Package org.freedesktop.gstreamer.app

Class AppSink

java.lang.Object

org.javagi.base.ProxyInstance

org.gnome.gobject.TypeInstance

org.gnome.gobject.GObject

org.gnome.gobject.InitiallyUnowned

org.freedesktop.gstreamer.gst.GstObject

org.freedesktop.gstreamer.gst.Element

org.freedesktop.gstreamer.base.BaseSink

org.freedesktop.gstreamer.app.AppSink

All Implemented Interfaces:

URIHandler, Proxy

@Generated("io.github.jwharm.JavaGI")
public class AppSink
extends BaseSink
implements URIHandler

Appsink is a sink plugin that supports many different methods for making the application get a handle on the GStreamer data in a pipeline. Unlike most GStreamer elements, Appsink provides external API functions.

appsink can be used by linking to the gstappsink.h header file to access the methods or by using the appsink action signals and properties.

The normal way of retrieving samples from appsink is by using the gst_app_sink_pull_sample() and gst_app_sink_pull_preroll() methods. These methods block until a sample becomes available in the sink or when the sink is shut down or reaches EOS. There are also timed variants of these methods, gst_app_sink_try_pull_sample() and gst_app_sink_try_pull_preroll(), which accept a timeout parameter to limit the amount of time to wait.

Appsink will internally use a queue to collect buffers from the streaming thread. If the application is not pulling samples fast enough, this queue will consume a lot of memory over time. The "max-buffers", "max-time" and "max-bytes" properties can be used to limit the queue size. The "drop" property controls whether the streaming thread blocks or if older buffers are dropped when the maximum queue size is reached. Note that blocking the streaming thread can negatively affect real-time performance and should be avoided.

If a blocking behaviour is not desirable, setting the "emit-signals" property to true will make appsink emit the "new-sample" and "new-preroll" signals when a sample can be pulled without blocking.

The "caps" property on appsink can be used to control the formats that appsink can receive. This property can contain non-fixed caps, the format of the pulled samples can be obtained by getting the sample caps.

If one of the pull-preroll or pull-sample methods return null, the appsink is stopped or in the EOS state. You can check for the EOS state with the "eos" property or with the gst_app_sink_is_eos() method.

The eos signal can also be used to be informed when the EOS state is reached to avoid polling.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	AppSink.AppSinkClass
static class	AppSink.Builder<B extends AppSink.Builder<B>>	Inner class implementing a builder pattern to construct a GObject with properties.
static interface	AppSink.EosCallback	Functional interface declaration of the EosCallback callback.
static interface	AppSink.NewPrerollCallback	Functional interface declaration of the NewPrerollCallback callback.
static interface	AppSink.NewSampleCallback	Functional interface declaration of the NewSampleCallback callback.
static interface	AppSink.NewSerializedEventCallback	Functional interface declaration of the NewSerializedEventCallback callback.
static interface	AppSink.ProposeAllocationCallback	Functional interface declaration of the ProposeAllocationCallback callback.
static interface	AppSink.PullPrerollCallback	Functional interface declaration of the PullPrerollCallback callback.
static interface	AppSink.PullSampleCallback	Functional interface declaration of the PullSampleCallback callback.
static interface	AppSink.TryPullPrerollCallback	Functional interface declaration of the TryPullPrerollCallback callback.
static interface	AppSink.TryPullSampleCallback	Functional interface declaration of the TryPullSampleCallback callback.

Nested classes/interfaces inherited from class org.freedesktop.gstreamer.base.BaseSink

BaseSink.BaseSink$Impl, BaseSink.BaseSinkClass

Nested classes/interfaces inherited from class org.freedesktop.gstreamer.gst.Element

Element.Element$Impl, Element.ElementClass, Element.NoMorePadsCallback, Element.PadAddedCallback, Element.PadRemovedCallback

Nested classes/interfaces inherited from class org.freedesktop.gstreamer.gst.GstObject

GstObject.DeepNotifyCallback, GstObject.Object$Impl, GstObject.ObjectClass

Nested classes/interfaces inherited from class org.gnome.gobject.InitiallyUnowned

InitiallyUnowned.InitiallyUnownedClass

Nested classes/interfaces inherited from class org.gnome.gobject.GObject

GObject.NotifyCallback

Nested classes/interfaces inherited from interface org.freedesktop.gstreamer.gst.URIHandler

URIHandler.URIHandler$Impl, URIHandler.URIHandlerInterface

Constructor Summary

Constructors

Constructor	Description
AppSink()	Creates a new AppSink.
AppSink(MemorySegment address)	Create a AppSink proxy instance for the provided memory address.

