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GStreamer 0.10 Core Reference Manual | ![]() |
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#include <gst/gst.h> GstMessage; enum GstMessageType; #define GST_MESSAGE_SRC (message) #define GST_MESSAGE_TIMESTAMP (message) #define GST_MESSAGE_TYPE (message) #define GST_MESSAGE_TYPE_NAME (message) #define GST_MESSAGE_TRACE_NAME GQuark gst_message_type_to_quark (GstMessageType type); const gchar* gst_message_type_get_name (GstMessageType type); #define gst_message_copy (msg) const GstStructure* gst_message_get_structure (GstMessage *message); #define gst_message_make_writable (msg) GstMessage* gst_message_new_application (GstObject *src, GstStructure *structure); GstMessage* gst_message_new_clock_provide (GstObject *src, GstClock *clock, gboolean ready); GstMessage* gst_message_new_clock_lost (GstObject *src, GstClock *clock); GstMessage* gst_message_new_custom (GstMessageType type, GstObject *src, GstStructure *structure); GstMessage* gst_message_new_element (GstObject *src, GstStructure *structure); GstMessage* gst_message_new_eos (GstObject *src); GstMessage* gst_message_new_error (GstObject *src, GError *error, gchar *debug); GstMessage* gst_message_new_new_clock (GstObject *src, GstClock *clock); GstMessage* gst_message_new_segment_done (GstObject *src, GstFormat format, gint64 position); GstMessage* gst_message_new_segment_start (GstObject *src, GstFormat format, gint64 position); GstMessage* gst_message_new_state_changed (GstObject *src, GstState oldstate, GstState newstate, GstState pending); GstMessage* gst_message_new_tag (GstObject *src, GstTagList *tag_list); GstMessage* gst_message_new_buffering (GstObject *src, gint percent); GstMessage* gst_message_new_warning (GstObject *src, GError *error, gchar *debug); GstMessage* gst_message_new_duration (GstObject *src, GstFormat format, gint64 duration); GstMessage* gst_message_new_state_dirty (GstObject *src); void gst_message_parse_clock_lost (GstMessage *message, GstClock **clock); void gst_message_parse_clock_provide (GstMessage *message, GstClock **clock, gboolean *ready); void gst_message_parse_error (GstMessage *message, GError **gerror, gchar **debug); void gst_message_parse_new_clock (GstMessage *message, GstClock **clock); void gst_message_parse_segment_done (GstMessage *message, GstFormat *format, gint64 *position); void gst_message_parse_segment_start (GstMessage *message, GstFormat *format, gint64 *position); void gst_message_parse_state_changed (GstMessage *message, GstState *oldstate, GstState *newstate, GstState *pending); void gst_message_parse_tag (GstMessage *message, GstTagList **tag_list); void gst_message_parse_buffering (GstMessage *message, gint *percent); void gst_message_parse_warning (GstMessage *message, GError **gerror, gchar **debug); void gst_message_parse_duration (GstMessage *message, GstFormat *format, gint64 *duration); GstMessage* gst_message_ref (GstMessage *msg); #define gst_message_unref (msg)
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:
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)
typedef struct { GstMiniObject mini_object; GstMessageType type; guint64 timestamp; GstObject *src; GstStructure *structure; } GstMessage;
A GstMessage.
mini_object
;GstMiniObjectmini_object
the parent structure
the parent structure
GstMessageType type
;GstMessageTypetype
the GstMessageType of the message
the GstMessageType of the message
GstMessageTypeGstMessageTypeguint64 timestamp
;guint64timestamp
the timestamp of the message
the timestamp of the message
GstObject *src
;GstObjectsrc
the src of the message
the src of the message
GstStructure *structure
;GstStructurestructure
the GstStructure containing the message info.
the GstStructure containing the message info.
