gstreamer/gst/gstmessage.c
2009-05-11 23:53:52 +02:00

1571 lines
45 KiB
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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, 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:
*
* <example>
* <title>Posting a #GstMessage</title>
* <programlisting>
* gst_bus_post (bus, gst_message_new_eos());
* </programlisting>
* </example>
*
* 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"
#define GST_MESSAGE_SEQNUM(e) ((GstMessage*)e)->abidata.ABI.seqnum
static void gst_message_finalize (GstMessage * message);
static GstMessage *_gst_message_copy (GstMessage * message);
static GstMiniObjectClass *parent_class = NULL;
void
_gst_message_initialize (void)
{
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 */
g_type_class_ref (gst_message_get_type ());
}
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, "duration", 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},
{0, NULL, 0}
};
/**
* 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;
}
#define _do_init \
{ \
gint i; \
\
for (i = 0; message_quarks[i].name; i++) { \
message_quarks[i].quark = \
g_quark_from_static_string (message_quarks[i].name); \
} \
}
G_DEFINE_TYPE_WITH_CODE (GstMessage, gst_message, GST_TYPE_MINI_OBJECT,
_do_init);
static void
gst_message_class_init (GstMessageClass * klass)
{
parent_class = g_type_class_peek_parent (klass);
klass->mini_object_class.copy = (GstMiniObjectCopyFunction) _gst_message_copy;
klass->mini_object_class.finalize =
(GstMiniObjectFinalizeFunction) gst_message_finalize;
}
static void
gst_message_init (GstMessage * message)
{
GST_CAT_LOG (GST_CAT_MESSAGE, "new message %p", message);
GST_MESSAGE_TIMESTAMP (message) = GST_CLOCK_TIME_NONE;
}
static void
gst_message_finalize (GstMessage * message)
{
g_return_if_fail (message != NULL);
GST_CAT_LOG (GST_CAT_MESSAGE, "finalize message %p", message);
if (GST_MESSAGE_SRC (message)) {
gst_object_unref (GST_MESSAGE_SRC (message));
GST_MESSAGE_SRC (message) = NULL;
}
if (message->lock) {
GST_MESSAGE_LOCK (message);
GST_MESSAGE_SIGNAL (message);
GST_MESSAGE_UNLOCK (message);
}
if (message->structure) {
gst_structure_set_parent_refcount (message->structure, NULL);
gst_structure_free (message->structure);
}
GST_MINI_OBJECT_CLASS (parent_class)->finalize (GST_MINI_OBJECT (message));
}
static GstMessage *
_gst_message_copy (GstMessage * message)
{
GstMessage *copy;
GST_CAT_LOG (GST_CAT_MESSAGE, "copy message %p", message);
copy = (GstMessage *) gst_mini_object_new (GST_TYPE_MESSAGE);
/* FIXME, need to copy relevant data from the miniobject. */
//memcpy (copy, message, sizeof (GstMessage));
GST_MESSAGE_GET_LOCK (copy) = GST_MESSAGE_GET_LOCK (message);
GST_MESSAGE_COND (copy) = GST_MESSAGE_COND (message);
GST_MESSAGE_TYPE (copy) = GST_MESSAGE_TYPE (message);
GST_MESSAGE_TIMESTAMP (copy) = GST_MESSAGE_TIMESTAMP (message);
GST_MESSAGE_SEQNUM (copy) = GST_MESSAGE_SEQNUM (message);
if (GST_MESSAGE_SRC (message)) {
GST_MESSAGE_SRC (copy) = gst_object_ref (GST_MESSAGE_SRC (message));
}
if (message->structure) {
copy->structure = gst_structure_copy (message->structure);
gst_structure_set_parent_refcount (copy->structure,
&copy->mini_object.refcount);
}
return copy;
}
/**
* gst_message_new_custom:
* @type: The #GstMessageType to distinguish messages
* @src: The object originating the message.
* @structure: 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: The new message.
*
* MT safe.
*/
GstMessage *
gst_message_new_custom (GstMessageType type, GstObject * src,
GstStructure * structure)
{
GstMessage *message;
message = (GstMessage *) gst_mini_object_new (GST_TYPE_MESSAGE);
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));
message->type = type;
if (src)
gst_object_ref (src);
message->src = src;
if (structure) {
gst_structure_set_parent_refcount (structure,
&message->mini_object.refcount);
}
message->structure = structure;
GST_MESSAGE_SEQNUM (message) = gst_util_seqnum_next ();
return message;
}
/**
* 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 not have the same sequence number unless
* that correspondence was made explicitly.
