:right-sidebar: True BaseSink =================================================================== .. currentmodule:: gi.repository.GstBase .. class:: BaseSink(**properties: ~typing.Any) :no-contents-entry: Superclasses: :class:`~gi.repository.Gst.Element`, :class:`~gi.repository.Gst.Object`, :class:`~gi.repository.GObject.InitiallyUnowned`, :class:`~gi.repository.GObject.Object` :Constructors: :: BaseSink(**properties) Methods ------- .. rst-class:: interim-class .. class:: BaseSink :no-index: .. method:: get_blocksize() -> int Get the number of bytes that the sink will pull when it is operating in pull mode. .. method:: get_drop_out_of_segment() -> bool Checks if ``sink`` is currently configured to drop buffers which are outside the current segment .. versionadded:: 1.12 .. method:: get_last_sample() -> ~gi.repository.Gst.Sample | None Get the last sample that arrived in the sink and was used for preroll or for rendering. This property can be used to generate thumbnails. The :obj:`~gi.repository.Gst.Caps` on the sample can be used to determine the type of the buffer. Free-function: gst_sample_unref .. method:: get_latency() -> int Get the currently configured latency. .. method:: get_max_bitrate() -> int Get the maximum amount of bits per second that the sink will render. .. versionadded:: 1.2 .. method:: get_max_lateness() -> int Gets the max lateness value. See :func:`~gi.repository.GstBase.BaseSink.set_max_lateness` for more details. .. method:: get_processing_deadline() -> int Get the processing deadline of ``sink``. see :func:`~gi.repository.GstBase.BaseSink.set_processing_deadline` for more information about the processing deadline. .. versionadded:: 1.16 .. method:: get_render_delay() -> int Get the render delay of ``sink``. see :func:`~gi.repository.GstBase.BaseSink.set_render_delay` for more information about the render delay. .. method:: get_stats() -> ~gi.repository.Gst.Structure Return various :obj:`~gi.repository.GstBase.BaseSink` statistics. This function returns a :obj:`~gi.repository.Gst.Structure` with name ``application/x-gst-base-sink-stats`` with the following fields: - "average-rate" G_TYPE_DOUBLE average frame rate - "dropped" G_TYPE_UINT64 Number of dropped frames - "rendered" G_TYPE_UINT64 Number of rendered frames .. versionadded:: 1.18 .. method:: get_sync() -> bool Checks if ``sink`` is currently configured to synchronize against the clock. .. method:: get_throttle_time() -> int Get the time that will be inserted between frames to control the maximum buffers per second. .. method:: get_ts_offset() -> int Get the synchronisation offset of ``sink``. .. method:: is_async_enabled() -> bool Checks if ``sink`` is currently configured to perform asynchronous state changes to PAUSED. .. method:: is_last_sample_enabled() -> bool Checks if ``sink`` is currently configured to store the last received sample in the last-sample property. .. method:: is_qos_enabled() -> bool Checks if ``sink`` is currently configured to send Quality-of-Service events upstream. .. method:: query_latency() -> tuple[bool, bool, bool, int, int] Query the sink for the latency parameters. The latency will be queried from the upstream elements. ``live`` will be :const:`True` if ``sink`` is configured to synchronize against the clock. ``upstream_live`` will be :const:`True` if an upstream element is live. If both ``live`` and ``upstream_live`` are :const:`True`, the sink will want to compensate for the latency introduced by the upstream elements by setting the ``min_latency`` to a strictly positive value. This function is mostly used by subclasses. .. method:: set_async_enabled(enabled: bool) -> None Configures ``sink`` to perform all state changes asynchronously. When async is disabled, the sink will immediately go to PAUSED instead of waiting for a preroll buffer. This feature is useful if the sink does not synchronize against the clock or when it is dealing with sparse streams. :param enabled: the new async value. .. method:: set_blocksize(blocksize: int) -> None Set the number of bytes that the sink will pull when it is operating in pull mode. :param blocksize: the blocksize in bytes .. method:: set_drop_out_of_segment(drop_out_of_segment: bool) -> None Configure ``sink`` to drop buffers which are outside the current segment .. versionadded:: 1.12 :param drop_out_of_segment: drop buffers outside the segment .. method:: set_last_sample_enabled(enabled: bool) -> None Configures ``sink`` to store the last received sample in the last-sample property. :param enabled: the new enable-last-sample value. .. method:: set_max_bitrate(max_bitrate: int) -> None Set the maximum amount of bits per second that the sink will render. .. versionadded:: 1.2 :param max_bitrate: the max_bitrate in bits per second .. method:: set_max_lateness(max_lateness: int) -> None Sets the new max lateness value to ``max_lateness``. This value is used to decide if a buffer should be dropped or not based on the buffer timestamp and the current clock time. A value of -1 means an unlimited time. :param max_lateness: the new max lateness value. .. method:: set_processing_deadline(processing_deadline: int) -> None Maximum amount of time (in nanoseconds) that the pipeline can take for processing the buffer. This is added to the latency of live pipelines. This function is usually called by subclasses. .. versionadded:: 1.16 :param processing_deadline: the new processing deadline in nanoseconds. .. method:: set_qos_enabled(enabled: bool) -> None Configures ``sink`` to send Quality-of-Service events upstream. :param enabled: the new qos value. .. method:: set_render_delay(delay: int) -> None Set the render delay in ``sink`` to ``delay``. The render delay is the time between actual rendering of a buffer and its synchronisation time. Some devices might delay media rendering which can be compensated for with this function. After calling this function, this sink will report additional latency and other sinks will adjust their latency to delay the rendering of their media. This function is usually called by subclasses. :param delay: the new delay .. method:: set_sync(sync: bool) -> None Configures ``sink`` to synchronize on the clock or not. When ``sync`` is :const:`False`, incoming samples will be played as fast as possible. If ``sync`` is :const:`True`, the timestamps of the incoming buffers will be used to schedule the exact render time of its contents. :param sync: the new sync value. .. method:: set_throttle_time(throttle: int) -> None Set the time that will be inserted between rendered buffers. This can be used to control the maximum buffers per second that the sink will render. :param throttle: the throttle time in nanoseconds .. method:: set_ts_offset(offset: int) -> None Adjust the synchronisation of ``sink`` with ``offset``. A negative value will render buffers earlier than their timestamp. A positive value will delay rendering. This function can be used to fix playback of badly timestamped buffers. :param offset: the new offset .. method:: wait(time: int) -> tuple[~gi.repository.Gst.FlowReturn, int] This function will wait for preroll to complete and will then block until ``time`` is reached. It is usually called by subclasses that use their own internal synchronisation but want to let some synchronization (like EOS) be handled by the base class. This function should only be called with the PREROLL_LOCK held (like when receiving an EOS event in the ::event vmethod or when handling buffers in ::render). The ``time`` argument should be the running_time of when the timeout should happen and will be adjusted with any latency and offset configured in the sink. :param time: the running_time to be reached .. method:: wait_clock(time: int) -> tuple[~gi.repository.Gst.ClockReturn, int] This function will block until ``time`` is reached. It is usually called by subclasses that use their own internal synchronisation. If ``time`` is not valid, no synchronisation is done and ``%GST_CLOCK_BADTIME`` is returned. Likewise, if synchronisation is disabled in the element or there is no clock, no synchronisation is done and ``%GST_CLOCK_BADTIME`` is returned. This function should only be called with the PREROLL_LOCK held, like when receiving an EOS event in the ``GstBaseSinkClass``::event vmethod or when receiving a buffer in the ``GstBaseSinkClass``::render vmethod. The ``time`` argument should be the running_time of when this method should return and is not adjusted with any latency or offset configured in the sink. :param time: the running_time to be reached .. method:: wait_preroll() -> ~gi.repository.Gst.FlowReturn If the ``GstBaseSinkClass``::render method performs its own synchronisation against the clock it must unblock when going from PLAYING to the PAUSED state and call this method before continuing to render the remaining data. If the ``GstBaseSinkClass``::render method can block on something else than the clock, it must also be ready to unblock immediately on the ``GstBaseSinkClass``::unlock method and cause the ``GstBaseSinkClass``::render method to immediately call this function. In this case, the subclass must be prepared to continue rendering where it left off if this function returns ``%GST_FLOW_OK``. This function will block until a state change to PLAYING happens (in which case this function returns ``%GST_FLOW_OK``) or the processing must be stopped due to a state change to READY or a FLUSH event (in which case this function returns ``%GST_FLOW_FLUSHING``). This function should only be called with the PREROLL_LOCK held, like in the render function. Properties ---------- .. rst-class:: interim-class .. class:: BaseSink :no-index: .. attribute:: props.async :type: bool If set to :const:`True`, the basesink will perform asynchronous state changes. When set to :const:`False`, the sink will not signal the parent when it prerolls. Use this option when dealing with sparse streams or when synchronisation is not required. .. attribute:: props.blocksize :type: int The amount of bytes to pull when operating in pull mode. .. attribute:: props.enable_last_sample :type: bool Enable the last-sample property. If :const:`False`, basesink doesn't keep a reference to the last buffer arrived and the last-sample property is always set to :const:`None`. This can be useful if you need buffers to be released as soon as possible, eg. if you're using a buffer pool. .. attribute:: props.last_sample :type: ~gi.repository.Gst.Sample The last buffer that arrived in the sink and was used for preroll or for rendering. This property can be used to generate thumbnails. This property can be :const:`None` when the sink has not yet received a buffer. .. attribute:: props.max_bitrate :type: int Control the maximum amount of bits that will be rendered per second. Setting this property to a value bigger than 0 will make the sink delay rendering of the buffers when it would exceed to max-bitrate. .. versionadded:: 1.2 .. attribute:: props.max_lateness :type: int .. attribute:: props.processing_deadline :type: int Maximum amount of time (in nanoseconds) that the pipeline can take for processing the buffer. This is added to the latency of live pipelines. .. versionadded:: 1.16 .. attribute:: props.qos :type: bool .. attribute:: props.render_delay :type: int The additional delay between synchronisation and actual rendering of the media. This property will add additional latency to the device in order to make other sinks compensate for the delay. .. attribute:: props.stats :type: ~gi.repository.Gst.Structure Various :obj:`~gi.repository.GstBase.BaseSink` statistics. This property returns a :obj:`~gi.repository.Gst.Structure` with name ``application/x-gst-base-sink-stats`` with the following fields: - "average-rate" G_TYPE_DOUBLE average frame rate - "dropped" G_TYPE_UINT64 Number of dropped frames - "rendered" G_TYPE_UINT64 Number of rendered frames .. versionadded:: 1.18 .. attribute:: props.sync :type: bool .. attribute:: props.throttle_time :type: int The time to insert between buffers. This property can be used to control the maximum amount of buffers per second to render. Setting this property to a value bigger than 0 will make the sink create THROTTLE QoS events. .. attribute:: props.ts_offset :type: int Controls the final synchronisation, a negative value will render the buffer earlier while a positive value delays playback. This property can be used to fix synchronisation in bad files. Virtual Methods --------------- .. rst-class:: interim-class .. class:: BaseSink :no-index: .. method:: do_activate_pull(active: bool) -> bool Subclasses should override this when they can provide an alternate method of spawning a thread to drive the pipeline in pull mode. Should start or stop the pulling thread, depending on the value of the "active" argument. Called after actually activating the sink pad in pull mode. The default implementation starts a task on the sink pad. :param active: .. method:: do_event(event: ~gi.repository.Gst.Event) -> bool Override this to handle events arriving on the sink pad :param event: .. method:: do_fixate(caps: ~gi.repository.Gst.Caps) -> ~gi.repository.Gst.Caps Only useful in pull mode. Implement if you have ideas about what should be the default values for the caps you support. :param caps: .. method:: do_get_caps(filter: ~gi.repository.Gst.Caps | None = None) -> ~gi.repository.Gst.Caps Called to get sink pad caps from the subclass. :param filter: .. method:: do_get_times(buffer: ~gi.repository.Gst.Buffer) -> tuple[int, int] Get the start and end times for syncing on this buffer. :param buffer: .. method:: do_prepare(buffer: ~gi.repository.Gst.Buffer) -> ~gi.repository.Gst.FlowReturn Called to prepare the buffer for ``render`` and ``preroll``. This function is called before synchronisation is performed. :param buffer: .. method:: do_prepare_list(buffer_list: ~gi.repository.Gst.BufferList) -> ~gi.repository.Gst.FlowReturn Called to prepare the buffer list for ``render_list``. This function is called before synchronisation is performed. :param buffer_list: .. method:: do_preroll(buffer: ~gi.repository.Gst.Buffer) -> ~gi.repository.Gst.FlowReturn Called to present the preroll buffer if desired. :param buffer: .. method:: do_propose_allocation(query: ~gi.repository.Gst.Query) -> bool configure the allocation query :param query: .. method:: do_query(query: ~gi.repository.Gst.Query) -> bool perform a :obj:`~gi.repository.Gst.Query` on the element. :param query: .. method:: do_render(buffer: ~gi.repository.Gst.Buffer) -> ~gi.repository.Gst.FlowReturn Called when a buffer should be presented or output, at the correct moment if the :obj:`~gi.repository.GstBase.BaseSink` has been set to sync to the clock. :param buffer: .. method:: do_render_list(buffer_list: ~gi.repository.Gst.BufferList) -> ~gi.repository.Gst.FlowReturn Same as ``render`` but used with buffer lists instead of buffers. :param buffer_list: .. method:: do_set_caps(caps: ~gi.repository.Gst.Caps) -> bool Notify subclass of changed caps :param caps: .. method:: do_start() -> bool Start processing. Ideal for opening resources in the subclass .. method:: do_stop() -> bool Stop processing. Subclasses should use this to close resources. .. method:: do_unlock() -> bool Unlock any pending access to the resource. Subclasses should unblock any blocked function ASAP and call :func:`~gi.repository.GstBase.BaseSink.wait_preroll` .. method:: do_unlock_stop() -> bool Clear the previous unlock request. Subclasses should clear any state they set during ``GstBaseSinkClass``::unlock, and be ready to continue where they left off after :func:`~gi.repository.GstBase.BaseSink.wait_preroll`, :func:`~gi.repository.GstBase.BaseSink.wait` or gst_wait_sink_wait_clock() return or ``GstBaseSinkClass``::render is called again. .. method:: do_wait_event(event: ~gi.repository.Gst.Event) -> ~gi.repository.Gst.FlowReturn Override this to implement custom logic to wait for the event time (for events like EOS and GAP). Subclasses should always first chain up to the default implementation. :param event: Fields ------ .. rst-class:: interim-class .. class:: BaseSink :no-index: .. attribute:: can_activate_pull .. attribute:: can_activate_push .. attribute:: clock_id .. attribute:: element .. attribute:: eos .. attribute:: flushing .. attribute:: have_newsegment .. attribute:: have_preroll .. attribute:: max_lateness .. attribute:: need_preroll .. attribute:: offset .. attribute:: pad_mode .. attribute:: playing_async .. attribute:: preroll_cond .. attribute:: preroll_lock .. attribute:: priv .. attribute:: running .. attribute:: segment .. attribute:: sinkpad .. attribute:: sync