Method Summary

Modifier and Type	Method	Description
protected AppSink	asParent()	Returns this instance as if it were its parent type.
static AppSink.Builder<? extends AppSink.Builder>	builder()	A AppSink.Builder object constructs a AppSink with the specified properties.
void	emitEos()	Emits the "eos" signal.
FlowReturn	emitNewPreroll()	Emits the "new-preroll" signal.
FlowReturn	emitNewSample()	Emits the "new-sample" signal.
boolean	emitNewSerializedEvent()	Emits the "new-serialized-event" signal.
boolean	emitProposeAllocation(@Nullable Query query)	Emits the "propose-allocation" signal.
Sample	emitPullPreroll()	Emits the "pull-preroll" signal.
Sample	emitPullSample()	Emits the "pull-sample" signal.
Sample	emitTryPullPreroll(long timeout)	Emits the "try-pull-preroll" signal.
Sample	emitTryPullSample(long timeout)	Emits the "try-pull-sample" signal.
protected void	eos()
boolean	getBufferListSupport()	Check if this AppSink supports buffer lists.
@Nullable Caps	getCaps()	Get the configured caps on appsink.
boolean	getDrop()	Check if this AppSink will drop old buffers when the maximum amount of queued data is reached (meaning max buffers, time or bytes limit, whichever is hit first).
boolean	getEmitSignals()	Check if appsink will emit the "new-preroll" and "new-sample" signals.
int	getMaxBuffers()	Get the maximum amount of buffers that can be queued in appsink.
long	getMaxBytes()	Get the maximum total size, in bytes, that can be queued in appsink.
ClockTime	getMaxTime()	Get the maximum total duration that can be queued in appsink.
static MemoryLayout	getMemoryLayout()	The memory layout of the native struct.
static @Nullable Type	getType()	Get the GType of the AppSink class
boolean	getWaitOnEos()	Check if this AppSink will wait for all buffers to be consumed when an EOS is received.
boolean	isEos()	Check if this AppSink is EOS, which is when no more samples can be pulled because an EOS event was received.
protected FlowReturn	newPreroll()
protected FlowReturn	newSample()
SignalConnection<AppSink.EosCallback>	onEos(AppSink.EosCallback handler)	Signal that the end-of-stream has been reached.
SignalConnection<AppSink.NewPrerollCallback>	onNewPreroll(AppSink.NewPrerollCallback handler)	Signal that a new preroll sample is available.
SignalConnection<AppSink.NewSampleCallback>	onNewSample(AppSink.NewSampleCallback handler)	Signal that a new sample is available.
SignalConnection<AppSink.NewSerializedEventCallback>	onNewSerializedEvent(AppSink.NewSerializedEventCallback handler)	Signal that a new downstream serialized event is available.
SignalConnection<AppSink.ProposeAllocationCallback>	onProposeAllocation(AppSink.ProposeAllocationCallback handler)	Signal that a new propose_allocation query is available.
SignalConnection<AppSink.PullPrerollCallback>	onPullPreroll(AppSink.PullPrerollCallback handler)	Get the last preroll sample in appsink. This was the sample that caused the appsink to preroll in the PAUSED state.
SignalConnection<AppSink.PullSampleCallback>	onPullSample(AppSink.PullSampleCallback handler)	This function blocks until a sample or EOS becomes available or the appsink element is set to the READY/NULL state.
SignalConnection<AppSink.TryPullPrerollCallback>	onTryPullPreroll(AppSink.TryPullPrerollCallback handler)	Get the last preroll sample in appsink. This was the sample that caused the appsink to preroll in the PAUSED state.
SignalConnection<AppSink.TryPullSampleCallback>	onTryPullSample(AppSink.TryPullSampleCallback handler)	This function blocks until a sample or EOS becomes available or the appsink element is set to the READY/NULL state or the timeout expires.
@Nullable MiniObject	pullObject()	This function blocks until a sample or an event becomes available or the appsink element is set to the READY/NULL state.
@Nullable Sample	pullPreroll()	Get the last preroll sample in appsink. This was the sample that caused the appsink to preroll in the PAUSED state.
@Nullable Sample	pullSample()	This function blocks until a sample or EOS becomes available or the appsink element is set to the READY/NULL state.
void	setBufferListSupport(boolean enableLists)	Instruct this AppSink to enable or disable buffer list support.
void	setCallbacks(AppSinkCallbacks callbacks, @Nullable MemorySegment userData)	Set callbacks which will be executed for each new preroll, new sample and eos.
void	setCapabilities(@Nullable Caps caps)	Set the capabilities on the appsink element.
void	setDrop(boolean drop)	Instruct this AppSink to drop old buffers when the maximum amount of queued data is reached, that is, when any configured limit is hit (max-buffers, max-time or max-bytes).
void	setEmitSignals(boolean emit)	Make appsink emit the "new-preroll" and "new-sample" signals.
void	setMaxBuffers(int max)	Set the maximum amount of buffers that can be queued in appsink. After this amount of buffers are queued in appsink, any more buffers will block upstream elements until a sample is pulled from appsink, unless 'drop' is set, in which case new buffers will be discarded.
void	setMaxBytes(long max)	Set the maximum total size that can be queued in appsink. After this amount of buffers are queued in appsink, any more buffers will block upstream elements until a sample is pulled from appsink, unless 'drop' is set, in which case new buffers will be discarded.
void	setMaxTime(ClockTime max)	Set the maximum total duration that can be queued in appsink. After this amount of buffers are queued in appsink, any more buffers will block upstream elements until a sample is pulled from appsink, unless 'drop' is set, in which case new buffers will be discarded.
void	setWaitOnEos(boolean wait_)	Instruct this AppSink to wait for all buffers to be consumed when an EOS is received.
@Nullable MiniObject	tryPullObject(ClockTime timeout)	This function blocks until a sample or an event or EOS becomes available or the appsink element is set to the READY/NULL state or the timeout expires.
@Nullable Sample	tryPullPreroll(ClockTime timeout)	Get the last preroll sample in appsink. This was the sample that caused the appsink to preroll in the PAUSED state.
@Nullable Sample	tryPullSample(ClockTime timeout)	This function blocks until a sample or EOS becomes available or the appsink element is set to the READY/NULL state or the timeout expires.

