Struct gstreamer_audio::AudioEncoder [−][src]
pub struct AudioEncoder(_);
Expand description
This base class is for audio encoders turning raw audio samples into encoded audio data.
GstAudioEncoder and subclass should cooperate as follows.
Configuration
-
Initially, GstAudioEncoder calls
startwhen the encoder element is activated, which allows subclass to perform any global setup. -
GstAudioEncoder calls
set_formatto inform subclass of the format of input audio data that it is about to receive. Subclass should setup for encoding and configure various base class parameters appropriately, notably those directing desired input data handling. While unlikely, it might be called more than once, if changing input parameters require reconfiguration. -
GstAudioEncoder calls
stopat end of all processing.
As of configuration stage, and throughout processing, GstAudioEncoder maintains various parameters that provide required context, e.g. describing the format of input audio data. Conversely, subclass can and should configure these context parameters to inform base class of its expectation w.r.t. buffer handling.
Data processing
- Base class gathers input sample data (as directed by the context’s
frame_samples and frame_max) and provides this to subclass’
handle_frame. - If codec processing results in encoded data, subclass should call
AudioEncoderExtManual::finish_frame()to have encoded data pushed downstream. Alternatively, it might also callAudioEncoderExtManual::finish_frame()(with a NULL buffer and some number of dropped samples) to indicate dropped (non-encoded) samples. - Just prior to actually pushing a buffer downstream,
it is passed to
pre_push. - During the parsing process GstAudioEncoderClass will handle both
srcpad and sinkpad events. Sink events will be passed to subclass
if
eventcallback has been provided.
Shutdown phase
- GstAudioEncoder class calls
stopto inform the subclass that data parsing will be stopped.
Subclass is responsible for providing pad template caps for
source and sink pads. The pads need to be named “sink” and “src”. It also
needs to set the fixed caps on srcpad, when the format is ensured. This
is typically when base class calls subclass’ set_format function, though
it might be delayed until calling AudioEncoderExtManual::finish_frame().
In summary, above process should have subclass concentrating on
codec data processing while leaving other matters to base class,
such as most notably timestamp handling. While it may exert more control
in this area (see e.g. pre_push), it is very much not recommended.
In particular, base class will either favor tracking upstream timestamps
(at the possible expense of jitter) or aim to arrange for a perfect stream of
output timestamps, depending on property::AudioEncoder::perfect-timestamp.
However, in the latter case, the input may not be so perfect or ideal, which
is handled as follows. An input timestamp is compared with the expected
timestamp as dictated by input sample stream and if the deviation is less
than property::AudioEncoder::tolerance, the deviation is discarded.
Otherwise, it is considered a discontuinity and subsequent output timestamp
is resynced to the new position after performing configured discontinuity
processing. In the non-perfect-timestamp case, an upstream variation
exceeding tolerance only leads to marking DISCONT on subsequent outgoing
(while timestamps are adjusted to upstream regardless of variation).
While DISCONT is also marked in the perfect-timestamp case, this one
optionally (see property::AudioEncoder::hard-resync)
performs some additional steps, such as clipping of (early) input samples
or draining all currently remaining input data, depending on the direction
of the discontuinity.
If perfect timestamps are arranged, it is also possible to request baseclass (usually set by subclass) to provide additional buffer metadata (in OFFSET and OFFSET_END) fields according to granule defined semantics currently needed by oggmux. Specifically, OFFSET is set to granulepos (= sample count including buffer) and OFFSET_END to corresponding timestamp (as determined by same sample count and sample rate).
Things that subclass need to take care of:
- Provide pad templates
- Set source pad caps when appropriate
- Inform base class of buffer processing needs using context’s frame_samples and frame_bytes.
- Set user-configurable properties to sane defaults for format and implementing codec at hand, e.g. those controlling timestamp behaviour and discontinuity processing.
- Accept data in
handle_frameand provide encoded results toAudioEncoderExtManual::finish_frame().
This is an Abstract Base Class, you cannot instantiate it.
Implements
AudioEncoderExt, gst::prelude::ElementExt, gst::prelude::GstObjectExt, glib::ObjectExt, AudioEncoderExtManual
Trait Implementations
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <=
operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
Returns the type identifier of Self.
