Trait BaseSrcImpl

pub trait BaseSrcImpl: ElementImpl + ObjectSubclass<Type: IsA<BaseSrc>> {
    // Provided methods
    fn start(&self) -> Result<(), ErrorMessage> { ... }
    fn stop(&self) -> Result<(), ErrorMessage> { ... }
    fn is_seekable(&self) -> bool { ... }
    fn size(&self) -> Option<u64> { ... }
    fn times(
        &self,
        buffer: &BufferRef,
    ) -> (Option<ClockTime>, Option<ClockTime>) { ... }
    fn fill(
        &self,
        offset: u64,
        length: u32,
        buffer: &mut BufferRef,
    ) -> Result<FlowSuccess, FlowError> { ... }
    fn alloc(&self, offset: u64, length: u32) -> Result<Buffer, FlowError> { ... }
    fn create(
        &self,
        offset: u64,
        buffer: Option<&mut BufferRef>,
        length: u32,
    ) -> Result<CreateSuccess, FlowError> { ... }
    fn do_seek(&self, segment: &mut Segment) -> bool { ... }
    fn query(&self, query: &mut QueryRef) -> bool { ... }
    fn event(&self, event: &Event) -> bool { ... }
    fn caps(&self, filter: Option<&Caps>) -> Option<Caps> { ... }
    fn negotiate(&self) -> Result<(), LoggableError> { ... }
    fn set_caps(&self, caps: &Caps) -> Result<(), LoggableError> { ... }
    fn fixate(&self, caps: Caps) -> Caps { ... }
    fn unlock(&self) -> Result<(), ErrorMessage> { ... }
    fn unlock_stop(&self) -> Result<(), ErrorMessage> { ... }
    fn decide_allocation(
        &self,
        query: &mut Allocation,
    ) -> Result<(), LoggableError> { ... }
}

Provided Methods

fn start(&self) -> Result<(), ErrorMessage>

Start processing. Subclasses should open resources and prepare to produce data. Implementation should call BaseSrcExt::start_complete() when the operation completes, either from the current thread or any other thread that finishes the start operation asynchronously.

fn stop(&self) -> Result<(), ErrorMessage>

Stop processing. Subclasses should use this to close resources.

fn is_seekable(&self) -> bool

Check if the source can seek

fn size(&self) -> Option<u64>

Get the total size of the resource in the format set by BaseSrcExt::set_format().

Returns

true if the size is available and has been set.

fn times(&self, buffer: &BufferRef) -> (Option<ClockTime>, Option<ClockTime>)

Given buffer, return start and end time when it should be pushed out. The base class will sync on the clock using these times.

Returns

fn fill( &self, offset: u64, length: u32, buffer: &mut BufferRef, ) -> Result<FlowSuccess, FlowError>

Ask the subclass to fill the buffer with data for offset and size. The passed buffer is guaranteed to hold the requested amount of bytes.

fn alloc(&self, offset: u64, length: u32) -> Result<Buffer, FlowError>

Ask the subclass to allocate an output buffer with offset and size, the default implementation will use the negotiated allocator.

Returns

fn create( &self, offset: u64, buffer: Option<&mut BufferRef>, length: u32, ) -> Result<CreateSuccess, FlowError>

Ask the subclass to create a buffer with offset and size, the default implementation will call alloc if no allocated buf is provided and then call fill.

fn do_seek(&self, segment: &mut Segment) -> bool

Perform seeking on the resource to the indicated segment.

fn query(&self, query: &mut QueryRef) -> bool

Handle a requested query.

fn event(&self, event: &Event) -> bool

Override this to implement custom event handling.

fn caps(&self, filter: Option<&Caps>) -> Option<Caps>

Called to get the caps to report.

fn negotiate(&self) -> Result<(), LoggableError>

Negotiates src pad caps with downstream elements. Unmarks GST_PAD_FLAG_NEED_RECONFIGURE in any case. But marks it again if GstBaseSrcClass::negotiate fails.

Do not call this in the GstBaseSrcClass::fill vmethod. Call this in GstBaseSrcClass::create or in GstBaseSrcClass::alloc, before any buffer is allocated.

Returns

true if the negotiation succeeded, else false.

fn set_caps(&self, caps: &Caps) -> Result<(), LoggableError>

Set new caps on the basesrc source pad.

caps

a gst::Caps

Returns

true if the caps could be set

fn fixate(&self, caps: Caps) -> Caps

Called if, in negotiation, caps need fixating.

Returns

the fixated caps

fn unlock(&self) -> Result<(), ErrorMessage>

Unlock any pending access to the resource. Subclasses should unblock any blocked function ASAP. In particular, any create() function in progress should be unblocked and should return GST_FLOW_FLUSHING. Any future GstBaseSrcClass::create function call should also return GST_FLOW_FLUSHING until the GstBaseSrcClass::unlock_stop function has been called.

fn unlock_stop(&self) -> Result<(), ErrorMessage>

Clear the previous unlock request. Subclasses should clear any state they set during GstBaseSrcClass::unlock, such as clearing command queues.

fn decide_allocation(&self, query: &mut Allocation) -> Result<(), LoggableError>

configure the allocation query

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors