Struct gstreamer_app::AppSrc

pub struct AppSrc { /* private fields */ }

The appsrc element can be used by applications to insert data into a GStreamer pipeline. Unlike most GStreamer elements, appsrc provides external API functions.

appsrc can be used by linking with the libgstapp library to access the methods directly or by using the appsrc action signals.

Before operating appsrc, the caps property must be set to fixed caps describing the format of the data that will be pushed with appsrc. An exception to this is when pushing buffers with unknown caps, in which case no caps should be set. This is typically true of file-like sources that push raw byte buffers. If you don’t want to explicitly set the caps, you can use gst_app_src_push_sample. This method gets the caps associated with the sample and sets them on the appsrc replacing any previously set caps (if different from sample’s caps).

The main way of handing data to the appsrc element is by calling the push_buffer() method or by emitting the push-buffer action signal. This will put the buffer onto a queue from which appsrc will read from in its streaming thread. It is important to note that data transport will not happen from the thread that performed the push-buffer call.

The “max-bytes”, “max-buffers” and “max-time” properties control how much data can be queued in appsrc before appsrc considers the queue full. A filled internal queue will always signal the “enough-data” signal, which signals the application that it should stop pushing data into appsrc. The “block” property will cause appsrc to block the push-buffer method until free data becomes available again.

When the internal queue is running out of data, the “need-data” signal is emitted, which signals the application that it should start pushing more data into appsrc.

In addition to the “need-data” and “enough-data” signals, appsrc can emit the “seek-data” signal when the “stream-mode” property is set to “seekable” or “random-access”. The signal argument will contain the new desired position in the stream expressed in the unit set with the “format” property. After receiving the seek-data signal, the application should push-buffers from the new position.

These signals allow the application to operate the appsrc in two different ways:

The push mode, in which the application repeatedly calls the push-buffer/push-sample method with a new buffer/sample. Optionally, the queue size in the appsrc can be controlled with the enough-data and need-data signals by respectively stopping/starting the push-buffer/push-sample calls. This is a typical mode of operation for the stream-type “stream” and “seekable”. Use this mode when implementing various network protocols or hardware devices.

The pull mode, in which the need-data signal triggers the next push-buffer call. This mode is typically used in the “random-access” stream-type. Use this mode for file access or other randomly accessible sources. In this mode, a buffer of exactly the amount of bytes given by the need-data signal should be pushed into appsrc.

In all modes, the size property on appsrc should contain the total stream size in bytes. Setting this property is mandatory in the random-access mode. For the stream and seekable modes, setting this property is optional but recommended.

When the application has finished pushing data into appsrc, it should call end_of_stream() or emit the end-of-stream action signal. After this call, no more buffers can be pushed into appsrc until a flushing seek occurs or the state of the appsrc has gone through READY.

Properties

block

When max-bytes are queued and after the enough-data signal has been emitted, block any further push-buffer calls until the amount of queued bytes drops below the max-bytes limit.

Readable | Writeable

caps

The GstCaps that will negotiated downstream and will be put on outgoing buffers.

Readable | Writeable

current-level-buffers

The number of currently queued buffers inside appsrc.

Readable

current-level-bytes

The number of currently queued bytes inside appsrc.

Readable

current-level-time

The amount of currently queued time inside appsrc.

Readable

duration

The total duration in nanoseconds of the data stream. If the total duration is known, it is recommended to configure it with this property.

Readable | Writeable

emit-signals

Make appsrc emit the “need-data”, “enough-data” and “seek-data” signals. This option is by default enabled for backwards compatibility reasons but can disabled when needed because signal emission is expensive.

Readable | Writeable

format

The format to use for segment events. When the source is producing timestamped buffers this property should be set to GST_FORMAT_TIME.

Readable | Writeable

handle-segment-change

When enabled, appsrc will check GstSegment in GstSample which was pushed via AppSrc::push_sample() or “push-sample” signal action. If a GstSegment is changed, corresponding segment event will be followed by next data flow.

