Return location for the percent.
*
* Extracts the buffering percent from the GstMessage. see also
* gst_message_new_buffering().
*
* MT safe.
*/
void
gst_message_parse_buffering (GstMessage * message, gint * percent)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_BUFFERING);
if (percent)
*percent =
g_value_get_int (gst_structure_id_get_value (GST_MESSAGE_STRUCTURE
(message), GST_QUARK (BUFFER_PERCENT)));
}
/**
* gst_message_set_buffering_stats:
* @message: A valid #GstMessage of type GST_MESSAGE_BUFFERING.
* @mode: a buffering mode
* @avg_in: the average input rate
* @avg_out: the average output rate
* @buffering_left: amount of buffering time left in milliseconds
*
* Configures the buffering stats values in @message.
*/
void
gst_message_set_buffering_stats (GstMessage * message, GstBufferingMode mode,
gint avg_in, gint avg_out, gint64 buffering_left)
{
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_BUFFERING);
gst_structure_id_set (GST_MESSAGE_STRUCTURE (message),
GST_QUARK (BUFFERING_MODE), GST_TYPE_BUFFERING_MODE, mode,
GST_QUARK (AVG_IN_RATE), G_TYPE_INT, avg_in,
GST_QUARK (AVG_OUT_RATE), G_TYPE_INT, avg_out,
GST_QUARK (BUFFERING_LEFT), G_TYPE_INT64, buffering_left, NULL);
}
/**
* gst_message_parse_buffering_stats:
* @message: A valid #GstMessage of type GST_MESSAGE_BUFFERING.
* @mode: (out) (allow-none): a buffering mode, or NULL
* @avg_in: (out) (allow-none): the average input rate, or NULL
* @avg_out: (out) (allow-none): the average output rate, or NULL
* @buffering_left: (out) (allow-none): amount of buffering time left in
* milliseconds, or NULL
*
* Extracts the buffering stats values from @message.
*/
void
gst_message_parse_buffering_stats (GstMessage * message,
GstBufferingMode * mode, gint * avg_in, gint * avg_out,
gint64 * buffering_left)
{
GstStructure *structure;
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_BUFFERING);
structure = GST_MESSAGE_STRUCTURE (message);
if (mode)
*mode = (GstBufferingMode)
g_value_get_enum (gst_structure_id_get_value (structure,
GST_QUARK (BUFFERING_MODE)));
if (avg_in)
*avg_in = g_value_get_int (gst_structure_id_get_value (structure,
GST_QUARK (AVG_IN_RATE)));
if (avg_out)
*avg_out = g_value_get_int (gst_structure_id_get_value (structure,
GST_QUARK (AVG_OUT_RATE)));
if (buffering_left)
*buffering_left =
g_value_get_int64 (gst_structure_id_get_value (structure,
GST_QUARK (BUFFERING_LEFT)));
}
/**
* gst_message_parse_state_changed:
* @message: a valid #GstMessage of type GST_MESSAGE_STATE_CHANGED
* @oldstate: (out) (allow-none): the previous state, or NULL
* @newstate: (out) (allow-none): the new (current) state, or NULL
* @pending: (out) (allow-none): the pending (target) state, or NULL
*
* Extracts the old and new states from the GstMessage.
*
* Typical usage of this function might be:
* |[
* ...
* switch (GST_MESSAGE_TYPE (msg)) {
* case GST_MESSAGE_STATE_CHANGED: {
* GstState old_state, new_state;
*
* gst_message_parse_state_changed (msg, &amp;old_state, &amp;new_state, NULL);
* g_print ("Element %s changed state from %s to %s.\n",
* GST_OBJECT_NAME (msg->src),
* gst_element_state_get_name (old_state),
* gst_element_state_get_name (new_state));
* break;
* }
* ...
* }
* ...
* ]|
*
* MT safe.
*/
void
gst_message_parse_state_changed (GstMessage * message,
GstState * oldstate, GstState * newstate, GstState * pending)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STATE_CHANGED);
structure = GST_MESSAGE_STRUCTURE (message);
if (oldstate)
*oldstate = (GstState)
g_value_get_enum (gst_structure_id_get_value (structure,
GST_QUARK (OLD_STATE)));
if (newstate)
*newstate = (GstState)
g_value_get_enum (gst_structure_id_get_value (structure,
GST_QUARK (NEW_STATE)));
if (pending)
*pending = (GstState)
g_value_get_enum (gst_structure_id_get_value (structure,
GST_QUARK (PENDING_STATE)));
}
/**
* gst_message_parse_clock_provide:
* @message: A valid #GstMessage of type GST_MESSAGE_CLOCK_PROVIDE.
* @clock: (out) (allow-none) (transfer none): a pointer to hold a clock
* object, or NULL
* @ready: (out) (allow-none): a pointer to hold the ready flag, or NULL
*
* Extracts the clock and ready flag from the GstMessage.
* The clock object returned remains valid until the message is freed.
*
* MT safe.