Auto Trait Implementations
Blanket Implementations
Mutably borrows from an owned value. Read more
Upcasts an object to a superclass or interface T. Read more
Upcasts an object to a reference of its superclass or interface T. Read more
Tries to downcast to a subclass or interface implementor T. Read more
Tries to downcast to a reference of its subclass or interface implementor T. Read more
Tries to cast to an object of type T. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast and upcast will do many checks at compile-time already. Read more
Tries to cast to reference to an object of type T. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast and upcast will do many checks at compile-time already. Read more
Casts to T unconditionally. Read more
Casts to &T unconditionally. Read more
Abort the state change of the element. This function is used by elements that do asynchronous state changes and find out something is wrong. Read more
Adds a pad (link point) to self. pad’s parent will be set to self;
see GstObjectExt::set_parent() for refcounting information. Read more
pub fn change_state(
&self,
transition: StateChange
) -> Result<StateChangeSuccess, StateChangeError>[src]
pub fn change_state(
&self,
transition: StateChange
) -> Result<StateChangeSuccess, StateChangeError>[src]Perform transition on self. Read more
pub fn continue_state(
&self,
ret: impl Into<StateChangeReturn>
) -> Result<StateChangeSuccess, StateChangeError>[src]
pub fn continue_state(
&self,
ret: impl Into<StateChangeReturn>
) -> Result<StateChangeSuccess, StateChangeError>[src]Commit the state change of the element and proceed to the next
pending state if any. This function is used
by elements that do asynchronous state changes.
The core will normally call this method automatically when an
element returned StateChangeReturn::Success from the state change function. Read more
v1_14 only.v1_14 only.v1_14 only.pub fn compatible_pad<P>(&self, pad: &P, caps: Option<&Caps>) -> Option<Pad> where
P: IsA<Pad>, [src]pub fn state(
&self,
timeout: impl Into<Option<ClockTime>>
) -> (Result<StateChangeSuccess, StateChangeError>, State, State)[src]pub fn link_filtered<P>(&self, dest: &P, filter: &Caps) -> Result<(), BoolError> where
P: IsA<Element>, [src]pub fn link_pads<P>(
&self,
srcpadname: Option<&str>,
dest: &P,
destpadname: Option<&str>
) -> Result<(), BoolError> where
P: IsA<Element>, [src]pub fn link_pads_filtered<P>(
&self,
srcpadname: Option<&str>,
dest: &P,
destpadname: Option<&str>,
filter: &Caps
) -> Result<(), BoolError> where
P: IsA<Element>, [src]pub fn link_pads_full<P>(
&self,
srcpadname: Option<&str>,
dest: &P,
destpadname: Option<&str>,
flags: PadLinkCheck
) -> Result<(), BoolError> where
P: IsA<Element>, [src]pub fn request_pad(
&self,
templ: &PadTemplate,
name: Option<&str>,
caps: Option<&Caps>
) -> Option<Pad>[src]v1_20 only.pub fn unlink_pads<P>(&self, srcpadname: &str, dest: &P, destpadname: &str) where
P: IsA<Element>, [src]pub fn connect_no_more_pads<F>(&self, f: F) -> SignalHandlerId where
F: 'static + Fn(&O) + Send + Sync, [src]pub fn connect_pad_added<F>(&self, f: F) -> SignalHandlerId where
F: 'static + Fn(&O, &Pad) + Send + Sync, [src]pub fn connect_pad_removed<F>(&self, f: F) -> SignalHandlerId where
F: 'static + Fn(&O, &Pad) + Send + Sync, [src]pub fn message_full<T>(
&self,
type_: ElementMessageType,
code: T,
message: Option<&str>,
debug: Option<&str>,
file: &str,
function: &str,
line: u32
) where
T: MessageErrorDomain, [src]pub fn message_full_with_details<T>(
&self,
type_: ElementMessageType,
code: T,
message: Option<&str>,
debug: Option<&str>,
file: &str,
function: &str,
line: u32,
structure: Structure
) where
T: MessageErrorDomain, [src]
pub fn message_full_with_details<T>(
&self,
type_: ElementMessageType,
code: T,
message: Option<&str>,
debug: Option<&str>,
file: &str,
function: &str,
line: u32,
structure: Structure
) where
T: MessageErrorDomain, [src]v1_10 only.pub fn add_property_deep_notify_watch(
&self,
property_name: Option<&str>,
include_value: bool
) -> NotifyWatchId[src]
pub fn add_property_deep_notify_watch(
&self,
property_name: Option<&str>,
include_value: bool
) -> NotifyWatchId[src]v1_10 only.pub fn add_property_notify_watch(
&self,
property_name: Option<&str>,
include_value: bool
) -> NotifyWatchId[src]
pub fn add_property_notify_watch(
&self,
property_name: Option<&str>,
include_value: bool