GstStructureGstStructure
GstMiniObject mini_object ; |
the parent structure |
GstMessageType type ; |
the GstMessageType of the message |
guint64 timestamp ; |
the timestamp of the message |
GstObject *src ; |
the src of the message |
GstStructure *structure ; |
the GstStructure containing the message info. |
typedef enum { GST_MESSAGE_UNKNOWN = 0, GST_MESSAGE_EOS = (1 << 0), GST_MESSAGE_ERROR = (1 << 1), GST_MESSAGE_WARNING = (1 << 2), GST_MESSAGE_INFO = (1 << 3), GST_MESSAGE_TAG = (1 << 4), GST_MESSAGE_BUFFERING = (1 << 5), GST_MESSAGE_STATE_CHANGED = (1 << 6), GST_MESSAGE_STATE_DIRTY = (1 << 7), GST_MESSAGE_STEP_DONE = (1 << 8), GST_MESSAGE_CLOCK_PROVIDE = (1 << 9), GST_MESSAGE_CLOCK_LOST = (1 << 10), GST_MESSAGE_NEW_CLOCK = (1 << 11), GST_MESSAGE_STRUCTURE_CHANGE = (1 << 12), GST_MESSAGE_STREAM_STATUS = (1 << 13), GST_MESSAGE_APPLICATION = (1 << 14), GST_MESSAGE_ELEMENT = (1 << 15), GST_MESSAGE_SEGMENT_START = (1 << 16), GST_MESSAGE_SEGMENT_DONE = (1 << 17), GST_MESSAGE_DURATION = (1 << 18), GST_MESSAGE_ANY = ~0 } GstMessageType;
The different message types that are available.
GST_MESSAGE_UNKNOWN
GST_MESSAGE_UNKNOWN
an undefined message
an undefined message
GST_MESSAGE_EOS
GST_MESSAGE_EOS
end-of-stream reached in a pipeline
end-of-stream reached in a pipeline
GST_MESSAGE_ERROR
GST_MESSAGE_ERROR
an error occured
an error occured
GST_MESSAGE_WARNING
GST_MESSAGE_WARNING
a warning occured.
a warning occured.
GST_MESSAGE_INFO
GST_MESSAGE_INFO
an info message occured
an info message occured
GST_MESSAGE_TAG
GST_MESSAGE_TAG
a tag was found.
a tag was found.
GST_MESSAGE_BUFFERING
GST_MESSAGE_BUFFERING
the pipeline is buffering
the pipeline is buffering
GST_MESSAGE_STATE_CHANGED
GST_MESSAGE_STATE_CHANGED
a state change happened
a state change happened
GST_MESSAGE_STATE_DIRTY
GST_MESSAGE_STATE_DIRTY
an element changed state in a streaming thread
an element changed state in a streaming thread
GST_MESSAGE_STEP_DONE
GST_MESSAGE_STEP_DONE
a framestep finished.
a framestep finished.
GST_MESSAGE_CLOCK_PROVIDE
GST_MESSAGE_CLOCK_PROVIDE
an element notifies its capability of providing
a clock.
an element notifies its capability of providing
a clock.
GST_MESSAGE_CLOCK_LOST
GST_MESSAGE_CLOCK_LOST
The current clock as selected by the pipeline became
unusable. The pipeline will select a new clock on
the next PLAYING state change.
The current clock as selected by the pipeline became
unusable. The pipeline will select a new clock on
the next PLAYING state change.
GST_MESSAGE_NEW_CLOCK
GST_MESSAGE_NEW_CLOCK
a new clock was selected in the pipeline
a new clock was selected in the pipeline
GST_MESSAGE_STRUCTURE_CHANGE
GST_MESSAGE_STRUCTURE_CHANGE
the structure of the pipeline changed.
the structure of the pipeline changed.
GST_MESSAGE_STREAM_STATUS
GST_MESSAGE_STREAM_STATUS
status about a stream, emitted when it starts,
stops, errors, etc..
status about a stream, emitted when it starts,
stops, errors, etc..
GST_MESSAGE_APPLICATION
GST_MESSAGE_APPLICATION
message posted by the application, possibly
via an application-specific element.
message posted by the application, possibly
via an application-specific element.
GST_MESSAGE_ELEMENT
GST_MESSAGE_ELEMENT
element-specific message, see the specific element's
documentation
element-specific message, see the specific element's
documentation
GST_MESSAGE_SEGMENT_START
GST_MESSAGE_SEGMENT_START
pipeline started playback of a segment.
pipeline started playback of a segment.