*
* Returns: The message's sequence number.
*
* Since: 0.10.22
*
* 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.
*
* Since: 0.10.22
*
* 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: 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: 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: The object originating the message.
* @error: 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
* occured. The pipeline will probably (partially) stop. The application
* receiving this message should stop the pipeline.
*
* Returns: 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_empty_new ("GstMessageError");
gst_structure_id_set (structure,
GST_QUARK (GERROR), GST_TYPE_G_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: The object originating the message.
* @error: The GError for this message.
* @debug: A debugging string.
*
* Create a new warning message. The message will make copies of @error and
* @debug.
*
* Returns: 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_empty_new ("GstMessageWarning");
gst_structure_id_set (structure,
GST_QUARK (GERROR), GST_TYPE_G_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: The object originating the message.
* @error: The GError for this message.
* @debug: A debugging string.
*
* Create a new info message. The message will make copies of @error and
* @debug.
*
* Returns: The new info message.
*
* Since: 0.10.12
*
* MT safe.
*/
GstMessage *
gst_message_new_info (GstObject * src, GError * error, const gchar * debug)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_empty_new ("GstMessageInfo");
gst_structure_id_set (structure, GST_QUARK (GERROR), GST_TYPE_G_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: The object originating the message.
* @tag_list: 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: The new tag message.
*
* MT safe.
*/
GstMessage *
gst_message_new_tag (GstObject * src, GstTagList * tag_list)
{
GstMessage *message;
g_return_val_if_fail (GST_IS_STRUCTURE (tag_list), NULL);
message =
gst_message_new_custom (GST_MESSAGE_TAG, src, (GstStructure *) tag_list);
return message;
}
/**
* gst_message_new_buffering:
* @src: 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.
*
* Returns: The new buffering message.
*
* Since: 0.10.11
*
* MT safe.
*/
GstMessage *
gst_message_new_buffering (GstObject * src, gint percent)
{
GstMessage *message;
GstStructure *structure;
g_return_val_if_fail (percent >= 0 && percent <= 100, NULL);
structure = gst_structure_empty_new ("GstMessageBuffering");
gst_structure_id_set (structure,
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, G_GINT64_CONSTANT (-1),
GST_QUARK (ESTIMATED_TOTAL), G_TYPE_INT64, G_GINT64_CONSTANT (-1), NULL);
message = gst_message_new_custom (GST_MESSAGE_BUFFERING, src, structure);
return message;
}
/**
* gst_message_new_state_changed:
* @src: 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: 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_empty_new ("GstMessageState");
gst_structure_id_set (structure,
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: 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: 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: The object originating the message.
* @clock: 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: 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_empty_new ("GstMessageClockProvide");
gst_structure_id_set (structure,
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: The object originating the message.
* @clock: 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: The new clock lost message.
*
* MT safe.
*/
GstMessage *
gst_message_new_clock_lost (GstObject * src, GstClock * clock)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_empty_new ("GstMessageClockLost");
gst_structure_id_set (structure,
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: The object originating the message.
* @clock: the new selected clock
*
* Create a new clock message. This message is posted whenever the
* pipeline selectes a new clock for the pipeline.
*
* Returns: The new new clock message.
*
* MT safe.
*/
GstMessage *
gst_message_new_new_clock (GstObject * src, GstClock * clock)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_empty_new ("GstMessageNewClock");
gst_structure_id_set (structure,
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: The object originating the message.
* @type: The change type.
* @owner: 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 srcpad that unlinked or linked.
*
* Returns: The new structure change message.
*
* MT safe.
*
* Since: 0.10.22.
*/
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_SRC, NULL);
g_return_val_if_fail (GST_IS_ELEMENT (owner), NULL);
structure = gst_structure_empty_new ("GstMessageStructureChange");
gst_structure_id_set (structure,
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: 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: 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_empty_new ("GstMessageSegmentStart");
gst_structure_id_set (structure,
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: 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: 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_empty_new ("GstMessageSegmentDone");
gst_structure_id_set (structure,
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: The object originating the message.
* @structure: 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: 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: The object originating the message.
* @structure: 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: 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:
* @src: The object originating the message.
* @format: The format of the duration
* @duration: The new duration
*
* Create a new duration message. This message is posted by elements that
* know the duration of a stream in a specific format. 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: The new duration message.