*/
void
gst_message_parse_clock_provide (GstMessage * message, GstClock ** clock,
gboolean * ready)
{
const GValue *clock_gvalue;
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_CLOCK_PROVIDE);
structure = GST_MESSAGE_STRUCTURE (message);
clock_gvalue = gst_structure_id_get_value (structure, GST_QUARK (CLOCK));
g_return_if_fail (clock_gvalue != NULL);
g_return_if_fail (G_VALUE_TYPE (clock_gvalue) == GST_TYPE_CLOCK);
if (ready)
*ready =
g_value_get_boolean (gst_structure_id_get_value (structure,
GST_QUARK (READY)));
if (clock)
*clock = (GstClock *) g_value_get_object (clock_gvalue);
}
/**
* gst_message_parse_clock_lost:
* @message: A valid #GstMessage of type GST_MESSAGE_CLOCK_LOST.
* @clock: (out) (allow-none) (transfer none): a pointer to hold the lost clock
*
* Extracts the lost clock from the GstMessage.
* The clock object returned remains valid until the message is freed.
*
* MT safe.
*/
void
gst_message_parse_clock_lost (GstMessage * message, GstClock ** clock)
{
const GValue *clock_gvalue;
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_CLOCK_LOST);
structure = GST_MESSAGE_STRUCTURE (message);
clock_gvalue = gst_structure_id_get_value (structure, GST_QUARK (CLOCK));
g_return_if_fail (clock_gvalue != NULL);
g_return_if_fail (G_VALUE_TYPE (clock_gvalue) == GST_TYPE_CLOCK);
if (clock)
*clock = (GstClock *) g_value_get_object (clock_gvalue);
}
/**
* gst_message_parse_new_clock:
* @message: A valid #GstMessage of type GST_MESSAGE_NEW_CLOCK.
* @clock: (out) (allow-none) (transfer none): a pointer to hold the selected
* new clock
*
* Extracts the new clock from the GstMessage.
* The clock object returned remains valid until the message is freed.
*
* MT safe.
*/
void
gst_message_parse_new_clock (GstMessage * message, GstClock ** clock)
{
const GValue *clock_gvalue;
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_NEW_CLOCK);
structure = GST_MESSAGE_STRUCTURE (message);
clock_gvalue = gst_structure_id_get_value (structure, GST_QUARK (CLOCK));
g_return_if_fail (clock_gvalue != NULL);
g_return_if_fail (G_VALUE_TYPE (clock_gvalue) == GST_TYPE_CLOCK);
if (clock)
*clock = (GstClock *) g_value_get_object (clock_gvalue);
}
/**
* gst_message_parse_structure_change:
* @message: A valid #GstMessage of type GST_MESSAGE_STRUCTURE_CHANGE.
* @type: (out): A pointer to hold the change type
* @owner: (out) (allow-none) (transfer none): The owner element of the
* message source
* @busy: (out) (allow-none): a pointer to hold whether the change is in
* progress or has been completed
*
* Extracts the change type and completion status from the GstMessage.
*
* MT safe.
*/
void
gst_message_parse_structure_change (GstMessage * message,
GstStructureChangeType * type, GstElement ** owner, gboolean * busy)
{
const GValue *owner_gvalue;
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STRUCTURE_CHANGE);
structure = GST_MESSAGE_STRUCTURE (message);
owner_gvalue = gst_structure_id_get_value (structure, GST_QUARK (OWNER));
g_return_if_fail (owner_gvalue != NULL);
g_return_if_fail (G_VALUE_TYPE (owner_gvalue) == GST_TYPE_ELEMENT);
if (type)
*type = (GstStructureChangeType)
g_value_get_enum (gst_structure_id_get_value (structure,
GST_QUARK (TYPE)));
if (owner)
*owner = (GstElement *) g_value_get_object (owner_gvalue);
if (busy)
*busy =
g_value_get_boolean (gst_structure_id_get_value (structure,
GST_QUARK (BUSY)));
}
/**
* gst_message_parse_error:
* @message: A valid #GstMessage of type GST_MESSAGE_ERROR.
* @gerror: (out) (allow-none) (transfer full): location for the GError
* @debug: (out) (allow-none) (transfer full): location for the debug message,
* or NULL
*
* Extracts the GError and debug string from the GstMessage. The values returned
* in the output arguments are copies; the caller must free them when done.
*
* Typical usage of this function might be:
* |[
* ...
* switch (GST_MESSAGE_TYPE (msg)) {
* case GST_MESSAGE_ERROR: {
* GError *err = NULL;
* gchar *dbg_info = NULL;
*
* gst_message_parse_error (msg, &amp;err, &amp;dbg_info);
* g_printerr ("ERROR from element %s: %s\n",
* GST_OBJECT_NAME (msg->src), err->message);
* g_printerr ("Debugging info: %s\n", (dbg_info) ? dbg_info : "none");
* g_error_free (err);
* g_free (dbg_info);
* break;
* }
* ...
* }
* ...
* ]|
*
* MT safe.