GST_MESSAGE_SEGMENT_DONE
GST_MESSAGE_SEGMENT_DONE
pipeline completed playback of a segment.
pipeline completed playback of a segment.
GST_MESSAGE_DURATION
GST_MESSAGE_DURATION
The duration of a pipeline changed.
The duration of a pipeline changed.
GST_MESSAGE_ANY
GST_MESSAGE_ANY
mask for all of the above messages.
mask for all of the above messages.
#define GST_MESSAGE_SRC(message) (GST_MESSAGE(message)->src)
Get the object that posted message
.
#define GST_MESSAGE_TIMESTAMP(message) (GST_MESSAGE(message)->timestamp)
Get the timestamp of message
. This is the timestamp when the message
was created.
#define GST_MESSAGE_TYPE(message) (GST_MESSAGE(message)->type)
Get the GstMessageType of message
.
#define GST_MESSAGE_TYPE_NAME(message) gst_message_type_get_name(GST_MESSAGE_TYPE(message))
Get a constant string representation of the GstMessageType of message
.
Since 0.10.4
#define GST_MESSAGE_TRACE_NAME "GstMessage"
The name used for memory allocation tracing
GQuark gst_message_type_to_quark (GstMessageType type);
Get the unique quark for the given message type.
type
:type
the message type
the message type
Returns :Returns the quark associated with the message type
the quark associated with the message type
type : |
the message type |
Returns : | the quark associated with the message type |
const gchar* gst_message_type_get_name (GstMessageType type);
Get a printable name for the given message type. Do not modify or free.
type
:type
the message type
the message type
Returns :Returns a reference to the static name of the message.
a reference to the static name of the message.
type : |
the message type |
Returns : | a reference to the static name of the message. |
#define gst_message_copy(msg) GST_MESSAGE (gst_mini_object_copy (GST_MINI_OBJECT (msg)))
Creates a copy of the message. Returns a copy of the message.
MT safe
msg
:msg
the message to copy
the message to copy
msg : |
the message to copy |
const GstStructure* gst_message_get_structure (GstMessage *message);
Access the structure of the message.
message
:message
The GstMessage.
The GstMessage.
GstMessageGstMessageReturns :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.
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.
message : |
The GstMessage. |
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. |
#define gst_message_make_writable(msg) GST_MESSAGE (gst_mini_object_make_writable (GST_MINI_OBJECT (msg)))
Checks if a message is writable. If not, a writable copy is made and returned. Returns a message (possibly a duplicate) that is writable.
MT safe
msg
:msg
the message to make writable
the message to make writable
msg : |
the message to make writable |
GstMessage* gst_message_new_application (GstObject *src, GstStructure *structure);
Create a new application-typed message. GStreamer will never create these messages; they are a gift from us to you. Enjoy.
src
:src
The object originating the message.
The object originating the message.
structure
:structure
The structure for the message. The message will take ownership of
the structure.
The structure for the message. The message will take ownership of
the structure.
Returns :Returns The new application message.
MT safe.
The new application message.
MT safe.
src : |
The object originating the message. |
structure : |
The structure for the message. The message will take ownership of the structure. |
Returns : | The new application message. MT safe. |
GstMessage* gst_message_new_clock_provide (GstObject *src, GstClock *clock, gboolean ready);
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.
src
:src
The object originating the message.
The object originating the message.
clock
:clock
The clock it provides
The clock it provides
ready
:ready
TRUE if the sender can provide a clock
TRUE if the sender can provide a clock
Returns :Returns The new provide clock message.
MT safe.
The new provide clock message.
MT safe.
src : |
The object originating the message. |
clock : |
The clock it provides |
ready : |
TRUE if the sender can provide a clock |
Returns : | The new provide clock message. MT safe. |
GstMessage* gst_message_new_clock_lost (GstObject *src, GstClock *clock);
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.
src
:src
The object originating the message.
The object originating the message.
clock
:clock
the clock that was lost
the clock that was lost
Returns :Returns The new clock lost message.
MT safe.
The new clock lost message.