*
* MT safe.
*/
GstMessage *
gst_message_new_duration (GstObject * src, GstFormat format, gint64 duration)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_empty_new ("GstMessageDuration");
gst_structure_id_set (structure,
GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
GST_QUARK (DURATION), G_TYPE_INT64, duration, NULL);
message = gst_message_new_custom (GST_MESSAGE_DURATION, src, structure);
return message;
}
/**
* gst_message_new_async_start:
* @src: The object originating the message.
* @new_base_time: if a new base_time should be set on the element
*
* This message is posted by elements when they start an ASYNC state change.
* @new_base_time is set to TRUE when the element lost its state when it was
* PLAYING.
*
* Returns: The new async_start message.
*
* MT safe.
*
* Since: 0.10.13
*/
GstMessage *
gst_message_new_async_start (GstObject * src, gboolean new_base_time)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_empty_new ("GstMessageAsyncStart");
gst_structure_id_set (structure,
GST_QUARK (NEW_BASE_TIME), G_TYPE_BOOLEAN, new_base_time, NULL);
message = gst_message_new_custom (GST_MESSAGE_ASYNC_START, src, structure);
return message;
}
/**
* gst_message_new_async_done:
* @src: The object originating the message.
*
* The message is posted when elements completed an ASYNC state change.
*
* Returns: The new async_done message.
*
* MT safe.
*
* Since: 0.10.13
*/
GstMessage *
gst_message_new_async_done (GstObject * src)
{
GstMessage *message;
message = gst_message_new_custom (GST_MESSAGE_ASYNC_DONE, src, NULL);
return message;
}
/**
* gst_message_new_latency:
* @src: The object originating the message.
*
* This message can be posted by elements when their latency requirements have
* changed.
*
* Returns: The new latency message.
*
* MT safe.
*
* Since: 0.10.12
*/
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: 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: The new requst state message.
*
* MT safe.
*
* Since: 0.10.23
*/
GstMessage *
gst_message_new_request_state (GstObject * src, GstState state)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_empty_new ("GstMessageRequestState");
gst_structure_id_set (structure,
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: 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 message->structure;
}
/**
* gst_message_parse_tag:
* @message: A valid #GstMessage of type GST_MESSAGE_TAG.
* @tag_list: 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.
*
* 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);
*tag_list = (GstTagList *) gst_structure_copy (message->structure);
}
/**
* gst_message_parse_buffering:
* @message: A valid #GstMessage of type GST_MESSAGE_BUFFERING.
* @percent: Return location for the percent.
*
* Extracts the buffering percent from the GstMessage. see also
* gst_message_new_buffering().
*
* Since: 0.10.11
*
* 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 (message->structure,
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.
*
* Since: 0.10.20
*/
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 (message->structure,
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: a buffering mode
* @avg_in: the average input rate
* @avg_out: the average output rate
* @buffering_left: amount of buffering time left in milliseconds.
*
* Extracts the buffering stats values from @message.
*
* Since: 0.10.20
*/
void
gst_message_parse_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);
if (mode)
*mode = g_value_get_enum (gst_structure_id_get_value (message->structure,
GST_QUARK (BUFFERING_MODE)));
if (avg_in)
*avg_in = g_value_get_int (gst_structure_id_get_value (message->structure,
GST_QUARK (AVG_IN_RATE)));
if (avg_out)
*avg_out = g_value_get_int (gst_structure_id_get_value (message->structure,
GST_QUARK (AVG_OUT_RATE)));
if (buffering_left)
*buffering_left =
g_value_get_int64 (gst_structure_id_get_value (message->structure,
GST_QUARK (BUFFERING_LEFT)));
}
/**
* gst_message_parse_state_changed:
* @message: a valid #GstMessage of type GST_MESSAGE_STATE_CHANGED
* @oldstate: the previous state, or NULL
* @newstate: the new (current) state, or NULL
* @pending: the pending (target) state, or NULL
*
* Extracts the old and new states from the GstMessage.
*
* MT safe.