*/
void
gst_message_parse_error (GstMessage * message, GError ** gerror, gchar ** debug)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_ERROR);
gst_structure_id_get (GST_MESSAGE_STRUCTURE (message),
GST_QUARK (GERROR), G_TYPE_ERROR, gerror,
GST_QUARK (DEBUG), G_TYPE_STRING, debug, NULL);
}
/**
* gst_message_parse_warning:
* @message: A valid #GstMessage of type GST_MESSAGE_WARNING.
* @gerror: (out) (allow-none) (transfer full): location for the GError
* @debug: (out) (allow-none) (transfer full): location for the debug message,
* or NULL
*
* Extracts the GError and debug string from the GstMessage. The values returned
* in the output arguments are copies; the caller must free them when done.
*
* MT safe.
*/
void
gst_message_parse_warning (GstMessage * message, GError ** gerror,
gchar ** debug)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_WARNING);
gst_structure_id_get (GST_MESSAGE_STRUCTURE (message),
GST_QUARK (GERROR), G_TYPE_ERROR, gerror,
GST_QUARK (DEBUG), G_TYPE_STRING, debug, NULL);
}
/**
* gst_message_parse_info:
* @message: A valid #GstMessage of type GST_MESSAGE_INFO.
* @gerror: (out) (allow-none) (transfer full): location for the GError
* @debug: (out) (allow-none) (transfer full): location for the debug message,
* or NULL
*
* Extracts the GError and debug string from the GstMessage. The values returned
* in the output arguments are copies; the caller must free them when done.
*
* MT safe.
*/
void
gst_message_parse_info (GstMessage * message, GError ** gerror, gchar ** debug)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_INFO);
gst_structure_id_get (GST_MESSAGE_STRUCTURE (message),
GST_QUARK (GERROR), G_TYPE_ERROR, gerror,
GST_QUARK (DEBUG), G_TYPE_STRING, debug, NULL);
}
/**
* gst_message_parse_segment_start:
* @message: A valid #GstMessage of type GST_MESSAGE_SEGMENT_START.
* @format: (out) (allow-none): Result location for the format, or NULL
* @position: (out) (allow-none): Result location for the position, or NULL
*
* Extracts the position and format from the segment start message.
*
* MT safe.
*/
void
gst_message_parse_segment_start (GstMessage * message, GstFormat * format,
gint64 * position)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_SEGMENT_START);
structure = GST_MESSAGE_STRUCTURE (message);
if (format)
*format = (GstFormat)
g_value_get_enum (gst_structure_id_get_value (structure,
GST_QUARK (FORMAT)));
if (position)
*position =
g_value_get_int64 (gst_structure_id_get_value (structure,
GST_QUARK (POSITION)));
}
/**
* gst_message_parse_segment_done:
* @message: A valid #GstMessage of type GST_MESSAGE_SEGMENT_DONE.
* @format: (out) (allow-none): Result location for the format, or NULL
* @position: (out) (allow-none): Result location for the position, or NULL
*
* Extracts the position and format from the segment done message.
*
* MT safe.
*/
void
gst_message_parse_segment_done (GstMessage * message, GstFormat * format,
gint64 * position)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_SEGMENT_DONE);
structure = GST_MESSAGE_STRUCTURE (message);
if (format)
*format = (GstFormat)
g_value_get_enum (gst_structure_id_get_value (structure,
GST_QUARK (FORMAT)));
if (position)
*position =
g_value_get_int64 (gst_structure_id_get_value (structure,
GST_QUARK (POSITION)));
}
/**
* gst_message_parse_async_done:
* @message: A valid #GstMessage of type GST_MESSAGE_ASYNC_DONE.
* @running_time: (out) (allow-none): Result location for the running_time or NULL
*
* Extract the running_time from the async_done message.
*
* MT safe.
*/
void
gst_message_parse_async_done (GstMessage * message, GstClockTime * running_time)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_ASYNC_DONE);
structure = GST_MESSAGE_STRUCTURE (message);
if (running_time)
*running_time =
g_value_get_uint64 (gst_structure_id_get_value (structure,
GST_QUARK (RUNNING_TIME)));
}
/**
* gst_message_parse_request_state:
* @message: A valid #GstMessage of type GST_MESSAGE_REQUEST_STATE.
* @state: (out) (allow-none): Result location for the requested state or NULL
*
* Extract the requested state from the request_state message.
*
* MT safe.
*/
void
gst_message_parse_request_state (GstMessage * message, GstState * state)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_REQUEST_STATE);
structure = GST_MESSAGE_STRUCTURE (message);
if (state)
*state = (GstState)
g_value_get_enum (gst_structure_id_get_value (structure,
GST_QUARK (NEW_STATE)));
}
/**
* gst_message_new_stream_status:
* @src: The object originating the message.
* @type: The stream status type.
* @owner: (transfer none): the owner element of @src.
*
* Create a new stream status message. This message is posted when a streaming
* thread is created/destroyed or when the state changed.
*
* Returns: (transfer full): the new stream status message.
*
* MT safe.