MT safe.
src : |
The object originating the message. |
clock : |
the clock that was lost |
Returns : | The new clock lost message. MT safe. |
GstMessage* gst_message_new_custom (GstMessageType type, GstObject *src, GstStructure *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.
type
:type
The GstMessageType to distinguish messages
The GstMessageType to distinguish messages
GstMessageTypeGstMessageTypesrc
:src
The object originating the message.
The object originating the message.
structure
:structure
The structure for the message. The message will take ownership of
the structure.
The structure for the message. The message will take ownership of
the structure.
Returns :Returns The new message.
MT safe.
The new message.
MT safe.
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. |
Returns : | The new message. MT safe. |
GstMessage* gst_message_new_element (GstObject *src, GstStructure *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.
src
:src
The object originating the message.
The object originating the message.
structure
:structure
The structure for the message. The message will take ownership of
the structure.
The structure for the message. The message will take ownership of
the structure.
Returns :Returns The new element message.
MT safe.
The new element message.
MT safe.
src : |
The object originating the message. |
structure : |
The structure for the message. The message will take ownership of the structure. |
Returns : | The new element message. MT safe. |
GstMessage* gst_message_new_eos (GstObject *src);
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.
src
:src
The object originating the message.
The object originating the message.
Returns :Returns The new eos message.
MT safe.
The new eos message.
MT safe.
src : |
The object originating the message. |
Returns : | The new eos message. MT safe. |
GstMessage* gst_message_new_error (GstObject *src, GError *error, gchar *debug);
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.
src
:src
The object originating the message.
The object originating the message.
error
:error
The GError for this message.
The GError for this message.
debug
:debug
A debugging string for something or other.
A debugging string for something or other.
Returns :Returns The new error message.
MT safe.
The new error message.
MT safe.
src : |
The object originating the message. |
error : |
The GError for this message. |
debug : |
A debugging string for something or other. |
Returns : | The new error message. MT safe. |
GstMessage* gst_message_new_new_clock (GstObject *src, GstClock *clock);
Create a new clock message. This message is posted whenever the pipeline selectes a new clock for the pipeline.
src
:src
The object originating the message.
The object originating the message.
clock
:clock
the new selected clock
the new selected clock
Returns :Returns The new new clock message.
MT safe.
The new new clock message.
MT safe.
src : |
The object originating the message. |
clock : |
the new selected clock |
Returns : | The new new clock message. MT safe. |
GstMessage* gst_message_new_segment_done (GstObject *src, GstFormat format, gint64 position);
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.
src
:src
The object originating the message.
The object originating the message.
format
:format
The format of the position being done
The format of the position being done
position
:position
The position of the segment being done
The position of the segment being done
Returns :Returns The new segment done message.
MT safe.
The new segment done message.
MT safe.
src : |
The object originating the message. |
format : |
The format of the position being done |
position : |
The position of the segment being done |
Returns : | The new segment done message. MT safe. |
GstMessage* gst_message_new_segment_start (GstObject *src, GstFormat format, gint64 position);
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.
src
:src
The object originating the message.
The object originating the message.
format
:format
The format of the position being played
The format of the position being played
position
:position
The position of the segment being played
The position of the segment being played
Returns :Returns The new segment start message.
MT safe.
The new segment start message.
MT safe.
src : |
The object originating the message. |
format : |
The format of the position being played |
position : |
The position of the segment being played |
Returns : | The new segment start message. MT safe. |
GstMessage* gst_message_new_state_changed (GstObject *src, GstState oldstate, GstState newstate, GstState pending);
Create a state change message. This message is posted whenever an element changed its state.
src
:src
the object originating the message
the object originating the message
oldstate
:oldstate
the previous state
the previous state
newstate
:newstate
the new (current) state
the new (current) state
pending
:pending
the pending (target) state
the pending (target) state
Returns :Returns The new state change message.
MT safe.
The new state change message.
MT safe.
src : |
the object originating the message |
oldstate : |
the previous state |
newstate : |
the new (current) state |
pending : |
the pending (target) state |
Returns : | The new state change message. MT safe. |
GstMessage* gst_message_new_tag (GstObject *src, GstTagList *tag_list);
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.
src
:src
The object originating the message.
The object originating the message.
tag_list
:tag_list
The tag list for the message.