*/
void
gst_message_parse_state_changed (GstMessage * message,
GstState * oldstate, GstState * newstate, GstState * pending)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STATE_CHANGED);
if (oldstate)
*oldstate =
g_value_get_enum (gst_structure_id_get_value (message->structure,
GST_QUARK (OLD_STATE)));
if (newstate)
*newstate =
g_value_get_enum (gst_structure_id_get_value (message->structure,
GST_QUARK (NEW_STATE)));
if (pending)
*pending = g_value_get_enum (gst_structure_id_get_value (message->structure,
GST_QUARK (PENDING_STATE)));
}
/**
* gst_message_parse_clock_provide:
* @message: A valid #GstMessage of type GST_MESSAGE_CLOCK_PROVIDE.
* @clock: A pointer to hold a clock object.
* @ready: A pointer to hold the ready flag.
*
* 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;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_CLOCK_PROVIDE);
clock_gvalue =
gst_structure_id_get_value (message->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 (message->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: 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;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_CLOCK_LOST);
clock_gvalue =
gst_structure_id_get_value (message->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: 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;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_NEW_CLOCK);
clock_gvalue =
gst_structure_id_get_value (message->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: A pointer to hold the change type
* @owner: The owner element of the message source
* @busy: 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.
*
* Since: 0.10.22
*/
void
gst_message_parse_structure_change (GstMessage * message,
GstStructureChangeType * type, GstElement ** owner, gboolean * busy)
{
const GValue *owner_gvalue;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STRUCTURE_CHANGE);
owner_gvalue =
gst_structure_id_get_value (message->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 = g_value_get_enum (gst_structure_id_get_value (message->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 (message->structure,
GST_QUARK (BUSY)));
}
/**
* gst_message_parse_error:
* @message: A valid #GstMessage of type GST_MESSAGE_ERROR.
* @gerror: Location for the GError
* @debug: 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_error (GstMessage * message, GError ** gerror, gchar ** debug)
{
const GValue *error_gvalue;
GError *error_val;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_ERROR);
error_gvalue =
gst_structure_id_get_value (message->structure, GST_QUARK (GERROR));
g_return_if_fail (error_gvalue != NULL);
g_return_if_fail (G_VALUE_TYPE (error_gvalue) == GST_TYPE_G_ERROR);
error_val = (GError *) g_value_get_boxed (error_gvalue);
if (error_val)
*gerror = g_error_copy (error_val);
else
*gerror = NULL;
if (debug)
*debug =
g_value_dup_string (gst_structure_id_get_value (message->structure,
GST_QUARK (DEBUG)));
}
/**
* gst_message_parse_warning:
* @message: A valid #GstMessage of type GST_MESSAGE_WARNING.
* @gerror: Location for the GError
* @debug: 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)
{
const GValue *error_gvalue;
GError *error_val;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_WARNING);
error_gvalue =
gst_structure_id_get_value (message->structure, GST_QUARK (GERROR));
g_return_if_fail (error_gvalue != NULL);
g_return_if_fail (G_VALUE_TYPE (error_gvalue) == GST_TYPE_G_ERROR);
error_val = (GError *) g_value_get_boxed (error_gvalue);
if (error_val)
*gerror = g_error_copy (error_val);
else
*gerror = NULL;
if (debug)
*debug =
g_value_dup_string (gst_structure_id_get_value (message->structure,
GST_QUARK (DEBUG)));
}
/**
* gst_message_parse_info:
* @message: A valid #GstMessage of type GST_MESSAGE_INFO.
* @gerror: Location for the GError
* @debug: 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.
*
* Since: 0.10.12
*/
void
gst_message_parse_info (GstMessage * message, GError ** gerror, gchar ** debug)
{
const GValue *error_gvalue;
GError *error_val;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_INFO);
error_gvalue =
gst_structure_id_get_value (message->structure, GST_QUARK (GERROR));
g_return_if_fail (error_gvalue != NULL);
g_return_if_fail (G_VALUE_TYPE (error_gvalue) == GST_TYPE_G_ERROR);
error_val = (GError *) g_value_get_boxed (error_gvalue);
if (error_val)
*gerror = g_error_copy (error_val);
else
*gerror = NULL;
if (debug)
*debug =
g_value_dup_string (gst_structure_id_get_value (message->structure,
GST_QUARK (DEBUG)));
}
/**
* gst_message_parse_segment_start:
* @message: A valid #GstMessage of type GST_MESSAGE_SEGMENT_START.
* @format: Result location for the format, or NULL
* @position: 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)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_SEGMENT_START);
if (format)
*format =
g_value_get_enum (gst_structure_id_get_value (message->structure,
GST_QUARK (FORMAT)));
if (position)
*position =
g_value_get_int64 (gst_structure_id_get_value (message->structure,
GST_QUARK (POSITION)));
}
/**
* gst_message_parse_segment_done:
* @message: A valid #GstMessage of type GST_MESSAGE_SEGMENT_DONE.
