MessageType

class MessageType

The different message types that are available.

Methods

class MessageType
get_name(type: MessageType) str

Get a printable name for the given message type. Do not modify or free.

Parameters:

type – the message type

to_quark(type: MessageType) int

Get the unique quark for the given message type.

Parameters:

type – the message type

Fields

class MessageType
ANY

Mask for all of the above messages.

APPLICATION

Message posted by the application, possibly via an application-specific element.

ASYNC_DONE

Posted by elements when they complete an ASYNC StateChange. The application will only receive this message from the toplevel pipeline.

ASYNC_START

Posted by elements when they start an ASYNC StateChange. This message is not forwarded to the application but is used internally.

BUFFERING

The pipeline is buffering. When the application receives a buffering message in the PLAYING state for a non-live pipeline it must PAUSE the pipeline until the buffering completes, when the percentage field in the message is 100%. For live pipelines, no action must be performed and the buffering percentage can be used to inform the user about the progress.

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 application should set the pipeline to PAUSED and back to PLAYING when this message is received.

CLOCK_PROVIDE

An element notifies its capability of providing a clock. This message is used internally and never forwarded to the application.

DEVICE_ADDED

Message indicating a Device was added to a DeviceProvider (Since: 1.4)

DEVICE_CHANGED

Message indicating a Device was changed a DeviceProvider (Since: 1.16)

DEVICE_REMOVED

Message indicating a Device was removed from a DeviceProvider (Since: 1.4)

DURATION_CHANGED

The duration of a pipeline changed. The application can get the new duration with a duration query.

ELEMENT

Element-specific message, see the specific element’s documentation

EOS

End-of-stream reached in a pipeline. The application will only receive this message in the PLAYING state and every time it sets a pipeline to PLAYING that is in the EOS state. The application can perform a flushing seek in the pipeline, which will undo the EOS state again.

ERROR

An error occurred. When the application receives an error message it should stop playback of the pipeline and not assume that more data will be played. It is possible to specify a redirection url to the error messages by setting a redirect-location field into the error message, application or high level bins might use the information as required.

EXTENDED

Message is an extended message type (see below). These extended message IDs can’t be used directly with mask-based API like poll() or timed_pop_filtered(), but you can still filter for GST_MESSAGE_EXTENDED and then check the result for the specific type. (Since: 1.4)

HAVE_CONTEXT

Message indicating that an element created a context (Since: 1.2)

INFO

An info message occurred

INSTANT_RATE_REQUEST

Message sent by elements to request the running time from the pipeline when an instant rate change should be applied (which may be in the past when the answer arrives). (Since: 1.18)

LATENCY

Posted by elements when their latency changes. The application should recalculate and distribute a new latency.

NEED_CONTEXT

Message indicating that an element wants a specific context (Since: 1.2)

NEW_CLOCK

A new clock was selected in the pipeline.

PROGRESS

A progress message.

PROPERTY_NOTIFY

Message indicating a Object property has changed (Since: 1.10)

QOS

A buffer was dropped or an element changed its processing strategy for Quality of Service reasons.

REDIRECT

Message indicating to request the application to try to play the given URL(s). Useful if for example a HTTP 302/303 response is received with a non-HTTP URL inside. (Since: 1.10)

REQUEST_STATE

Posted by elements when they want the pipeline to change state. This message is a suggestion to the application which can decide to perform the state change on (part of) the pipeline.

RESET_TIME

Message to request resetting the pipeline’s running time from the pipeline. This is an internal message which applications will likely never receive.

SEGMENT_DONE

Pipeline completed playback of a segment. This message is forwarded to the application after all elements that posted GST_MESSAGE_SEGMENT_START posted a GST_MESSAGE_SEGMENT_DONE message.

SEGMENT_START

Pipeline started playback of a segment. This message is used internally and never forwarded to the application.

STATE_CHANGED

A state change happened

STATE_DIRTY

An element changed state in a streaming thread. This message is deprecated.

STEP_DONE

A stepping operation finished.

STEP_START

A stepping operation was started.

STREAMS_SELECTED

Message indicating the active selection of Stream has changed (Since: 1.10)

STREAM_COLLECTION

Message indicating a new StreamCollection is available (Since: 1.10)

STREAM_START

Message indicating start of a new stream. Useful e.g. when using playbin in gapless playback mode, to get notified when the next title actually starts playing (which will be some time after the URI for the next title has been set).

STREAM_STATUS

Status about a stream, emitted when it starts, stops, errors, etc..

STRUCTURE_CHANGE

The structure of the pipeline changed. This message is used internally and never forwarded to the application.

TAG

A tag was found.

TOC

A new table of contents (TOC) was found or previously found TOC was updated.

UNKNOWN

An undefined message

WARNING

A warning occurred.