Methods inherited from class org.freedesktop.gstreamer.base.BaseSink

activatePull, doPreroll, event, fixate, getBlocksize, getCaps, getDropOutOfSegment, getLastSample, getLatency, getMaxBitrate, getMaxLateness, getProcessingDeadline, getRenderDelay, getStats, getSync, getThrottleTime, getTimes, getTsOffset, isAsyncEnabled, isLastSampleEnabled, isQosEnabled, prepare, prepareList, preroll, proposeAllocation, query, queryLatency, render, renderList, setAsyncEnabled, setBlocksize, setCaps, setDropOutOfSegment, setLastSampleEnabled, setMaxBitrate, setMaxLateness, setProcessingDeadline, setQosEnabled, setRenderDelay, setSync, setThrottleTime, setTsOffset, start, stop, unlock, unlockStop, wait_, waitClock, waitEvent, waitPreroll

Methods inherited from class org.freedesktop.gstreamer.gst.Element

abortState, addPad, addPropertyDeepNotifyWatch, addPropertyNotifyWatch, callAsync, changeState, continueState, createAllPads, decorateStreamId, decorateStreamIdPrintf, emitNoMorePads, emitPadAdded, emitPadRemoved, foreachPad, foreachSinkPad, foreachSrcPad, getBaseTime, getBus, getClock, getCompatiblePad, getCompatiblePadTemplate, getContext, getContexts, getContextUnlocked, getCurrentClockTime, getCurrentRunningTime, getFactory, getMetadata, getPadTemplate, getPadTemplateList, getRequestPad, getStartTime, getState, getStaticPad, isLockedState, iteratePads, iterateSinkPads, iterateSrcPads, link, linkFiltered, linkMany, linkPads, linkPadsFiltered, linkPadsFull, linkPadsFull, lostState, makeFromUri, messageFull, messageFull, messageFullWithDetails, messageFullWithDetails, noMorePads, onNoMorePads, onPadAdded, onPadRemoved, padAdded, padRemoved, postMessage, provideClock, queryConvert, queryDuration, queryPosition, register, releasePad, releaseRequestPad, removePad, removePropertyNotifyWatch, requestPad, requestPadSimple, seek, seek, seekSimple, seekSimple, sendEvent, setBaseTime, setBus, setClock, setContext, setLockedState, setStartTime, setState, stateChanged, stateChangeReturnGetName, stateGetName, syncStateWithParent, typeSetSkipDocumentation, unlink, unlinkMany, unlinkPads