The tag list for the message.
Returns :Returns The new tag message.
MT safe.
The new tag message.
MT safe.
src : |
The object originating the message. |
tag_list : |
The tag list for the message. |
Returns : | The new tag message. MT safe. |
GstMessage* gst_message_new_buffering (GstObject *src, gint 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.
src
:src
The object originating the message.
The object originating the message.
percent
:percent
The buffering percent
The buffering percent
Returns :Returns The new buffering message.
The new buffering message.
src : |
The object originating the message. |
percent : |
The buffering percent |
Returns : | The new buffering message. |
Since 0.10.11 MT safe.
GstMessage* gst_message_new_warning (GstObject *src, GError *error, gchar *debug);
Create a new warning message. The message will make copies of error
and
debug
.
src
:src
The object originating the message.
The object originating the message.
error
:error
The GError for this message.
The GError for this message.
debug
:debug
A debugging string for something or other.
A debugging string for something or other.
Returns :Returns The new warning message.
MT safe.
The new warning message.
MT safe.
src : |
The object originating the message. |
error : |
The GError for this message. |
debug : |
A debugging string for something or other. |
Returns : | The new warning message. MT safe. |
GstMessage* gst_message_new_duration (GstObject *src, GstFormat format, gint64 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.
src
:src
The object originating the message.
The object originating the message.
format
:format
The format of the duration
The format of the duration
duration
:duration
The new duration
The new duration
Returns :Returns The new duration message.
MT safe.
The new duration message.
MT safe.
src : |
The object originating the message. |
format : |
The format of the duration |
duration : |
The new duration |
Returns : | The new duration message. MT safe. |
GstMessage* gst_message_new_state_dirty (GstObject *src);
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.
src
:src
the object originating the message
the object originating the message
Returns :Returns The new state dirty message.
MT safe.
The new state dirty message.
MT safe.
src : |
the object originating the message |
Returns : | The new state dirty message. MT safe. |
void gst_message_parse_clock_lost (GstMessage *message, GstClock **clock);
Extracts the lost clock from the GstMessage. The clock object returned remains valid until the message is freed.
MT safe.
message
:message
A valid GstMessage of type GST_MESSAGE_CLOCK_LOST.
A valid GstMessage of type GST_MESSAGE_CLOCK_LOST.
GstMessageGstMessageclock
:clock
A pointer to hold the lost clock
A pointer to hold the lost clock
message : |
A valid GstMessage of type GST_MESSAGE_CLOCK_LOST. |
clock : |
A pointer to hold the lost clock |
void gst_message_parse_clock_provide (GstMessage *message, GstClock **clock, gboolean *ready);
Extracts the clock and ready flag from the GstMessage. The clock object returned remains valid until the message is freed.
MT safe.
message
:message
A valid GstMessage of type GST_MESSAGE_CLOCK_PROVIDE.
A valid GstMessage of type GST_MESSAGE_CLOCK_PROVIDE.
GstMessageGstMessageclock
:clock
A pointer to hold a clock object.
A pointer to hold a clock object.
ready
:ready
A pointer to hold the ready flag.
A pointer to hold the ready flag.
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. |
void gst_message_parse_error (GstMessage *message, GError **gerror, gchar **debug);
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.
message
:message
A valid GstMessage of type GST_MESSAGE_ERROR.
A valid GstMessage of type GST_MESSAGE_ERROR.
GstMessageGstMessagegerror
:gerror
Location for the GError
Location for the GError
debug
:debug
Location for the debug message, or NULL
Location for the debug message, or NULL
message : |
A valid GstMessage of type GST_MESSAGE_ERROR. |
gerror : |
Location for the GError |
debug : |
Location for the debug message, or NULL |
void gst_message_parse_new_clock (GstMessage *message, GstClock **clock);
Extracts the new clock from the GstMessage. The clock object returned remains valid until the message is freed.
MT safe.
message
:message
A valid GstMessage of type GST_MESSAGE_NEW_CLOCK.
A valid GstMessage of type GST_MESSAGE_NEW_CLOCK.