FIXME: currently only GST_FORMAT_TIME format is supported and therefore GstAppSrc::format should be time. However, possibly AppSrc can support other formats.

Readable | Writeable

is-live

Instruct the source to behave like a live source. This includes that it will only push out buffers in the PLAYING state.

Readable | Writeable

leaky-type

When set to any other value than GST_APP_LEAKY_TYPE_NONE then the appsrc will drop any buffers that are pushed into it once its internal queue is full. The selected type defines whether to drop the oldest or new buffers.

Readable | Writeable

max-buffers

The maximum amount of buffers that can be queued internally. After the maximum amount of buffers are queued, appsrc will emit the “enough-data” signal.

Readable | Writeable

max-bytes

The maximum amount of bytes that can be queued internally. After the maximum amount of bytes are queued, appsrc will emit the “enough-data” signal.

Readable | Writeable

max-latency

Readable | Writeable

max-time

The maximum amount of time that can be queued internally. After the maximum amount of time are queued, appsrc will emit the “enough-data” signal.

Readable | Writeable

min-latency

The minimum latency of the source. A value of -1 will use the default latency calculations of GstBaseSrc.

Readable | Writeable

min-percent

Make appsrc emit the “need-data” signal when the amount of bytes in the queue drops below this percentage of max-bytes.

Readable | Writeable

size

The total size in bytes of the data stream. If the total size is known, it is recommended to configure it with this property.

Readable | Writeable

stream-type

The type of stream that this source is producing. For seekable streams the application should connect to the seek-data signal.

Readable | Writeable

BaseSrc

automatic-eos

See gst_base_src_set_automatic_eos()

Readable | Writeable

blocksize

Readable | Writeable

do-timestamp

Readable | Writeable

num-buffers

Readable | Writeable

typefind

Readable | Writeable

Object

name

Readable | Writeable | Construct

parent

The parent of the object. Please note, that when changing the ‘parent’ property, we don’t emit notify and deep-notify signals due to locking issues. In some cases one can use GstBin::element-added or GstBin::element-removed signals on the parent to achieve a similar effect.

Readable | Writeable

Signals

end-of-stream

Notify appsrc that no more buffer are available.

Action

enough-data

Signal that the source has enough data. It is recommended that the application stops calling push-buffer until the need-data signal is emitted again to avoid excessive buffer queueing.

need-data

Signal that the source needs more data. In the callback or from another thread you should call push-buffer or end-of-stream.

length is just a hint and when it is set to -1, any number of bytes can be pushed into appsrc.

You can call push-buffer multiple times until the enough-data signal is fired.

push-buffer

Adds a buffer to the queue of buffers that the appsrc element will push to its source pad.

This function does not take ownership of the buffer, but it takes a reference so the buffer can be unreffed at any time after calling this function.

When the block property is TRUE, this function can block until free space becomes available in the queue.

Action

push-buffer-list

Adds a buffer list to the queue of buffers and buffer lists that the appsrc element will push to its source pad.

This function does not take ownership of the buffer list, but it takes a reference so the buffer list can be unreffed at any time after calling this function.

When the block property is TRUE, this function can block until free space becomes available in the queue.

Action

push-sample

Extract a buffer from the provided sample and adds the extracted buffer to the queue of buffers that the appsrc element will push to its source pad. This function set the appsrc caps based on the caps in the sample and reset the caps if they change. Only the caps and the buffer of the provided sample are used and not for example the segment in the sample.

This function does not take ownership of the sample, but it takes a reference so the sample can be unreffed at any time after calling this function.

When the block property is TRUE, this function can block until free space becomes available in the queue.

Action

seek-data

Seek to the given offset. The next push-buffer should produce buffers from the new offset. This callback is only called for seekable stream types.