Methods inherited from class org.freedesktop.gstreamer.gst.GstObject

addControlBinding, checkUniqueness, deepNotify, defaultDeepNotify, defaultError, emitDeepNotify, getControlBinding, getControlRate, getGValueArray, getName, getParent, getPathString, getValue, getValueArray, hasActiveControlBindings, hasAncestor, hasAsAncestor, hasAsParent, onDeepNotify, ref, refSink, removeControlBinding, replace, setControlBindingDisabled, setControlBindingsDisabled, setControlRate, setName, setParent, suggestNextSync, syncValues, unparent, unref

Methods inherited from class org.gnome.gobject.GObject

addToggleRef, addWeakPointer, bindProperty, bindProperty, bindProperty, bindPropertyFull, bindPropertyFull, bindPropertyWithClosures, bindPropertyWithClosures, compatControl, connect, connect, connect, constructed, disconnect, dispatchPropertiesChanged, dispose, dupData, dupQdata, emit, emitNotify, finalize_, forceFloating, freezeNotify, get, getData, getProperty, getProperty, getProperty, getQdata, getv, interfaceFindProperty, interfaceInstallProperty, interfaceListProperties, isFloating, newInstance, newInstance, newv, notify, notify, notifyByPspec, onNotify, refSink, removeToggleRef, removeWeakPointer, replaceData, replaceQdata, runDispose, set, setData, setDataFull, setProperty, setProperty, setProperty, setQdata, setQdataFull, setv, stealData, stealQdata, takeRef, thawNotify, watchClosure, weakRef, weakUnref, withProperties

Methods inherited from class org.gnome.gobject.TypeInstance

callParent, callParent, cast, getPrivate, readGClass, writeGClass

Methods inherited from class org.javagi.base.ProxyInstance

equals, handle, hashCode

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.javagi.base.Proxy

handle

Methods inherited from interface org.freedesktop.gstreamer.gst.URIHandler

getProtocols, getUri, getUriType, setUri

Constructor Details

AppSink

public AppSink(MemorySegment address)

Create a AppSink proxy instance for the provided memory address.

Parameters:

address - the memory address of the native object

AppSink

public AppSink()

Creates a new AppSink.

Method Details

getType

public static @Nullable Type getType()

Get the GType of the AppSink class

Returns:

the GType

getMemoryLayout

public static MemoryLayout getMemoryLayout()

The memory layout of the native struct.

Returns:

the memory layout

asParent

protected AppSink asParent()

Returns this instance as if it were its parent type. This is mostly synonymous to the Java super keyword, but will set the native typeclass function pointers to the parent type. When overriding a native virtual method in Java, "chaining up" with super.methodName() doesn't work, because it invokes the overridden function pointer again. To chain up, call asParent().methodName(). This will call the native function pointer of this virtual method in the typeclass of the parent type.

Overrides:

asParent in class BaseSink

getBufferListSupport

public boolean getBufferListSupport()

Check if this AppSink supports buffer lists.

Returns:

true if this AppSink supports buffer lists.

Since:

1.12

getCaps

public @Nullable Caps getCaps()

Get the configured caps on appsink.

Returns:

the GstCaps accepted by the sink. gst_caps_unref() after usage.

getDrop

public boolean getDrop()

Check if this AppSink will drop old buffers when the maximum amount of queued data is reached (meaning max buffers, time or bytes limit, whichever is hit first).

Returns:

true if this AppSink is dropping old buffers when the queue is filled.

getEmitSignals

public boolean getEmitSignals()

Check if appsink will emit the "new-preroll" and "new-sample" signals.

Returns:

true if this AppSink is emitting the "new-preroll" and "new-sample" signals.

getMaxBuffers

public int getMaxBuffers()

Get the maximum amount of buffers that can be queued in appsink.

Returns:

The maximum amount of buffers that can be queued.

getMaxBytes

public long getMaxBytes()

Get the maximum total size, in bytes, that can be queued in appsink.

Returns:

The maximum amount of bytes that can be queued

Since:

1.24

getMaxTime

public ClockTime getMaxTime()

Get the maximum total duration that can be queued in appsink.

Returns:

The maximum total duration that can be queued.

Since:

1.24

getWaitOnEos

public boolean getWaitOnEos()

Check if this AppSink will wait for all buffers to be consumed when an EOS is received.

Returns:

true if this AppSink will wait for all buffers to be consumed when an EOS is received.

isEos

public boolean isEos()

Check if this AppSink is EOS, which is when no more samples can be pulled because an EOS event was received.

This function also returns true when the appsink is not in the PAUSED or PLAYING state.

Returns:

true if no more samples can be pulled and the appsink is EOS.

pullObject

public @Nullable MiniObject pullObject()

This function blocks until a sample or an event becomes available or the appsink element is set to the READY/NULL state.

This function will only return samples when the appsink is in the PLAYING state. All rendered buffers and events will be put in a queue so that the application can pull them at its own rate. Note that when the application does not pull samples fast enough, the queued buffers could consume a lot of memory, especially when dealing with raw video frames. Events can be pulled when the appsink is in the READY, PAUSED or PLAYING state.

This function will only pull serialized events, excluding the EOS event for which this functions returns null. Use gst_app_sink_is_eos() to check for the EOS condition.

This method is a variant of gst_app_sink_pull_sample() that can be used to handle incoming events events as well as samples.

Note that future releases may extend this API to return other object types so make sure that your code is checking for the actual type it is handling.

Returns:

a GstSample, or a GstEvent or NULL when the appsink is stopped or EOS. Call gst_mini_object_unref() after usage.

Since:

1.20

pullPreroll

public @Nullable Sample pullPreroll()

Get the last preroll sample in appsink. This was the sample that caused the appsink to preroll in the PAUSED state.

This function is typically used when dealing with a pipeline in the PAUSED state. Calling this function after doing a seek will give the sample right after the seek position.

Calling this function will clear the internal reference to the preroll buffer.

Note that the preroll sample will also be returned as the first sample when calling gst_app_sink_pull_sample().

If an EOS event was received before any buffers, this function returns null. Use gst_app_sink_is_eos () to check for the EOS condition.

This function blocks until a preroll sample or EOS is received or the appsink element is set to the READY/NULL state.

Returns:

a GstSample or NULL when the appsink is stopped or EOS. Call gst_sample_unref() after usage.

pullSample

public @Nullable Sample pullSample()

This function blocks until a sample or EOS becomes available or the appsink element is set to the READY/NULL state.

This function will only return samples when the appsink is in the PLAYING state. All rendered buffers will be put in a queue so that the application can pull samples at its own rate. Note that when the application does not pull samples fast enough, the queued buffers could consume a lot of memory, especially when dealing with raw video frames.

If an EOS event was received before any buffers, this function returns null. Use gst_app_sink_is_eos () to check for the EOS condition.

Returns:

a GstSample or NULL when the appsink is stopped or EOS. Call gst_sample_unref() after usage.

setBufferListSupport

public void setBufferListSupport(boolean enableLists)

Instruct this AppSink to enable or disable buffer list support.

For backwards-compatibility reasons applications need to opt in to indicate that they will be able to handle buffer lists.

Parameters:

enableLists - enable or disable buffer list support

Since:

1.12

setCallbacks

public void setCallbacks(AppSinkCallbacks callbacks,
 @Nullable MemorySegment userData)

Set callbacks which will be executed for each new preroll, new sample and eos. This is an alternative to using the signals, it has lower overhead and is thus less expensive, but also less flexible.

If callbacks are installed, no signals will be emitted for performance reasons.

Before 1.16.3 it was not possible to change the callbacks in a thread-safe way.

Parameters:

callbacks - the callbacks

userData - a user_data argument for the callbacks

setCapabilities

public void setCapabilities(@Nullable Caps caps)

Set the capabilities on the appsink element. This function takes a copy of the caps structure. After calling this method, the sink will only accept caps that match caps. If caps is non-fixed, or incomplete, you must check the caps on the samples to get the actual used caps.