*/
GstMessage *
gst_message_new_stream_status (GstObject * src, GstStreamStatusType type,
GstElement * owner)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_STREAM_STATUS),
GST_QUARK (TYPE), GST_TYPE_STREAM_STATUS_TYPE, (gint) type,
GST_QUARK (OWNER), GST_TYPE_ELEMENT, owner, NULL);
message = gst_message_new_custom (GST_MESSAGE_STREAM_STATUS, src, structure);
return message;
}
/**
* gst_message_parse_stream_status:
* @message: A valid #GstMessage of type GST_MESSAGE_STREAM_STATUS.
* @type: (out): A pointer to hold the status type
* @owner: (out) (transfer none): The owner element of the message source
*
* Extracts the stream status type and owner the GstMessage. The returned
* owner remains valid for as long as the reference to @message is valid and
* should thus not be unreffed.
*
* MT safe.
*/
void
gst_message_parse_stream_status (GstMessage * message,
GstStreamStatusType * type, GstElement ** owner)
{
const GValue *owner_gvalue;
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STREAM_STATUS);
structure = GST_MESSAGE_STRUCTURE (message);
owner_gvalue = gst_structure_id_get_value (structure, GST_QUARK (OWNER));
g_return_if_fail (owner_gvalue != NULL);
if (type)
*type = (GstStreamStatusType)
g_value_get_enum (gst_structure_id_get_value (structure,
GST_QUARK (TYPE)));
if (owner)
*owner = (GstElement *) g_value_get_object (owner_gvalue);
}
/**
* gst_message_set_stream_status_object:
* @message: A valid #GstMessage of type GST_MESSAGE_STREAM_STATUS.
* @object: the object controlling the streaming
*
* Configures the object handling the streaming thread. This is usually a
* GstTask object but other objects might be added in the future.
*/
void
gst_message_set_stream_status_object (GstMessage * message,
const GValue * object)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STREAM_STATUS);
structure = GST_MESSAGE_STRUCTURE (message);
gst_structure_id_set_value (structure, GST_QUARK (OBJECT), object);
}
/**
* gst_message_get_stream_status_object:
* @message: A valid #GstMessage of type GST_MESSAGE_STREAM_STATUS.
*
* Extracts the object managing the streaming thread from @message.
*
* Returns: a GValue containing the object that manages the streaming thread.
* This object is usually of type GstTask but other types can be added in the
* future. The object remains valid as long as @message is valid.
*/
const GValue *
gst_message_get_stream_status_object (GstMessage * message)
{
const GValue *result;
GstStructure *structure;
g_return_val_if_fail (GST_IS_MESSAGE (message), NULL);
g_return_val_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STREAM_STATUS,
NULL);
structure = GST_MESSAGE_STRUCTURE (message);
result = gst_structure_id_get_value (structure, GST_QUARK (OBJECT));
return result;
}
/**
* gst_message_new_step_done:
* @src: The object originating the message.
* @format: the format of @amount
* @amount: the amount of stepped data
* @rate: the rate of the stepped amount
* @flush: is this an flushing step
* @intermediate: is this an intermediate step
* @duration: the duration of the data
* @eos: the step caused EOS
*
* This message is posted by elements when they complete a part, when @intermediate set
* to TRUE, or a complete step operation.
*
* @duration will contain the amount of time (in GST_FORMAT_TIME) of the stepped
* @amount of media in format @format.
*
* Returns: (transfer full): the new step_done message.
*
* MT safe.
*/
GstMessage *
gst_message_new_step_done (GstObject * src, GstFormat format, guint64 amount,
gdouble rate, gboolean flush, gboolean intermediate, guint64 duration,
gboolean eos)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_STEP_DONE),
GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate,
GST_QUARK (DURATION), G_TYPE_UINT64, duration,
GST_QUARK (EOS), G_TYPE_BOOLEAN, eos, NULL);
message = gst_message_new_custom (GST_MESSAGE_STEP_DONE, src, structure);
return message;
}
/**
* gst_message_parse_step_done:
* @message: A valid #GstMessage of type GST_MESSAGE_STEP_DONE.
* @format: (out) (allow-none): result location for the format
* @amount: (out) (allow-none): result location for the amount
* @rate: (out) (allow-none): result location for the rate
* @flush: (out) (allow-none): result location for the flush flag
* @intermediate: (out) (allow-none): result location for the intermediate flag
* @duration: (out) (allow-none): result location for the duration
* @eos: (out) (allow-none): result location for the EOS flag
*
* Extract the values the step_done message.
*
* MT safe.
*/
void
gst_message_parse_step_done (GstMessage * message, GstFormat * format,
guint64 * amount, gdouble * rate, gboolean * flush, gboolean * intermediate,
guint64 * duration, gboolean * eos)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STEP_DONE);
structure = GST_MESSAGE_STRUCTURE (message);
gst_structure_id_get (structure,
GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate,
GST_QUARK (DURATION), G_TYPE_UINT64, duration,
GST_QUARK (EOS), G_TYPE_BOOLEAN, eos, NULL);
}
/**
* gst_message_new_step_start:
* @src: The object originating the message.
* @active: if the step is active or queued
* @format: the format of @amount
* @amount: the amount of stepped data
* @rate: the rate of the stepped amount
* @flush: is this an flushing step
* @intermediate: is this an intermediate step
*
* This message is posted by elements when they accept or activate a new step
* event for @amount in @format.
*
* @active is set to FALSE when the element accepted the new step event and has
* queued it for execution in the streaming threads.
*
* @active is set to TRUE when the element has activated the step operation and
* is now ready to start executing the step in the streaming thread. After this
* message is emitted, the application can queue a new step operation in the
* element.
*
* Returns: (transfer full): The new step_start message.
*
* MT safe.
*/
GstMessage *
gst_message_new_step_start (GstObject * src, gboolean active, GstFormat format,
guint64 amount, gdouble rate, gboolean flush, gboolean intermediate)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_STEP_START),
GST_QUARK (ACTIVE), G_TYPE_BOOLEAN, active,
GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
message = gst_message_new_custom (GST_MESSAGE_STEP_START, src, structure);
return message;
}
/**
* gst_message_parse_step_start:
* @message: A valid #GstMessage of type GST_MESSAGE_STEP_DONE.
* @active: (out) (allow-none): result location for the active flag
* @format: (out) (allow-none): result location for the format
* @amount: (out) (allow-none): result location for the amount
* @rate: (out) (allow-none): result location for the rate
* @flush: (out) (allow-none): result location for the flush flag
* @intermediate: (out) (allow-none): result location for the intermediate flag
*
* Extract the values from step_start message.
*
* MT safe.
*/
void
gst_message_parse_step_start (GstMessage * message, gboolean * active,
GstFormat * format, guint64 * amount, gdouble * rate, gboolean * flush,
gboolean * intermediate)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STEP_START);
structure = GST_MESSAGE_STRUCTURE (message);
gst_structure_id_get (structure,
GST_QUARK (ACTIVE), G_TYPE_BOOLEAN, active,
GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
}
/**
* gst_message_new_qos:
* @src: The object originating the message.
* @live: if the message was generated by a live element
* @running_time: the running time of the buffer that generated the message
* @stream_time: the stream time of the buffer that generated the message
* @timestamp: the timestamps of the buffer that generated the message
* @duration: the duration of the buffer that generated the message
*
* A QOS message is posted on the bus whenever an element decides to drop a
* buffer because of QoS reasons or whenever it changes its processing strategy
* because of QoS reasons (quality adjustments such as processing at lower
* accuracy).
*
* This message can be posted by an element that performs synchronisation against the
* clock (live) or it could be dropped by an element that performs QoS because of QOS
* events received from a downstream element (!live).
*
* @running_time, @stream_time, @timestamp, @duration should be set to the
* respective running-time, stream-time, timestamp and duration of the (dropped)
* buffer that generated the QoS event. Values can be left to
* GST_CLOCK_TIME_NONE when unknown.
*
* Returns: (transfer full): The new qos message.
*
* MT safe.
*/
GstMessage *
gst_message_new_qos (GstObject * src, gboolean live, guint64 running_time,
guint64 stream_time, guint64 timestamp, guint64 duration)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_QOS),
GST_QUARK (LIVE), G_TYPE_BOOLEAN, live,
GST_QUARK (RUNNING_TIME), G_TYPE_UINT64, running_time,
GST_QUARK (STREAM_TIME), G_TYPE_UINT64, stream_time,
GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp,
GST_QUARK (DURATION), G_TYPE_UINT64, duration,
GST_QUARK (JITTER), G_TYPE_INT64, (gint64) 0,
GST_QUARK (PROPORTION), G_TYPE_DOUBLE, (gdouble) 1.0,
GST_QUARK (QUALITY), G_TYPE_INT, (gint) 1000000,
GST_QUARK (FORMAT), GST_TYPE_FORMAT, GST_FORMAT_UNDEFINED,
GST_QUARK (PROCESSED), G_TYPE_UINT64, (guint64) - 1,
GST_QUARK (DROPPED), G_TYPE_UINT64, (guint64) - 1, NULL);
message = gst_message_new_custom (GST_MESSAGE_QOS, src, structure);
return message;
}
/**
* gst_message_set_qos_values:
* @message: A valid #GstMessage of type GST_MESSAGE_QOS.
* @jitter: The difference of the running-time against the deadline.
* @proportion: Long term prediction of the ideal rate relative to normal rate
* to get optimal quality.
* @quality: An element dependent integer value that specifies the current
* quality level of the element. The default maximum quality is 1000000.
*
* Set the QoS values that have been calculated/analysed from the QoS data
*
* MT safe.
*/
void
gst_message_set_qos_values (GstMessage * message, gint64 jitter,
gdouble proportion, gint quality)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_QOS);
structure = GST_MESSAGE_STRUCTURE (message);
gst_structure_id_set (structure,
GST_QUARK (JITTER), G_TYPE_INT64, jitter,
GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
GST_QUARK (QUALITY), G_TYPE_INT, quality, NULL);
}
/**
* gst_message_set_qos_stats:
* @message: A valid #GstMessage of type GST_MESSAGE_QOS.
* @format: Units of the 'processed' and 'dropped' fields. Video sinks and video
* filters will use GST_FORMAT_BUFFERS (frames). Audio sinks and audio filters
* will likely use GST_FORMAT_DEFAULT (samples).
* @processed: Total number of units correctly processed since the last state
* change to READY or a flushing operation.
* @dropped: Total number of units dropped since the last state change to READY
* or a flushing operation.
*
* Set the QoS stats representing the history of the current continuous pipeline
* playback period.
*
* When @format is @GST_FORMAT_UNDEFINED both @dropped and @processed are
* invalid. Values of -1 for either @processed or @dropped mean unknown values.
*
* MT safe.
*/
void
gst_message_set_qos_stats (GstMessage * message, GstFormat format,
guint64 processed, guint64 dropped)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_QOS);
structure = GST_MESSAGE_STRUCTURE (message);
gst_structure_id_set (structure,
GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
GST_QUARK (PROCESSED), G_TYPE_UINT64, processed,
GST_QUARK (DROPPED), G_TYPE_UINT64, dropped, NULL);
}
/**
* gst_message_parse_qos:
* @message: A valid #GstMessage of type GST_MESSAGE_QOS.
* @live: (out) (allow-none): if the message was generated by a live element
* @running_time: (out) (allow-none): the running time of the buffer that
* generated the message
* @stream_time: (out) (allow-none): the stream time of the buffer that
* generated the message
* @timestamp: (out) (allow-none): the timestamps of the buffer that
* generated the message
* @duration: (out) (allow-none): the duration of the buffer that
* generated the message
*
* Extract the timestamps and live status from the QoS message.
*
* The returned values give the running_time, stream_time, timestamp and
* duration of the dropped buffer. Values of GST_CLOCK_TIME_NONE mean unknown
* values.
*
* MT safe.
*/
void
gst_message_parse_qos (GstMessage * message, gboolean * live,
guint64 * running_time, guint64 * stream_time, guint64 * timestamp,
guint64 * duration)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_QOS);
structure = GST_MESSAGE_STRUCTURE (message);
gst_structure_id_get (structure,
GST_QUARK (LIVE), G_TYPE_BOOLEAN, live,
GST_QUARK (RUNNING_TIME), G_TYPE_UINT64, running_time,
GST_QUARK (STREAM_TIME), G_TYPE_UINT64, stream_time,
GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp,
GST_QUARK (DURATION), G_TYPE_UINT64, duration, NULL);
}
/**
* gst_message_parse_qos_values:
* @message: A valid #GstMessage of type GST_MESSAGE_QOS.
* @jitter: (out) (allow-none): The difference of the running-time against
* the deadline.
* @proportion: (out) (allow-none): Long term prediction of the ideal rate
* relative to normal rate to get optimal quality.
* @quality: (out) (allow-none): An element dependent integer value that
* specifies the current quality level of the element. The default
* maximum quality is 1000000.
*
* Extract the QoS values that have been calculated/analysed from the QoS data
*
* MT safe.
*/
void
gst_message_parse_qos_values (GstMessage * message, gint64 * jitter,
gdouble * proportion, gint * quality)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_QOS);
structure = GST_MESSAGE_STRUCTURE (message);
gst_structure_id_get (structure,
GST_QUARK (JITTER), G_TYPE_INT64, jitter,
GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
GST_QUARK (QUALITY), G_TYPE_INT, quality, NULL);
}
/**
* gst_message_parse_qos_stats:
* @message: A valid #GstMessage of type GST_MESSAGE_QOS.
* @format: (out) (allow-none): Units of the 'processed' and 'dropped' fields.
* Video sinks and video filters will use GST_FORMAT_BUFFERS (frames).
* Audio sinks and audio filters will likely use GST_FORMAT_DEFAULT
* (samples).
* @processed: (out) (allow-none): Total number of units correctly processed
* since the last state change to READY or a flushing operation.
* @dropped: (out) (allow-none): Total number of units dropped since the last
* state change to READY or a flushing operation.
*
* Extract the QoS stats representing the history of the current continuous
* pipeline playback period.
*
* When @format is @GST_FORMAT_UNDEFINED both @dropped and @processed are
* invalid. Values of -1 for either @processed or @dropped mean unknown values.
*
* MT safe.
*/
void
gst_message_parse_qos_stats (GstMessage * message, GstFormat * format,
guint64 * processed, guint64 * dropped)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_QOS);
structure = GST_MESSAGE_STRUCTURE (message);
gst_structure_id_get (structure,
GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
GST_QUARK (PROCESSED), G_TYPE_UINT64, processed,
GST_QUARK (DROPPED), G_TYPE_UINT64, dropped, NULL);
}
/**
* gst_message_new_progress:
* @src: The object originating the message.