Element

no-more-pads

This signals that the element will not generate more dynamic pads. Note that this signal will usually be emitted from the context of the streaming thread.

pad-added

a new GstPad has been added to the element. Note that this signal will usually be emitted from the context of the streaming thread. Also keep in mind that if you add new elements to the pipeline in the signal handler you will need to set them to the desired target state with [ElementExtManual::set_state()][crate::gst::prelude::ElementExtManual::set_state()] or [ElementExtManual::sync_state_with_parent()][crate::gst::prelude::ElementExtManual::sync_state_with_parent()].

pad-removed

a GstPad has been removed from the element

Object

deep-notify

The deep notify signal is used to be notified of property changes. It is typically attached to the toplevel bin to receive notifications from all the elements contained in that bin.

Detailed

Implements

gst::prelude::ElementExt, gst::prelude::ObjectExt, [trait@glib::ObjectExt], gst::prelude::URIHandlerExt

GLib type: GObject with reference counted clone semantics.

Implementations

impl AppSrc

pub fn end_of_stream(&self) -> Result<FlowSuccess, FlowError>

Indicates to the appsrc element that the last buffer queued in the element is the last buffer of the stream.

Returns

gst::FlowReturn::Ok when the EOS was successfully queued. gst::FlowReturn::Flushing when self is not PAUSED or PLAYING.

pub fn caps(&self) -> Option<Caps>

Get the configured caps on self.

Returns

the gst::Caps produced by the source. gst_caps_unref() after usage.

pub fn current_level_buffers(&self) -> u64

Get the number of currently queued buffers inside self.

Returns

The number of currently queued buffers.

pub fn current_level_bytes(&self) -> u64

Get the number of currently queued bytes inside self.

Returns

The number of currently queued bytes.

pub fn current_level_time(&self) -> Option<ClockTime>

Get the amount of currently queued time inside self.

Returns

The amount of currently queued time.

pub fn duration(&self) -> Option<ClockTime>

Get the duration of the stream in nanoseconds. A value of GST_CLOCK_TIME_NONE means that the duration is not known.

Returns

the duration of the stream previously set with set_duration();

pub fn leaky_type(&self) -> AppLeakyType

Returns the currently set AppLeakyType. See set_leaky_type() for more details.

Returns

The currently set AppLeakyType.

pub fn max_buffers(&self) -> u64

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

Returns

The maximum amount of buffers that can be queued.

pub fn max_bytes(&self) -> u64

Get the maximum amount of bytes that can be queued in self.

Returns

The maximum amount of bytes that can be queued.

pub fn max_time(&self) -> Option<ClockTime>

Get the maximum amount of time that can be queued in self.

Returns

The maximum amount of time that can be queued.

pub fn size(&self) -> i64

Get the size of the stream in bytes. A value of -1 means that the size is not known.

Returns

the size of the stream previously set with set_size();

pub fn stream_type(&self) -> AppStreamType

Get the stream type. Control the stream type of self with set_stream_type().

Returns

the stream type.

pub fn push_buffer(&self, buffer: Buffer) -> Result<FlowSuccess, FlowError>

Adds a buffer to the queue of buffers that the appsrc element will push to its source pad. This function takes ownership of the buffer.

When the block property is TRUE, this function can block until free space becomes available in the queue.

buffer

a gst::Buffer to push

Returns

gst::FlowReturn::Ok when the buffer was successfully queued. gst::FlowReturn::Flushing when self is not PAUSED or PLAYING. gst::FlowReturn::Eos when EOS occurred.

pub fn push_buffer_list( &self, buffer_list: BufferList, ) -> Result<FlowSuccess, FlowError>

Adds a buffer list to the queue of buffers and buffer lists that the appsrc element will push to its source pad. This function takes ownership of buffer_list.

When the block property is TRUE, this function can block until free space becomes available in the queue.

buffer_list

a gst::BufferList to push

Returns

gst::FlowReturn::Ok when the buffer list was successfully queued. gst::FlowReturn::Flushing when self is not PAUSED or PLAYING. gst::FlowReturn::Eos when EOS occurred.

pub fn push_sample(&self, sample: &Sample) -> Result<FlowSuccess, FlowError>

Extract a buffer from the provided sample and adds it to the queue of buffers that the appsrc element will push to its source pad. Any previous caps that were set on appsrc will be replaced by the caps associated with the sample if not equal.