Parameters:

caps - caps to set

setDrop

public void setDrop(boolean drop)

Instruct this AppSink to drop old buffers when the maximum amount of queued data is reached, that is, when any configured limit is hit (max-buffers, max-time or max-bytes).

Parameters:

drop - the new state

setEmitSignals

public void setEmitSignals(boolean emit)

Make appsink emit the "new-preroll" and "new-sample" signals. This option is by default disabled because signal emission is expensive and unneeded when the application prefers to operate in pull mode.

Parameters:

emit - the new state

setMaxBuffers

public void setMaxBuffers(int max)

Set the maximum amount of buffers that can be queued in appsink. After this amount of buffers are queued in appsink, any more buffers will block upstream elements until a sample is pulled from appsink, unless 'drop' is set, in which case new buffers will be discarded.

Parameters:

max - the maximum number of buffers to queue

setMaxBytes

public void setMaxBytes(long max)

Set the maximum total size that can be queued in appsink. After this amount of buffers are queued in appsink, any more buffers will block upstream elements until a sample is pulled from appsink, unless 'drop' is set, in which case new buffers will be discarded.

Parameters:

max - the maximum total size of buffers to queue, in bytes

Since:

1.24

setMaxTime

public void setMaxTime(ClockTime max)

Set the maximum total duration that can be queued in appsink. After this amount of buffers are queued in appsink, any more buffers will block upstream elements until a sample is pulled from appsink, unless 'drop' is set, in which case new buffers will be discarded.

Parameters:

max - the maximum total duration to queue

Since:

1.24

setWaitOnEos

public void setWaitOnEos(boolean wait_)

Instruct this AppSink to wait for all buffers to be consumed when an EOS is received.

Parameters:

wait_ - the new state

tryPullObject

public @Nullable MiniObject tryPullObject(ClockTime timeout)

This function blocks until a sample or an event or EOS becomes available or the appsink element is set to the READY/NULL state or the timeout expires.

This function will only return samples when the appsink is in the PLAYING state. All rendered buffers and events will be put in a queue so that the application can pull them at its own rate. Note that when the application does not pull samples fast enough, the queued buffers could consume a lot of memory, especially when dealing with raw video frames. Events can be pulled when the appsink is in the READY, PAUSED or PLAYING state.

This function will only pull serialized events, excluding the EOS event for which this functions returns null. Use gst_app_sink_is_eos() to check for the EOS condition.

This method is a variant of gst_app_sink_try_pull_sample() that can be used to handle incoming events events as well as samples.

Note that future releases may extend this API to return other object types so make sure that your code is checking for the actual type it is handling.

Parameters:

timeout - the maximum amount of time to wait for a sample

Returns:

a GstSample, or GstEvent or NULL when the appsink is stopped or EOS or the timeout expires. Call gst_mini_object_unref() after usage.

Since:

1.20

tryPullPreroll

public @Nullable Sample tryPullPreroll(ClockTime timeout)

Get the last preroll sample in appsink. This was the sample that caused the appsink to preroll in the PAUSED state.

This function is typically used when dealing with a pipeline in the PAUSED state. Calling this function after doing a seek will give the sample right after the seek position.

Calling this function will clear the internal reference to the preroll buffer.

Note that the preroll sample will also be returned as the first sample when calling gst_app_sink_pull_sample().

If an EOS event was received before any buffers or the timeout expires, this function returns null. Use gst_app_sink_is_eos () to check for the EOS condition.

This function blocks until a preroll sample or EOS is received, the appsink element is set to the READY/NULL state, or the timeout expires.

Parameters:

timeout - the maximum amount of time to wait for the preroll sample

Returns:

a GstSample or NULL when the appsink is stopped or EOS or the timeout expires. Call gst_sample_unref() after usage.

Since:

1.10

tryPullSample

public @Nullable Sample tryPullSample(ClockTime timeout)

This function blocks until a sample or EOS becomes available or the appsink element is set to the READY/NULL state or the timeout expires.

This function will only return samples when the appsink is in the PLAYING state. All rendered buffers will be put in a queue so that the application can pull samples at its own rate. Note that when the application does not pull samples fast enough, the queued buffers could consume a lot of memory, especially when dealing with raw video frames.