GstMessageGstMessageclock
:clock
A pointer to hold the selected new clock
A pointer to hold the selected new clock
message : |
A valid GstMessage of type GST_MESSAGE_NEW_CLOCK. |
clock : |
A pointer to hold the selected new clock |
void gst_message_parse_segment_done (GstMessage *message, GstFormat *format, gint64 *position);
Extracts the position and format from the segment start message.
MT safe.
message
:message
A valid GstMessage of type GST_MESSAGE_SEGMENT_DONE.
A valid GstMessage of type GST_MESSAGE_SEGMENT_DONE.
GstMessageGstMessageformat
:format
Result location for the format, or NULL
Result location for the format, or NULL
position
:position
Result location for the position, or NULL
Result location for the position, or NULL
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 |
void gst_message_parse_segment_start (GstMessage *message, GstFormat *format, gint64 *position);
Extracts the position and format from the segment start message.
MT safe.
message
:message
A valid GstMessage of type GST_MESSAGE_SEGMENT_START.
A valid GstMessage of type GST_MESSAGE_SEGMENT_START.
GstMessageGstMessageformat
:format
Result location for the format, or NULL
Result location for the format, or NULL
position
:position
Result location for the position, or NULL
Result location for the position, or NULL
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 |
void gst_message_parse_state_changed (GstMessage *message, GstState *oldstate, GstState *newstate, GstState *pending);
Extracts the old and new states from the GstMessage.
MT safe.
message
:message
a valid GstMessage of type GST_MESSAGE_STATE_CHANGED
a valid GstMessage of type GST_MESSAGE_STATE_CHANGED
GstMessageGstMessageoldstate
:oldstate
the previous state, or NULL
the previous state, or NULL
newstate
:newstate
the new (current) state, or NULL
the new (current) state, or NULL
pending
:pending
the pending (target) state, or NULL
the pending (target) state, or NULL
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 |
void gst_message_parse_tag (GstMessage *message, GstTagList **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.
message
:message
A valid GstMessage of type GST_MESSAGE_TAG.
A valid GstMessage of type GST_MESSAGE_TAG.
GstMessageGstMessagetag_list
:tag_list
Return location for the tag-list.
Return location for the tag-list.
message : |
A valid GstMessage of type GST_MESSAGE_TAG. |
tag_list : |
Return location for the tag-list. |
void gst_message_parse_buffering (GstMessage *message, gint *percent);
Extracts the buffering percent from the GstMessage. see also
gst_message_new_buffering()
.
message
:message
A valid GstMessage of type GST_MESSAGE_BUFFERING.
A valid GstMessage of type GST_MESSAGE_BUFFERING.
GstMessageGstMessagepercent
:percent
Return location for the percent.
Return location for the percent.
message : |
A valid GstMessage of type GST_MESSAGE_BUFFERING. |
percent : |
Return location for the percent. |
Since 0.10.11 MT safe.
void gst_message_parse_warning (GstMessage *message, GError **gerror, gchar **debug);
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.
message
:message
A valid GstMessage of type GST_MESSAGE_WARNING.
A valid GstMessage of type GST_MESSAGE_WARNING.
GstMessageGstMessagegerror
:gerror
Location for the GError
Location for the GError
debug
:debug
Location for the debug message, or NULL
Location for the debug message, or NULL
message : |
A valid GstMessage of type GST_MESSAGE_WARNING. |
gerror : |
Location for the GError |
debug : |
Location for the debug message, or NULL |
void gst_message_parse_duration (GstMessage *message, GstFormat *format, gint64 *duration);
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.
message
:message
A valid GstMessage of type GST_MESSAGE_DURATION.
A valid GstMessage of type GST_MESSAGE_DURATION.
GstMessageGstMessageformat
:format
Result location for the format, or NULL
Result location for the format, or NULL
duration
:duration
Result location for the duration, or NULL
Result location for the duration, or NULL
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 |
GstMessage* gst_message_ref (GstMessage *msg);
Convenience macro to increase the reference count of the message.
msg
:msg
the message to ref
the message to ref
Returns :Returns msg
(for convenience when doing assignments)
msg
(for convenience when doing assignments)
msg
msg : |
the message to ref |
Returns : | msg (for convenience when doing assignments)
|