This function does not take ownership of the sample so the sample needs to be unreffed after calling this function.

When the block property is TRUE, this function can block until free space becomes available in the queue.

sample

a gst::Sample from which buffer and caps may be extracted

Returns

gst::FlowReturn::Ok when the buffer was successfully queued. gst::FlowReturn::Flushing when self is not PAUSED or PLAYING. gst::FlowReturn::Eos when EOS occurred.

pub fn set_caps(&self, caps: Option<&Caps>)

Set the capabilities on the appsrc element. This function takes a copy of the caps structure. After calling this method, the source will only produce caps that match caps. caps must be fixed and the caps on the buffers must match the caps or left NULL.

caps

caps to set

pub fn set_duration(&self, duration: impl Into<Option<ClockTime>>)

Set the duration of the stream in nanoseconds. A value of GST_CLOCK_TIME_NONE means that the duration is not known.

duration

the duration to set

pub fn set_leaky_type(&self, leaky: AppLeakyType)

When set to any other value than GST_APP_LEAKY_TYPE_NONE then the appsrc will drop any buffers that are pushed into it once its internal queue is full. The selected type defines whether to drop the oldest or new buffers.

leaky

the AppLeakyType

pub fn set_max_buffers(&self, max: u64)

Set the maximum amount of buffers that can be queued in self. After the maximum amount of buffers are queued, self will emit the “enough-data” signal.

max

the maximum number of buffers to queue

pub fn set_max_bytes(&self, max: u64)

Set the maximum amount of bytes that can be queued in self. After the maximum amount of bytes are queued, self will emit the “enough-data” signal.

max

the maximum number of bytes to queue

pub fn set_max_time(&self, max: impl Into<Option<ClockTime>>)

Set the maximum amount of time that can be queued in self. After the maximum amount of time are queued, self will emit the “enough-data” signal.

max

the maximum amonut of time to queue

pub fn set_size(&self, size: i64)

Set the size of the stream in bytes. A value of -1 means that the size is not known.

size

the size to set

pub fn set_stream_type(&self, type_: AppStreamType)

Set the stream type on self. For seekable streams, the “seek” signal must be connected to.

A stream_type stream

type_

the new state

pub fn is_block(&self) -> bool

When max-bytes are queued and after the enough-data signal has been emitted, block any further push-buffer calls until the amount of queued bytes drops below the max-bytes limit.

pub fn set_block(&self, block: bool)

When max-bytes are queued and after the enough-data signal has been emitted, block any further push-buffer calls until the amount of queued bytes drops below the max-bytes limit.

pub fn format(&self) -> Format

The format to use for segment events. When the source is producing timestamped buffers this property should be set to GST_FORMAT_TIME.

pub fn set_format(&self, format: Format)

The format to use for segment events. When the source is producing timestamped buffers this property should be set to GST_FORMAT_TIME.

pub fn is_handle_segment_change(&self) -> bool

When enabled, appsrc will check GstSegment in GstSample which was pushed via push_sample() or “push-sample” signal action. If a GstSegment is changed, corresponding segment event will be followed by next data flow.

FIXME: currently only GST_FORMAT_TIME format is supported and therefore GstAppSrc::format should be time. However, possibly AppSrc can support other formats.

pub fn set_handle_segment_change(&self, handle_segment_change: bool)

When enabled, appsrc will check GstSegment in GstSample which was pushed via push_sample() or “push-sample” signal action. If a GstSegment is changed, corresponding segment event will be followed by next data flow.