* @type: a #GstProgressType
* @code: a progress code
* @text: free, user visible text describing the progress
*
* Progress messages are posted by elements when they use an asynchronous task
* to perform actions triggered by a state change.
*
* @code contains a well defined string describing the action.
* @test should contain a user visible string detailing the current action.
*
* Returns: (transfer full): The new qos message.
*/
GstMessage *
gst_message_new_progress (GstObject * src, GstProgressType type,
const gchar * code, const gchar * text)
{
GstMessage *message;
GstStructure *structure;
gint percent = 100, timeout = -1;
g_return_val_if_fail (code != NULL, NULL);
g_return_val_if_fail (text != NULL, NULL);
if (type == GST_PROGRESS_TYPE_START || type == GST_PROGRESS_TYPE_CONTINUE)
percent = 0;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_PROGRESS),
GST_QUARK (TYPE), GST_TYPE_PROGRESS_TYPE, type,
GST_QUARK (CODE), G_TYPE_STRING, code,
GST_QUARK (TEXT), G_TYPE_STRING, text,
GST_QUARK (PERCENT), G_TYPE_INT, percent,
GST_QUARK (TIMEOUT), G_TYPE_INT, timeout, NULL);
message = gst_message_new_custom (GST_MESSAGE_PROGRESS, src, structure);
return message;
}
/**
* gst_message_parse_progress:
* @message: A valid #GstMessage of type GST_MESSAGE_PROGRESS.
* @type: (out) (allow-none): location for the type
* @code: (out) (allow-none) (transfer full): location for the code
* @text: (out) (allow-none) (transfer full): location for the text
*
* Parses the progress @type, @code and @text.
*/
void
gst_message_parse_progress (GstMessage * message, GstProgressType * type,
gchar ** code, gchar ** text)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_PROGRESS);
structure = GST_MESSAGE_STRUCTURE (message);
gst_structure_id_get (structure,
GST_QUARK (TYPE), GST_TYPE_PROGRESS_TYPE, type,
GST_QUARK (CODE), G_TYPE_STRING, code,
GST_QUARK (TEXT), G_TYPE_STRING, text, NULL);
}
/**
* gst_message_new_toc:
* @src: the object originating the message.
* @toc: (transfer none): #GstToc structure for the message.
* @updated: whether TOC was updated or not.
*
* Create a new TOC message. The message is posted by elements
* that discovered or updated a TOC.
*
* Returns: (transfer full): a new TOC message.
*
* MT safe.
*/
GstMessage *
gst_message_new_toc (GstObject * src, GstToc * toc, gboolean updated)
{
GstStructure *toc_struct;
g_return_val_if_fail (toc != NULL, NULL);
toc_struct = gst_structure_new_id (GST_QUARK (MESSAGE_TOC),
GST_QUARK (TOC), GST_TYPE_TOC, toc,
GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
return gst_message_new_custom (GST_MESSAGE_TOC, src, toc_struct);
}
/**
* gst_message_parse_toc:
* @message: a valid #GstMessage of type GST_MESSAGE_TOC.
* @toc: (out) (transfer full): return location for the TOC.
* @updated: (out): return location for the updated flag.
*
* Extract the TOC from the #GstMessage. The TOC returned in the
* output argument is a copy; the caller must free it with
* gst_toc_unref() when done.
*
* MT safe.
*/
void
gst_message_parse_toc (GstMessage * message, GstToc ** toc, gboolean * updated)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_TOC);
g_return_if_fail (toc != NULL);
gst_structure_id_get (GST_MESSAGE_STRUCTURE (message),
GST_QUARK (TOC), GST_TYPE_TOC, toc,
GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
}
/**
* gst_message_new_reset_time:
* @src: (transfer none): The object originating the message.
* @running_time: the requested running-time
*
* This message is posted when the pipeline running-time should be reset to
* @running_time, like after a flushing seek.
*
* Returns: (transfer full): The new reset_time message.
*
* MT safe.
*/
GstMessage *
gst_message_new_reset_time (GstObject * src, GstClockTime running_time)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_RESET_TIME),
GST_QUARK (RUNNING_TIME), G_TYPE_UINT64, running_time, NULL);
message = gst_message_new_custom (GST_MESSAGE_RESET_TIME, src, structure);
return message;
}
/**
* gst_message_parse_reset_time:
* @message: A valid #GstMessage of type GST_MESSAGE_RESET_TIME.
* @running_time: (out) (allow-none): Result location for the running_time or
* NULL
*
* Extract the running-time from the RESET_TIME message.
*
* MT safe.
*/
void
gst_message_parse_reset_time (GstMessage * message, GstClockTime * running_time)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_RESET_TIME);
structure = GST_MESSAGE_STRUCTURE (message);
if (running_time)
*running_time =
g_value_get_uint64 (gst_structure_id_get_value (structure,
GST_QUARK (RUNNING_TIME)));
}
/**
* gst_message_new_stream_start:
* @src: (transfer none): The object originating the message.
*
* Create a new stream_start message. This message is generated and posted in
* the sink elements of a GstBin. The bin will only forward the STREAM_START
* message to the application if all sinks have posted an STREAM_START message.