* @format: Result location for the format, or NULL
* @position: Result location for the position, or NULL
*
* Extracts the position and format from the segment start message.
*
* MT safe.
*/
void
gst_message_parse_segment_done (GstMessage * message, GstFormat * format,
gint64 * position)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_SEGMENT_DONE);
if (format)
*format =
g_value_get_enum (gst_structure_id_get_value (message->structure,
GST_QUARK (FORMAT)));
if (position)
*position =
g_value_get_int64 (gst_structure_id_get_value (message->structure,
GST_QUARK (POSITION)));
}
/**
* gst_message_parse_duration:
* @message: A valid #GstMessage of type GST_MESSAGE_DURATION.
* @format: Result location for the format, or NULL
* @duration: Result location for the duration, or NULL
*
* Extracts the duration and format from the duration message. The duration
* might be GST_CLOCK_TIME_NONE, which indicates that the duration has
* changed. Applications should always use a query to retrieve the duration
* of a pipeline.
*
* MT safe.
*/
void
gst_message_parse_duration (GstMessage * message, GstFormat * format,
gint64 * duration)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION);
if (format)
*format =
g_value_get_enum (gst_structure_id_get_value (message->structure,
GST_QUARK (FORMAT)));
if (duration)
*duration =
g_value_get_int64 (gst_structure_id_get_value (message->structure,
GST_QUARK (DURATION)));
}
/**
* gst_message_parse_async_start:
* @message: A valid #GstMessage of type GST_MESSAGE_ASYNC_DONE.
* @new_base_time: Result location for the new_base_time or NULL
*
* Extract the new_base_time from the async_start message.
*
* MT safe.
*
* Since: 0.10.13
*/
void
gst_message_parse_async_start (GstMessage * message, gboolean * new_base_time)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_ASYNC_START);
if (new_base_time)
*new_base_time =
g_value_get_boolean (gst_structure_id_get_value (message->structure,
GST_QUARK (NEW_BASE_TIME)));
}
/**
* gst_message_parse_request_state:
* @message: A valid #GstMessage of type GST_MESSAGE_REQUEST_STATE.
* @state: Result location for the requested state or NULL
*
* Extract the requested state from the request_state message.
*
* MT safe.
*
* Since: 0.10.23
*/
void
gst_message_parse_request_state (GstMessage * message, GstState * state)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_REQUEST_STATE);
if (state)
*state = g_value_get_enum (gst_structure_id_get_value (message->structure,
GST_QUARK (NEW_STATE)));
}
/**
* gst_message_new_stream_status:
* @src: The object originating the message.
* @type: The stream status type.
* @owner: 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: The new stream status message.
*
* MT safe.
*
* Since: 0.10.24.
*/
GstMessage *
gst_message_new_stream_status (GstObject * src, GstStreamStatusType type,
GstElement * owner)
{
GstMessage *message;
GstStructure *structure;
structure = gst_structure_empty_new ("GstMessageStreamStatus");
gst_structure_id_set (structure,
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: A pointer to hold the status type
* @owner: 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.
*
* Since: 0.10.24.
*
* MT safe.
*/
void
gst_message_parse_stream_status (GstMessage * message,
GstStreamStatusType * type, GstElement ** owner)
{
const GValue *owner_gvalue;
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STREAM_STATUS);
owner_gvalue =
gst_structure_id_get_value (message->structure, GST_QUARK (OWNER));
g_return_if_fail (owner_gvalue != NULL);
if (type)
*type = g_value_get_enum (gst_structure_id_get_value (message->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.
*
* Since: 0.10.24
*/
void
gst_message_set_stream_status_object (GstMessage * message,
const GValue * object)
{
g_return_if_fail (GST_IS_MESSAGE (message));
g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STREAM_STATUS);
gst_structure_id_set_value (message->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.
*
* Since: 0.10.24
*/
const GValue *
gst_message_get_stream_status_object (GstMessage * message)
{
const GValue *result;
g_return_val_if_fail (GST_IS_MESSAGE (message), NULL);
g_return_val_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STREAM_STATUS,
NULL);
result = gst_structure_id_get_value (message->structure, GST_QUARK (OBJECT));
return result;
}