FIXME: currently only GST_FORMAT_TIME format is supported and therefore GstAppSrc::format should be time. However, possibly AppSrc can support other formats.

pub fn is_live(&self) -> bool

Instruct the source to behave like a live source. This includes that it will only push out buffers in the PLAYING state.

pub fn set_is_live(&self, is_live: bool)

Instruct the source to behave like a live source. This includes that it will only push out buffers in the PLAYING state.

pub fn max_latency(&self) -> i64

pub fn set_max_latency(&self, max_latency: i64)

pub fn min_latency(&self) -> i64

The minimum latency of the source. A value of -1 will use the default latency calculations of GstBaseSrc.

pub fn set_min_latency(&self, min_latency: i64)

The minimum latency of the source. A value of -1 will use the default latency calculations of GstBaseSrc.

pub fn min_percent(&self) -> u32

Make appsrc emit the “need-data” signal when the amount of bytes in the queue drops below this percentage of max-bytes.

pub fn set_min_percent(&self, min_percent: u32)

Make appsrc emit the “need-data” signal when the amount of bytes in the queue drops below this percentage of max-bytes.

pub fn connect_block_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_caps_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_current_level_buffers_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_current_level_bytes_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_current_level_time_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_duration_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_format_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_handle_segment_change_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_is_live_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_leaky_type_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_max_buffers_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_max_bytes_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_max_latency_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_max_time_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_min_latency_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_min_percent_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_size_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn connect_stream_type_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

impl AppSrc

pub fn builder() -> AppSrcBuilder

Creates a new builder-pattern struct instance to construct AppSrc objects.

This method returns an instance of AppSrcBuilder which can be used to create AppSrc objects.

pub fn set_callbacks(&self, callbacks: AppSrcCallbacks)

Set callbacks which will be executed when data is needed, enough data has been collected or when a seek should be performed. 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.

callbacks

the callbacks

notify

a destroy notify function

pub fn set_latency( &self, min: impl Into<Option<ClockTime>>, max: impl Into<Option<ClockTime>>, )

Configure the min and max latency in src. If min is set to -1, the default latency calculations for pseudo-live sources will be used.

min

the min latency

max

the max latency

pub fn latency(&self) -> (Option<ClockTime>, Option<ClockTime>)

Retrieve the min and max latencies in min and max respectively.

Returns

min

the min latency

max

the max latency

pub fn set_do_timestamp(&self, timestamp: bool)

pub fn do_timestamp(&self) -> bool

pub fn connect_do_timestamp_notify<F: Fn(&Self) + Send + Sync + 'static>( &self, f: F, ) -> SignalHandlerId

pub fn set_automatic_eos(&self, automatic_eos: bool)

pub fn sink(&self) -> AppSrcSink

Trait Implementations

impl Clone for AppSrc

fn clone(&self) -> Self

Makes a clone of this shared reference.

This increments the strong reference count of the object. Dropping the object will decrement it again.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AppSrc

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl HasParamSpec for AppSrc

type ParamSpec = ParamSpecObject

type SetValue = AppSrc

Preferred value to be used as setter for the associated ParamSpec.

type BuilderFn = fn(_: &str) -> ParamSpecObjectBuilder<'_, AppSrc>

fn param_spec_builder() -> Self::BuilderFn

impl Hash for AppSrc

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Hashes the memory address of this object.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for AppSrc

fn cmp(&self, other: &Self) -> Ordering

Comparison for two GObjects.

Compares the memory addresses of the provided objects.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl ParentClassIs for AppSrc

type Parent = Element

impl<OT: ObjectType> PartialEq<OT> for AppSrc

fn eq(&self, other: &OT) -> bool

Equality for two GObjects.

Two GObjects are equal if their memory addresses are equal.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<OT: ObjectType> PartialOrd<OT> for AppSrc

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

Partial comparison for two GObjects.

Compares the memory addresses of the provided objects.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for AppSrc

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for AppSrc

impl IsA<Element> for AppSrc

impl IsA<Object> for AppSrc

impl IsA<URIHandler> for AppSrc

impl Send for AppSrc

impl Sync for AppSrc