*
* Returns: (transfer full): The new stream_start message.
*
* MT safe.
*/
GstMessage *
gst_message_new_stream_start (GstObject * src)
{
GstMessage *message;
GstStructure *s;
s = gst_structure_new_id_empty (GST_QUARK (MESSAGE_STREAM_START));
message = gst_message_new_custom (GST_MESSAGE_STREAM_START, src, s);
return message;
}
/**
* gst_message_set_group_id:
* @message: the message
* @group_id: the group id
*
* Sets the group id on the stream-start message.
*
* All streams that have the same group id are supposed to be played
* together, i.e. all streams inside a container file should have the
* same group id but different stream ids. The group id should change
* each time the stream is started, resulting in different group ids
* each time a file is played for example.
*
* MT safe.
*
* Since: 1.2
*/
void
gst_message_set_group_id (GstMessage * message, guint group_id)
{
GstStructure *structure;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STREAM_START);
g_return_if_fail (gst_message_is_writable (message));
structure = GST_MESSAGE_STRUCTURE (message);
gst_structure_id_set (structure, GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id,
NULL);
}
/**
* gst_message_parse_group_id:
* @message: A valid #GstMessage of type GST_MESSAGE_STREAM_START.
* @group_id: (out) (allow-none): Result location for the group id or
* NULL
*
* Extract the group from the STREAM_START message.
*
* Returns: %TRUE if the message had a group id set, %FALSE otherwise
*
* MT safe.
*
* Since: 1.2
*/
gboolean
gst_message_parse_group_id (GstMessage * message, guint * group_id)
{
GstStructure *structure;
const GValue *v;
g_return_val_if_fail (GST_IS_MESSAGE (message), FALSE);
g_return_val_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STREAM_START,
FALSE);
if (!group_id)
return TRUE;
structure = GST_MESSAGE_STRUCTURE (message);
v = gst_structure_id_get_value (structure, GST_QUARK (GROUP_ID));
if (!v)
return FALSE;
*group_id = g_value_get_uint (v);
return TRUE;
}
/**
* gst_message_new_need_context:
* @src: (transfer none): The object originating the message.
* @context_type: The context type that is needed
*
* This message is posted when an element needs a specific #GstContext.
*
* Returns: (transfer full): The new need-context message.
*
* MT safe.
*
* Since: 1.2
*/
GstMessage *
gst_message_new_need_context (GstObject * src, const gchar * context_type)
{
GstMessage *message;
GstStructure *structure;
g_return_val_if_fail (context_type != NULL, NULL);
structure = gst_structure_new_id (GST_QUARK (MESSAGE_NEED_CONTEXT),
GST_QUARK (CONTEXT_TYPE), G_TYPE_STRING, context_type, NULL);
message = gst_message_new_custom (GST_MESSAGE_NEED_CONTEXT, src, structure);
return message;
}
/**
* gst_message_parse_context_type:
* @message: a GST_MESSAGE_NEED_CONTEXT type message
* @context_type: (out) (allow-none): the context type, or NULL
*
* Parse a context type from an existing GST_MESSAGE_NEED_CONTEXT message.
*
* Returns: a #gboolean indicating if the parsing succeeded.
*
* Since: 1.2
*/
gboolean
gst_message_parse_context_type (GstMessage * message,
const gchar ** context_type)
{
GstStructure *structure;
const GValue *value;
g_return_val_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_NEED_CONTEXT,
FALSE);
structure = GST_MESSAGE_STRUCTURE (message);
if (context_type) {
value = gst_structure_id_get_value (structure, GST_QUARK (CONTEXT_TYPE));
*context_type = g_value_get_string (value);
}
return TRUE;
}
/**
* gst_message_new_have_context:
* @src: (transfer none): The object originating the message.
* @context: (transfer full): the context
*
* This message is posted when an element has a new local #GstContext.
*
* Returns: (transfer full): The new have-context message.
*
* MT safe.
*
* Since: 1.2
*/
GstMessage *
gst_message_new_have_context (GstObject * src, GstContext * context)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_new_id (GST_QUARK (MESSAGE_HAVE_CONTEXT),
GST_QUARK (CONTEXT), GST_TYPE_CONTEXT, context, NULL);
message = gst_message_new_custom (GST_MESSAGE_HAVE_CONTEXT, src, structure);
gst_context_unref (context);
return message;
}
/**
* gst_message_parse_have_context:
* @message: A valid #GstMessage of type GST_MESSAGE_HAVE_CONTEXT.
* @context: (out) (transfer full) (allow-none): Result location for the
* context or NULL
*
* Extract the context from the HAVE_CONTEXT message.
*
* MT safe.
*
* Since: 1.2
*/
void
gst_message_parse_have_context (GstMessage * message, GstContext ** context)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_HAVE_CONTEXT);
if (context)
gst_structure_id_get (GST_MESSAGE_STRUCTURE (message),
GST_QUARK (CONTEXT), GST_TYPE_CONTEXT, context, NULL);
}