If an EOS event was received before any buffers or the timeout expires, this function returns null. Use gst_app_sink_is_eos () to check for the EOS condition.

Parameters:

timeout - the maximum amount of time to wait for a sample

Returns:

a GstSample or NULL when the appsink is stopped or EOS or the timeout expires. Call gst_sample_unref() after usage.

Since:

1.10

eos

protected void eos()

newPreroll

protected FlowReturn newPreroll()

newSample

protected FlowReturn newSample()

onEos

public SignalConnection<AppSink.EosCallback> onEos(AppSink.EosCallback handler)

Signal that the end-of-stream has been reached. This signal is emitted from the streaming thread.

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• AppSink.EosCallback.run()

emitEos

public void emitEos()

Emits the "eos" signal. See onEos(org.freedesktop.gstreamer.app.AppSink.EosCallback).

onNewPreroll

public SignalConnection<AppSink.NewPrerollCallback> onNewPreroll(AppSink.NewPrerollCallback handler)

Signal that a new preroll sample is available.

This signal is emitted from the streaming thread and only when the "emit-signals" property is true.

The new preroll sample can be retrieved with the "pull-preroll" action signal or gst_app_sink_pull_preroll() either from this signal callback or from any other thread.

Note that this signal is only emitted when the "emit-signals" property is set to true, which it is not by default for performance reasons.

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• AppSink.NewPrerollCallback.run()

emitNewPreroll

public FlowReturn emitNewPreroll()

Emits the "new-preroll" signal. See onNewPreroll(org.freedesktop.gstreamer.app.AppSink.NewPrerollCallback).

onNewSample

public SignalConnection<AppSink.NewSampleCallback> onNewSample(AppSink.NewSampleCallback handler)

Signal that a new sample is available.

This signal is emitted from the streaming thread and only when the "emit-signals" property is true.

The new sample can be retrieved with the "pull-sample" action signal or gst_app_sink_pull_sample() either from this signal callback or from any other thread.

Note that this signal is only emitted when the "emit-signals" property is set to true, which it is not by default for performance reasons.

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• AppSink.NewSampleCallback.run()

emitNewSample

public FlowReturn emitNewSample()

Emits the "new-sample" signal. See onNewSample(org.freedesktop.gstreamer.app.AppSink.NewSampleCallback).

onNewSerializedEvent

public SignalConnection<AppSink.NewSerializedEventCallback> onNewSerializedEvent(AppSink.NewSerializedEventCallback handler)

Signal that a new downstream serialized event is available.

This signal is emitted from the streaming thread and only when the "emit-signals" property is true.

The new event can be retrieved with the "try-pull-object" action signal or gst_app_sink_pull_object() either from this signal callback or from any other thread.

EOS will not be notified using this signal, use GstAppSink::eos instead. EOS cannot be pulled either, use gst_app_sink_is_eos() to check for it.

Note that this signal is only emitted when the "emit-signals" property is set to true, which it is not by default for performance reasons.

The callback should return true if the event has been handled, which will skip basesink handling of the event, false otherwise.

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

Since:

1.20

See Also:

• AppSink.NewSerializedEventCallback.run()

emitNewSerializedEvent

public boolean emitNewSerializedEvent()

Emits the "new-serialized-event" signal. See onNewSerializedEvent(org.freedesktop.gstreamer.app.AppSink.NewSerializedEventCallback).

onProposeAllocation

public SignalConnection<AppSink.ProposeAllocationCallback> onProposeAllocation(AppSink.ProposeAllocationCallback handler)

Signal that a new propose_allocation query is available.

This signal is emitted from the streaming thread and only when the "emit-signals" property is true.

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

Since:

1.24

See Also:

• AppSink.ProposeAllocationCallback.run(org.freedesktop.gstreamer.gst.Query)

emitProposeAllocation

public boolean emitProposeAllocation(@Nullable Query query)

Emits the "propose-allocation" signal. See onProposeAllocation(org.freedesktop.gstreamer.app.AppSink.ProposeAllocationCallback).

onPullPreroll

public SignalConnection<AppSink.PullPrerollCallback> onPullPreroll(AppSink.PullPrerollCallback handler)

Get the last preroll sample in appsink. This was the sample that caused the appsink to preroll in the PAUSED state.

