FrameWriter

Kotlin |Java

@ExperimentalApi
public interface FrameWriter extends AutoCloseable

Known direct subclasses

`EncoderFrameWriter`	An implementation of `FrameWriter` that uses an `ImageWriter` to forward frames to a `encoder` via `Surface`.
`SurfaceHolderFrameWriter`	A `FrameWriter` that outputs frames to a `SurfaceHolder`.

Allocates Frame instances, allowing callers to dequeue and fill them, before processing the filled frames.

Summary

Nested types
`public interface FrameWriter.Info` Describes the capabilities of a `FrameWriter`.

Public methods
`abstract void`	`close()` Blocks until all resources are released.
`abstract void`	`configure(Format format, @Frame.Usage long usage)` Format and usage support can be `checked` on the `Info` before configuring.
`abstract @Nullable AsyncFrame`	`dequeueInputFrame(Executor wakeupExecutor, Runnable wakeupListener)` Dequeues an `AsyncFrame` storing a `Frame` of the `configured` format and usage, and a `SyncFenceWrapper` that must be waited on before filling the frame.
`abstract FrameWriter.Info`	`getInfo()` Returns the `Info` for this FrameWriter.
`abstract void`	`queueInputFrame( Frame frame, @Nullable SyncFenceWrapper writeCompleteFence )` Queues a filled frame for further processing.
`abstract void`	`signalEndOfStream()` Notifies this `FrameWriter` that the current stream has ended.

abstract void close()

Blocks until all resources are released.

abstract void configure(Format format, @Frame.Usage long usage)

Format and usage support can be checked on the Info before configuring.

Must be called before dequeueInputFrame.

Parameters
`Format format`	The format to configure.
`@Frame.Usage long usage`	The `@FrameUsage` flags describing how the frame will be used.

Throws
`java.lang.IllegalStateException`	if any frames are dequeued at the point this method is called.
`java.lang.IllegalArgumentException`	if the format or usage is unsupported.

abstract @Nullable AsyncFrame dequeueInputFrame(Executor wakeupExecutor, Runnable wakeupListener)

Dequeues an AsyncFrame storing a Frame of the configured format and usage, and a SyncFenceWrapper that must be waited on before filling the frame.

The returned frame must be filled and queued back for processing.

If the FrameWriter is at capacity, this method returns null and will notify the listener when capacity is available, and it can be called again.

Only the most recent wakeupListener will be notified when capacity is available.

Parameters
`Executor wakeupExecutor`	The `Executor` on which the `wakeupListener` is invoked.
`Runnable wakeupListener`	A `Runnable` to be invoked when capacity becomes available.

Returns
`@Nullable AsyncFrame`	The dequeued frame, or null if the writer is at capacity.

Throws
`java.lang.IllegalStateException`	if `configure` has not been called.

abstract FrameWriter.Info getInfo()

Returns the Info for this FrameWriter.

abstract void queueInputFrame(
    Frame frame,
    @Nullable SyncFenceWrapper writeCompleteFence
)

Queues a filled frame for further processing.

The queued frame must have been previously dequeued from this writer.

Parameters
`Frame frame`	The filled frame to queue.
`@Nullable SyncFenceWrapper writeCompleteFence`	A `SyncFenceWrapper` that will signal when the caller has finished writing to the frame, or `null` if the write was synchronous.

abstract void signalEndOfStream()

Notifies this FrameWriter that the current stream has ended.

More frames may be queued after calling this method, if the current stream changes.