) -> NotifyWatchId[src]v1_10 only.v1_10 only.pub fn query_convert<V, U>(&self, src_val: V) -> Option<U> where
V: Into<GenericFormattedValue>,
U: SpecificFormattedValue, [src]pub fn query_convert_generic<V>(
&self,
src_val: V,
dest_format: Format
) -> Option<GenericFormattedValue> where
V: Into<GenericFormattedValue>, [src]pub fn seek<V>(
&self,
rate: f64,
flags: SeekFlags,
start_type: SeekType,
start: V,
stop_type: SeekType,
stop: V
) -> Result<(), BoolError> where
V: Into<GenericFormattedValue>, [src]pub fn seek_simple<V>(
&self,
seek_flags: SeekFlags,
seek_pos: V
) -> Result<(), BoolError> where
V: Into<GenericFormattedValue>, [src]v1_10 only.v1_10 only.pub fn add_control_binding<P>(&self, binding: &P) -> Result<(), BoolError> where
P: IsA<ControlBinding>, [src]
pub fn add_control_binding<P>(&self, binding: &P) -> Result<(), BoolError> where
P: IsA<ControlBinding>, [src]Attach the ControlBinding to the object. If there already was a
ControlBinding for this property it will be replaced. Read more
A default error function that uses g_printerr() to display the error message
and the optional debug string.. Read more
Gets the corresponding ControlBinding for the property. This should be
unreferenced again after use. Read more
Obtain the control-rate for this self. Audio processing Element
objects will use this rate to sub-divide their processing loop and call
sync_values() in between. The length of the processing segment
should be up to control-rate nanoseconds. Read more
Returns the parent of self. This function increases the refcount
of the parent object so you should gst_object_unref() it after usage. Read more
Generates a string describing the path of self in
the object hierarchy. Only useful (or used) for debugging. Read more
Gets the value for the given controlled property at the requested time. Read more
pub fn connect_parent_notify<F>(&self, f: F) -> SignalHandlerId where
F: 'static + Fn(&O) + Send + Sync, [src]Returns true if the object is an instance of (can be cast to) T.
pub fn set_properties(
&self,
property_values: &[(&str, &dyn ToValue)]
) -> Result<(), BoolError>[src]pub fn set_properties_from_value(
&self,
property_values: &[(&str, Value)]
) -> Result<(), BoolError>[src]pub fn set_property<'a, N, V>(
&self,
property_name: N,
value: V
) -> Result<(), BoolError> where
V: ToValue,
N: Into<&'a str>, [src]pub fn set_property_from_value<'a, N>(
&self,
property_name: N,
value: &Value
) -> Result<(), BoolError> where
N: Into<&'a str>, [src]pub fn property<'a, N>(&self, property_name: N) -> Result<Value, BoolError> where
N: Into<&'a str>, [src]Safety Read more
Safety Read more
Safety Read more
Safety Read more
pub fn connect_notify<F>(&self, name: Option<&str>, f: F) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec) + Send + Sync, [src]pub fn connect_notify_local<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec), [src]pub unsafe fn connect_notify_unsafe<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: Fn(&T, &ParamSpec), [src]pub fn has_property<'a, N>(&self, property_name: N, type_: Option<Type>) -> bool where
N: Into<&'a str>, [src]pub fn find_property<'a, N>(&self, property_name: N) -> Option<ParamSpec> where
N: Into<&'a str>, [src]pub fn connect<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
F: Fn(&[Value]) -> Option<Value> + Send + Sync + 'static,
N: Into<&'a str>, [src]Same as connect but takes a SignalId instead of a signal name.
pub fn connect_local<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
F: Fn(&[Value]) -> Option<Value> + 'static,
N: Into<&'a str>, [src]Same as connect_local but takes a SignalId instead of a signal name.
pub unsafe fn connect_unsafe<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
F: Fn(&[Value]) -> Option<Value>,
N: Into<&'a str>, [src]Same as connect_unsafe but takes a SignalId instead of a signal name.
Emit signal by signal id.
Emit signal with details by signal id.
Emit signal by it’s name.
pub fn bind_property<'a, O, N, M>(
&'a self,
source_property: N,
target: &'a O,
target_property: M
) -> BindingBuilder<'a> where
O: ObjectType,
N: Into<&'a str>,
M: Into<&'a str>, [src]Same as emit but takes Value for the arguments.
Same as emit_by_name but takes Value for the arguments.
Returns a SendValue clone of self.
impl<'a, T, C> FromValueOptional<'a> for T where
C: ValueTypeChecker<Error = ValueTypeMismatchOrNoneError>,
T: FromValue<'a, Checker = C>, [src]