This function is typically used when dealing with a pipeline in the PAUSED state. Calling this function after doing a seek will give the sample right after the seek position.

Calling this function will clear the internal reference to the preroll buffer.

Note that the preroll sample will also be returned as the first sample when calling gst_app_sink_pull_sample() or the "pull-sample" action signal.

If an EOS event was received before any buffers, this function returns null. Use gst_app_sink_is_eos () to check for the EOS condition.

This function blocks until a preroll sample or EOS is received or the appsink element is set to the READY/NULL state.

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• AppSink.PullPrerollCallback.run()

emitPullPreroll

public Sample emitPullPreroll()

Emits the "pull-preroll" signal. See onPullPreroll(org.freedesktop.gstreamer.app.AppSink.PullPrerollCallback).

onPullSample

public SignalConnection<AppSink.PullSampleCallback> onPullSample(AppSink.PullSampleCallback handler)

This function blocks until a sample or EOS becomes available or the appsink element is set to the READY/NULL state.

This function will only return samples when the appsink is in the PLAYING state. All rendered samples will be put in a queue so that the application can pull samples at its own rate.

Note that when the application does not pull samples fast enough, the queued samples could consume a lot of memory, especially when dealing with raw video frames. It's possible to control the behaviour of the queue with the "drop" and "max-buffers" / "max-bytes" / "max-time" set of properties.

If an EOS event was received before any buffers, this function returns null. Use gst_app_sink_is_eos () to check for the EOS condition.

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• AppSink.PullSampleCallback.run()

emitPullSample

public Sample emitPullSample()

Emits the "pull-sample" signal. See onPullSample(org.freedesktop.gstreamer.app.AppSink.PullSampleCallback).

onTryPullPreroll

public SignalConnection<AppSink.TryPullPrerollCallback> onTryPullPreroll(AppSink.TryPullPrerollCallback handler)

Get the last preroll sample in appsink. This was the sample that caused the appsink to preroll in the PAUSED state.

This function is typically used when dealing with a pipeline in the PAUSED state. Calling this function after doing a seek will give the sample right after the seek position.

Calling this function will clear the internal reference to the preroll buffer.

Note that the preroll sample will also be returned as the first sample when calling gst_app_sink_pull_sample() or the "pull-sample" action signal.

If an EOS event was received before any buffers or the timeout expires, this function returns null. Use gst_app_sink_is_eos () to check for the EOS condition.

This function blocks until a preroll sample or EOS is received, the appsink element is set to the READY/NULL state, or the timeout expires.

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

Since:

1.10

See Also:

• AppSink.TryPullPrerollCallback.run(long)

emitTryPullPreroll

public Sample emitTryPullPreroll(long timeout)

Emits the "try-pull-preroll" signal. See onTryPullPreroll(org.freedesktop.gstreamer.app.AppSink.TryPullPrerollCallback).

onTryPullSample

public SignalConnection<AppSink.TryPullSampleCallback> onTryPullSample(AppSink.TryPullSampleCallback handler)

This function blocks until a sample or EOS becomes available or the appsink element is set to the READY/NULL state or the timeout expires.

This function will only return samples when the appsink is in the PLAYING state. All rendered samples will be put in a queue so that the application can pull samples at its own rate.

Note that when the application does not pull samples fast enough, the queued samples could consume a lot of memory, especially when dealing with raw video frames. It's possible to control the behaviour of the queue with the "drop" and "max-buffers" / "max-bytes" / "max-time" set of properties.

If an EOS event was received before any buffers or the timeout expires, this function returns null. Use gst_app_sink_is_eos () to check for the EOS condition.

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

Since:

1.10

See Also:

• AppSink.TryPullSampleCallback.run(long)

emitTryPullSample

public Sample emitTryPullSample(long timeout)

Emits the "try-pull-sample" signal. See onTryPullSample(org.freedesktop.gstreamer.app.AppSink.TryPullSampleCallback).

builder

public static AppSink.Builder<? extends AppSink.Builder> builder()

A AppSink.Builder object constructs a AppSink with the specified properties. Use the various set...() methods to set properties, and finish construction with AppSink.Builder.build().

Returns:

the builder object